Protect
IT
Multifunction Protection and Switchgear Control Unit
Model REF542plus
Protection Functions
Configuration and Settings
ABB
Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Table of Contents
1
IT
1.1
Industrial ....................................................................................................13
1.2
REF542plus Network address ....................................................................13
2
Safety Information ............................................................................................13
3
Acronyms and definitions................................................................................14
3.1
Acronyms.....................................................................................................14
3.2
Definitions....................................................................................................14
3.3
Document information ................................................................................14
4
4.1
5
5.1
6
6.1
1VTA10002 Rev02
Valid beginning since version V4D02
About this manual ............................................................................................13
REF542plus analog measurement ..................................................................15
Measured-value processing .......................................................................15
Analog Inputs ...................................................................................................16
Terminals .....................................................................................................16
5.1.1
Analog Inputs ............................................................................16
5.1.1.1
Analog Board selection................................................................17
5.1.1.2
Current Transformer....................................................................17
5.1.1.3
Current Rogowski........................................................................18
5.1.1.4
Voltage Transformer....................................................................18
5.1.1.4.1 Phase-Voltage Transformer ........................................................19
5.1.1.4.2 Line Voltage Transformer ............................................................20
5.1.1.4.3 Residual Voltage Transformer (open delta) .................................21
5.1.1.5
Voltage Sensor............................................................................22
5.1.2
General constraints...................................................................22
5.1.3
Network characteristics ............................................................23
5.1.4
Calculated values ......................................................................23
Control and monitoring....................................................................................24
Analog Objects ............................................................................................24
6.1.1
Measurement supervision NPS and PPS.................................24
6.1.1.1
Input/Output description ..............................................................24
6.1.1.2
Configuration ...............................................................................25
6.1.1.2.1 General .......................................................................................25
6.1.1.2.2 Sensors .......................................................................................25
6.1.1.2.3 Parameters..................................................................................26
6.1.1.2.4 Events .........................................................................................26
6.1.1.2.5 Pins .............................................................................................27
6.1.1.3
Measurement mode ....................................................................27
6.1.1.4
Operation criteria.........................................................................27
6.1.1.5
Setting groups .............................................................................27
6.1.1.6
Parameters and Events ...............................................................27
6.1.1.6.1 Setting values..............................................................................27
6.1.1.6.2 Events .........................................................................................28
6.1.2
Power Factor Controller............................................................28
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
6.1.2.1
6.1.2.2
6.1.2.2.1
6.1.2.2.2
6.1.2.2.3
6.1.2.2.4
6.1.2.2.5
6.1.2.2.6
6.1.2.3
6.1.2.4
6.1.2.5
6.1.2.6
6.1.2.7
6.1.2.8
6.1.2.9
6.1.2.9.1
6.1.2.9.2
7
7.1
1VTA10002 Rev02
Valid beginning since version V4D02
Input/Output description ..............................................................28
Configuration ...............................................................................30
General .......................................................................................30
Capacitor banks ..........................................................................30
Control Data ................................................................................31
Time ............................................................................................31
Events .........................................................................................32
Pins .............................................................................................32
Measurement mode ....................................................................32
Operating modes and requirements ............................................34
Time settings ...............................................................................35
Indications ...................................................................................35
Automatic power factor controlling...............................................36
Setting Example ..........................................................................39
Parameter and Events.................................................................40
Setting values..............................................................................40
Events .........................................................................................40
Protection Functions........................................................................................42
Current protection functions ......................................................................42
7.1.1
Inrush blocking..........................................................................42
7.1.1.1
Input/Output description ..............................................................42
7.1.1.2
Configuration ...............................................................................43
7.1.1.2.1 General .......................................................................................43
7.1.1.2.2 Sensors .......................................................................................43
7.1.1.2.3 Parameters..................................................................................44
7.1.1.2.4 Events .........................................................................................44
7.1.1.2.5 Pins .............................................................................................45
7.1.1.3
Measurement mode ....................................................................45
7.1.1.4
Operation criteria.........................................................................45
7.1.1.5
Setting groups .............................................................................47
7.1.1.6
Parameters and Events ...............................................................47
7.1.1.6.1 Setting values..............................................................................47
7.1.1.6.2 Events .........................................................................................47
7.1.2
Inrush Harmonic........................................................................48
7.1.2.1
Input/Output description ..............................................................48
7.1.2.2
Configuration ...............................................................................49
7.1.2.2.1 General .......................................................................................49
7.1.2.2.2 Sensors .......................................................................................49
7.1.2.2.3 Parameters..................................................................................50
7.1.2.2.4 Events .........................................................................................50
7.1.2.2.5 Pins .............................................................................................51
7.1.2.3
Measurement mode ....................................................................51
7.1.2.4
Operation criteria.........................................................................51
7.1.2.5
Steady-state detection.................................................................52
7.1.2.6
Setting groups .............................................................................53
7.1.2.7
Parameters and Events ...............................................................53
7.1.2.7.1 Setting values..............................................................................53
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.2.7.2
7.1.3
7.1.3.1
7.1.3.2
7.1.3.2.1
7.1.3.2.2
7.1.3.2.3
7.1.3.2.4
7.1.3.2.5
7.1.3.3
7.1.3.4
7.1.3.5
7.1.3.6
7.1.3.7
7.1.3.8
7.1.3.8.1
7.1.3.8.2
7.1.4
7.1.4.1
7.1.4.2
7.1.4.2.1
7.1.4.2.2
7.1.4.2.3
7.1.4.2.4
7.1.4.2.5
7.1.4.3
7.1.4.4
7.1.4.5
7.1.4.6
7.1.4.6.1
7.1.4.6.2
7.1.5
7.1.5.1
7.1.5.2
7.1.5.2.1
7.1.5.2.2
7.1.5.2.3
7.1.5.2.4
7.1.5.2.5
7.1.5.2.6
7.1.5.3
7.1.5.4
7.1.5.5
7.1.5.6
7.1.5.6.1
7.1.5.6.2
7.1.6
7.1.6.1
1VTA10002 Rev02
Valid beginning since version V4D02
PTMV, 2003.12.10
Events .........................................................................................53
Directional overcurrent protection...........................................54
Input/Output description ..............................................................54
Configuration ...............................................................................55
General .......................................................................................55
Sensors .......................................................................................55
Parameters..................................................................................56
Events .........................................................................................56
Pins .............................................................................................57
Measurement mode ....................................................................57
Operation criteria.........................................................................57
Current direction..........................................................................57
Voltage memory ..........................................................................58
Setting groups .............................................................................58
Parameters and Events ...............................................................58
Setting values..............................................................................58
Events .........................................................................................59
Overcurrent Protection .............................................................60
Input/Output description ..............................................................60
Configuration ...............................................................................61
General .......................................................................................61
Sensors .......................................................................................61
Parameters..................................................................................62
Events .........................................................................................62
Pins .............................................................................................63
Measurement mode ....................................................................63
Operation criteria.........................................................................63
Setting groups .............................................................................64
Parameters and Events ...............................................................64
Setting values..............................................................................64
Events .........................................................................................64
Overcurrent IDMT ......................................................................65
Input/Output description ..............................................................65
Configuration ...............................................................................66
General .......................................................................................66
IDMT Type ..................................................................................66
Sensors .......................................................................................67
Parameters..................................................................................67
Events .........................................................................................68
Pins .............................................................................................68
Measurement mode ....................................................................68
Operation criteria.........................................................................68
Setting groups .............................................................................69
Parameters and Events ...............................................................69
Setting values..............................................................................69
Events .........................................................................................69
Earth fault protection ................................................................70
Input/Output description ..............................................................70
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.6.2
7.1.6.2.1
7.1.6.2.2
7.1.6.2.3
7.1.6.2.4
7.1.6.2.5
7.1.6.3
7.1.6.4
7.1.6.5
7.1.6.6
7.1.6.6.1
7.1.6.6.2
7.1.7
7.1.7.1
7.1.7.2
7.1.7.2.1
7.1.7.2.2
7.1.7.2.3
7.1.7.2.4
7.1.7.2.5
7.1.7.3
7.1.7.4
7.1.7.5
7.1.7.6
7.1.7.6.1
7.1.7.6.2
7.1.8
7.1.8.1
7.1.8.2
7.1.8.2.1
7.1.8.2.2
7.1.8.2.3
7.1.8.2.4
7.1.8.2.5
7.1.8.3
7.1.8.4
7.1.8.5
7.1.8.6
7.1.8.6.1
7.1.8.6.2
7.1.9
7.1.9.1
7.1.9.2
7.1.9.2.1
7.1.9.2.2
7.1.9.2.3
7.1.9.2.4
7.1.9.2.5
1VTA10002 Rev02
Valid beginning since version V4D02
PTMV, 2003.12.10
Configuration ...............................................................................70
General .......................................................................................70
Sensors .......................................................................................71
Parameters..................................................................................71
Events .........................................................................................72
Pins .............................................................................................72
Measurement mode ....................................................................72
Operation criteria.........................................................................72
Setting groups .............................................................................73
Parameters and Events ...............................................................73
Setting values..............................................................................73
Events .........................................................................................73
Directional earth fault protection .............................................74
Input/Output description ..............................................................74
Configuration ...............................................................................75
General .......................................................................................75
Sensors .......................................................................................75
Parameters..................................................................................76
Events .........................................................................................76
Pins .............................................................................................77
Measurement mode ....................................................................77
Operation criteria.........................................................................77
Setting groups .............................................................................79
Parameters and Events ...............................................................79
Setting values..............................................................................79
Events .........................................................................................79
Sensitive earth fault protection ................................................80
Input/Output description ..............................................................80
Configuration ...............................................................................81
General .......................................................................................81
Sensors .......................................................................................81
Parameters..................................................................................82
Events .........................................................................................82
Pins .............................................................................................83
Measurement mode ....................................................................83
Operation criteria.........................................................................83
Setting groups .............................................................................85
Parameters and Events ...............................................................85
Setting values..............................................................................85
Events .........................................................................................85
Earth fault IDMT.........................................................................86
Input/Output description ..............................................................86
Configuration ...............................................................................87
General .......................................................................................87
IDMT Type ..................................................................................87
Sensors .......................................................................................88
Parameters..................................................................................88
Events .........................................................................................89
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.9.2.6
7.1.9.3
7.1.9.4
7.1.9.5
7.1.9.6
7.1.9.6.1
7.1.9.6.2
7.2
1VTA10002 Rev02
Valid beginning since version V4D02
Pins .............................................................................................89
Measurement mode ....................................................................89
Operation criteria.........................................................................89
Setting groups .............................................................................90
Parameters and Events ...............................................................90
Setting values..............................................................................90
Events .........................................................................................90
Voltage Protection.......................................................................................91
7.2.1
Overvoltage Protection .............................................................91
7.2.1.1
Input/Output description ..............................................................91
7.2.1.2
Configuration ...............................................................................92
7.2.1.2.1 General .......................................................................................92
7.2.1.2.2 Sensors .......................................................................................92
7.2.1.2.3 Parameters..................................................................................93
7.2.1.2.4 Events .........................................................................................93
7.2.1.2.5 Pins .............................................................................................94
7.2.1.3
Measurement mode ....................................................................94
7.2.1.4
Operation criteria.........................................................................94
7.2.1.5
Setting groups .............................................................................95
7.2.1.6
Parameters and Events ...............................................................95
7.2.1.6.1 Setting values..............................................................................95
7.2.1.6.2 Events .........................................................................................95
7.2.2
Undervoltage Protection...........................................................96
7.2.2.1
Input/Output description ..............................................................96
7.2.2.2
Configuration ...............................................................................97
7.2.2.2.1 General .......................................................................................97
7.2.2.2.2 Sensors .......................................................................................97
7.2.2.2.3 Parameters..................................................................................98
7.2.2.2.4 Events .........................................................................................98
7.2.2.2.5 Pins .............................................................................................99
7.2.2.3
Measurement mode ....................................................................99
7.2.2.4
Operation criteria.........................................................................99
7.2.2.5
Behavior at low voltage values ..................................................100
7.2.2.6
Setting groups ...........................................................................101
7.2.2.7
Parameters and Events .............................................................101
7.2.2.7.1 Setting values............................................................................101
7.2.2.7.2 Events .......................................................................................101
7.2.3
Residual Overvoltage Protection ...........................................102
7.2.3.1
Input/Output description ............................................................102
7.2.3.2
Configuration .............................................................................103
7.2.3.2.1 General .....................................................................................103
7.2.3.2.2 Sensors .....................................................................................103
7.2.3.2.3 Parameters................................................................................104
7.2.3.2.4 Events .......................................................................................104
7.2.3.2.5 Pins ...........................................................................................105
7.2.3.3
Measurement mode ..................................................................105
7.2.3.4
Operation criteria.......................................................................105
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.3.5
7.2.3.6
7.2.3.6.1
7.2.3.6.2
7.3
1VTA10002 Rev02
Valid beginning since version V4D02
Setting groups ...........................................................................106
Parameters and Events .............................................................106
Setting values............................................................................106
Events .......................................................................................106
Motor Protection........................................................................................107
7.3.1
Thermal Overload Protection .................................................107
7.3.1.1
Input/Output description ............................................................107
7.3.1.2
Configuration .............................................................................108
7.3.1.2.1 General .....................................................................................108
7.3.1.2.2 Sensors .....................................................................................108
7.3.1.2.3 Parameters................................................................................109
7.3.1.2.4 Events .......................................................................................110
7.3.1.2.5 Pins ...........................................................................................110
7.3.1.3
Measurement mode ..................................................................110
7.3.1.4
Operation Criteria ......................................................................111
7.3.1.5
Thermal model ..........................................................................111
7.3.1.6
Thermal memory at power-down ...............................................112
7.3.1.7
Setting groups ...........................................................................113
7.3.1.8
Parameters and Events .............................................................113
7.3.1.8.1 Setting values............................................................................113
7.3.1.8.2 Events .......................................................................................113
7.3.2
Motor Start Protection.............................................................114
7.3.2.1
Input/Output description ............................................................114
7.3.2.2
Configuration .............................................................................114
7.3.2.2.1 General .....................................................................................114
7.3.2.2.2 Sensors .....................................................................................115
7.3.2.2.3 Parameters................................................................................115
7.3.2.2.4 Events .......................................................................................116
7.3.2.2.5 Pins ...........................................................................................116
7.3.2.3
Measurement mode ..................................................................116
7.3.2.4
Operation criteria.......................................................................116
7.3.2.5
Setting groups ...........................................................................117
7.3.2.6
Parameters and Events .............................................................117
7.3.2.6.1 Setting values............................................................................117
7.3.2.6.2 Events .......................................................................................117
7.3.3
Blocking Rotor.........................................................................118
7.3.3.1
Input/Output description ............................................................118
7.3.3.2
Configuration .............................................................................119
7.3.3.2.1 General .....................................................................................119
7.3.3.2.2 Sensors .....................................................................................119
7.3.3.2.3 Parameters................................................................................120
7.3.3.2.4 Events .......................................................................................120
7.3.3.2.5 Pins ...........................................................................................121
7.3.3.3
Measurement mode ..................................................................121
7.3.3.4
Operation criteria.......................................................................121
7.3.3.5
Setting groups ...........................................................................122
7.3.3.6
Parameters and Events .............................................................122
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.3.3.6.1
7.3.3.6.2
7.3.4
7.3.4.1
7.3.4.2
7.3.4.2.1
7.3.4.2.2
7.3.4.2.3
7.3.4.2.4
7.3.4.3
7.3.4.4
7.3.4.5
7.3.4.6
7.3.4.6.1
7.3.4.6.2
7.4
1VTA10002 Rev02
Valid beginning since version V4D02
Setting values............................................................................122
Events .......................................................................................122
Number of Starts .....................................................................123
Input/Output description ............................................................123
Configuration .............................................................................124
General .....................................................................................124
Parameters................................................................................124
Events .......................................................................................125
Pins ...........................................................................................125
Measurement mode ..................................................................125
Operation criteria.......................................................................125
Setting groups ...........................................................................126
Parameters and Events .............................................................126
Setting values............................................................................126
Events .......................................................................................126
Distance Protection...................................................................................127
7.4.1
Distance Protection.................................................................127
7.4.1.1
Input/Output description ............................................................127
7.4.1.2
Configuration .............................................................................128
7.4.1.2.1 General .....................................................................................128
7.4.1.2.2 Start Values...............................................................................128
7.4.1.2.3 Zones ........................................................................................129
7.4.1.2.4 Phase selection .........................................................................133
7.4.1.2.5 Parameters Earth factors...........................................................133
7.4.1.2.6 Events .......................................................................................134
7.4.1.3
Operation Mode.........................................................................134
7.4.1.3.1 Start ..........................................................................................135
7.4.1.3.2 Phase selection .........................................................................138
7.4.1.3.3 Calculation of the impedance ....................................................138
7.4.1.3.4 Directional voltage memory .......................................................140
7.4.1.3.5 Tripping logic .............................................................................140
7.4.1.3.6 Adaptation to Autoreclosure ......................................................141
7.4.1.3.7 Signal comparison scheme .......................................................143
7.4.1.3.8 Switching onto faults .................................................................145
7.4.1.4
Switchover to Emergency Overcurrent Protection .....................145
7.4.1.5
Setting the Impedance Zone .....................................................145
7.4.1.6
Setting groups ...........................................................................147
7.4.1.7
Parameters and Events .............................................................147
7.4.1.7.1 General parameter ....................................................................147
7.4.1.7.2 Start values ...............................................................................147
7.4.1.7.3 Choose zone .............................................................................148
7.4.1.7.4 Zone 1, 2, 3, Zone Overreach, Autoreclose (border) .................148
7.4.1.7.5 Drectional backup......................................................................148
7.4.1.7.6 Non-directional backup..............................................................148
7.4.1.7.7 Phase selection .........................................................................148
7.4.1.7.8 Earth factor................................................................................149
7.4.1.7.9 Events .......................................................................................149
PTMV, 2003.12.10
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
1VTA10002 Rev02
Valid beginning since version V4D02
7.5
Differential protection ...............................................................................150
7.5.1
Transformer Differential Protection .......................................150
7.5.1.1
Input/Output description ............................................................150
7.5.1.2
Configuration .............................................................................151
7.5.1.2.1 General .....................................................................................151
7.5.1.2.2 Sensors .....................................................................................151
7.5.1.2.3 Transformer...............................................................................152
7.5.1.2.4 Current ......................................................................................152
7.5.1.2.5 Harmonics .................................................................................153
7.5.1.2.6 Events .......................................................................................154
7.5.1.2.7 Pins ...........................................................................................154
7.5.1.3
Measurement mode ..................................................................154
7.5.1.4
Operation criteria.......................................................................154
7.5.1.5
Transformer ratio compensation................................................156
7.5.1.6
Vector group adaptation ............................................................156
7.5.1.7
Tripping characteristic ...............................................................160
7.5.1.8
Inrush stabilization.....................................................................161
7.5.1.9
Setting groups ...........................................................................161
7.5.1.10 Parameters and Events .............................................................162
7.5.1.10.1 Setting values............................................................................162
7.5.1.10.2 Events .......................................................................................162
7.5.2
Restricted Differential Protection...........................................163
7.5.2.1
Input/Output description ............................................................163
7.5.2.2
Configuration .............................................................................164
7.5.2.2.1 General .....................................................................................164
7.5.2.2.2 Sensors .....................................................................................164
7.5.2.2.3 Parameters................................................................................166
7.5.2.2.4 Events .......................................................................................166
7.5.2.2.5 Pins ...........................................................................................167
7.5.2.3
Measurement mode ..................................................................167
7.5.2.4
Operation criteria.......................................................................167
7.5.2.5
Tripping characteristic ...............................................................168
7.5.2.6
Directional Criterion for stabilization against CT saturation........169
7.5.2.7
Setting groups ...........................................................................171
7.5.2.8
Parameters and Events .............................................................171
7.5.2.8.1 Setting values............................................................................171
7.5.2.8.2 Events .......................................................................................171
7.6
Other Protections ......................................................................................172
7.6.1
Unbalanced Load Protection ..................................................172
7.6.1.1
Input/Output description ............................................................172
7.6.1.2
Configuration .............................................................................173
7.6.1.2.1 General .....................................................................................173
7.6.1.2.2 Sensors .....................................................................................173
7.6.1.2.3 Parameters................................................................................174
7.6.1.2.4 Events .......................................................................................174
7.6.1.2.5 Pins ...........................................................................................175
7.6.1.3
Measurement mode ..................................................................175
PTMV, 2003.12.10
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.6.1.4
7.6.1.4.1
7.6.1.5
7.6.1.6
7.6.1.6.1
7.6.1.6.2
7.6.2
7.6.2.1
7.6.2.2
7.6.2.2.1
7.6.2.2.2
7.6.2.2.3
7.6.2.2.4
7.6.2.3
7.6.2.4
7.6.2.5
7.6.2.6
7.6.2.6.1
7.6.2.6.2
7.6.3
7.6.3.1
7.6.3.2
7.6.3.2.1
7.6.3.2.2
7.6.3.2.3
7.6.3.2.4
7.6.3.2.5
7.6.3.3
7.6.3.4
7.6.3.5
7.6.3.6
7.6.3.6.1
7.6.3.6.2
7.6.4
7.6.4.1
7.6.4.2
7.6.4.2.1
7.6.4.2.2
7.6.4.2.3
7.6.4.2.4
7.6.4.2.5
7.6.4.3
7.6.4.4
7.6.4.5
7.6.4.6
7.6.4.6.1
7.6.4.6.2
7.6.5
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Operation criteria.......................................................................175
Thermal memory .......................................................................176
Setting groups ...........................................................................176
Parameters and Events .............................................................176
Setting values............................................................................176
Events .......................................................................................176
Directional Power Protection..................................................177
Input/Output description ............................................................177
Configuration .............................................................................177
General .....................................................................................177
Parameters................................................................................178
Events .......................................................................................178
Pins ...........................................................................................179
Measurement mode ..................................................................179
Operation criteria.......................................................................179
Setting groups ...........................................................................180
Parameters and Events .............................................................180
Setting values............................................................................180
Events .......................................................................................180
Low Load Protection ...............................................................181
Input/Output description ............................................................181
Configuration .............................................................................181
General .....................................................................................181
Sensors .....................................................................................182
Parameters................................................................................182
Events .......................................................................................183
Pins ...........................................................................................183
Measurement mode ..................................................................183
Operation criteria.......................................................................183
Setting groups ...........................................................................184
Parameters and Events .............................................................184
Setting values............................................................................184
Events .......................................................................................184
Frequency supervision ...........................................................185
Input/Output description ............................................................185
Configuration .............................................................................186
General .....................................................................................186
Sensors .....................................................................................186
Parameters................................................................................186
Events .......................................................................................187
Pins ...........................................................................................187
Measurement mode ..................................................................187
Operation criteria.......................................................................187
Setting groups ...........................................................................188
Parameters and Events .............................................................188
Setting values............................................................................188
Events .......................................................................................188
Synchronism check ................................................................189
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7.6.5.1
7.6.5.2
7.6.5.2.1
7.6.5.2.2
7.6.5.2.3
7.6.5.2.4
7.6.5.2.5
7.6.5.3
7.6.5.4
7.6.5.5
7.6.5.6
7.6.5.6.1
7.6.5.6.2
7.6.5.6.3
7.6.6
7.6.6.1
7.6.6.2
7.6.6.2.1
7.6.6.2.2
7.6.6.2.3
7.6.6.2.4
7.6.6.2.5
7.6.6.3
7.6.6.4
7.6.6.5
7.6.6.6
7.6.6.6.1
7.6.6.6.2
7.6.7
7.6.7.1
7.6.7.2
7.6.7.2.1
7.6.7.2.2
7.6.7.2.3
7.6.7.2.4
7.6.7.2.5
7.6.7.3
7.6.7.4
7.6.7.5
7.6.7.6
7.6.7.6.1
7.6.7.6.2
7.6.8
7.6.8.1
7.6.8.2
7.6.8.2.1
7.6.8.2.2
7.6.8.2.3
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Input/Output description ............................................................189
Configuration .............................................................................190
General .....................................................................................190
Sensors .....................................................................................190
Parameters................................................................................191
Events .......................................................................................192
Pins ...........................................................................................192
Measurement mode ..................................................................192
Operation criteria.......................................................................192
Setting groups ...........................................................................193
Parameters and Events .............................................................193
Setting values............................................................................193
193
Events .......................................................................................194
Switching Resonance Protection...........................................194
Input/Output description ............................................................194
Configuration .............................................................................195
General .....................................................................................195
Sensors .....................................................................................195
Parameters................................................................................196
Events .......................................................................................196
Pins ...........................................................................................197
Measurement mode ..................................................................197
Operation criteria.......................................................................197
Setting groups ...........................................................................198
Parameters and Events .............................................................198
Setting values............................................................................198
Events .......................................................................................198
High Harmonic Protection ......................................................199
Input/Output description ............................................................199
Configuration .............................................................................199
General .....................................................................................199
Sensors .....................................................................................200
Parameters................................................................................200
Events .......................................................................................201
Pins ...........................................................................................201
Measurement mode ..................................................................201
Operation criteria.......................................................................201
Setting groups ...........................................................................202
Parameters and Events .............................................................202
Setting values............................................................................202
Events .......................................................................................202
Frequency Protection..............................................................202
Input/Output description ............................................................203
Configuration .............................................................................203
General .....................................................................................203
Trip Logic ..................................................................................204
Sensors .....................................................................................204
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7.6.8.2.4
7.6.8.2.5
7.6.8.2.6
7.6.8.3
7.6.8.4
7.6.8.5
7.6.8.6
7.6.8.6.1
7.6.8.6.2
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Parameters................................................................................205
Events .......................................................................................205
Pins ...........................................................................................206
Measurement mode ..................................................................206
Operation criteria.......................................................................206
Setting groups ...........................................................................208
Parameters and Events .............................................................208
Setting values............................................................................208
Events .......................................................................................208
7.7
Autoreclose................................................................................................209
7.7.1
Autoreclose .............................................................................209
7.7.1.1
Input/Output description ............................................................209
7.7.1.2
Configuration .............................................................................210
7.7.1.2.1 General .....................................................................................210
7.7.1.2.2 Parameters................................................................................210
7.7.1.2.3 Events .......................................................................................211
7.7.1.2.4 Pins ...........................................................................................212
7.7.1.3
Operation Mode.........................................................................212
7.7.1.3.1 Start and Trip Controlled ...........................................................212
7.7.1.3.2 Start Controlled .........................................................................212
7.7.1.4
Setting groups ...........................................................................215
7.7.1.5
Parameters and Events .............................................................216
7.7.1.5.1 Setting values............................................................................216
7.7.1.5.2 Events .......................................................................................216
7.8
Fault recorder ............................................................................................218
7.8.1
Fault recorder ..........................................................................218
7.8.1.1
Input/Output description ............................................................218
7.8.1.2
Configuration .............................................................................219
7.8.1.2.1 General and setting parameters ................................................219
7.8.1.2.2 Pins ...........................................................................................219
7.8.1.3
Operation ..................................................................................220
7.8.1.4
Parameters and Events .............................................................221
7.8.1.4.1 Setting values............................................................................221
7.9
Appendix A – Connection Diagram..........................................................222
7.9.1
Directional protections Connection Diagram........................222
7.9.2
Differential and Restricted differential protections Connection
Diagram....................................................................................224
7.9.3
Synchro Check Connection Diagram.....................................225
7.10
Appendix B –IDMT Protection Curve Characteristics.............................226
7.10.1
IDMT Protection Functions.....................................................226
7.10.1.1 Overcurrent IDMT......................................................................226
7.10.1.2 Earth fault IDMT ........................................................................226
7.10.1.3 Operating time calculation .........................................................227
7.11
Appendix C: Product Information ............................................................233
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1 About this manual
This manual describes how to use the protection functions available in the
REF542plus.
This manual is addressed to engineering personnel and to anyone who needs to
configure the REF542plus.
1.1 IndustrialIT
IT
This product has been tested and certified as Industrial Enabled. All product information is supplied in interactive electronic format, compatible with ABB Aspect ObIT
jectTM technology. The Industrial commitment from ABB ensures that every enterprise building block is equipped with the integral tools necessary to install, operate,
and maintain efficiently throughout the product lifecycle.
IT
Detailed information on Industrial
is available at <http://www.abb.com/industrialit>.
1.2 REF542plus Network address
The network address can be found in "Field bus address" parameter in the
“General tab” dialog window of every protection module.
The SPA registers reference is reported in the "REF542 plus network address.xls",
version V4D02 table.
2 Safety Information
There are safety warnings and notes in the following text. They are in a different format to distinguish them from normal text.
Safety warning
The safety warnings should always be observed. Non-observance can result in death,
personal injury or substantial damages to property. Guarantee claims might not be
accepted when safety warnings are not respected. They look like below:
Warning!
Do not make any changes to the REF542plus configuration unless you are familiar with the REF542plus and its Operating Tool. This might result in disoperation and loss of warranty.
Note
A note contains additional information worth noting in the specific context, and looks
like below:
Note
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The selection of this control mode requires caution, because operations are allowed
both from the HMI and remotely.
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3 Acronyms and definitions
3.1 Acronyms
CT
Current Transformer
PFC
Power Factor Controller
HMI
Panel (Remote) Human Machine Interface
ROA
Relay Operating angle
VT
Voltage Transformer
3.2 Definitions
Active signal
A signal is active when high, e.g. “1”
Inactive signal
A signal is inactive when low, e.g.”0”
3.3 Document information
Revision History
Version
Date
Comment
1VTA0002
15.07.2003
1st release, valid since SW V4C01
1VTA10002 Rev02
10.12.2003
2 release, valid since SW V4D02
nd
Applicability
This manual is applicable to REF542plus Release 2.0, software version V4D02.
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4 REF542plus analog measurement
4.1 Measured-value processing
The eight available Analog Input channel measures are acquired and processed according to the following flowchart:
AA LP Filter
HP Filter
ADC
(2.2 KHz)
(0,720 Hz)
19.2KHz
LP1 Filter
(1.5 KHz)
Down sampling
4.8 KHz
LP2 Filter
LP3 Filter
(380 Hz) 8th order IIR
(100 Hz) 3th order IIR
DFT / RMS & Math
Protection & Control
The analog signal entering the Analog Input board goes through two hardware filters
to reduce noise and is then sampled and converted to digital information by a sigmadelta Analog/Digital converter with an acquisition rate of 19.2kHz.
The acquisition is performed in parallel on all 8 analogue channels, so the data samples of the network currents and voltages are contemporary (i.e. no phase shift/time
delay is introduced between network quantities).
The digital data is then processed by a digital filter LP1 to reduce the information
bandwidth to 1,5 kHz.
This information is then provided directly to the DFT/ RMS and Math block, performing the Discrete Fourier Transformation and RMS value analysis for the protection
working on the full RMS harmonic content up to the 25th harmonic (Switching Resonance, High Harmonic) and to the Frequency protection for higher discrimination of
zero crossing.
For all the other protection function the digital data are down sampled (.i.e. one sample each 4 is used to 4800 samples/s , maintaining the same information bandwidth).
This signal is furthermore digitally filtered by LP2 and LP3 (HSTS function analogue
quantities only) and provided to the DFT/ RMS and Math block, performing the Discrete Fourier Transformation and RMS value analysis.
All protection functions are based on the RMS value at the network rated frequency.
In addition the following functions utilize:
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Overcurrent instantaneous:
The function the peak value of the measured current under transient condition
for a faster response: when the instantaneous peak value is higher then three times
SQRT (2) the RMS value, ( I x _ peak
2 > 3 ⋅ I x _ RMS ).
Inrush Harmonic:
The function evaluates the ratio between current values at 2nd harmonic and at
fundamental frequency.
Differential Protection:
The function evaluates the measured amount of differential current at the fundamental, 2nd and 5th harmonic frequencies.
5 Analog Inputs
The Analog Inputs dialog windows allow the user to configure:
analog input channels
network characteristics (REF542plus can handle currents/voltages from
two different networks)
calculated values (power, THD, mean and maximum current values over
the desired time interval)
5.1 Terminals
5.1.1 Analog Inputs
To ease the input of analog input channels, the user can push the button labeled “Get
group data” in Inputs tab of Analog Inputs dialog and then select the used board from
the list. This automatically configures used analog input channels to the proper sensor type and sets default values for each sensor type.
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5.1.1.1 Analog Board selection
To complete the configuration of each analog input channel (e.g. setting the appropriate Rated Primary and Secondary Values) the user must double-click on the line in
Inputs tab of Analog Inputs dialog.
5.1.1.2 Current Transformer
Board Input Rated Value (IRV) at present can be 0.2, 1 or 5 A only (depending on the
type of CT mounted on Analog Input Board).
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds.
Default direction of the polarity for the CT is “Line”. If “Bus” is selected, the polarity of
analog signal will be inverted to preserve directions in directional protections. Amplitude and phase corrections can be introduced.
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5.1.1.3 Current Rogowski
Board Input Rated Value (IRV) at present can be only 0.150 V (depending on the
Rogowski sensor input on Analog Input Board)
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds.
Default direction for the polarity of the Rogowski current sensors is “Line”. If “Bus” is
selected, the polarity of analog signal will be inverted to preserve directions in directional protections. Amplitude and phase corrections can be introduced.
5.1.1.4 Voltage Transformer
Voltage Transformers can be phase, line or residual (open delta) voltage transformers.
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5.1.1.4.1 Phase-Voltage Transformer
Phase-voltage transformers normally refer rated phase-voltage at primary sidewith
rated phase voltage on the secondary side, e.g.
20kV 100V
. This is shown below
:
3
3
RSV line in “Transformer ratio” dialog window. When entering VT rated voltage data,
it is therefore not necessary to perform division by
3.
Board Input Rated Value (IRV) at present can be100 V only (depending on the input
transformer mounted on Analog Input Board)
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds. If “Invert phase” is selected, the polarity of analog signal will be inverted. Amplitude and
phase corrections can be introduced.
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5.1.1.4.2 Line Voltage Transformer
Line voltage transformers normally refer rated line voltage at primary side with rated
voltage on secondary side, e.g. 20kV : 100V . This is shown below RSV line in
“Transformer ratio” dialog window.
Board Input Rated Value (IRV) at present can be 100 V only (depending on the input
transformer mounted on Analog Input Board)
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds. If “Invert phase” is selected, the polarity of analog signal will be inverted. Amplitude and
phase corrections can be introduced.
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5.1.1.4.3 Residual Voltage Transformer (open delta)
Residual voltage transformers normally refer rated phase-voltage at the primary side
with secondary side rated voltage of each winding in the open delta, e.g.
20kV 100
:
. This is shown below RSV line in “Transform ratio” dialog window.
3
3
When entering VT rated voltage data, it is not necessary for the user to perform any
division. Simply, the user must select in “VT type” dialog window the corresponding
secondary winding denominator.
Board Input Rated Value (IRV) at present can be 100 V only (depending on the input
transformer mounted on Analog Input Board)
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds. If “Invert phase” is selected, the polarity of analog signal will be inverted. Amplitude and
phase corrections can be introduced.
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5.1.1.5 Voltage Sensor
Voltage sensors can be connected as phase-voltage only, but the Rated Primary
Value (RPV) to be insertedis the rated line (phase to phase) voltage at primary side
When entering the sensor rated voltage data, it is therefore not necessary to perform
division by
3.
Board Input Rated Value (IRV) at present can be 2 V only (depending on the voltage
sensor input on Analog Input Board)
In case of mismatch between Rated Secondary Value (RSV) and Board Input Rated
Value, REF542plus automatically compensates protection function thresholds. If “Invert phase” is selected, the polarity of analog signal will be inverted. Amplitude and
phase corrections can be introduced.
5.1.2 General constraints
• Channels 1-6 can be used only for phase currents, phase voltages or line voltages
• Channels 7 and 8 can be used also either for earth currents or residual voltages
• Current and voltage sensors inside the triples 1-3 and 4-6 must have the same
characteristics (RPV, RSV and IRV)
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5.1.3 Network characteristics
REF542plus can handle two different networks or network parts having the same frequency. By default only one network is used.
If the second network is needed it must be enabled in Networks tab of Analog Inputs
dialog window.
For each network the Rated Nominal Voltage and Current can be configured. These
values are used by HMI led bars to scale displayed quantities.
5.1.4 Calculated values
The preferred reference system (i.e. load or generator) and some calculations can be
enabled in REF542plus:
Power (either three-phase or Aaron)
Mean and maximum current values
Total Harmonic Distortion (on voltage sensors only)
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6 Control and monitoring
6.1 Analog Objects
6.1.1 Measurement supervision NPS and PPS
The REF542plus provides two types of measurement supervision functions. Each of
them can be independently activated:
Positive Phase Sequence (PPS)
Negative Phase Sequence (NPS)
6.1.1.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the measurement supervision function is reset (no
matter its state), i.e. all output pins go low generating the required events (if any) and
all internal registers and timers are cleared. The protection function will then remain in
idle state until BS signal goes low.
Output
Name
Type
Description
Warning
Digital signal (active high)
Warning signal
Failing
Digital signal (active high)
Failing signal
Warning is the start signal. Warning signal will be activated when the start conditions
are true (negative phase sequence value exceeds the setting threshold value for
NPS; positive phase sequence value falls below the setting threshold value for PPS).
Failing signal will be activated when the start conditions are true and the operating
time has elapsed.
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Protection Functions: Configuration and Settings
6.1.1.2 Configuration
6.1.1.2.1 General
6.1.1.2.2 Sensors
The measurement supervision functions operate on all sensors in a triple (analog
channels 1-3 or 4-6 can be used to supervise phase currents, phase voltages or line
voltages).
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6.1.1.2.3 Parameters
Start Value:
Positive/Negative phase sequence threshold for Start condition
detection.
Time:
Time delay for Trip condition detection.
6.1.1.2.4 Events
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6.1.1.2.5 Pins
6.1.1.3 Measurement mode
Measurement supervision functions evaluate the measured amount of positive and
negative phase sequence values at the fundamental frequency.
6.1.1.4 Operation criteria
If the negative phase sequence value exceeds the setting threshold value (Start
value) (in the NPS-based functions), or if the positive phase sequence value falls
below the setting threshold (Start value) the function enters the START status
and raises the warning. After the preset operating time (Time delay)has elapsed,
the failing signal is generated.
The measurement function will come back in passive status and the warning signal
will be cleared if the negative phase sequence value falls below 0.95 the setting
threshold value for NPS or if the positive phase sequence value exceed 1.05 the setting threshold value for PPS.
The measurement function will exit the Failing status and the failing signal will be
cleared when the negative phase sequence value falls below 0.4 the setting threshold
value for NPS or if the positive phase sequence value exceed 1.05 the setting threshold value for PPS.
6.1.1.5 Setting groups
Two parameter sets can be configured for each of the measurement supervision functions.
6.1.1.6 Parameters and Events
6.1.1.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start value (PPS)
Time delay
0.30 .. 0.90
30 .. 30000
In/Un
ms
0.85
1000
PPS threshold to undergo.
Time delay from start condition (warning signal)
to failing signal.
Start value (NPS)
Time delay
0.05 .. 0.40
30 .. 30000
In/Un
ms
0.10
1000
NPS threshold to be exceeded.
Time delay from start condition to failing signal.
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6.1.1.6.2 Events
Code
Event reason
E0
Warning signal is active
E1
Warning signal cancelled.
E6
Failing signal is active
E7
Failing signal is back to inactive state
E18
Function block signal is active
E19
Function block signal is back to inactive state
By default all events are disabled.
6.1.2 Power Factor Controller
The power factor controller is a control function in the REF542plus. Due to the complex setting parameter, this function is also described in this protection part.
The power factor controller is designed to control reactive power compensation in
power systems. The magnitude of the reactive power in the network is derived from
the measured power factor. Consequently the power factor controller permanently
monitors the power factor, which is defined as the ratio of the effective power to the
active power. The PFC then controls the switching ON/OFF of the available capacitors banks to reach the set power factor target.
6.1.2.1 Input/Output description
Input
1VTA10002 Rev02
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Name
Type
Description
BL
Digital signal (active high)
Blocking signal
DISCONNECT
Digital signal (active high)
Disconnect all capacitor banks
RESET
Digital signal (active high)
Reset the function
OVERTEMP.
Digital signal (active high)
Overtemperature
VMIN / VMAX
Digital signal (active high)
Voltage out of range
VA MAX
Digital signal (active high)
Overload due to overvoltage
MODE: MAN.
Digital signal (active high)
Mode manual
SET NIGHT
Digital signal (active high)
Set night parameter
MANUAL CONTROL BANK 0
Digital signal (active high)
Switch bank 0 manually
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Name
Type
Description
MANUAL CONTROL BANK 1
Digital signal (active high)
Switch bank 1 manually
MANUAL CONTROL BANK 2
Digital signal (active high)
Switch bank 2 manually
MANUAL CONTROL BANK 3
Digital signal (active high)
Switch bank 3 manually
CHECKED
BACK BANK 0
Digital signal (active high)
Status on indication bank 0
CHECKED
BACK BANK 1
Digital signal (active high)
Status on indication bank 1
CHECKED
BACK BANK 2
Digital signal (active high)
Status on indication bank 2
CHECKED
BACK BANK 3
Digital signal (active high)
Status on indication bank 3
TROL BANK 0
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Output
1VTA10002 Rev02
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Name
Type
Description
Q ALARM
Digital signal (active high)
Alarm indication Q
COS ϕ ALARM
Digital signal (active high)
Alarm indication cos ϕ
OPERAT. ALARM
Digital signal (active high)
Operation Alarm (reset only by power off)
GENERAL ALARM Digital signal (active high)
General alarm
SWITCH ON/OFF
BANK 0
Digital signal (active high)
Bank 0 on (high), off (low)
SWITCH ON/OFF
BANK 1
Digital signal (active high)
Bank 1 on (high), off (low)
SWITCH ON/OFF
BANK 2
Digital signal (active high)
Bank 2 on (high), off (low)
SWITCH ON/OFF
BANK 3
Digital signal (active high)
Bank 3 on (high), off (low)
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6.1.2.2 Configuration
6.1.2.2.1 General
6.1.2.2.2 Capacitor banks
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6.1.2.2.3 Control Data
6.1.2.2.4 Time
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
6.1.2.2.5 Events
By default all events are disabled.
6.1.2.2.6 Pins
6.1.2.3 Measurement mode
When a reactive power consumer is switched into the network, the current variable
increases. Simultaneously the phase displacement increases in relation to the related
voltage quantity. As a result, the reactive power increases and the power factor is reduced correspondingly. Because of the increase in the current measured quantity and
the angle of the phase displacement, an increased voltage drop in the power system
must be taking into account.
The following figure shows the reason of the increased voltage drop. The section on
the left shows the single line diagram of the power system. In this case U 1 is the
source voltage, which is assumed to be constant, U 2 is the voltage in the network
with a motor, that requires as well as the active power as also the reactive power. To
simplify the explanation, the transformation ratio of the transformer is assumed to be
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
1. The center of the diagram shows the case where only pure active power is consumed. The current and voltage quantities are in phase. As shown in the vector diagram, the amplitude of the voltage U 2 is virtually uninfluenced by this. However, if
additional inductive reactive power is used, as shown in the vector diagram on the
right, the amplitude of the voltage U 2 in the network can be substantially reduced.
U1
U1
U2
U1
U2
U2
I
I
M
Figure 1: Increase in voltage drop resulting from inductive reactive power
To maintain the voltage drop within a certain limits in the event of a high consumption
of reactive power, capacitors must be used for compensation. The power factor controller function is implemented in the REF542plus, that offers the option of regulating
the demand for capacitive reactive power to compensate the inductive reactive power
in medium voltage system by switching of the required capacitor banks optimally.
Warning!
If a power factor control function is applied, it is recommended to provide the
resonance protection function, switching resonance protection and high harmonic resonance protection too, in order to protect the capacitor banks against
overloading by the possible appearance of harmonics.
The principle of compensation of the reactive power is explained in Figure 2. P is the
active power and Q the reactive power. As in the vector diagram in the previous illustration, the active power P is shown on the vertical axis and the reactive power Q on
the horizontal axis. The power factor cos ϕ1 , which is shown as a straight line in the
diagram, shows the relationship between the active power P1 and the apparent
power S1. The apparent power S1 is again dependent on the magnitude of the consumed reactive power Q1 . This enables the consumption of reactive power to be
compensated with the aid of the measured power factor so that the voltage drop in
the network always remains within the allowable tolerance limits.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Q
Q1
S1
ϕ1
P
P1
Figure 2: Reactive power diagram
The capacitor output required to compensate the reactive power consumption can be
determined as shown in the power diagram in the Figure 3. In this case cos ϕ1 is the
setting value for limitation of the power factor, which is generally referred to as the reversal point in the power factor controlling. The resulting apparent power is S1 , active
power P1 and reactive power Q1. Furthermore, S2 is the actual apparent power, P2
the actual active power and Q2 the actual reactive power in the power system.
Q
Q2
S2
Q1
S1
ϕ1
P
P1 = P2
Figure 3: Determining the capacitor output for compensation
To determine the required capacitor output, the active power P1 at the reversal point
or at the set power factor cos ϕ1 is set to be equal to the instantaneous active power
P2. The associated or the allowable reactive power Q1 can then be calculated with
the following equation:
Q1 =
1 − cos 2 ϕ1
cos ϕ1
The reactive power ∆Q that must be compensated is calculated from the difference of
the instantaneous and the allowable reactive power.
As a result, the value of the capacitance for the capacitor banks that are to be
switched on or off to compensate for the reactive power can be determined.
6.1.2.4 Operating modes and requirements
The power factor controller has the following operating modes:
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Manual
Automatic
During manual operation every individual capacitor bank can be switched on or off via
the inputs provided for the purpose. This requires the signals for switching on and off
to be pulse-type signals.
If a capacitor bank is switched on, a logical signal 1 will show at the associated output. When it is switched off, the output will show a logical signal 0.
To ensure that the controller is always informed of the switch status of the capacitor
banks, checked confirmations of the switch settings must be fed back via the binary
inputs (checked back inputs, bank 0-3).
The reactive power compensation should normally only be required when the power
system is in operational status. Therefore, the power factor controller's activities are
made dependent on the voltage status of the power system. For this reason the
power factor controller shall always includes the overvoltage (U>>) function and the
undervoltage (U<<) function for monitoring the voltage status in the system. If one of
the set voltage limits, either overvoltage or undervoltage, is exceeded and the associated time delay has expired, all active capacitor banks are immediately switched off.
This function is independent of whether the power factor controller is in manual or
automatic operating mode. The binary input VMIN/MAX is used for this function.
The binary input DISCONNECT also has the capacity to disconnect all active capacitor banks on receiving the logical signal 1.
6.1.2.5 Time settings
After the auxiliary voltage supply has been activated, the function of the power factor
controller is first blocked by the initialization period. It is in operation again only after
expiry of this initialization period. The initialization period is also started when the system voltage recovers after a system fault, e.g. when the undervoltage protection is reset from the operating position, the binary input DISCONNECT is active. Reasonably,
the initialization period should always be set to be greater than the blocking time for
discharging the capacitor banks.
If a capacitor bank is switched on to compensate for reactive power during a control
process, transient phenomena will generally be initiated in the network. Determining
of the power for the power factor control must therefore be delayed until the transient
process has mostly subsided. The dead time required for this must be set in the
power factor controller. Further switching of the capacitor group will only be enabled
when the dead time has expired. However, this requires the capacitor bank in question to be already fully discharged.
Warning!
When a capacitor bank is switched off, the stored electrical energy must first
be discharged before it shall being switched on again (capacitor discharge
must be provided by internal resistors or by external voltage transformers), to
avoid high inrush current phenomena.
The power factor controller foresees a discharge blocking period set. This ensures
that a capacitor bank has sufficient time to discharge the accumulated power before
being switched on again.
6.1.2.6 Indications
As noted in the previous section, control is started only when the input of reactive
power in the system falls below the power factor cos ϕ set as the reversal point. In
addition, to be able to supervise the input of reactive power in the network continuously, the power factor controller has an additional setting for power factor cos ϕ to
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
generate an alarm message (binary output ALARM COS ϕ). It makes sense for the
setting value for cos ϕ alarm to be set to less than the setting value for cos ϕ reversal
point for starting the control process. This enables the cos ϕ warning to be generated
only if the power factor controller cannot switch on a capacitor bank because of operating conditions.
However, if all capacitor banks are already switched on and the reversal point still has
not been reached, the alarm Q (binary output ALARM Q) will be generated. This signals that the needed reactive power can no longer be compensated, because all capacitor banks are already switched on.
In the event of a power system fault, such as when the overvoltage protection or undervoltage protection function is activated (binary input V MIN/V MAX is used for this
function), all switched-on capacitor banks will be switched off. Then the General
Alarm (binary output ALARM GENERAL) is generated.
The power factor controller also has inputs that will generate the General Alarm message when they receive a signal. In this case information on Over-temperature (binary
input OVERTEMP.) in the capacitor banks or the upper limit of the operation voltage
U> (binary input V A MAX) on the relevant inputs being exceeded is present. As soon
as the General Alarm is generated, the power factor controller functions are blocked
in the automatic mode. The power factor controller can only be reactivated after this
indication has been reset.
Note
If the general alarm is set, the power factor controller is blocked until a reset is performed.
The number of switchgear switching cycles for switching the individual capacitor
banks on or off is monitored and compared with the set value for the switching cycles.
If this value is exceeded, an alarm is sent (binary output ALARM OPERAT.)
Note
Operation Alarm can only be reset by power off.
6.1.2.7 Automatic power factor controlling
In automatic operating mode the power factor and its required reactive power in the
network is continuously monitored. The sign of the difference of the reactive power
∆Q, which is determined from the current and allowed reactive power, enables the
capacitor banks to be switched on or off with reference to compensation for the reactive power. If the sign is positive, a capacitor bank must be switched on. In the event
of a negative sign, an appropriate bank must be switched off.
To switch on a capacitor bank, a reactive power must first be defined as the activating
threshold QON . The activating threshold here must be set by multiplying an adjustable
factor KON in percent by the smallest installed reactive power of a capacitor bank QCO.
QON = K ON QC0
Then capacitor bank 0 (C0) is set as the smallest bank. The controller is enabled for
the reversal point set as power factor cos ϕ as soon as the relationship between the
compensating reactive power ∆Q in the network and the smallest installed capacitor
output QC0 is greater than the set activating threshold QON in percent. This is shown
by the following equation:
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
 ∆Q

K

− ON  > 0
 QC0 100% 
The number NON (QCO) of the capacitor banks to be switched on can be determined
with the following relationship:
 ∆Q

K
N ON (QC 0 ) = 
− ON  + 1
 QC0 100% 
Once a capacitor bank is switched on, a set dead time sequence starts. It should be
delayed until the transient processes in the network have somewhat subsided. Power
calculation will only be resumed after expiry of this dead time and only then a control
process will be permitted to start again.
However, if the inductive reactive power decreases, the current power factor cos ϕ in
the network may become capacitive. In this case, the reactive power ∆Q, which is
generated from the difference between the current and the resulting reactive power
corresponding to the reversal point, will naturally have a negative sign. This capacitive state is also not desirable for system operation, because in these circumstances
overvoltages could be expected in the system. As a result, in this case at least one
capacitor bank must be switched off. A criterion for the switch-off threshold must also
be defined, similar to that above for switching on.
QOFF = (K OFF − K ON ) QC0
In this case QOFF is the switch-off threshold defined here to switch off the capacitor
bank, KOFF is the so called neutral zone in percent (hysterisis) that can be set on the
power factor controller, KON is the adjustable factor for the activating threshold in percent and QC0 is again the smallest installed power of a capacitor bank. But please
note, that the condition has to be fulfilled:
(K OFF − K ON ) > 1
Otherwise the capacitor bank will always be switch on and off all the time.
The power factor controller will enable the control for switching off the capacitor bank
if the ratio of the negative reactive power difference ∆Q to the smallest installed capacitor output is greater than the switch-off threshold QOFF in percent. This is shown
by the following equation:
 ∆Q K OFF 

 > 0
−
 QC0 100% 
The number NOFF (QC0) of the capacitor units that are to be switched off can be determined. with the following relationship:
 ∆Q K OFF 
 − 1
−
NOFF (QC 0 ) = 
 QC0 100% 
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
cos ϕ
M
Figure 4: Configuration of the capacitor banks for reactive power compensation in the network
The figure above shows an example of the configuration of the capacitor banks for
compensating reactive power in a single-line view. Capacitor banks must be switched
on and off depending on the power intake of the inductive consumer, so that the
power factor does not drop below the allowable limit.
The REF542plus bay control and protection unit enables a control process to be run
with a maximum of 4 capacitor banks. The various capacitor banks are referred to as
bank C0, bank C1, bank C2 and bank C3. The individual capacitor banks can be defined separately or differently with the same reactive power. In the case of different
power ratings, bank C0 must be configured with the smallest capacitor output. Then
the recommended power rating based on C0 is listed in the following table.
Table 1: Definition of the capacitor banks
C0 / C0
C1 / C 0
C 2 / C0
C3 / C 0
1
1
1
1
1
1
2
2
1
2
2
2
1
2
4
4
1
2
4
8
If all capacitor banks are defined equally, it is possible to switch them on and off in
accordance with a linear or a circular switching program. With a linear switching program the capacitor banks are switched on in ascending order and switched off in descending order of indices. In contrast, with a circular switching program the capacitor
banks are always switched on and off in ascending order.
The capacitor banks are switched on or off in accordance with the calculated number
NON or NOFF . Only the calculated whole number before the decimal point is taken into
account. For example, if it is assumed that the calculated number of capacitor banks
to be switched on is equal to 3 and if the configuration of the capacitor banks is set to
1:2:4:8, the controller first attempts to switch on the next lower bank C1 with 2QC0 . If
it is known from the reconfirmation of the switch that bank C1 is already switched on,
the next smaller bank C0 will be addressed with QC0 . However, if bank C1 is already
switched on, the next free bank, for example bank C2 with capacitor output 4 QC0 ,
will be selected and switched on.
After bank C2 has been switched on, the control function is first blocked for the duration of the set dead time. The reactive power controller only becomes active again after expiry of the dead time. Because the switched-on capacitor output is too big in the
event of unchanged network conditions, the power factor controller will have to detect
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
that a capacitor bank with power QC0 should be switched off. If the switch-off conditions, which must be determined from the setting of the neutral zone, are met, the
switch-off process for bank C0 will be started. Switching off the capacitor banks is in
principle similar to switching them on.
6.1.2.8 Setting Example
A capacitor banks of each 6.36 µF shall be applied to compensate the reactive power
in 10kV power system. Consequently each capacitor bank is able to compensate a
reactive power of:
QCO = 200 kVAr
which is also equal to the value of the smallest capacitor bank.
If it is required, that one of the capacitor bank shall be switch on at a certain apparent
power, e.g. 250 kVAr and a power factor 0.7. The portion of the reactive power can
be calculated as following:
QON = sin (arc cos 0.7) x 250 kVAr = 178.5 kVAr
Accordingly the pick up value of the power factor controller shall be set to:.
Pick Up =
178.5
100% = 89.2%
200
From the difference of the reactive power the threshold for the setting for the neutral
zone for switching off can be determined.
QOFF = (178.5 − 200) = 21,5 kVAr
∆Q 21,5 kVAr
=
100% = 10,75%
QC0 200 kVAr
One of the same capacitor bank will be switch off again, if the reactive power becomes negative. To avoid continuously switching on and off of the capacitor bank, the
setting of the neutral zone has to be higher than the following:
Neutral Zone ≥ (100 + 10.75)% = 110.75%
The setting for the neutral zone is selected to be 115%. Consequently the reactive
power at the switch off moment can be check as following:
Q OFF = − 0.15 × 200 kVAr = - 30 kVAr
The next setting parameter is dedicated for the capacitor banks. As mentioned in the
calculation above, each capacitor bank has a reactive power of 200 kVAr. The banks
are equal to each other and the number is 2. The maximum switching cycles shall be
limited to a number, that is to be confirmed by the manufacturer of the circuit breaker,
e.g. 10,000.
The parameter of the control data give the limitation of control activities. The controller shall be activated, if the power factor is less than 0.7. The switching on of a specific capacitor banks can only be initiated, if the condition of the pick up value, is fulfilled.
The time setting has to be adapted to the system operation condition. The discharge
blocking time is the blocking duration of a capacitor bank after it is switched off. After
switching on a capacitor bank the power factor control is deactivated as long as the
dead time is not expired. After a complete switch off of all banks and recovery of the
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
power supply for the power factor controller no capacitor banks can be switched on
before the power on delay time is elapsed.
6.1.2.9 Parameter and Events
6.1.2.9.1 Setting values
Parameter
Values
Unit
Default
Neutral zone
105… 200
% QCO
115
Pickup zone
0…100
% QCO
0
Reactive power of
smallest QCO
1…20000
kVA
100
Number of banks
1…4
1
Maximum switching cycles
1…10000
2500
Set point cos phi
0.7..1.0
Ind/cap
0.9 ind
Limiting value cos
phi
0…1
Ind/cap
0
Discharge blocking
time
1…7200
s
900
Dead Time
1…120
s
10
Power on delay
1…7200
s
900
Duration of integra- 1…7200
tion
s
900
Explanation
6.1.2.9.2 Events
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Code
Event reason
E0
Bank 0 on
E1
Bank 1 on
E2
Bank 2 on
E3
Bank 3 on
E4
Bank 0 off
E5
Bank 1 off
E6
Bank 2 off
E7
Bank 3 off
E8
Overtemperature started
E9
Overtemperature back
E10
Va max started
E11
Va max back
E12
Vmin/Vmax started
E13
Vmin/Vmax back
E14
Command DISCONNECT started
E15
Command DISCONNECT back
E16
Cos phi warning started
E17
Cos phi warning back
E18
Alarm Q started
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
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Code
Event reason
E19
Alarm Q back
E20
Warning switching cycle
E21
Alarm reset
E22
Block signal started
E23
Block signal back
E24
Manual operating mode
E25
Automatic operating mode
E26
Night mode
E27
Day mode
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7 Protection Functions
7.1 Current protection functions
7.1.1 Inrush blocking
REF542plus has one inrush blocking protection function. This function is replaced
from the Inrush Harmonic function and it has to be preferred when very fast response
time is required only.
The following current protection functions are blocked by the inrush blocking protection function without the need of additional wiring in the FUPLA (i.e. the block to the
protection functions is implicit).
Overcurrent instantaneous
Overcurrent high
Overcurrent low
Directional overcurrent high
Directional overcurrent low
IDMT
Earthfault IDMT
7.1.1.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Output
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true and the overcurrent
protection will be implicitly blocked until the operating time (Time) has elapsed.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
The TRIP signal will be activated when the start conditions are true (inrush detection)
the maximum measured current exceeds the threshold (limit N·I>>) an the relevant
overcurrent protection operating time has elapsed.
7.1.1.2 Configuration
7.1.1.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.1.2.2 Sensors
The protection function operates on any combination of current phases in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.1.2.3 Parameters
N:
M:
Time:
Threshold I>> multiplier for fault detection and inrush protection trip
Threshold I> multiplier for inrush detection
Overcurrent protection blocking Time at inrush detection
7.1.1.2.4 Events
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.1.2.5 Pins
7.1.1.3 Measurement mode
Inrush blocking function evaluates the current at the fundamental frequency.
7.1.1.4 Operation criteria
An inrush is detected if the maximum measured current exceeds the threshold M·I>
within 60 ms after it exceeded 10% of current threshold I>.
Here I> is the threshold (Start value I>) of the overcurrent low protection function. If this protection function is not installed, the threshold of IDMT protection function (Base current Ieb:, if installed) is used or a standard value of 0.05·IN (if
IDMT also is not installed).
If an inrush is detected, the above-listed protection functions are blocked until the end
of inrush has been detected or the maximum preset inrush duration (i.e. Time) has
elapsed.
The end of inrush condition is detected when the maximum measured current falls
below M·0.65·I>. A counter is then started and 100 ms later the end of inrush is assumed. The current protection functions are then released from the block.
Note
At feeder start-up, with current zero, the implicit block of the overcurrent protection
function is already active. Only as the current increase the inrush condition is evaluated and the block can be released if an inrush is not present.
The inrush blocking itself becomes a protection function, if the maximum measured
current exceeds the limit N·I>> after the inrush detection. The operating time is that of
the overcurrent instantaneous (if installed) or 80 ms.
Here I>> is the threshold (Start value I>>) of the overcurrent high protection
function. If this protection function is not installed, the threshold of overcurrent instantaneous protection function (if installed) is used or a standard value of 0.10·IN (if overcurrent instantaneous also is not installed).
The following three diagrams are not scaled and are provided solely for a better understanding of the explanations of how the inrush blocking works.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Tesb is the operation counter that is compared to the set overcurrent protection blocking Time (i.e. Time).
Fig. 5: Inrush is detected within the 60ms window, then the end of inrush condition is
detected and the block released before protection-blocking Time exI [A]
N I>>
Overcurrent
high-set tripping
Inrush Tripping
Inrush
detected
M I>
I>>
0.65 M I>
Overcurrent
low-set tripping
I>
0.1 I>
t
60 ms
100 ms
tESB
pires.
Figure 5: Current-time characteristic of the detected inrush process
Fig. 6: Inrush is detected within the 60ms window, then the end of inrush condition is
detected and the block released before protection-blocking Time expires. The current
value is over the I> threshold and that protection function will start timing and trip in
due time.
I [A]
N I>>
Overcurrent
high-set tripping
Inrush Tripping
Inrush
detected
M I>
I>>
0.65 M I>
Overcurrent
low-set tripping
I>
0.1 I>
t
60 ms
100 ms
tESB
Figure 6: Current-time characteristic of the detected overload
Fig. 7: Inrush is detected within the 60ms window, no end of inrush condition is detected and the protection-blocking Time expires. The current value is over the I>>
threshold and that protection function will start timing and trip in due time.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
I [A]
N I>>
Inrush Tripping
Overcurrent
high-set tripping
Inrush
detected
M I>
I>>
0.65 M I>
Overcurrent
low-set tripping
I>
0.1 I>
t
60 ms
Blocking time expires
Figure 7: Current-time characteristic of the detected fault
7.1.1.5 Setting groups
Two parameter sets can be configured for the inrush blocking protection function.
7.1.1.6 Parameters and Events
7.1.1.6.1 Setting values
Parameter
Values
N
M
Time
2.0 .. 8.0
3.0 .. 4.0
200 .. 100000
Unit
Default
Explanation
ms
2.0
3.0
250
Threshold I>> multiplier for fault detection and trip
Threshold I> multiplier for inrush detection
overcurrent protection blocking Time after inrush
detection
7.1.1.6.2 Events
Code
Event reason
E0
Start L1 started
E1
Start L1 back
E2
Start L2 started
E3
Start L2 back
E4
Start L3 started
E5
Start L3 back
E6
Trip started
E7
Trip back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.2 Inrush Harmonic
REF542plus has one Inrush Harmonic function, which can be used to temporarily
block other protection functions.
The following current protection functions are blocked by the Inrush Harmonic protection function without the need of additional wiring in the FUPLA (i.e. the block to the
protection functions is implicit).
Overcurrent instantaneous
Overcurrent high
Overcurrent low
Directional overcurrent high
Directional overcurrent low
IDMT
Earthfault IDMT
7.1.2.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Output
Name
Type
Description
Start
Digital signal (active high)
Start signal
Start signal can be wired in the FUPLA to signal inrush condition status or to protection functions BS input pins (different from those listed above and implicitly blocked)
to temporarily block during an inrush transient (i.e. the block to the protection functions is explicit).
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Protection Functions: Configuration and Settings
7.1.2.2 Configuration
7.1.2.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.2.2.2 Sensors
The protection function operates on any set of phase currents in a triple.
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7.1.2.2.3 Parameters
Minimum current threshold:
Current threshold for inrush detection.
Fault current threshold:
Current threshold for fault detection.
Harmonic ratio threshold:
2nd/fundamental current ratio threshold for inrush detection.
7.1.2.2.4 Events
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7.1.2.2.5 Pins
7.1.2.3 Measurement mode
Inrush harmonic protection function evaluates the ratio between current values at 2nd
harmonic and at fundamental frequency.
7.1.2.4 Operation criteria
If for at least one phase current:
the current is not in steady-state condition,
AND the current value at fundamental frequency is above the preset minimum
current threshold (i.e. Min current threshold),
AND the current value is below the preset maximum current threshold (i.e.
Fault current threshold),
AND the Harmonic ratio between current values at 2nd harmonic and at fundamental frequency exceeds the preset threshold (i.e. Harmonic ratio
threshold)
then the protection function is started and the start signal will be activated.
The start criteria are illustrated in the following flowchart:
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Min current Thr
0.05 .. 40.00 In
Fundamental
Frequency
Start
Fault current Thr
0.05 .. 40.00 In
&
Start
Steady State
detection
0.95 .. 105%
Second
Harmonics
I2H/Fundamental
5% .. 50%
The protection function will remain in START status until at least for one phase the
above conditions (steady state excluded) are true. It will come back in passive status
with a 10ms delay when:
for all the phases at least one condition falls below 0.95 the setting threshold
value (i.e Min Current threshold or Harmonic ratio threshold respectively),
OR at least for one phase the current value exceeds the preset maximum current threshold (i.e. Fault current threshold).
7.1.2.5 Steady-state detection
Steady-state condition is detected if:
the current value at fundamental frequency falls below the preset minimum current threshold (i.e. Min current threshold) for at least 10ms,
OR the current value at fundamental frequency is between 95% and 105% of
the previous period for at least one period.
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7.1.2.6 Setting groups
Two parameter sets can be configured for the harmonic inrush protection function.
7.1.2.7 Parameters and Events
7.1.2.7.1 Setting values
Parameter
Values
Unit
Default
Explanation
Minimum current
threshold
Fault current
threshold
Harmonic ratio
threshold
0.05 .. 40.00
In
0.5
Current threshold for inrush detection, if exceeded the inrush conditions are evaluated
0.05 .. 40.00
In
2
5 .. 50
%
10
Current threshold for fault detection, if exceeded
the inrush start is set to low.
2nd/fundamental current ratio threshold for inrush detection.
7.1.2.7.2 Events
Code
Event reason
E0
Protection has started timing
E1
Timing is cancelled
E18
Protection block signal is active started
E19
Protection block signal is back to inactive state
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.3 Directional overcurrent protection
The REF542plus has two directional definite time functions, each of which can be independently activated:
Overcurrent directional high set (I>>
Overcurrent directional low set. (I>
)
)
7.1.3.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
BO
Digital signal (active high)
Block output signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true (current exceeds the
setting threshold value and the fault is in the specified direction).
The TRIP signal will be activated when at least for a phase current the start conditions are true and the operating time has elapsed.
The Block Output (BO) signal becomes active when the protection function detects a
current exceeding the preset value and the fault direction opposite to the specified direction.
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Protection Functions: Configuration and Settings
7.1.3.2 Configuration
7.1.3.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.3.2.2 Sensors
The protection function operates on any combination of current phases in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
The faulty phase current is combined with the voltage of the corresponding sound
phases. The required voltage measure is automatically selected and displayed in the
“General” dialog window.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.3.2.3 Parameters
Direction:
Directional criteria to be assessed together to overcurrent condition
for START detection.
Start Value:
Current threshold for overcurrent condition detection.
Time:
Time delay for overcurrent Trip condition detection.
(An example the typical connection diagram of current and voltage transformers for a
generic feeder and the convention used to define Forward and Backward direction of
the power flow is provided in the Appendix - Connection Diagram).
7.1.3.2.4 Events
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Protection Functions: Configuration and Settings
7.1.3.2.5 Pins
7.1.3.3 Measurement mode
The directional overcurrent protection function evaluates the current and voltage at
the fundamental frequency.
7.1.3.4 Operation criteria
If the measured current exceeds the setting threshold value (Start Value), and the
fault is in the specified direction (backward/forward), the protection function is
started. The start signal is phase selective; i.e. when at least for one phase current
the above conditions are true then the relevant start signal will be activated.
If the preset threshold value (Start Value) is exceeded and the fault is in the opposite direction to the specified one, the Block Output signal becomes active. The
protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the current falls below 0.95 the setting threshold value (or the fault current
changes direction).
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value.
To determine the fault direction the REF542plus must be connected to the threephase voltages. The protection function has a voltage memory, which allows a directional decision to be produced even if a fault occurs in the close up area of the voltage transformer/sensor (when the voltage falls below 0.1 x Un).
7.1.3.5 Current direction
Detection of the current direction is obtained by calculating the reactive power, which
is computed combining the faulty phase current with the voltage of the corresponding
sound phases. The reactive power calculation uses voltage and current measurements at the fundamental frequency. Before the calculations, the voltages are shifted
to a lagging angle of 45°.
The reactive power is calculated like the following:
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Q = (IL1 x U 23 x sin ϕ1 ) + (IL2 x U 31 x sin ϕ 2 ) + (IL3 x U12 x sin ϕ 3 )
Where is:
Q
Reactive power
IL1,2,3
Current of phase 1, 2 and 3
U12,23,31
Line voltages between phases 1-2, 2-3 and 3-1 after shifting -45°
ϕ1,2,3
Angles between the currents and the corresponding voltages
Only the phases whose current exceeds preset threshold are used in the calculation.
If the result of the calculation leads to a negative reactive power, which is greater than
5% of the nominal apparent power, the fault is in forward direction. Otherwise, the
fault is in backward direction.
A directional signal can be sent to the opposite station using the output (trip) and/or
the Block Output (BO) signal. The content of a directional signal from the opposite
station (BO output) can be used to release tripping of its own directional protective
function. This enables a directional comparison protection to be established.
The following figure shows the forward and backward direction in the impedance
plane in case of a balanced three-phase fault.
Error! Objects cannot be created from editing field codes.
Figure 8: Diagram of the directional overcurrent protection in case of balanced three-phase
faults
Because the application of the fault-current is in combination with the sound voltages,
the directional decision area can change. This change depends on the power system
parameters in case of non-symmetrical fault condition. The criteria for forward and
backward direction is derived from the calculated reactive power.
7.1.3.6 Voltage memory
The directional overcurrent protection function includes a voltage memory feature.
This allows a directional decision to be produced even if a fault occurs in the close up
area of the voltage transformer/sensor.
At a sudden loss of voltage, a fictive voltage is used for direction detection. The fictive
voltage is the voltage measured before the fault has occurred, assuming that the voltage is not affected by the fault. The memory function enables the function block to
operate up to 300 seconds after a total loss of voltage.
When the voltage falls below 0.1 x Un, the fictive voltage is used. The actual voltage
is applied again as soon as the voltage rises above 0.1 x Un for at least 100 ms. The
fictive voltage is also discarded if the measured voltage stays below 0.1 x Un for more
than 300 seconds.
7.1.3.7 Setting groups
Two parameter sets can be configured for each of the overcurrent directional definite
time protection functions.
7.1.3.8 Parameters and Events
7.1.3.8.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start Value
0.05 .. 40
In
0.2
Current threshold for fault detection.
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Protection Functions: Configuration and Settings
Time
40 .. 30000
ms
80
Operating Time between start and trip.
Direction
forward/backward
-
backward
Direction criteria.
7.1.3.8.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block signal is active
E17
Block signal is back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.4 Overcurrent Protection
The REF542plus provides three overcurrent definite time protection functions. Each
of them can be independently activated:
Overcurrent definite time instantaneous (I>>>)
Overcurrent definite time high set (I>>)
Overcurrent definite time low set. (I>)
7.1.4.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true.
The TRIP signal will be activated when at least for a phase current the start conditions are true and the operating time has elapsed.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.4.2 Configuration
7.1.4.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.4.2.2 Sensors
The protection functions operate on any combination of phase currents in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
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7.1.4.2.3 Parameters
Start Value:
Current threshold for overcurrent condition detection.
Time:
Time delay for overcurrent Trip condition detection.
7.1.4.2.4 Events
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Protection Functions: Configuration and Settings
7.1.4.2.5 Pins
7.1.4.3 Measurement mode
All overcurrent definite time functions evaluate the current RMS value at the fundamental frequency. In case of the overcurrent definite time instantaneous, the peak
value of the measured current is also used under transient condition for a faster response: when the instantaneous peak value is higher then three times SQRT (2) the
RMS value ( I x _ peak
2 > 3 ⋅ I x _ RMS ).
7.1.4.4 Operation criteria
If the measured current exceeds the setting threshold value (Start Value), the
overcurrent protection function is started. The start signal is phase selective; i.e. when
at least the value of one phase current is above the setting threshold value then the
relevant start signal will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the current falls below 0.95 the setting threshold value. After the protection has entered the start status and the preset operating time (Time) has elapsed,
function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value.
All overcurrent definite time functions can be used in parallel to generate a current
time-step characteristic, as shown in the following figure.
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Protection Functions: Configuration and Settings
t
tI>
tI>>
tI>>>
I>
I>>
I>>>
I
Figure 9: Schematic view of the definite time tripping steps
7.1.4.5 Setting groups
Two parameter sets can be configured for each of the overcurrent definite time protection functions.
7.1.4.6 Parameters and Events
7.1.4.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start Value I >, I >>
0.05 .. 40.00
In
0.50
Current threshold for overcurrent condition detection.
Time
20 .. 300000
ms
80
Time delay for overcurrent Trip condition.
Start Value I >>>
0.1 .. 40.00
In
0.50
Current threshold for overcurrent condition detection.
Time
15 .. 30000
ms
80
Time delay for overcurrent Trip condition.
7.1.4.6.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Protection block signal is active
E19
Protection block signal is back to inactive state
By default all events are disabled.
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Protection Functions: Configuration and Settings
7.1.5 Overcurrent IDMT
The REF542plus makes available an IDMT function in which one at the time of the
four current-time characteristics can be activated:
Normal inverse,
Very inverse,
Extremely inverse and
Long-term inverse.
7.1.5.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true (phase current value is
above 1.2 times the setting threshold value).
The TRIP signal will be activated when at least for a phase current the start conditions are true and the calculated operating time has elapsed.
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Protection Functions: Configuration and Settings
7.1.5.2 Configuration
7.1.5.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.5.2.2 IDMT Type
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7.1.5.2.3 Sensors
The protection functions operate on any combination of phase currents in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
7.1.5.2.4 Parameters
Base current (Ieb):
Current threshold for overcurrent condition detection.
Time multiplier (k):
Parameter to vary time delay for Trip condition
The trip time is calculated according to British Standard (BS 142) when the time multiplier k is used. When the time multiplier k is set to one (k=1) the IDMT curve is in accordance to IEC 60255-3.
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Protection Functions: Configuration and Settings
7.1.5.2.5 Events
7.1.5.2.6 Pins
7.1.5.3 Measurement mode
IDMT protection function evaluates the RMS value of phase currents at the fundamental frequency.
7.1.5.4 Operation criteria
If the measured current exceeds the setting threshold value (Base current Ieb),
by a factor 1.2 then the protection function is started. The start signal is phase selective; i.e. when at least one phase current is above 1.2 times the setting threshold
value then the relevant start signal will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the current falls below 1.15 the setting threshold value. When the protection enters the start status the operating time is continuously recalculated according
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Protection Functions: Configuration and Settings
to the set parameters and measured current value. If the calculated operating time is
exceeded, the function goes in TRIP status and the trip signal becomes active.
The operating time depends on the measured current and the selected current-time
characteristic. The formulas for the trip time according to British Standard (BS 142)
and IEC 60255-3 are reported in the Appendix – IDMT Protection Curve Characteristics.The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value.
7.1.5.5 Setting groups
Two parameter sets can be configured for the IDMT protection function.
7.1.5.6 Parameters and Events
7.1.5.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Type
NI/VI/EI/LTI
-
NI
Tripping characteristic according to
the IEC 60255-3 curve definition.
Base current (Ieb):
0.05 .. 40
In
0.5
Fault current factor threshold for start
condition detection.
Time multiplier (k):
0.05 .. 1.50
-
0.50
Time multiplier to vary time delay for
Trip condition according to BS 142
7.1.5.6.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Protection block signal is active
E19
Protection block signal is back to inactive state
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.6 Earth fault protection
The REF542plus has two earth fault definite time protection functions, which can be
activated and the parameters set independently of each other:
Earth fault low and
Earth fault high.
7.1.6.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the measured or calculated earth current exceeds the setting threshold value (Start Value).
The TRIP signal will be activated when the start conditions are true and the operating
time (Time) has elapsed.
7.1.6.2 Configuration
7.1.6.2.1 General
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Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.6.2.2 Sensors
The protection functions can operate on measured or calculated (on any set of phase
currents in a triple) earth current.
7.1.6.2.3 Parameters
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Start Value:
Current threshold for earth fault condition detection.
Time:
Time delay for earth fault Trip condition detection.
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7.1.6.2.4 Events
7.1.6.2.5 Pins
7.1.6.3 Measurement mode
All earth fault definite time protection functions evaluate the measured residual current or the calculated neutral current at the fundamental frequency.
7.1.6.4 Operation criteria
If the measured or calculated earth current exceeds the setting threshold value
(Start Value), the earth fault protection function is started.
The protection function will come back in passive status and the start signal will be
cleared if the earth current falls below 0.95 the setting threshold value.
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
The protection function will exit the TRIP status and the trip signal will be cleared
when the earth current value falls below 0.4 the setting threshold value.
7.1.6.5 Setting groups
Two parameter sets can be configured for each earth fault protection function.
7.1.6.6 Parameters and Events
7.1.6.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start value
0.05 .. 40.00
In
0.10
Current threshold for earth fault condition detection.
Time
40 .. 30000
ms
200
Time delay for earth fault Trip condition detection.
7.1.6.6.2 Events
Code
Event reason
E0
Start started
E1
Start back
E6
Trip started
E7
Trip back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.7 Directional earth fault protection
REF542plus has two directional earth fault protection functions, each of which can be
independently activated and configured:
Earth fault directional low
Earth fault directional high.
7.1.7.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Output
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
BO
Digital signal (active high)
Block output signal
The Start signal will be activated when the measured or calculated earth current exceeds the setting threshold value (Start Value) and the fault is in the specified direction.
The TRIP signal will be activated when the start conditions are true and the operating
time (Time) has elapsed.
The Block Output (BO) signal becomes active when the protection function detects a
current exceeding the preset value and the fault direction opposite to the specified direction.
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Protection Functions: Configuration and Settings
7.1.7.2 Configuration
7.1.7.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.7.2.2 Sensors
The protection functions can operate on earth current and residual voltage quantities
measured through dedicated sensor(s) or calculated from the current and voltage
phase components in a triple.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.7.2.3 Parameters
Net Type:
Parameter defining the connection to ground network typology.
Direction:
Directional criteria to be assessed together to earth fault condition
for START detection.
Start Value:
Current threshold for earth fault condition detection.
Time:
Time delay for earth fault Trip condition detection.
Voltage U0:
Residual or neutral voltage threshold.
(An example the typical connection diagram of current and voltage transformers for a
generic feeder and the convention used to define Forward and Backward direction of
the power flow is provided in the Appendix - Connection Diagram).
7.1.7.2.4 Events
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.7.2.5 Pins
aggiornare pin ou nuova bitmap
7.1.7.3 Measurement mode
All directional earth fault definite time protection functions evaluate the measured or
calculated amount of neutral current I0 and voltage V0 at the fundamental frequency.
7.1.7.4 Operation criteria
The direction is determined (hence the protection function is active) only if the neutral
voltage is above the preset threshold (i.e. Voltage U0).
The way the direction is determined depends on the selected network type (isolated/earthed).
If parameter “Net type” is set to isolated, then the “significant” component of neutral
current is its projection on a line orthogonal to neutral voltage.
Earthfault in forward direction
U0
I0
Block
Passive
Trip
Figure 10: Vector diagrams of the directional earth fault protection (isolated networks sin ϕ)
If parameter ”Net type” is set to earthed, then the “significant” component of neutral
current is its projection parallel to neutral voltage.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Earthfault in forward direction
Block
U0
Passive
Trip
I0
Figure 11: Vector diagrams of the directional earth fault protection (grounded networks cos ϕ)
If the following conditions are true:
Neutral voltage value is above the preset threshold (i.e. Voltage U0)
AND “significant” component of neutral current value exceeds the setting
threshold value (Start Value)
AND the direction is as selected (i.e. backward/forward),
then the protection function is started.
When the preset threshold values (Start Value and Uo) are exceeded and the
first two conditions are true but the fault is in the opposite direction to the specified
one, the Block Output signal becomes active.
The protection function will come back in passive status and the start signal will be
cleared if the earth current “significant” component value falls below 0.95 the setting
threshold value OR if the conditions on Neutral voltage value OR direction are not
true.
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the earth current “significant” component value falls below 0.4 the setting
threshold value.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.7.5 Setting groups
Two parameter sets can be configured for each directional earthfault protection function.
7.1.7.6 Parameters and Events
7.1.7.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Net type
Isolated/earthed
-
Isolated
Network grounding typology.
Direction
Forward/backward
-
Backward
Directional criteria.
Start value
0.05 .. 40.00
In
0.10
“Significant” component threshold
Time
40 .. 30000
ms
200
Operating Time between start and trip.
Voltage U0
0.02 .. 0.70
Un
0.10
Neutral or residual voltage threshold.
7.1.7.6.2 Events
Code
Event reason
E0
Protection started timing
E1
Timing is cancelled
E6
Trip signal is active
E7
Trip signal is back to inactive
E16
Block output signal is active
E17
Block output signal is back to inactive
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.8 Sensitive earth fault protection
REF542plus has one sensitive directional earth fault protection function (67S).
With respect to the two directional earth fault protection functions (67N), the 67S protection can be configured so to set the maximum sensitivity direction at a user defined
angle (Angle delta). The only additional requirement it to acquire the neutral current I0 through a dedicated earth transformer in order to have the proper precision.
7.1.8.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
BO
Digital signal (active high)
Block output signal
The Start signal will be activated when the measured earth current exceeds the setting threshold value (Start Value) and the fault is in the specified direction.
The TRIP signal will be activated when the start conditions are true and the operating
time (Time) has elapsed.
The Block Output (BO) signal becomes active when the protection function detects a
current exceeding the preset value and the fault direction opposite to the specified direction.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.8.2 Configuration
7.1.8.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.1.8.2.2 Sensors
The protection functions can operate on earth current and residual voltage quantities.
The neutral current I0 is acquired through the dedicated transformer in order to have
the proper precision. The Residual voltage U0 can be either measured through a
dedicated sensor or calculated from the voltage phase components a triple.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.8.2.3 Parameters
Current I0:
Current threshold for dir. earth fault condition detection.
Time:
Time delay for dir. earth fault Trip condition detection.
Angle alpha:
Parameter to improve the discrimination of the directional decision.
Angle delta:
Angle between U0 vector and the direction of maximum sensitivity
Voltage U0:
Residual or neutral voltage threshold.
7.1.8.2.4 Events
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.8.2.5 Pins
7.1.8.3 Measurement mode
Sensitive earth fault direction protection function evaluates the amount of residual
current I0 and voltage U0 at the fundamental frequency.
7.1.8.4 Operation criteria
If the following conditions are true:
Residual voltage value is above the preset threshold (i.e. Voltage U0)
AND Neutral current value is in the trip area of the protection function, then the
protection function is started.
If the condition of the voltage U0 is true but the neutral current value is in the block
area, then the protection function remains idle and the Block Output signal becomes
active. When the neutral current value is in the passive area both Start and Block signals are inactive.
The protection function will come back in passive status and the start signal will be
cleared if the earth current OR residual voltage value fall below 0.95 the setting
threshold value.
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the earth current OR residual voltage value fall below 0.4 the setting threshold
value. To ensure the required sensitivity and discrimination for the earth fault detection, in its implementation in the REF542plus the operating characteristic is formed
with additional adjustability. The following diagram shows the shape of the operating
characteristic.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
α
Trip
UN
UN
IN
IN
Passive
α
Block
Block
δ=0°
Passive
Trip
δ=90°
Figure 12: Operating characteristic of the earth fault directional sensitive protection function
The value of δ (i.e. Angle delta between U0 vector and the direction of maximum sensitivity) can be configured in the range –180° to 180°. This provides the option of using the earth fault directional sensitive protection for every type of network grounding
situation (isolated, earthed or compensated).
The “significant” component of neutral current is its projection on the direction of
maximum sensitivity. Neutral current value is in the trip or block area when the “significant” component exceeds the setting threshold value (Current I0).
The other parameter α (i.e. Angle alpha) is used to improve the discrimination of the
directional decision.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.8.5 Setting groups
Two parameter sets can be configured for the sensitive directional earthfault protection function.
7.1.8.6 Parameters and Events
7.1.8.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Current I0
0.05 .. 2.00
In
1.00
Earth fault current threshold.
Time
115 .. 10000
ms
1000
Operating Time between start and trip.
Angle alpha
0.0 .. 20.0
°
20.0
Discrimination of the directional decision.
Angle delta
-180.0 .. 180.0
°
0.0
Angle between U0 and maximum sensitivity direction
Voltage U0
0.05 .. 0.70
Un
0.50
Neutral or residual voltage threshold.
7.1.8.6.2 Events
Code
Event reason
E0
Protection is timing
E1
Timing is cancelled
E6
Trip signal is active
E7
Trip signal is back to inactive
E16
Block output is active
E17
Block output is back to inactive
E18
Protection block is active
E19
Protection block is back to inactive
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.9 Earth fault IDMT
The dependent earth fault current timer protection, like the IDMT, is a time-delay function with a set of hyperbolic current-time characteristics. An earthfault IDMT function
in which four current-time characteristics may be selected, can be activated in the
REF542:
Normal inverse,
Very inverse,
Extremely inverse and
Long-term inverse.
7.1.9.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the measured or calculated earth current exceeds the setting threshold value (Base current Ieb) by a factor 1.2.The TRIP
signal will be activated when the start conditions are true and the calculated operating
time has elapsed.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.9.2 Configuration
7.1.9.2.1 General
Output Channel different
from 0 means direct execution of the trip command (i.e. skipping FUPLA cyclic
evaluation).
7.1.9.2.2 IDMT Type
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.9.2.3 Sensors
The protection function can operate on measured or calculated (on any set of phase
currents in a triple) earth current.
7.1.9.2.4 Parameters
Base current (Ieb): Current threshold for overcurrent condition detection.
Time multiplier (k): Parameter to vary time delay for Trip condition
The trip time is calculated according to British Standard (BS 142) when the time multiplier k is used. When the time multiplier k is set to one (k=1) the IDMT curve is in accordance to IEC 60255-3.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.1.9.2.5 Events
7.1.9.2.6 Pins
7.1.9.3 Measurement mode
Earth fault IDMT function evaluates the measured amount of residual current at the
fundamental frequency.
7.1.9.4 Operation criteria
If the measured or calculated earth current exceeds the setting threshold value (Base
current Ieb) by a factor 1.2 then the protection function is started.
The protection function will come back in passive status and the start signal will be
cleared if the earth current falls below 1.15 the setting threshold value.
When the protection enters the start status the operating time is continuously recalculated according to the set parameters and measured current value. If the calculated
operating time is exceeded, the function goes in TRIP status and the trip signal becomes active.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
The operating time depends on the measured current and the selected current-time
characteristic.
The formulas for the trip time according to British Standard (BS 142) and IEC 60255-3
are reported in the Appendix – IDMT Protection Curve Characteristics.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured or calculated earth current value falls below 0.4 the setting
threshold value.
7.1.9.5 Setting groups
Two parameter sets can be configured for Earthfault IDMT protection function.
7.1.9.6 Parameters and Events
7.1.9.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Type
NI/VI/EI/LTI
-
NI
Tripping characteristic according to the
IEC 60255-3 curve definition.
Base current (Ieb):
0.05 .. 40
-
0.5
Fault current factor threshold for start
condition detection.
Time multiplier (k):
0.05 .. 1.50
-
0.50
Time multiplier to vary time delay for Trip
condition according to BS 142
7.1.9.6.2 Events
Code
Event reason
E0
Protection is timing
E1
Timing is cancelled
E6
Trip signal is active
E7
Trip signal is back to inactive
E18
Protection block is active
E19
Protection block is back to inactive
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2 Voltage Protection
7.2.1 Overvoltage Protection
There are three overvoltage definite time protection functions in the REF542plus,
which can be independently activated and parameterized:
Overvoltage low,
Overvoltage high,
Overvoltage instantaneous.
7.2.1.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase (line) voltage start conditions are true (voltage exceeds
the setting threshold value).
The TRIP signal will be activated when at least for a phase voltage the start conditions are true and the operating time has elapsed.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.1.2 Configuration
7.2.1.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.2.1.2.2 Sensors
The protection functions can operate on any combination of phase (or line) voltages
in a triple, e.g., it can operate as single phase, double phase, three-phase protection
on voltages belonging to the same system.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.1.2.3 Parameters
Start Value:
Voltage threshold for overvoltage condition detection.
Time:
Time delay for overvoltage Trip condition detection.
7.2.1.2.4 Events
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.1.2.5 Pins
7.2.1.3 Measurement mode
Overvoltage protection functions evaluate the phase or line voltage RMS value at the
fundamental frequency.
7.2.1.4 Operation criteria
If the measured voltage exceeds the setting threshold value (Start Value), the
overvoltage protection function is started. The start signal is phase selective; i.e.
when at least the value of one phase voltage is above the setting threshold value then
the relevant start signal will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the voltage falls below 0.95 the setting threshold value. After the protection has entered the start status and the preset operating time (Time) has elapsed,
function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured voltage value falls below 0.4 the setting threshold value.
The overvoltage protective functions, like the overcurrent protective functions, are
used in a time graded coordination. An example of grading is shown in the following
diagram.
Figure 13: Overvoltage response grading.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.1.5 Setting groups
Two parameter sets can be configured for each of the overvoltage protection functions.
7.2.1.6 Parameters and Events
7.2.1.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start Value U >, U >>
0.1 .. 3.00
Un
0.50
Voltage threshold for Start condition detection.
Time
40 .. 30000
ms
80
Time delay for Trip condition.
Start Value U >>>
0.1 .. 3.00
Un
0.50
Voltage threshold for Start condition detection.
Time
15 .. 300000
ms
80
Time delay for Trip condition.
7.2.1.6.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Block signal is active
E19
Block signal is back to inactive state
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2 Undervoltage Protection
There are three undervoltage protection functions in the REF542plus, which can be
activated and parameters set independently of one another:
Undervoltage low.
Undervoltage high.
Undervoltage instantaneous.
7.2.2.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase (line) voltage start conditions are true (voltage falls below the setting threshold value).
The TRIP signal will be activated when at least for a phase voltage the start conditions are true and the operating time has elapsed.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2.2 Configuration
7.2.2.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.2.2.2.2 Sensors
The protection functions can operate can operate on any combination of phase (or
line) voltages in a triple, e.g., it can operate as single phase, double phase, threephase protection on voltages belonging to the same system.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2.2.3 Parameters
Start Value:
Voltage threshold for undervoltage condition detection.
Time:
Time delay for undervoltage Trip condition detection.
7.2.2.2.4 Events
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2.2.5 Pins
7.2.2.3 Measurement mode
Undervoltage protection functions evaluate the phase or line voltage RMS value at
the fundamental frequency.
7.2.2.4 Operation criteria
If the measured voltage falls below the setting threshold value (Start Value), the
undervoltage protection function is started. The start signal is phase selective; i.e.
when at least the value of one phase voltage is below the setting threshold value then
the relevant start signal will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the voltage raises above 1.05 the setting threshold value. After the protection has entered the start status and the preset operating time (Time) has elapsed,
function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured voltage value falls below 0.4 the setting threshold value.
The undervoltage protection functions are used in a graded coordination. An example
of staging is shown in the following diagram.
Figure 14: Undervoltage protection response stages
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2.5 Behavior at low voltage values
Because a de-energized feeder has no voltage, an undervoltage protection function
remains activated. It is not be possible then to switch the feeder on again.
Therefore, the “Under Voltage” configuration dialog provides the option of deactivating the undervoltage protection functions when the voltage is in the range of 0 to 40%
of the setting voltage threshold (Start Value).
The diagrams below shows how this feature works when the “lowest voltage = 0” flag
is checked:
Figure 15: Configuration of the undervoltage limit = 0
If 40% is considered too high, the undervoltage function can also be blocked, e.g.
through the circuit-breaker auxiliary contact, by connecting a signal (high at CB open)
to the BS input pin inside the FUPLA.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.2.6 Setting groups
Two parameter sets can be configured for each of the undervoltage protection functions.
7.2.2.7 Parameters and Events
7.2.2.7.1 Setting values
Parameter
Values
Unit
Default
Explanation
lowest voltage = 0
used
used/not used
-
not used
When “used” the U< functions are active below the 0.4 Start Value
Start Value U <, U <<
0.1 .. 1.20
Un
0.50
Voltage threshold for Start condition
detection.
Time
40 .. 30000
ms
80
Time delay for Trip condition.
Start Value U <<<
0.1 .. 1.20
Un
0.50
Voltage threshold for Start condition
detection.
Time
15 .. 30000
ms
80
Time delay for Trip condition.
7.2.2.7.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.2.3 Residual Overvoltage Protection
There are two residual overvoltage protection functions in the REF542plus, which can
be independently activated and parameterized:
Residual overvoltage high and
Residual overvoltage low.
7.2.3.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the measured or calculated residual voltage
exceeds the setting threshold value (Start Value).
The TRIP signal will be activated when the start condition is true and the operating
time (Time) has elapsed.
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7.2.3.2 Configuration
7.2.3.2.1 General
Output Channel different
from 0 means direct execution of the trip command (i.e. skipping FUPLA cyclic
evaluation).
7.2.3.2.2 Sensors
The protection functions can operate on residual voltage measured through a dedicated sensor (e.g. open delta connected voltage transformers) or calculated from the
voltage phase (line) components in a triple.
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7.2.3.2.3 Parameters
UNe
Voltage threshold for residual overvoltage condition detection.
Time:
Time delay for residual overvoltage Trip condition detection.
7.2.3.2.4 Events
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7.2.3.2.5 Pins
7.2.3.3 Measurement mode
Residual overvoltage protection functions evaluate the residual voltage at the fundamental frequency.
7.2.3.4 Operation criteria
If the measured voltage exceeds the setting threshold value (UNe), the residual overvoltage protection function is started.
The protection function will come back in passive status and the start signal will be
cleared if the voltage falls below 0.95 the setting threshold value.
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured voltage value falls below 0.4 the setting threshold value.
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7.2.3.5 Setting groups
Two parameter sets can be configured for each of the residual overvoltage protection
functions.
7.2.3.6 Parameters and Events
7.2.3.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
UNe
0.10 .. 3.00
Un
0.50
Voltage threshold for Start condition detection.
20 .. 300000
ms
50
Time delay for Trip condition.
Time
7.2.3.6.2 Events
Code
Event reason
E0
Start started
E1
Start back
E6
Trip started
E7
Trip back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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7.3 Motor Protection
The protection functions described in the following subsections are provided for protection of the motor from overloads and faults.
7.3.1 Thermal Overload Protection
REF542plus has one thermal overload protection function.
7.3.1.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
RST
Trigger signal (active low-tohigh)
Reset signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
When the reset input pin (RST) is triggered, the estimated motor temperature is set to
the parameter value Trst (Reset Temperature Trst).Outputs
Name
Type
Description
Warn
Digital signal (active high)
Warning signal
TRIP
Digital signal (active high)
Trip signal
Overheat
Digital signal (active high)
Overheat signal
Sensor Error
Digital signal (active high)
Error on RTD (used with 0..20ma input)
The Warn signal will be activated when the calculated temperature exceeds the setting threshold value (Twarn).
The Trip signal will be activated when the calculated temperature exceeds the setting
threshold value (Ttrip).
The Overheat signal will be activated when the calculated temperature exceeds the
setting threshold value Nominal Motor Temperature (TMn).
The Sensor Error signal will be activated the external environment temperature
(Tenv) sensor use is set and its failure is detected.
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7.3.1.2 Configuration
7.3.1.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.3.1.2.2 Sensors
The protection function operates on any combination of phase currents in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
An external sensor connected to the 4-20mA Analog Input can directly measure the
environment temperature. When it is used it is automatically selected and displayed in
the “General” dialog window.
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7.3.1.2.3 Parameters
Nominal Motor Temperature (TMn): Nominal Motor Temperature, asymptotically reached at IMn with environment temperature Tenv.
Nominal Motor Current (IMn):
Nominal Motor current for operational
condition detection.
Initial Temperature (Tini): Initial motor temperature at protection initialasing.
Time Constant Off:
Time constant for cooling down.
Time Constant Normal:
Time constant for motor operational condition.
Time Constant Overheat:
Time constant for overload condition.
Trip Temperature (Ttrip):
Temperature threshold for trip condition.
Warning Temperature (Twarn): Temperature threshold for warning condition.
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Environment Temperature (Tenv):
Ambient temperature.
Reset Temperature (Trst):
Initial (i.e. after reset by RST input PIN)
motor temperature.
7.3.1.2.4 Events
7.3.1.2.5 Pins
7.3.1.3 Measurement mode
Thermal overload protection function evaluates the square average of phase currents
at the fundamental frequency.The instantaneous temperature estimation is based on
the average of the phase currents monitored.
The environment temperature can either be set in the “Parameter” dialog window
(Tenv) or measured through and external sensor and a 4-20mA Analog Input. In case
of external measure failure the set parameter Tenv is used as back-up.
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7.3.1.4 Operation Criteria
The Thermal Overload protection function estimates the instantaneous value of motor
temperature.
If the estimated instantaneous temperature exceeds the first setting threshold value
(Twarn), then the protection function enters the START status and generates a
WARNING signal.
If the estimated instantaneous temperature exceeds the second setting threshold
value (Ttrip), then the protection function generates a TRIP signal.
If the estimated instantaneous temperature exceeds the setting threshold value
(Nominal Motor Temperature TMn), then the protection function generates a
OVERHEAT signal.
The protection function will exit START status, come back in passive status and the
start signal will be cleared if the estimated temperature falls below the setting threshold value Twarn.
The protection function will exit the TRIP status and the trip signal will be cleared
when the estimated temperature falls below the setting threshold value Ttrip.
The protection function avoids also reconnection after a trip of overheated machines
until estimated motor temperature has fallen below the below the warning temperature Twarn (according to calculated motor cooling process, based on Time Constant
OFF).
When the Thermal Overload protection is instantiated the motor temperature can be
estimated. Therefore, after a trip for maximum number of starts, an overheated motor
cannot be reconnected until its temperature has fallen below the warning temperature
(Twarn). Therefore the time to decrement the number of start counters will be the
maximum between the setting time interval (Reset Time, t rst) and the motor
cooling-down time estimation.
If the protection function is reset by means of the reset input pin (RST), then the estimated motor temperature will be set to value Trst (Reset Temperature).
7.3.1.5 Thermal model
It is assumed the heating (or cooling) process works according to the following equation
t
−

T = T f ⋅ 1 − e τ

where:
Tf
t
−

 + Tini ⋅ e τ


is the final (asymptotical) temperature Tini is the initial motor temperature τ
is the thermal constant of the heating (or cooling) process t is the actual time,
counted from t=0 starting at Tini
It is also assumed that at nominal environment temperature (i.e. Environment
Temperature Tenv) and at nominal current (i.e. Nominal Motor Current IMn)
the motor will reach (asymptotically) its nominal temperature (i.e. Nominal Motor
Temperature TMn), i.e.
T f = TMn = ∆Tn + Tenv
where
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∆Tn is the nominal (asymptotical) temperature increment of motor
Tenv is the environmental temperature
The value of ∆Tn is related to the thermal energy dissipation in the motor, and is
proportional to the squared value of current
∆Tn ∝ I 2
In general, the value of (asymptotical) temperature increment when the generic current I is flowing into the motor is then given by
∆T = ∆Tn ⋅
I2
2
I Mn
According to the above considerations, the estimated instantaneous temperature T of
the motor, taking into account the environment temperature and the actual motor current, is calculated according to:
T = Tenv + (Tini − Tenv ) ⋅ e
−
t
τ
+ (TMn
 I 

− Tenv )
 I Mm 
2
t
−

1 - e τ






To better approximate different motor operational conditions, the time constant τ can
assume three different values, depending on the on the actual motor current I ,
namely:Time Constant OFF, when
I < 0.1⋅ I Mn
Time Constant NORMAL, when 0.1 ⋅ I Mn ≤ I ≤ 2 ⋅ I Mn
Time Constant OVERHEAT, when I > 2 ⋅ I Mn
7.3.1.6 Thermal memory at power-down
At power-down, REF542plus saves the estimated motor temperature (T) and at subsequent power-up is able to estimate the new motor temperature, under the hypothesis that the motor was cooling in the meantime (i.e. the timeconstant OFF is used).
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7.3.1.7 Setting groups
Two parameter sets can be configured for the thermal overload protection function.
7.3.1.8 Parameters and Events
7.3.1.8.1 Setting values
Parameter
Values
Unit
Default
Explanation
Nominal Motor Temperature (TMn)
50 .. 400
°C
100
Motor temp. @ IMn and Tenv
Nominal Motor Current (IMn)
0.1 .. 5.0
In
1.0
Current for operational mode (τ) detection
Initial Temperature (Tini)
10 .. 400
°C
50
Initial (e.g. after reset by BS PIN) temperature
Constant Off (I < 0.1 IMn)
10 .. 100000
s
500
Cooling time constant.
Time Constant Normal
10 .. 20000
s
500
Time const. used in Normal operation.
Time Constant Overheat (I > 2 IMn)
10 .. 20000
s
500
Overheating time constant.
Trip Temperature (Ttrip)
50 .. 400
°C
100
Temperature threshold for Trip condition.
Warning Temperature (Twarn)
50 .. 400
°C
100
Temperature threshold for Start condition.
Environment Temperature (Tenv)
10 .. 50
°C
20
Ambient Temperature.
Reset Temperature (Trst)
10 .. 400
°C
100
Initial (i.e. after reset by RST PIN) motor temperature.
7.3.1.8.2 Events
Code
Event reason
E0
Warning signal is active
E1
Warning signal is back to inactive state
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Overheat signal is active
E17
Overheat signal is back to inactive state
E18
Protection block signal is active
E19
Protection block signal is back to inactive state
E20
Reset input signal is active
E21
Reset input signal is back to inactive state
E22
Sensor error is active
E23
Sensor error is back to inactive state
By default all events are disabled.
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7.3.2 Motor Start Protection
REF542plus has one motor start protection function.
7.3.2.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
BO
Digital signal (active high)
Block output signal
The Start signal will be activated when the current exceeds 10% motor nominal current value IMn and within 100 ms the setting threshold value (Motor Start IMs).
The TRIP signal will be activated when the start conditions are true and the calculated
current-time integration (Is2 x Time) is exceed.
The Block Output (BO) signal becomes active at protection initialization until when the
current exceeds 10% motor nominal current value IMn.
7.3.2.2 Configuration
7.3.2.2.1 General
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Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.3.2.2.2 Sensors
The protection function operates on any set of phase currents in a triple.
7.3.2.2.3 Parameters
Nominal Motor Current (IMn):
Nominal Motor current for operational condition detection
Start Value (Is):
Motor start current for Trip condition detection (start energy
integral I2t).
Time:
Time for Trip condition detection.
Motor Start (IMs): Current threshold for motor start condition detection.
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7.3.2.2.4 Events
7.3.2.2.5 Pins
7.3.2.3 Measurement mode
Motor start protection function evaluates the current at the fundamental frequency.
The maximum measured motor current I RMS _ max is used to detect Start and Trip
conditions.
The motor start behavior depends on the switching torque of the specific machine
load. The manufacturer assigns an allowable current-time start integral I2t for motors
or, as an alternative, information on the maximum allowable start current and the
maximum allowable start time is provided.
7.3.2.4 Operation criteria
A motor start is detected if:
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the maximum measured motor current exceeds 0.10 the setting threshold value
nominal motor current (i.e. Nominal Motor Current IMn)
AND within 100 ms later the measured motor current exceeds the setting motor
start detection (Motor Start IMs).When a motor start is detected the protection is
∫
2
started, the start signal is activated and the current-time integral ( i (t ) dt ) is calculated.
The protection function will come back in passive status and the start signal will be
cleared if the maximum motor current falls below 0.95 the setting motor start detection threshold value (IMs). At that time calculation of current-time integral is stopped.
After the protection has entered the start status and the calculated current-time integration exceeds the default I s ⋅ T value, where:
2
•
I s is Start current parameter (Start Value Is).
•
T is Time parameter (Time),
the function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.95 the setting motor start detection
threshold value (IMs).
7.3.2.5 Setting groups
Two parameter sets can be configured for the motor start protection function.
7.3.2.6 Parameters and Events
7.3.2.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Nominal Motor Current (IMn)
0.20 .. 2.00
In
1.00
Motor nominal current for Start condition.
Start Value (Is)
1.00 .. 20.00
IMn
1.00
Trip condition detection (integral I2t).
Time
40 .. 300000
ms
10000
Time for integral Trip condition.
Motor Start (IMs)
0.20 .. 0.80
Is
0.70
Current threshold for Start condition.
7.3.2.6.2 Events
Code
Event reason
E0
Protection started timing
E1
Timing cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block signal is active
E17
Block signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
By default all events are disabled.
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7.3.3 Blocking Rotor
7.3.3.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low. This input can be assigned to the speed indicator signal (tachometer generator or a speed switch).
Outputs
Name
Type
Description
S L1
Digital signal (active high)
Start signal of IL1
S L2
Digital signal (active high)
Start signal of IL2
S L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true (one phase current exceeds Start Value Is).
The TRIP signal will be activated when at least for a phase current the start conditions are true and the operating time has elapsed.
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7.3.3.2 Configuration
7.3.3.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.3.3.2.2 Sensors
The protection function operates on any combination of phase currents in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
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7.3.3.2.3 Parameters
Nominal Motor Current (IMn):
Nominal Motor current
Start Value (Is):
Current threshold for motor start condition
detection.
Time:
Time delay for Trip condition detection.
7.3.3.2.4 Events
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7.3.3.2.5 Pins
7.3.3.3 Measurement mode
Blocking Rotor protection function evaluates the current at the fundamental frequency. It operates like an overcurrent protection function.
The Blocking Rotor protective function is utilized to detect a locked rotor condition by
sensing the current increase arising from the loss of synchronism between the rotor
revolving and phase voltages.
It can be used to monitor the starting characteristics of three-phase asynchronous
motors to check whether the rotor braking is on and other conditions preventing the
motor to speed up. If this malfunction occurs, the starting current would flow permanently and the motor would be thermally overloaded.
7.3.3.4 Operation criteria
The Blocking Rotor protection function can be blocked on the BS input. The blocking
input can be provided by a speed switch or by the start signal output from the Motor
Start protection function.
A tachometer generator or a speed switch is used to send a defined signal at a specified speed. If the rotor of the monitored motor is locked, the missing speed signal will
ensure that the overcurrent function in the protective function will continue to remain
active.
The protection function can also be used without a speed signal using the start signal
output from the Motor Start protection function to block it during motor starting phase.
When the motor start condition is detected the Blocking Rotor function is blocked by
the BS input.
If the measured current exceeds the setting motor starting threshold value (Start
Value, Is), the protection function is started. The start signal is phase selective; i.e.
when at least the value of one phase current is above the setting threshold value then
the relevant start signal will be activated (SL 1-3).
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the current falls below 0.95 the setting threshold value. After the protec-
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tion has entered the start status and the preset operating time (Time) has elapsed,
function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value.
7.3.3.5 Setting groups
Two parameter sets can be configured for the blocking rotor protection functions.
7.3.3.6 Parameters and Events
7.3.3.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Nominal Motor Current IMn
0.20 2.00
In
1.00
Nominal Motor current
Start Value Is
1.00..20.00
Imn
1.00
Current threshold for motor start condition detection.
Time
40 .. 30000
ms
10000
Time delay for Trip condition detection.
7.3.3.6.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
By default all events are disabled.
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7.3.4 Number of Starts
REF542plus has an additional motor protection function that supervises the number
of motor starts. It distinguishes between cold starts and warm starts, the allowable
number of which is generally provided by the motor manufacturer. The starting signal
(Start output) of the Motor Start protection function is used to count the starts.
7.3.4.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
SI
Trigger signal (active high)
Motor start signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
SI signal is used to provide to the Number of Start function the Start signal output
from the Motor Start protection function by wiring the connection in the FUPLA. It is
used to count the motor number of starts. Outputs
Name
Type
Description
Warn
Digital signal (active high)
Warning signal
TRIP
Digital signal (active high)
Trip signal
The Warn signal will be activated when the cold (OR warm) starts counter reaches
the setting threshold value maximum number of starts (Ncs and Nws respectively).
The TRIP signal will be activated when the cold (OR warm) starts counter exceeds
the setting threshold value maximum number of starts (Ncs and Nws respectively).
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7.3.4.2 Configuration
7.3.4.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.3.4.2.2 Parameters
Max Num. of Warm Starts (Nws): Motor manufacturer declared N° of starts
above temperature threshold Tws.
Max Num. of Cold Starts (Ncs): Motor manufacturer declared N° of starts
below temperature threshold Tws.
Reset Time (t rst):
Cooling down motor time; time to dissipate
the heat of a motor start.
Warm Start Temp. Threshold (Tws): Above Tws temperature thereshold a
start is assumed to be “warm”.
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7.3.4.2.3 Events
7.3.4.2.4 Pins
7.3.4.3 Measurement mode
Number of starts protection function supervises the Motor number of starts. The starting signal of Motor Start protection function is used to count starts.
It is also important to distinguish between cold starts and warm starts, the allowable
number of which is generally provided by the motor manufacturer.
Motor temperature estimated by the Thermal Overload function is used to determine
whether a start is cold or a warm. When the Thermal Overload function is not instantiated, a cold start is assumed.
7.3.4.4 Operation criteria
If Thermal Overload protection is not enabled the estimated machine temperature
isn’t available and the Warm counter is not increased (the Warm counter is frozen to
zero). In this case all counted starts are classified as cold.
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When the Thermal Overload protection is enabled the estimated motor temperature is
compared with the setting temperature threshold (Warm Start Temp. Threshold
Tws). Above Tws temperature thereshold a start is assumed to be “warm”, below it is
assumed to be a cold start.
At every motor start (detected by the Motor Start protection function), depending on
the type of start (i.e. warm or cold start) the related counter is incremented by one
unit. At every warm start both the warm counter and the cold counter are incremented. Cold starts increment only the cold counter.
If no start has occurred after the setting time interval (Reset Time, t rst) it is assumed that the motor had time to cool down and both cold and warm start counters
are decremented by one unit.
If the preset number of warm (Max Num. of Warm Starts, Nws) OR respectively of cold starts (Max Num. of Cold Starts, Ncs) is reached, then the protection function is started and the relevant Warning signal will be activated. If there is
another start, the protection function will enter the TRIP status and the trip signal will
be activated.
If the protection function is in TRIP status and the above condition is satisfied, then
the protection function will exit the trip status and the trip signal will be cleared.The
protection function is in TRIP status and the trip signal remains active until the reset
period t rst has expired; then both cold and warm start counters are decremented
and the trip signal will be cleared.
The protection function will exit START status, come back in passive status and the
start signal will be cleared if the cold AND warm counters falls below the respective
maximum setting values Ncs and Nws, i.e. after the reset period t rst has expired.
7.3.4.5 Setting groups
Two parameter sets can be configured for the number of starts protection functions.
7.3.4.6 Parameters and Events
7.3.4.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Max Num. Of Warm Starts (Nws):
1 .. 10
-
1
Number of starts above Tws.
Max Num. Of Cold Starts (Ncs):
1 .. 10
-
1
Number of starts below Tws.
Reset Time (t rst):
1.00..
7200.00
s
30.00
Time to cool down after a start.
Warm Start Temp. Threshold (Tws):
20 .. 200
°C
80
Temperature threshold to define a
warm start.
7.3.4.6.2 Events
Code
Event reason
E0
E1
E6
E7
E14
E15
E18
E19
Protection started timing
Timing cancelled.
Trip signal is active
Trip signal is back to inactive state
Warning signal is active
Warning signal is back to inactive state
Block signal is active
Block signal is back to inactive state
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By default all events are disabled.
7.4 Distance Protection
7.4.1 Distance Protection
The distance protection is dedicated to protect a meshed medium-voltage system or a
simple high-voltage system.
7.4.1.1 Input/Output description
Inputs
Name
Type
Description
BL
Digital signal (active high)
Blocking signal
SIGNAL COMP
Digital signal (active high)
Signal comparison scheme
When BL signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BL signal goes low.
Output
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Name
Type
Description
< Z1
Digital signal (active high)
Z1 signal used for signal comparison
START L1
Digital signal (active high)
Start signal in L1
START L2
Digital signal (active high)
Start signal in L2
START L3
Digital signal (active high)
Start signal in L3
EARTH START
Digital signal (active high)
Start Earth signal
GENERAL
START
Digital signal (active high)
General start signal
TRIP
Digital signal (active high)
Trip signal
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7.4.1.2 Configuration
7.4.1.2.1 General
Output channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cycle evaluation).
7.4.1.2.2 Start Values
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7.4.1.2.3 Zones
Zone 1
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Zone 2
Zone 3
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Zone Overreach
Zone Autoreclose (control)
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Directional Backup
Non-directional Backup
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7.4.1.2.4 Phase selection
7.4.1.2.5 Parameters Earth factors
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7.4.1.2.6 Events
7.4.1.3 Operation Mode
The distance protection comprises the following subordinate functions:
Start
Impedance determination
Directional memory
Tripping logic
To run the protection function, phase currents and the phase voltages measurement
quantities are required. The phase currents and the phase voltages are arranged in
consecutive groups of three. The following combinations can be configured:
Measuring input 1,2,3: current signals; measuring input 4,5,6: voltage signals in
phase L1, L2, L3,
Measuring input 1,2,3: voltage signals; measuring input 4,5,6: current signals in
phase L1, L2, L3
The start function is intended to check for the presence of a system failure and to detect the type of the fault. The appropriate measured quantities for determining the impedance and the directional decision are selected depending on the type of system
fault. Once the direction and the zone of the system fault have been determined, the
tripping logic is used to determine the trip time in accordance with the set impedance
time characteristic.
A signal comparison protection scheme, which enables to protect a very short line selectively, is also integrated. This requires pilot wires for signal exchange.
For network operation, it is important to localize the fault as soon as possible after
system fault has been switched off in order to repair the damage. Because mediumvoltage networks are usually spread over wide areas, fault-tracking information in km
or in reactive ohm is desirable for network operation after the system fault has been
tripped. For this reason, the fault locator, which can derive the fault distance from the
measured fault impedance, is also implemented in the distance protection. It calculates the distance in km to the fault from the nominal value of the cable reactance.
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Caution
The requirement of current transformers for distance protection must be fulfilled. Otherwise the proper function behavior can not be assure. Beside that
the fault locator would not be in position to display the correct value.
Once the system fault has been switched off, it may also be of interest for the system
operator to carry out a fault analysis from a disturbance recorder and the sequences
of the appearance of the signaling events. The fault recorder function can be started
either by an external signal (via a binary input) or by a signal from the distance
protection. The general start or the trip signal can be used for this purpose.
If the fault recorder is started by the general start signal, the system quantities will be
recorded. However, a correct fault reactance can only be detected if the fault is in the
first protection zone. Therefore it is recommended to start the fault recorder by a trip
signal.
The option of switching the distance protection over to the overcurrent protection shall
normally be provided. This procedure is generally referred to the so-called emergency
overcurrent protection and is required if the voltage measurement quantities do not
exist anymore, for example due to an MCB failure. Using the FUPLA (FUnction block
Programming Language) to program the configuration, a related scheme must be designed to block the distance protection by binary input signal.
7.4.1.3.1 Start
The start function in the distance protection is used to detect the system faults selectively and shall enable the distance protection to function properly in different system,
either with high-resistance grounding or in networks with low-resistance grounding.
Here, the high-resistance grounding means that the network is operated with an isolated neutral point or with earth fault compensation coil. The distance protection must
also work properly, if the system is switched over from earth fault compensation to
low-resistance grounding for a short time for the purpose of earth fault tripping.
The start function must also be able of adapting to the variable short circuit power in
the related electrical system. During the day for example the minimum fault current is
normally much greater than the maximum occurring load current because of the
availability of the short circuit power. During this time period a normal overcurrent
starting is sufficient to detect the fault fast and selectively.
However, at night time the short circuit power of the system can decrease, that the
maximum fault current may be less than the above-mentioned load current. Under
these circumstances reliable fault detection is not possible without processing the
voltage information.
To ensure a proper function for the distance protection in all situations, the start function consists of:
Overcurrent starting I>,
Earth fault current starting IE> and
Undervoltage controlled overcurrent starting UF</ IF>
The overcurrent starting I> is used to monitor the line currents exceeding the threshold values. The following diagram shows the associated signal processing.
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I>
IL1
START L1
IL2
START L2
IL3
START L3
IE>
START E
IE
With START E
P
1
G-START
Figure 16: Logic diagram of overcurrent starting
If the set overcurrent threshold value is exceeded, the starting signals Start L1, Start
L2 and Start L3 for the corresponding phase appear. The Start E signal is derived
from the earth current supervision, which is calculated from the sum of the phase currents. Then the General Start signal is generated with the OR Gate of all starting signals (optionally also with the Start E signal).
Note
The Start E value shall be set in such a way, that a starting by an earth fault current
occurring in a system with isolated neutral point or with earth fault compensation can
be prevented.
IF>
IL1
IF1>
IL2
IF2>
IL3
IF3>
UF<
U1
UF1<
U2
UF2<
U3
UF3<
U12
UF12<
U23
UF23<
U31
UF31<
With High Ohmic Grounding:
Start L1 =
(IFL1> Λ IFL2> Λ UF12<) v
(IFL3> Λ IFL1> Λ UF31<) v
(IFL1> Λ IE> Λ UF12<) v
(IFL1> Λ IE> Λ UF31<)
Start L2 =
(IFL2> Λ IFL3> Λ UF23<) v
(IFL1> Λ IFL2> Λ UF12<) v
(IFL2> Λ IE> Λ UF23<) v
(IFL2> Λ IE> Λ UF12<)
Start L3 =
(IFL3> Λ IFL1> Λ UF31<) v
(IFL2> Λ IFL3> Λ UF23<) v
(IFL3> Λ IE> Λ UF31<) v
(IFL3> Λ IE> Λ UF23<)
Figure 17: Undervoltage-controlled overcurrent starting in case of high - ohmic grounding
The undervoltage voltage controlled overcurrent starting is formed from the logical
scheme between the current threshold value IF> and the setting value of the undervoltage UF<, as shown in above figure. The phase voltage in this case must be less
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than undervoltage UF< setting and the corresponding phase current must exceed the
current threshold value IF>. As shown in above logical scheme, the start signals for
the two or three phase fault without earth are formed from the combinations of two
phase currents, each with the corresponding phase voltage. Only a start signal is
generate, if the current threshold value IF> are exceeded in two phases and the undervoltage condition of the related line voltage is fulfilled.
In system with low ohmic grounding the signal of the residual (earth) current is logically combined to the signals of the phase voltages. In contrary, in system with high
ohmic grounding the signal of the residual current is combined with the signals of corresponding line voltages. The combination with the line voltages shall enable the correct starting in case of a cross-country fault (earth fault on two different places).
IF>
IL1
IF1>
IL2
IF2>
IL3
IF3>
UF<
U1
UF1<
U2
UF2<
U3
UF3<
U12
UF12<
U23
UF23<
U31
UF31<
With Low Ohmic Grounding:
Start L1 =
(IFL1> Λ IFL2> Λ UF12<) v
(IFL3> Λ IFL1> Λ UF31<) v
(IFL1> Λ IE> Λ UF1<)
Start L2 =
(IFL2> Λ IFL3> Λ UF23<) v
(IFL1> Λ IFL2> Λ UF12<) v
(IFL2> Λ IE> Λ UF2<)
Start L3 =
(IFL3> Λ IFL1> Λ UF31<) v
(IFL2> Λ IFL3> Λ UF23<) v
(IFL3> Λ IE> Λ UF3<) v
Figure 18: Undervoltage-controlled overcurrent starting in case of low - ohmic grounding
The entire logical scheme (Boolean algebra) of the signals to form the corresponding
start signals can be seen as following:
For system with high – ohmic grounding:
Start L1 =
IL1> ∨ {(IFL1 > ∧ IFL2> ∧ UF12<) v (IFL3> ∧ IFL1> ∧ UF31<)}
∨ {(IFL1> ∧ IE> ∧ UF12<) v (IFL1> ∧ IE> ∧ UF31<)}
Start L2 =
IL2> ∨ {(IFL2 > ∧ IFL3> ∧ UF23<) v (IFL1> ∧ IFL2> ∧ UF12<)}
∨ {(IFL2> ∧ IE> ∧ UF23<) v (IFL2> ∧IE> ∧ UF12<)}
Start L3 =
IL3> ∨ {(IFL3> ∧ IFL1> ∧ UF31<) v (IFL2> ∧ IFL3> ∧ UF23<)}
∨ {(IFL3> ∧ IE> ∧ UF31<) v (IFL3> ∧ IE> ∧ UF23<)}
and for system with low – ohmic grounding:
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Start L1 =
IL1> ∨ {(IFL1> ∧ IFL2> ∧ UF12<) v (IFL3> ∧ IFL1> ∧ UF31<)}
∨ (IFL1> ∧ IE> ∧ UF1<)
Start L2 =
IL2> ∨ {(IFL2 > ∧ IFL3> ∧ UF23<) ∧ (IFL1> ∧ IFL2> ∧ UF12<)}
∨ (IFL2> ∧ IE> ∧ UF2<)
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IL3> ∨ {(IFL3> ∧ IFL1> ∧ UF31<) ∧ (IFL2> ∧ IFL3> ∧ UF23<)}
∨ ( IFL3> ∧ IE> ∧ UF3<)
Start L3 =
∨: OR Gate
∧: AND Gate
Note
In system with short time low resistance grounding the setting "High Ohmic Grounding" shall be selected.
7.4.1.3.2 Phase selection
System with isolated neutral point or with earth fault compensation, for reasons of
power supply availability, shall not be disconnected in case of an earth fault. If the
earth fault becomes to a cross-country fault, then one of the two earth fault footing
points shall be disconnected.
To coordinate the disconnection of the earth fault footing point, a phase selection can
be programmed into the distance protection. This enables the distance protection to
disconnect the corresponding phase with the earth fault according to a certain set sequence. The following phase selection setting can be selected:
Acyclical:
L3 before L1 before L2
Cyclical:
L3 before L1 before L2 before L3
Acyclical:
L1 before L3 before L2
Anticyclical:
L1 before L3 before L2 before L1
For example, if the acyclical phase setting L3 before L1 before L2 is selected in the
distance protection, in case of a cross-country fault between the phases L3 and L1 to
earth, the earth fault footing point in phase L3 will be disconnected. The earth fault in
phase L1 will remain until it is disconnected by the system control center after appropriate switchover action in the system.
Note
To ensure correct functioning of the conductor preference, the measured quantities of
the phase voltages must be correctly connected (correct phase sequence).
7.4.1.3.3 Calculation of the impedance
After the starting has correctly detected the system fault, the fault impedance will be
calculated by applying the discrete Fourier transformation (DFT). The DFT is used
because the measured quantities are mostly superimposed by transient phenomena
or harmonic disturbances of varying frequency. By applying the DFT high harmonic
disturbances can be eliminated effectively that the fault impedance can be calculated
properly.
The fault impedance is determined with the following equation for the phase-to-phase
fault:
ZL − L =
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U L −L
I L −L
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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ZL-L is the fault impedance to be determined. UL-L and IL-L are the corresponding line
voltage and the calculated line current variable.
The following equation shall then be used in case of an earth fault or two phase to
ground fault:
ZL − E =
U L −E
IL + k ⋅ IE
ZL-E is again the fault impedance to be determined. UL-E and IL are the corresponding
voltage or current measurement quantities of the relevant phase current and IE is the
earth current respectively the residual current resulting from the sum of all phase currents.
I E = I R + I S + IT
However, for the final calculation of the impedance, the earth current must first be
corrected with the complex earth factor k as follows:
k =

1  Z0
⋅ 
− 1
3  Z1

In this case Z0 is the impedance of the zero sequence and Z1 is the impedance of the
positive-sequence. Positive-sequence, negative-sequence and zero sequence are
defined in the theory of the symmetrical components.
To calculate all fault types correctly, six impedance loops must be calculated; three l
for faults between the phases and three for faults between phase and earth. Because
of various influencing quantities the fault impedance may deviate from the theoretical
impedance value of the line unit. A typical example for this is a short circuit with arcing. In this case, the fault impedance is overlain with the non-linear arc characteristic.
To avoid the non tripping, a tripping area need to be defined. For the distance protection function a polygonal tripping characteristic is foreseen.
The following figure shows this polygon tripping characteristic for the distance protection.
X
Im
δ2
R
δ1
Re
Figure 19: Tripping characteristic for the distance protection
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The first quadrant the tripping characteristic is set by a horizontal and a vertical line.
The reactance setting X defines the value of the horizontal line and the resistor setting R for the vertical line. The tripping area is finally closed by another two lines in
the second and the fourth quadrants. The angle of rotation for the line is δ2 in the
second quadrant and δ1 in the fourth quadrant.
7.4.1.3.4 Directional voltage memory
The directional decision is normally derived from the result of the complex fault impedance value. Therefore, the voltage measured related to the fault is used to determine the direction. However, if the fault occurs in the close up area where the voltage
transformers or the voltage sensors are installed, the generation of the directional decision can be seriously affected because of the small value of the voltage measured
quantity. For this reason a directional voltage memory is always used to form the directional decision. All voltages (phase and line voltages) that were measured before
the fault occurred are saved in the directional voltage memory. After the fault occurs a
phase displacement angle of approximately ± 30° may occur. For example, this may
occur on the transition to a cross-country fault. This fact should be taken into account
when setting the tripping characteristic.
The tripping characteristic should be set as follows to obtain a correct directional decision permanently:
In the second quadrant at
δ2 = 90° + 30° = 120°
and in the fourth quadrant at
δ1 = 0° – 30° = – 30°.
7.4.1.3.5 Tripping logic
The tripping logic generates from the distance and directional decision in logical combination with the timer function the different zone characteristics. In total, three impedance zones, one directional zone, one non-directional zone and the corresponding five timer functions are available. The adjustable zone characteristics can be seen
in the following diagram.
As can be seen in the next figure, every impedance zone and the directional zone can
be set either backwards or forwards. The timer functions are assigned as follows:
Time t1 of impedance zone Z1,
Time t2 of impedance zone Z2,
Time t3 of impedance zone Z3,
Time t4 of impedance-independent directional zone as directional backup and
Time t5 of impedance and direction-independent zone as non-directional backup.
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t
t
t5
t5
t4
t4
t3
t3
t2
t2
t1
t1
Z1
Z2
Z3
Z
t
Z3
t5
t5
t4
t4
t3
t3
t2
t2
t1
t1
Z1
Z2
Z3
Z
Z2
Z1
Z2
Z
Z1
Z3
Z
Figure 20: Impedance-timer characteristics
Every single zone can be deactivated. Which of the impedance zone characteristics
should be selected depends on one hand by the network topology and on the other
hand by the design of the protection scheme.
Moreover, the tripping logic provide also the interface to the autoreclose function
(AR), signal comparison protection scheme and switching onto fault scheme. For that
reason, the function of the first impedance zone Z1 is superimposed by another two
special zones, the "overreach zone" and the autoreclosure blocking zone. The corresponding setting parameters must accordingly adapt.
7.4.1.3.6 Adaptation to Autoreclosure
The figure below shows the principal view of the impedance-time characteristic in
conjunction with autoreclose function. The line that is to be protected is between stations A and B. The impedance-time characteristic is shown for the distance protection
with autoreclosure in station A.
Station A
Station B
t2
t1
DP
Z1
Zov
Figure 21: Zone characteristics for autoreclosure on overhead line
DP
Distance Protection
Z1
First impedance zone
Zov
Overreach zone
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In system with overhead line the overreach zone Zov is generally set approximately in
the range of 120 to 150% of the line impedance ZL. The timer setting tov should, in
this case, be set equal to the time t1 of the first impedance zone Z1. The autoreclosure zone ZAR must be set to inactive.
When the General-Start signal occurs, the specified time is started. The setting of this
specified time should be set higher or equal to the time setting of the overreach zone
tov. In case that a trip is generated that is longer than the specified time, the autoreclosure is blocked. Only for a trip, which appears within this time, the autoreclosure is
started. On the expiry of the specified time the overreach zone Zov will be deactivated
again.
If a multi shot autoreclosing is set, another autoreclose cycle is released if the first
one is unsuccessful. Here also, similarly to the first autoreclosure, the specific time is
activated by the General-Start signal. This should be adjusted to the time setting t2 of
the second impedance zone Z2. The second impedance zone should be set in this
case in forward direction immediately above the first impedance zone Z1.
In the event that a mixed line, comprising cable and overhead line, need to be protected, an autoreclosing is allowed only in the area of the overhead line. From the distance protection point of view, if the line connection starts with an overhead cable and
ends with a cable, in principle the same setting as described above with the standard
autoreclosure is valid. The autoreclosure zone ZAR will only be set to approximately
90% of the impedance of the overhead line of the first section. The following figure
shows the corresponding zone characteristic.
Station A
Station B
t2
t1
DP
ZAR
Overhead Line
Z1
Cable
Figure 22: Zone setting for autoreclosure on overhead line –cable
DP
Distance Protection
Z1
First impedance zone
ZAR
Autoreclose zone to release or block the autoreclosing
In this case, the autoreclosing blocking zone operates to release the autoreclosure
within the set zone. If the fault occurs in the second cable area, the autoreclosure will
be blocked.
The restriction on the reach of the overreach zone is required because it is known
that faults of approximately 5% must be expected with the current and voltage measurement. If the current and voltage measurement is more precise, the reach of the
overreach zone should be set correspondingly.
From the distance protection point of view, if in the first section of the line connection
a cable is installed and behind it the overhead line, the autoreclosing blocking zone
ZAR is used to block the autoreclosing in case of system fault in the first section with
cable. The following figure shows the impedance-time characteristic that must be set.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Station A
Station B
t2
t1
DP
ZAR
Cable
Z1
Overhead Line
Figure 23: Zone setting for autoreclosure on cable-overhead line
DP
Distance Protection
Z1
First impedance zone
ZAR
Autoreclose zone to release or block the autoreclosing
If there is a fault on the cable the autoreclosure need to be blocked by the autoreclosing zone ZAR. The autoreclosing zone ZAR, due to the above-mentioned faults with
current and voltage measurement, should be set to approximately 110% of the total
cable impedance. The reach of the overreach zone Zov with the associated time tov
sets the range for activating the autoreclosure on the overhead cable side.
7.4.1.3.7 Signal comparison scheme
If the zone for the protection reach is less than the smallest possible impedance setting value, the distance protection can be supplemented with a signal comparison
scheme. This enables the relative selective protection with time discrimination to function as a absolute selective protection. With the signal comparison scheme, the distance protection becomes a protection system with data transmission link. However,
there are no specific requirements on the signal connection and transmission as this
would be the case with the line differential protection. A part of the protection system,
in this case the distance protection, will also works properly without the communications link. The following figure illustrates the principle of distance protection with the
signal comparison scheme by using a pair of pilot wires.
Station A
DP
Station B
Pilot wire
DP
Z1
Z1
Figure 24: Zone characteristic of the distance protection with signal comparison scheme
DP
Distance Protection
Z1
First impedance zone of the corresponding distance protection
As noted above, the impedance of the line to be protected is so small that the discrimination by applying of the first impedance zone Z1 can not be guaranteed. There1VTA10002 Rev02
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fore the zone can only be set greater than the impedance of the entire line. To ensure
the selective tripping, a signal comparison scheme must be added. The time t1 of the
first impedance zone need in this case to be increased, for example to 0.2 to 0.3 s. In
this way, a fault can always be tripped by distance protection in the increased base
time independent of the status of the link.
The two distance protection units at each end of the line unit are connected to each
other with a pair of pilot wires to form a comparison protection scheme. This enables
the General-Start and impedance Z1< protection signals occurring during the fault to
be compared with each other. The following figure shows an example of the functioning of the signal comparison protection with the aid of simple relay contacts.
L+
L-
G Start
G Start
Z < Z1
Z < Z1
REF542plus
REF542plus
Figure 25: Principle of the distance protection with signal comparison scheme
The two distance protection units are connected with the pair of pilot wires. This forms
a loop over the two protection devices. An auxiliary voltage is applied at one end of
the loop. The auxiliary voltage is assigned to the two binary inputs in use. It can also
be used to monitor the pair of pilot wires. If the auxiliary voltage is down an indication
signal can be generated after the expiry of a configurable time delay of, for example,
5 s. If necessary, this will then be forwarded to the upper level control system. As described above, also in the case of a failure of the pilot wire the line will continue to be
protected by distance protection, but with the slightly increased operation time.
If a fault occurs in the power system, both distance protection units (at each line
ends) will be tripped. Each of them will send a General-Start signal. The GeneralStart N/C (normally closed) contacts and with them the pilot wire loop will be opened.
The connection to the signal comparison is broken for a while. Because the loop is
only open for a fraction of time, less than 5 s, an indication signal is not sent.
The tripping of the distance protection is only possible if both protection units acknowledge a fault impedance within the first impedance zone Z1. In this case, the signal Z1< appears, which is used to close the comparison loop again. The closed state
of the loop means that the fault is within the protection zone of both distance protection units. In the event of a fault outside the protection zone, the loop cannot be
closed due to the missing signal Z1<. Therefore, a trip does not occur.
The signal comparison protection also functions if the line unit is fed from only one
side after for example a switchover actions in the power system. A quasi-echo circuit
is implemented within the signal comparison scheme. The loop remains closed because the distance protection at the other end of the line is and remains in idle status,
if a fault is occurred within the protection zone. The tripping is then generated on the
side of the distance protection, which detect the system fault.
A fault within the protection zones can be tripped quickly and selectively with the signal comparison scheme. However, when making the settings, the propagation time of
the signals must be taken into account. It is important that the General Start signal
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always appears before the signal Z1< to ensure that the loop is opened at the right
time.
In addition, the fact that the signals required for the signal comparison protection are
not always received simultaneously at both ends of the line unit must be considered.
Sufficient time delays must be defined at the binary inputs.
7.4.1.3.8 Switching onto faults
The distance protection consist also the function of the so-called “switching onto
faults”. With this setting activated, the tripping response of the distance protection can
be remotely or locally influenced by the closing command of the circuit-breaker as follows:
Standard operation
In this case the function "switching onto fault“ is not activated. The distance protection
ignores the closing command of the circuit-breaker. A fault is only tripped in accordance with the zone characteristic. This means that a fault will be tripped in the first
impedance zone with the time t1 and in the second impedance zone with the time t2.
Use overreach zone
With this setting the overreach zone will be activated for about 200 ms by the closing
command of the circuit-breaker. The protection zone is given by the setting of the
overreach stage ZOR. This is normally about 120 … 150% of the line impedance ZL.
The tripping then will occurs with the corresponding time tOV. When the circuit-breaker
is closed by the autoreclosure function, the overreach zone will not be activated anymore.
Tripping after general starting:
In this setting the General-Start signal will define the behaviour of the protection tripping. If the general starting signal occurs when the circuit-breaker is closed, the distance protection trips with a fixed operation time of 50ms. The impedance measurement will not be used.
Note
If the switching onto fault shall be used, the distance protection must be connected to
a function block 2-2 switch object, which is defined as a circuit breaker. Otherwise the
switching on process of the circuit breaker will not be recognized.
7.4.1.4 Switchover to Emergency Overcurrent Protection
In the event of an MCB failure in the voltage instrument transformer the distance protection will be unable to function correctly because of missing the voltage measured
quantities. For this reason it is necessary to block the distance protection and to
switch over to the so-called emergency overcurrent protection functions. The automatic switchover scheme to the emergency definite time overcurrent protection must
be designed in the FUPLA.
7.4.1.5 Setting the Impedance Zone
Distance protection is a non-unit protection (relative selectivity). In order to get the required selectivity, time-grading is used for this purpose. The individual ranges are limited by means of impedance zones.
After generating the trip, the fault impedance and the reactance are indicated on the
LCD screen for fault-locating purposes. The values of the fault impedance and of the
reactance, as usual for fault-locator, are indicated as primary values.
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In contrary the impedance zones have to be set as secondary values. These values
need to be calculated, depending on the transducers or sensors used. The secondary
setting of the impedance zone is normally based on current and voltage transformers
with secondary nominal values 1A and 100 V. By default, the input transformers for
converting current and voltage values are nominal at 1A and 100 V. Therefore, the
conversion is based on the following relation:
Zsec = Zpri
Ti
Tu
where Zsec is the secondary impedance quantity, Zpri is the primary impedance
quantity, Ti is the transformation ratio for the current transformer, and Tu is the transformation ratio for the voltage transformer.
If the secondary nominal value of the current transformers deviates from 1A, the
equation needs to be extended as follows:
Zsec = Zpri
Ti Isn
Tu 1A
where, as before, Zsec is the secondary impedance quantity, Zpri is the primary impedance quantity, Ti is the transformation ratio for the current transformer, and Tu is
the transformation ratio for the voltage transformer. Furthermore, the nominal current,
Isn, and the nominal voltage, Usn, on the secondary side of the transducers have to
be taken into consideration.
The following example of distance protection illustrates how the primary impedance is
converted for setting the respective impedance value. For this purpose, a series of
data from the transducers and sensors are used.
CT 100/1 A and VT 20,000/100 V
The above-mentioned data for the current and voltage transformers can be used to
calculate the secondary impedance value for the protection by using the first equation:
Zsec = Zpri
100
= 0.5 Zpri
200
The primary impedance values can be converted into the secondary impedance values by applying factor 0.5.
CT 100/5 A and VT 20,000/100 V
With this transducer, the calculation must be made using the second equation which
looks like this:
Zsec = Zpri
Note
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20 5 A
= 0.5 Zpri
200 1A
Please note that the input transformer for the nominal current of 5A must be used for
connecting.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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CT 100/1 A and VT 20,000/110 V
Since the voltage transformer transforms the primary line voltage to 110V, the reference quantity for the calculation in distance protection needs to be adapted. For this
purpose, the calibration factors for the voltage inputs have to be adjusted from 100V
to 110V, by setting them to 1.1. For converting, the same relation is used:
Zsec = Zpri
100
= 0.5 Zpri
181.81
Sensor 80A/150mV and 20,000V/2V
The sensors transform the primary measured quantities directly to the reference
quantity for signal processing in the REF 542plus. The current quantity is then converted to 150 mV and the voltage quantity is converted to 2V. In principle, the first
equation can be used for calculation. However, this is based on the assumption that
the primary measured quantities are converted to secondary quantities of 1A and
100V. Moreover, it must be assumed that the nominal quantities for the interposing
transformers are 1A and 100 V as well. Consequently, the secondary setting is determined as follows:
Zsec = Zpri
Note
80
= 0.4 Zpri
200
The same voltage sensor that is used for 20 kV nominal voltage with a divider ratio of
10,000:1 is also used for systems with nominal voltages below 20 kV. Therefore the
calculation of impedance values must be based on the same nominal voltage 2V x
10.000 = 20 kV. The nominal voltage must always be based on the actual divider ratio. For example, a sensor with a divider ratio of 20,000 : 1 corresponds to a resulting
nominal voltage of 2V x 20,000 = 40 kV.
7.4.1.6 Setting groups
Two parameter sets can be configured for the thermal overload protection function.
7.4.1.7 Parameters and Events
7.4.1.7.1 General parameter
Net type:
high ohmic, low ohmic
Used sensors:
I: 1-3; U: 4-6 or I: 4-6; U: 1-3
Earth start:
IE> used or IE> unused (residual current)
Switching onto faults:
normal behavior, overreach zone used or trip after occurrence of general start signal
Signal Comp. Time:
30 … 30,000 ms (set 1/set 2), default 30 ms
7.4.1.7.2 Start values
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Parameter
Values
Unit
Default
Explanation
I>
0.05..4.00
In
1.00
Phase current high set
IN>
0.05..4.00
In
0.20
Residual current
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Parameter
Values
Unit
Default
Explanation
UF
0.05..0.90
Un
0.50
Phase or line voltage (net type)
IF>
0,05..4
In
0.50
Phase current low set
7.4.1.7.3 Choose zone
Parameter
Values
Unit
Default
Cable reactance
0.05 .. 120
Ohm/km
1
OH line reactance
0.05 .. 120
Ohm/km
1
Border OH/cable
0.05 .. 120
Ohm
1
Type of transmission line
Explanation
only cable, only OH line, OH line before cable or
cable before OH line
7.4.1.7.4 Zone 1, 2, 3, Zone Overreach, Autoreclose (border)
Parameter
Values
Unit
Default
Resistance R
0.05 .. 120
Ohm
1
Reactance X
0.05 .. 120
Ohm
1
Angle delta 1
-45 .. 0
°
0
Angle delta 2
90 .. 135
°
90
Time
20 .. 10000
ms
20
Direction
forward,
backward or
zone unused
-
zone unused
Explanation
7.4.1.7.5 Drectional backup
Parameter
Values
Unit
Default
Angle delta 1
-45 .. 0
°
0
Angle delta 2
90 .. 135
°
90
Time
20. 10000
ms
20
Direction
forward,
backward or
zone unused
-
zone unused
Explanation
7.4.1.7.6 Non-directional backup
Parameter
Values
Unit
Default
Time
20. 10000
ms
20
Explanation
7.4.1.7.7 Phase selection
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Normal acycle
L3-L1-L2
Normal cycle
L3-L1-L2-L3
Inverse acycle
L1-L3-L2
Inverse cycle
L3-L2-L1-L3
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7.4.1.7.8 Earth factor
Parameter
Code
Values
Factor k
0 .. 10
Angle k
-60 .. 60
Unit
Default
Explanation
°
7.4.1.7.9 Events
Code
Event reason
E0
Start L1 started
E1
Start L1 back
E2
Start L2 started
E3
Start L2 back
E4
Start L3 started
E5
Start L3 back
E6
Trip started
E7
Trip back
E16
Z1< started
E17
Z1< back
E18
Protection block started
E19
Protection block back
E22
General start started
E23
General start back
E24
Earth start started
E25
Earth start back
E28
Signal comparison started
E29
Signal comparison back
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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7.5 Differential protection
7.5.1 Transformer Differential Protection
Differential protection can be used to protect power transformers, motors and generators. The protection function has the following properties:
Differential protection of two windings power transformer
Amplitude and vector group adaptation
Zero sequence current compensation
Three-fold tripping characteristic
Inrush stabilization by 2nd and 5th harmonics
Stabilization during through-faults also in case of current transformers (CT) saturation
7.5.1.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
TRIP
Digital signal (active high)
Trip signal
BH2
Digital signal (active high)
Block by 2
BH5
Digital signal (active high)
Block by 5th harmonic signal
GB
Digital signal (active high)
General Block output signal
nd
harmonic signal
The TRIP signal will be activated when at least one of the calculated differential currents Id exceeds the bias-dependent setting threshold value AND if the harmonic stabilization is enabled, the harmonic content of differential current is below the set
thresholds (2nd ,5th Threshold).
When the harmonic stabilization is enabled, the Block Output (BH2, BH5) signals become active if the protection function detects a differential current exceeding the preset threshold and the harmonic content of differential current is above the set thresholds (2nd ,5th Threshold).
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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7.5.1.2 Configuration
7.5.1.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.5.1.2.2 Sensors
Transformer differential protection requires 6 current sensors; it operates on two sets
of phase currents in a triple on primary and secondary side of the transformer.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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7.5.1.2.3 Transformer
7.5.1.2.4 Current
Note
Primary nominal current
Nominal transformer current on primary side.
Secondary nominal current
Nominal transformer current on secondary
side, to be used for power transformer ratio
compensation.
All the Differential protection thresholds are referred the Rated power transformer current Ir (p.u) in per unit; i.e. normalized on the primary or secondary nominal power
transformer current (Primary, Secondary nominal current). In this way all
differences due to CT ratios and board transformer analog input are automatically
normalized.
Threshold current
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First region Id threshold.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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Unbiased region limit
First region Ib threshold.
Slightly biased region threshold Second region Id threshold.
Slightly biased region limit
Second region Ib threshold.
Heavily biased slope
Third region slope.
Trip by Id>
Upper Id threshold for Trip condition detection.
7.5.1.2.5 Harmonics
2nd, 5th Harmonic
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Threshold
Threshold value for 2nd, 5th harmonic content detection.
Block
Flag enabling the harmonic content detection. When threshold
value is exceeded it blocks the protection function and generates a
blocking signal.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.5.1.2.6 Events
7.5.1.2.7 Pins
7.5.1.3 Measurement mode
Differential protection function evaluates the measured amount of differential current
at the fundamental, 2nd and 5th harmonic frequencies.
7.5.1.4 Operation criteria
Transformer differential protection is a current comparison scheme for the protection
of a component with two sides, like e.g. two windings power transformer, therefore
the incoming and outgoing currents through the component to be protected are compared with each other.
If no fault exists in the protection zone, the incoming current and the outgoing current
are identical.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Therefore the difference between those currents, the differential current Id, is used as
criteria for fault detection. The protection zone of transformer differential protection is
limited by the place where the current transformers or current sensors are installed.
The signals path and the measurement processing to obtain the differential current Id
sed as criteria for fault detection are described in the following flowchart:
Protected
Object
Primary
currents
Secondary
currents
Analog
A/D
Input
Analog
A/D
Input
Transformation
Ratio
Compensation
Vector Group
Compensation
Bias Currents
Calculation
Ib
Differential
Currents
Calculation
DFT
∆I(f 0)
∆I(2f 0)
∆I(5f 0)
After transformer ratio compensation and vector group adaptation the bias and differential currents are calculated on the three phases.
If harmonic stabilization is enabled (in “Harmonic” dialog window), 2nd and/or 5th harmonic contents of differential currents are calculated.
If at least one of the calculated differential currents Id is above the bias (of the considered phase) dependent setting threshold (given by the tripping characteristic,
Threshold current, Slightly biased region threshold, Heavily
biased slope or Trip by Id>), then (if required) the check for harmonic stabilization is performed.
If harmonic content of differential current Id is above the set threshold (2nd ,5th
Threshold), then the protection function will be blocked and the relevant Block sig1VTA10002 Rev02
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
nal will be activated, else it goes in TRIP status and the trip signal is generated. The
Block is released If the Id harmonic content falls below 0.4 the setting threshold value
(for 2nd ,5th. Threshold respectively). .
The protection function will remain in TRIP status until there is at least one differential
current above the threshold. It will come back in passive status and the Trip signal will
be cleared if for all the phases the differential current falls below 0.4 the setting
threshold value.
7.5.1.5 Transformer ratio compensation
To perform the current comparison, it is necessary to correct the amplitude of the currents to compensate the transformer ratio. The amplitude correction is done by software. In the case of power transformer protection for example, the current measurement quantities on the primary and the secondary side are corrected by taking into
account the different nominal values of the sensors and primary/secondary nominal
current parameters.
7.5.1.6 Vector group adaptation
The vector Adaptation table is shown below. PS is the primary side, SS the secondary side of the power transformer, IL1 to IL3 the current in the phase L1 to L3 and the
indexes 1 and 2 represent the primary and the secondary side of the transformer respectively. If a transformer is grounded on the primary or on the secondary side it
must also take into consideration that the earthing is carried out by grounding transformers. The vector group adaptation is also in position to cover the situation, where
the grounding transformer is inside the protection zone.
Vector
group
Grounding
0
No
PS
No
Yes
Yes
1
No
No
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Calculation of the current comparison
SS
No
Yes
No
Yes
No
Yes
PS
SS
IL11
IL12
IL21
IL22
IL31
IL32
( IL11 - IL21 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL12 ) / √3
( IL11 - IL21 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL12 ) / √3
( IL11 - IL21 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL12 ) / √3
( IL11 - IL31 ) / √3
IL12
( IL21 - IL11 ) / √3
IL22
( IL31 - IL21 ) / √3
IL32
IL11
( IL12 - IL22 ) / √3
IL21
( IL22 - IL32 ) / √3
IL31
( IL32 - IL12 ) / √3
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Vector
group
Grounding
PS
Yes
Yes
2
No
No
Yes
Yes
3
No
No
Yes
Yes
4
No
No
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Calculation of the current comparison
SS
No
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
No
Yes
PS
SS
( IL11 - IL31 ) / √3
IL12
( IL21 - IL11 ) / √3
IL22
( IL31 - IL21 ) / √3
IL32
( IL11 - IL31 ) / √3
IL12 - IL02
( IL21 - IL11 ) / √3
IL22 -- IL02
( IL31 - IL21 ) / √3
IL32 - IL02
IL11
- IL22
IL21
- IL32
IL31
- IL12
( IL11 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL11 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL11 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL11 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL11 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL21 - IL11 ) / √3
( IL22 - IL32 ) / √3
( IL31 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL21 - IL31 ) / √3
IL12
( IL31 - IL11 ) / √3
IL22
( IL11 - IL21 ) / √3
IL32
IL11
( IL32 - IL22 ) / √3
IL21
( IL12 - IL32 ) / √3
IL31
( IL22 - IL12 ) / √3
( IL21 - IL31 ) / √3
IL12
( IL31 - IL11 ) / √3
IL22
( IL11 - IL21 ) / √3
IL32
( IL21 - IL31 ) / √3
IL12 - IL02
( IL31 - IL11 ) / √3
IL22 -- IL02
( IL11 - IL21 ) / √3
IL32 - IL02
IL11
IL32
IL21
IL12
IL31
IL22
( IL11 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL22 - IL32 ) / √3
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Vector
group
Grounding
PS
Yes
Yes
5
No
No
Yes
Yes
6
No
No
Yes
Yes
7
No
No
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Calculation of the current comparison
SS
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
PS
SS
( IL11 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL22 - IL32 ) / √3
( IL11 - IL21 ) / √3
( IL32 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL12 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL22 - IL32 ) / √3
( IL21 - IL11 ) / √3
IL12
( IL31 - IL21 ) / √3
IL22
( IL11 - IL31 ) / √3
IL32
IL11
( IL32 - IL12 ) / √3
IL21
( IL12 - IL22 ) / √3
IL31
( IL22 - IL32 ) / √3
( IL21 - IL11 ) / √3
IL12
( IL31 - IL21 ) / √3
IL22
( IL11 - IL31 ) / √3
IL32
( IL21 - IL11 ) / √3
IL12 - IL02
( IL31 - IL21 ) / √3
IL22 -- IL02
( IL11 - IL31 ) / √3
IL32 - IL02
IL11
- IL12
IL21
- IL22
IL31
- IL32
( IL11 - IL21 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL12 - IL32 ) / √3
( IL11 - IL21 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL12 - IL32 ) / √3
( IL11 - IL21 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL31 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL11 ) / √3
( IL12 - IL32 ) / √3
( IL11 - IL31 ) / √3
- IL12
( IL21 - IL11 ) / √3
- IL22
( IL31 - IL21 ) / √3
- IL32
- IL11
( IL12 - IL22 ) / √3
- IL21
( IL22 - IL32 ) / √3
- IL31
( IL32 - IL12 ) / √3
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Vector
group
Grounding
PS
Yes
Yes
8
No
No
Yes
Yes
9
No
No
Yes
Yes
10
No
No
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Calculation of the current comparison
SS
No
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
No
Yes
PS
SS
( IL11 - IL31 ) / √3
- IL12
( IL21 - IL11 ) / √3
- IL22
( IL31 - IL21 ) / √3
- IL32
( IL11 - IL31 ) / √3
- IL12 + IL02
( IL21 - IL11 ) / √3
- IL22 + IL02
( IL31 - IL21 ) / √3
- IL32 + IL02
IL11
IL22
IL21
IL31
IL32
IL12
( IL11 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL11 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL11 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL11 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL11 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL21 - IL11 ) / √3
( IL32 - IL22 ) / √3
( IL31 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL21 - IL31 ) / √3
- IL12
( IL31 - IL11 ) / √3
- IL22
( IL11 - IL21 ) / √3
- IL32
- IL11
( IL32 - IL22 ) / √3
- IL21
( IL12 - IL32 ) / √3
- IL31
( IL22 - IL12 ) / √3
( IL21 - IL31 ) / √3
- IL12
( IL31 - IL11 ) / √3
- IL22
( IL11 - IL21 ) / √3
- IL32
( IL21 - IL31 ) / √3
- IL12 + IL02
( IL31 - IL11 ) / √3
- IL22 + IL02
( IL11 - IL21 ) / √3
- IL32 + IL02
IL11
- IL32
IL21
- IL12
IL31
- IL22
( IL11 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL22 ) / √3
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Protection Functions: Configuration and Settings
Vector
group
Grounding
PS
Yes
Yes
11
No
No
Yes
Yes
Calculation of the current comparison
SS
No
Yes
No
Yes
No
Yes
PS
SS
( IL11 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL22 ) / √3
( IL11 - IL21 ) / √3
( IL12 - IL32 ) / √3
( IL21 - IL31 ) / √3
( IL22 - IL12 ) / √3
( IL31 - IL11 ) / √3
( IL32 - IL22 ) / √3
( IL21 - IL11 ) / √3
- IL12
( IL31 - IL21 ) / √3
- IL22
( IL11 - IL31 ) / √3
- IL32
- IL11
( IL32 - IL12 ) / √3
- IL21
( IL12 - IL22 ) / √3
- IL31
( IL22 - IL32 ) / √3
( IL21 - IL11 ) / √3
- IL12
( IL31 - IL21 ) / √3
- IL22
( IL11 - IL31 ) / √3
- IL32
( IL21 - IL11 ) / √3
- IL12 + IL02
( IL31 - IL21 ) / √3
- IL22 + IL02
( IL11 - IL31 ) / √3
- IL32 + IL02
7.5.1.7 Tripping characteristic
The tripping characteristic of the transformer differential protection function is a threefold characteristic. In the following figure the characteristic is shown.
III - Heavily
biased
region
I - Unbiased
region
II - Slightly
biased
region
Figure 26: Tripping characteristic of the transformer differential protection function
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Protection Functions: Configuration and Settings
The tripping characteristic is drawn on p.u. basis after normalization of I1 and I2 currents on on the primary or secondary nominal power transformer current (Primary,
Secondary nominal current). Therefore Id and Ib currents are expressed in p.u.
as multiples of the Rated power transformer current Ir (p.u).
The bias currents are defined as the average values (in p.u.) between primary and
secondary currents obtained after transformation ratio compensation and vector
group adaptation.
Due to the measurement error of the current quantities on both sides of the object to
be protected, a small differential current Id will occur during normal operation condition.
The first fold of the characteristic curve is given by the settable threshold value of the
differential current (Threshold current) and the bias current limit (Unbiased
region limit).
The second fold of the characteristic curve is defined by the threshold value of the differential current (Slightly biased region threshold) and the bias current
limit (Slightly biased region limit).
Afterwards a line with a selectable slope (Heavily biased slope) continues the
characteristic.
In case of the occurrence of a high differential current, a direct tripping can also be
generated by the threshold value (Trip by Id>) as the third fold of the tripping
characteristic. The setting value should be selected in such a way, that no tripping
could happen during the energizing of the power transformer.
7.5.1.8 Inrush stabilization
When switching on a power transformer without connected loads high inrush current
might occur. As a consequence undesired tripping could happen.
nd
To stabilize this condition of the power transformer the presence of the 2 harmonic
in the differential current can be used as criteria. Therefore the ratio of the 2nd harmonic current to the current at fundamental frequency is important. As soon as the
threshold value (threshold) is exceeded, the protection function is blocked and a
blocking signal is activated..
Also in case of switching on in parallel a power transformer without connected loads
the inrush current can also be generated in the transformer which is already in operation. In this case it is necessary to detect the 5th harmonic in the differential current to
avoid the undesired tripping.
For that reason the differential protection in REF542plus is foreseen with the 2nd and
the 5th harmonic blocking possibilities, which can be set separately from each other.
7.5.1.9 Setting groups
Two parameter sets can be configured for the transformer differential protection function.
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Protection Functions: Configuration and Settings
7.5.1.10 Parameters and Events
7.5.1.10.1 Setting values
Parameter
Values
Unit
Default
Explanation
Transformer group
0 .. 11
-
0
Transformer Earthing:
Primary side
Secondary side
Yes/No
Yes/No
-
No
No
Parameters for: vector group
adaptation and
transformation ratio compensation between primary - secondary currents.
Primary nominal current
10 .. 100000
A
100
Secondary nominal current
10 .. 100000
A
100
Threshold current
0.10 .. 0.50
Ir (p.u.)
0.20
First region Id threshold.
Unbiased region limit
0.50 .. 5.00
Ir (p.u.)
0.50
First region Ib threshold.
Slightly biased region
threshold
0.20 .. 2.00
Ir (p.u.)
0.20
Second region Id threshold.
Slightly biased region limit
1.00 .. 10.00
Ir (p.u.)
3.00
Second region Ib threshold.
Heavily biased region
slope
0.40 .. 1.00
-
0.40
Third region slope.
Trip by Id>
5.00 .. 40.00
Ir (p.u.)
6.00
Upper Id threshold for Trip.
Second Harmonic:
Threshold
Block
0.10 .. 0.30
Enabled/Disabled
Id
-
0.30
Enabled
Fifth Harmonic:
Threshold
Block
0.10 .. 0.30
Enabled/Disabled
Id
-
0.30
Enabled
Parameters for:
inrush stabilization and
No load transformer Inrush
stabilization
7.5.1.10.2 Events
Code
Event reason
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal back to inactive
E20
Block signal due to 2nd harmonic is active
E21
Block signal due to 2nd harmonic back to inactive
E24
Block signal due to 5 harmonic is active
E25
Block signal due to 5th harmonic is back to inactive
E26
General block harmonic start
E27
General block harmonic back
th
By default all events are disabled.
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Protection Functions: Configuration and Settings
7.5.2 Restricted Differential Protection
Restricted differential protection can be used as well restricted earth fault protection
to detect and disconnect of fault in grounding system of the transformer as also as
line differential protection with 2 pair of pilot wire.
7.5.2.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the differential current Id exceeds the setting
threshold value.
The TRIP signal will be activated when the start and trip conditions are true and the
operating time (Time) has elapsed.
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Protection Functions: Configuration and Settings
7.5.2.2 Configuration
7.5.2.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.5.2.2.2 Sensors
The protection function operates on the comparison of two earth currents; the zerosequence current, calculated by means of current measures acquired from the lines
(on any set of phase currents in a triple), and the measured earth-fault current flowing
through the neutral conductor towards the ground. The protection is used in case of
star windings with earthed neutral transformers.
Example of a typical current transformers connection diagram for a transformer Restricted Differential (earthfault) protection is provided in the Appendix - Connection
Diagram).
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Protection Functions: Configuration and Settings
In the application as line differential protection the earth currents from both line sides
shall be provided for each line side REF542plus to two dedicated Analog Inputs (AI 7
and AI8). The earth currents can be directly measured through dedicated sensors, by
star connecting the three phase CTs to provide the neutral current or with a matching
transformer on each end of the line in order to generate from the three phase currents
a measurement quantity proportional to the earth currents.
Line side 1
Earth current
I1
Line side 2
Earth current
I2
Figure 27: Connection scheme of the application as line differential protection
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Protection Functions: Configuration and Settings
7.5.2.2.3 Parameters
Rated current
Rated current for CT ratio compensation
and currents normalization.
Unbiased region Threshold
First region Id threshold.
Unbiased region limit
First region Ib threshold.
Slightly biased region threshold Second region Id threshold.
Slightly biased region limit
Second region Ib threshold.
Heavily biased slope
Third region slope.
Relay Operate Angle
Directional criteria.
Time
Time delay for Trip condition detection.
7.5.2.2.4 Events
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Protection Functions: Configuration and Settings
7.5.2.2.5 Pins
7.5.2.3 Measurement mode
The restricted differential protection function evaluates the differential current between two earth currents at the fundamental frequency.
The two currents can be the calculated or measured residual current I0 from the
phase currents compared with the neutral current IG in the transformer restricted
earthfault applicationor, in case of line differential protection, the earth currents of
each end of the line (I1.and I2).
7.5.2.4 Operation criteria
The restricted differential protection is a current comparison scheme. Therefore the
incoming and outgoing currents through the object to be protected are compared with
each other. If no fault exists in the protection zone, the incoming current and the outgoing current are identical. That is why difference between those currents, the differential current I d = I 0 − I G = I 2 − I 1 , is used as criteria for fault detection.
The protection zone of the restricted differential protection is limited by the place
where the current transformers or current sensors are installed.
If the calculated differential current Id is above the bias-dependent setting threshold
(given by the tripping characteristic, Unbiased region threshold, Slightly
biased region threshold or Heavily biased slope), then protection
function is started and the Start signal will be activated.
The protection function will come back in passive status and the start signal will be
cleared if the differential current Id falls below 0.95 the setting threshold value.
If the start conditions are true then the following conditions are checked:
Direction. The directional check is made only if I0 is more than 3 % of the rated current (Rated current Ir). If the result of the check means “external fault”, then the
trip is not issued. If the directional check cannot be executed, then direction is no
longer a condition for a trip.
External fault. For as long as the external fault persists (flag enabled in passive condition only, for Id< 0.5 the lower setting threshold and IG> 0.5 the Rated current
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Ir) an additional temporary condition is introduced, which requires, that IG has to be
higher than 0.5 Ir, for protection temporarily desensitization.
Bias. The bias current Ib is above 0.5 the maximum bias current calculated during the
start condition period. Ibtrip > 0.5 Ibmax (start period).
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated if all the
above conditions are true.
The protection function will exit TRIP status to come back in passive status and the
Trip signal will be cleared if the differential current Id falls below 0.4 the setting
threshold value.
7.5.2.5 Tripping characteristic
The tripping characteristic of the Restricted Differential protection function is a threefold characteristic. In the following figure the characteristic is shown.
Id/Ir
I1 = IG
I2 = I0
Assumptions:
I1 > I2, then I1 = Ib
Ib Biased current
Id Differential current
Id
III - Heavily
biased
region
Trip area
Id1/ Ir
I - Unbiased
region
II - Slightly
biased
region
Ib1/ Ir
Ib2/ Ir
Ib/Ir
Figure 28: Tripping characteristic
The tripping characteristic is drawn on p.u. basis after normalization of I1 and I2 currents on power transformer Rated current (Rated current Ir).
The bias current is per definition always the one with the higher magnitude, Ib = max
(IG, I0) or Ib = max (I1, I2).
After compensation of different sensor nominal values the differential current Id and
the bias current Ib are calculated.
The first fold of the characteristic curve is given by the settable threshold value of the
differential current (Unbiased region threshold) and the bias current limit (Unbiased region limit).
The second fold of the characteristic curve is defined by the threshold value of the differential current (Slightly biased region threshold) and the bias current
limit (Slightly biased region limit).
Afterwards a line with a selectable slope (Heavily biased slope) continues the characteristic.
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Protection Functions: Configuration and Settings
In case of an external fault characterized from a high fault current, it could happen
that the different CTs don’t transform the primary current in the same way (even if
they have the same characteristics), allowing the circulation of a differential current
through the protection.
The tripping characteristic allows facing CT introduced error (e.g. due to phase and
ratio error, different CT load or magnetic properties), without decreasing the sensitivity of the differential protection. In fact in case of high line currents and then high
ground current, even if there are differences about the I0 and IG transformation, the
higher differential current threshold compensates such an error.
7.5.2.6 Directional Criterion for stabilization against CT saturation
Earth faults on lines connecting the power transformer occur much more often than
earth faults on a power transformer winding. It is important therefore that the restricted earth fault protection should remain secure during an external fault, and immediately after the fault has been cleared by some other protection.
The directional criterion is applied in order to distinguish between internal and external earth faults in case of CT saturation, to prevent misoperations at heavy external
earth faults. This criterion is applicable is the residual current I0 is at least 3% Ir.
For an external earth fault with no CT saturation, the residual current in the lines I0
and the neutral current IG are equal in magnitude and phase. The current in the neutral IG is used as directional reference because it flows for all earth faults in the same
direction.
To stabilize the behavior against CT saturation, a phase comparison scheme is introduced. In case of a heavy current fault with saturation of one or more CTs, the measured currents IG and I0 may no more be equal, nor will their positions in the complex
plane be the same, anda certain value of false differential current Id can appear.
If the fault is inside of the protection zone, the currents to be compared must have a
phase shift to each other. That is why a so-called relay operate angle ROA is introduced, like shown in the next figure. The direction of neutral current is inside of the
ROA, if it is an internal fault. The direction of both current is outside of the ROA for
external faults.
Figure 29: Currents at an external earth fault with CTs saturation
In case of internal fault then the I0 lies into the operate area for internal fault and the
protection is allowed to operate, see:
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Figure 30: Currents at an internal earth fault
The ROA can be taken out of operation by setting it to 180° if no CT saturation has to
be considered.
In case the Restricted Differential is used for line application the same considerations
apply using I1 and I2 earth currents.
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Protection Functions: Configuration and Settings
7.5.2.7 Setting groups
Two parameter sets can be configured for the restricted differential protection function.
7.5.2.8 Parameters and Events
7.5.2.8.1 Setting values
Parameter
Values
Unit
Default
Explanation
Reference nominal current
1 .. 100000
A
100
Reference current for CT ratio compensation/ currents normalization.
Unbiased region
threshold
0.05 .. 0.50
Ir
0.30
First region Id threshold.
Unbiased region
limit
0.01 .. 1.00
Ir
0.50
First region Ib threshold.
Slightly biased
region slope
0.01 .. 2.00
-
0.70
Second region Id threshold.
Slightly biased
region limit
0.01 .. 2.00
Ir
1.25
Second region Ib threshold.
Heavily biased
region slope
0.10 .. 1.00
-
1.00
Third region slope.
Relay Operate
Angle
60 .. 180
°
75
Directional criteria.
Time
0.04 .. 100.00
s
0.05
Time delay for Trip condition detection.
7.5.2.8.2 Events
Code
Event reason
E0
Protection started timing
E1
Timing cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block signal is active state
E17
Block signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
By default all events are disabled.
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Protection Functions: Configuration and Settings
7.6 Other Protections
7.6.1 Unbalanced Load Protection
REF542plus has one unbalanced load protection function.
7.6.1.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
RST
Trigger signal (active low-to-high)
Reset signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
When the reset input pin (RST) is triggered, the protection function is reset. Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
BO
Digital signal (active high)
Block output signal
The Start signal will be activated when the calculated negative phase sequence current exceeds the setting threshold value (Is).
The TRIP signal will be activated when the start conditions are true and the operating
time has elapsed.
The Block Output (BO) signal becomes active when the protection function exit TRIP
status and remains active for the setting delay time (Reset Time ).
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Protection Functions: Configuration and Settings
7.6.1.2 Configuration
7.6.1.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.6.1.2.2 Sensors
The protection function operates on any set of phase currents in a triple.
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7.6.1.2.3 Parameters
Is
Current threshold for negative sequence condition detection.
K
Heating parameter to vary time delay for Trip condition
Reset Time
Time BO output is high (e.g. to block the re-closing possibility of a
motor).
Timer decreasing rate
Parameter to vary thermal memory effect.
7.6.1.2.4 Events
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7.6.1.2.5 Pins
7.6.1.3 Measurement mode
Unbalanced load protection function evaluates the measured amount of negative
phase sequence current at the fundamental frequency.
The negative-sequence three phase system L1 - L3 - L2 is superimposed on the
three-phase system that corresponds to the standard phase sequence. This results in
different field intensities in the magnetic laminated cores. Points with particularly high
field intensities, "hot spots“, lead to local overheating.
7.6.1.4 Operation criteria
If the calculated negative phase sequence current exceeds setting threshold value
(Is), then the protection function is started and the start signal will be activated.
When the protection enters the START status the operating time is continuously recalculated according to the set parameters (K, Is) and the negative phase sequence current value.
If the calculated operating time is exceeded, the function goes in TRIP status and the
trip signal becomes active.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value. The operating time depends on the calculated negative phase sequence as follows:
t=
K
2
I2 − Is
2
where:
t:
K:
I2 :
IS :
time until the protective function trips under sustained overcurrent
heating parameter of the component
calculated negative phase sequence current expressed in In
start threshold expressed in In
According to the standard the characteristic is only defined for I2/Is in the range up to
20. If the values of the mentioned ratio is higher than 20, the operation time remains
constant as the operation time calculated for Is/I2= 20.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
If a trip is generated, e.g. in case of a motor protection, the motor should be blocked
for re-closing. The signal BO is in this case dedicated to block the re-closing possibility of the motor. The signal BO remains active for the “reset time” after the functions
exit TRIP status.
7.6.1.4.1 Thermal memory
To avoid machine overheating in case of intermittent negative phase sequence current, the internal time counter is not cleared when the negative phase sequence current falls below the start threshold. Instead, it is linearly decremented with time, using
a user-configurable slope (i.e. Timer decreasing rate). 100% means full memory, 0%
means no memory.
7.6.1.5 Setting groups
Two parameter sets can be configured for the unbalanced load protection function.
7.6.1.6 Parameters and Events
7.6.1.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Is
0.05 .. 0.30
In
0.10
Current threshold for negative seq. detection.
K
2.0 .. 30.0
-
10.0
Heating parameter.
Reset time
0 .. 2000
s
60
Time to reset BO after a trip.
Timer decreasing rate
0 .. 100
%
10
Parameter to vary thermal memory effect.
7.6.1.6.2 Events
Code
Event reason
E0
Protection started timing on phase L3
E1
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block signal is active
E17
Block signal is back to inactive state
E18
Protection block is back to inactive state
E19
Protection block is back to inactive state
E20
Reset input is active
E21
Reset input is back to inactive state
By default all events are disabled.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.6.2 Directional Power Protection
Directional power protection function can be added as a supervision function with
generators, transformers and three-phase asynchronous motors.
7.6.2.1 Input/Output description
Inputs
Name
Type
Description
BI
Digital signal (active high)
Blocking signal
When BI signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BI signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the calculated active power exceeds the setting threshold value (Max Reverse Load) and the power flow is in the opposite direction to the specified one.
The TRIP signal will be activated when the start conditions are true and the operating
time has elapsed.
7.6.2.2 Configuration
7.6.2.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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7.6.2.2.2 Parameters
Direction:
Directional criteria to be assessed with Power flow for
START detection.
Nominal Real Power:
Power reference Pn for quantities normalization.
Max Reverse Load:
Power threshold in opposition to set direction for start
detection.
Operating Time:
Time delay for Trip condition detection.
7.6.2.2.3 Events
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7.6.2.2.4 Pins
7.6.2.3 Measurement mode
The directional power protection function evaluates the active power at the fundamental frequency.
7.6.2.4 Operation criteria
The directional power supervision compares the calculated active power with a preset
nominal value (Pn, Nominal Real Power) and a set power flow direction (Direction).
If the calculated active power exceeds the setting threshold value (Max Reverse
Load), and the power flow is in the opposite direction to the specified one (backward/forward), the protection function is started and the Start signal is generated.
The protection function will come back in passive status and the start signal will be
cleared if the calculated active power falls below 0.95 the setting threshold value (or
the power flow changes direction).
After the protection has entered the start status and the preset operating time (Operating Time) has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured current value falls below 0.4 the setting threshold value.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.6.2.5 Setting groups
Two parameter sets can be configured for the directional power protection function.
7.6.2.6 Parameters and Events
7.6.2.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Direction
Forward /
Backward
Backward
Directional criteria for START detection.
Nom. Active Power
1 .. 1000000
kW
1000
Power reference for normalization.
Max Reverse Load
1 .. 50
% Pn
5
Power threshold for START detection.
Operating time
1.0.. 1000
s
10
Time delay for Trip condition.
7.6.2.6.2 Events
Code
Event reason
E0
Protection started timing
E1
Timing cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
By default all events are disabled.
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7.6.3 Low Load Protection
REF542plus has one Low load protection function.
Three-phase asynchronous motors are subject to load variations. The low load monitoring function is provided to supervise the motor operational conditions for operation
below the required load.
7.6.3.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the function is enabled (maximum phase current above Min. Current) and the calculated active power falls below 0.95 the setting threshold value (Min. Load).
The TRIP signal will be activated when the start conditions are true and the operating
time (Operating Time) has elapsed.
7.6.3.2 Configuration
7.6.3.2.1 General
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Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.6.3.2.2 Sensors
The protection functions operate on any combination of phase currents in a triple,
e.g., it can operate as single phase, double phase, three-phase protection on phase
currents belonging to the same system.
7.6.3.2.3 Parameters
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Nominal Real Power:
Power reference Pn for quantities normalization.
Min. Load:
Power threshold for start detection.
Min. Current:
Current threshold for start detection.
Operating Time:
Time delay for Trip condition detection.
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7.6.3.2.4 Events
7.6.3.2.5 Pins
7.6.3.3 Measurement mode
The low load protection function evaluates the measured amount of current and of active power at the fundamental frequency.
7.6.3.4 Operation criteria
Low load protection function is enabled only if the maximum phase current of the configured sensors is above the preset threshold value (Min Current). It then normalizes the active power on a preset nominal value (Pn, Nominal Real Power).
When enabled, if the calculated active power falls below 0.95 the preset threshold
value (Min. Load) the protection function is started and the Start signal is generated.
The protection function will come back in passive status and the start signal will be
cleared if the calculated active power exceeds the setting threshold value.
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After the protection has entered the start status and the preset operating time (Operating Time) has elapsed, function goes in TRIP status and the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the calculated active power exceeds 1.05 the setting threshold value.
7.6.3.5 Setting groups
Two parameter sets can be configured for low load protection function.
7.6.3.6 Parameters and Events
7.6.3.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Nom. Real Power
1 .. 1000000
kW
1000
Power reference for normalization.
Min Load
5 .. 100
% Pn
10
Power threshold for start detection.
Min Current
2 .. 20
% In
5
Current threshold for start detection.
Operating time
1.0 .. 1000
s
10
Time delay for Trip condition detection.
7.6.3.6.2 Events
Code
Event reason
E0
Start started
E1
Start back
E6
Trip started
E7
Trip back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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Protection Functions: Configuration and Settings
7.6.4 Frequency supervision
REF542plus has one frequency supervision function.
It is worthwhile checking the network frequency so it remains within set limits whentime and frequency-dependent processes are involved. Frequency changes influence,
for example, the power dissipation, the speed (motors) and the firing characteristics
(converters) of equipment. The frequency supervision function is used to report frequency variations in a configurable frequency range.
7.6.4.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
The Start signal will be activated when the frequency exceeds the setting threshold
value (Start Value).
The TRIP signal will be activated when the start conditions are true and the operating
time (Time) has elapsed.
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7.6.4.2 Configuration
7.6.4.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.6.4.2.2 Sensors
The supervision function selects automatically the best sensor. It operates preferably
on voltage sensor but it can work also on current sensor.
7.6.4.2.3 Parameters
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Start Value:
Frequency threshold for start condition detection.
Time:
Time delay for Trip condition detection.
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7.6.4.2.4 Events
7.6.4.2.5 Pins
7.6.4.3 Measurement mode
The frequency supervision function evaluates network frequency on the measured
value of the first available (voltage or current) sensor.
7.6.4.4 Operation criteria
If the measured network frequency is outside the allowed range, then the supervision
function is started.
If the measured network frequency remains outside the allowed range for at least operating time setting, a trip signal becomes active.
If the measured network frequency falls outside the allowed range, i.e the network
nominal frequency plus/minus the setting threshold value (Start Value), the frequency supervision function is started and the Start signal is generated.
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The frequency supervision function will come back in passive status and the start signal will be cleared if the frequency difference to the nominal network frequency falls
below 0.95 the setting threshold value.
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the Trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the measured frequency value falls back within the allowed range, i.e the network nominal frequency plus/minus 0.95 the setting threshold value.
7.6.4.5 Setting groups
Two parameter sets can be configured for frequency supervision function.
7.6.4.6 Parameters and Events
7.6.4.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Start value
0.04 .. 5.0
Hz
0.20
Frequency threshold for start condition
detection.
Time
1.0 .. 300.00
s
10.00
Time delay for Trip condition detection.
7.6.4.6.2 Events
Code
Event reason
E0
Start started
E1
Start back
E6
Trip started
E7
Trip back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
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7.6.5 Synchronism check
REF542plus has one synchronism check protection function.
Paralleling monitoring is required if two networks are interconnected whose voltages
may differ in quantity, phase angle and frequency as a result of different power supplies. (SYN). The switching operation for coupling the separate systems can be enabled by the Synchronism Check SYN signal.
7.6.5.1 Input/Output description
Input
Name
Type
Description
BI
Digital signal (active high)
Blocking signal
When BI signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BI signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
SYN
Digital signal (active high)
Sync signal
The Start signal will be activated when both differential voltage ∆U and phase difference ∆ϕ between corresponding line voltages of two networks fall below the setting
threshold values (Delta Voltage AND Delta Phase respectively).
The SYN signal to parallel networks will be activated when the start conditions are
true and the operating time (Time) has elapsed.
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7.6.5.2 Configuration
7.6.5.2.1 General
7.6.5.2.2 Sensors
The protection function operates on the combinations of phase (or line) voltages reported in the following table. Two phase voltages belonging to the two networks (or a
line voltage belonging to the second network) are needed.
In table the comparison of corresponding line1-2 voltages of two networks is reported
as example; the third phase voltage U1 L3 is indicated (in gray, as additional earth
sensors) to complete the three-phase voltage system. An indication of possible board
list part number is provided.
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AI
Channel
AI1
U1L1
U1L1
U1L1
U1L1
AI2
U1 L2
U1 L2
U1 L2
U1 L2
AI3
U2 L1
U1 L3
U1 L3
U2 L1
750170
/811
750170
/804
/814
/819
CT
CT
CT
CT
CT
CT
AI4
U1 L1
U1 L1
U1 L1
U1 L1
AI5
U1 L2
U1 L2
U1 L2
U1 L2
U1 L3
U2 L1
U1 L3
U1 L3
U2 L2
U2 L2
U2 L12
CT
CT
U2 L12
AI6
AI7
U2 L1
U2 L2
U2 L2
AI8
U2 L12
U2 L12
(Example of a typical voltage transformers connection diagram for the Synchro check
function is provided in the Appendix - Connection Diagram).
7.6.5.2.3 Parameters
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Delta Voltage:
Maximum allowed amplitude difference between two synchronous networks.
Delta Phase:
Maximum allowed phase difference between two synchronous networks.
Time:
Time delay for Synchro condition detection.
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7.6.5.2.4 Events
7.6.5.2.5 Pins
7.6.5.3 Measurement mode
Synchronism check protection function evaluates the measured amplitude and rate of
change of differential voltage between two networks corresponding line voltages.
7.6.5.4 Operation criteria
The synchronism check protection function monitors the differential voltage ∆U between corresponding line voltages of two networks and their phase difference ∆ϕ.
If the measured differential voltage and phase difference fall below the setting threshold values (Delta Voltage AND Delta Phase respectively), the Synchro
Check protection function is started.
The protection function will come back in passive status and the start signal will be
cleared if differential voltage and phase difference exceed 1.05 the setting threshold
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value. After the protection has entered the start status and the preset operating time
(Time) has elapsed, the signal for parallel switching of networks (SYN) is generated.
The protection function will exit the Synchro status and the SYN signal will be cleared
when the start conditions on differential voltage and phase difference values become
false.Delta Voltage: Maximum allowed amplitude difference between two synchronous networks.
V1
V2
Figure 31: Delta Voltage condition not satisfied. The gray circle radius is the Delta Voltage
value set in the ”Parameters” dialog window.
V1
V2
Figure 32: The Delta Voltage condition AND Delta Phase condition are satisfied, after the operating time is expired, the synchronism condition is fulfilled and the SYN signal is generated.
7.6.5.5 Setting groups
Two parameter sets can be configured for the synchronism check protection function.
7.6.5.6 Parameters and Events
7.6.5.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Delta Voltage
0.02 .. 0.40
Un
0.05
Max amplitude difference.
Delta Phase
5 .. 50
°
10
Max phase difference.
Time
0.2 ... 1000
s°
100.00
Time delay to Syncro detection.
7.6.5.6.2
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7.6.5.6.3 Events
Code
Event reason
E0
Protection started timing
E1
Timing cancelled.
E6
Synch is present
E7
Synch is not present
E18
Protection block is active
E19
Protection block is back to inactive
By default all events are disabled.
7.6.6 Switching Resonance Protection
REF542plus has one Switching Resonance protection function, to be used preferably
together with the Power Factor Controller.
7.6.6.1 Input/Output description
Inputs
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
PFC OP
Trigger signal (active low-tohigh)
PFC operation trigger
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
PFC OP trigger is provided by the PFC function block to temporarly enable the resonance protection function at switching-in, switching-out of PFC controlled capacitor
banks.
Outputs
Name
Type
Description
Start L1
Digital signal (active high)
Start signal of IL1
Start L2
Digital signal (active high)
Start signal of IL2
Start L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true.
The TRIP signal will be activated when at least for a phase current the start conditions are true and the operating time has elapsed.
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7.6.6.2 Configuration
7.6.6.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.6.6.2.2 Sensors
The protection function operates on any combination of line or phase voltages in a triple, e.g., it can operate as single phase, double phase, three-phase protection on
voltages belonging to the same system.
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7.6.6.2.3 Parameters
Voltage THD Startvalue:
THD amplitude threshold.
Delta Voltage THD Startvalue:
THD amplitude difference threshold.
Voltage THD Time Delay:
Time delay for THD detection.
Time:
Time delay for Trip condition detection.
PFC OP Time:
Enabling time at PFC trigger.
Rms Voltage Startvalue:
Function enabling Voltage threshold condition.
7.6.6.2.4 Events
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7.6.6.2.5 Pins
7.6.6.3 Measurement mode
Switching Resonance protection function evaluates the amount of voltage RMS with
th
harmonic content up to 25 harmoinic and THD (Total Harmonic Distortion).
7.6.6.4 Operation criteria
Operation of switching resonance protection function is triggered by an external signal
connected to input pin ‘PFC OP’ (provided by the PFC function SwitchON/OFF output
pins) and remains enabled for the preset time (i.e. PFC OP Time).
At PFC OP trigger instant, voltage THD values are saved.
While enabled, if for at least one phase voltage (respectively line voltage, depending
on the configuration):
RMS value is above the preset threshold (i.e. Rms Voltage Start value)
AND THD value is above the preset threshold (i.e. Voltage THD Start value)
for at least the preset detection time (i.e. Voltage THD Time Delay)
AND the variation of THD value with respect to the saved value (i.e. THD value at
trigger time) is above the preset threshold (i.e. Delta Voltage THD Start
value) for at least the preset detection time (i.e. Voltage THD Time Delay)
then the protection function is started. The start signal is phase selective; i.e. when at
least the for one phase voltage the above conditions are true, then the relevant start
signal (S L1-3) will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the voltage falls below 0.95 one of the setting threshold values (Rms OR
Voltage THD OR Delta Voltage THD).
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
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7.6.6.5 Setting groups
Two parameter sets can be configured for the switching resonance protection function.
7.6.6.6 Parameters and Events
7.6.6.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Voltage THD Start
value
5 .. 50
%
5
THD amplitude threshold.
Delta Voltage
THD Start value
1 .. 50
%
2
THD amplitude difference threshold.
Voltage THD
Time Delay
0.01 .. 60.00
s
0.03
Stabilizing delay for THD detection.
Time
0.05 .. 60.00
s
0.10
Time delay for Trip condition detection.
PFC OP Time
0.01 .. 120.00
s
0.06
Function enabling time at PFC trigger.
Rms Voltage Start
value
0.10 .. 1.00
Un
0.50
Function enabling Voltage threshold
condition
7.6.6.6.2 Events
Code
Event reason
E0
Protection started timing on phase L1
E1
Timing on phase L1 cancelled.
E2
Protection started timing on phase L2
E3
Timing on phase L2 cancelled.
E4
Protection started timing on phase L3
E5
Timing on phase L3 cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block output signal is active
E17
Block output signal is back to inactive
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
E20
PFC operation started
E21
PFC operation back
By default all events are disabled.
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7.6.7 High Harmonic Protection
REF542plus has one High Harmonic protection function.
7.6.7.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start L1
Digital signal (active high)
Start signal of IL1
Start L2
Digital signal (active high)
Start signal of IL2
Start L3
Digital signal (active high)
Start signal of IL3
TRIP
Digital signal (active high)
Trip signal
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true.
The TRIP signal will be activated when at least for a phase current the start conditions are true and the operating time has elapsed.
7.6.7.2 Configuration
7.6.7.2.1 General
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Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
7.6.7.2.2 Sensors
The protection function operates on phase or line voltages in a triple.
7.6.7.2.3 Parameters
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Voltage THD Startvalue:
THD amplitude threshold.
Voltage THD Time Delay:
Time delay for THD detection.
Time:
Time delay for Trip condition detection.
Rms Voltage Startvalue:
Function enabling Voltage threshold condition.
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7.6.7.2.4 Events
7.6.7.2.5 Pins
7.6.7.3 Measurement mode
High Harmonic protection function evaluates the measured amount of voltage RMS
and THD (Total Harmonic Distortion).
7.6.7.4 Operation criteria
If for at least one phase voltage (respectively line voltage, depending on the configuration):
RMS value is above the preset threshold (i.e. Rms Voltage Start value)
AND THD value is above the preset threshold (i.e. Voltage THD Start value)
for at least the preset detection time (i.e. Voltage THD Time Delay)
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then the protection function is started. The start signal is phase selective; i.e. when at
least the for one phase voltage the above conditions are true, then the relevant start
signal (S L1-3) will be activated.
The protection function will remain in START status until there is at least one phase
started. It will come back in passive status and the start signal will be cleared if for all
the phases the voltage falls below 0.95 one of the setting threshold values (Rms OR
Voltage THD OR Delta Voltage THD).
After the protection has entered the start status and the preset operating time (Time)
has elapsed, function goes in TRIP status and the trip signal is generated.
7.6.7.5 Setting groups
Two parameter sets can be configured for the high harmonic protection function.
7.6.7.6 Parameters and Events
7.6.7.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Voltage THD Start
value
1 .. 50
%
10
THD amplitude threshold.
Voltage THD
Time Delay
0.01 .. 360
s
0.50
Stabilizing delay for THD detection.
Time
0.05 .. 360
s
0.50
Time delay for Trip condition detection.
Rms Voltage Start
value
0.10 .. 1.00
Un
0.50
Function enabling Voltage threshold
condition
7.6.7.6.2 Events
Code
Event reason
E0
Start L1 started
E1
Start L1 back
E2
Start L2 started
E3
Start L2 back
E4
Start L3 started
E5
Start L3 back
E6
Trip started
E7
Trip back
E16
Block signal started
E17
Block signal back
E18
Protection block started
E19
Protection block back
By default all events are disabled.
7.6.8 Frequency Protection
REF542plus can install up to 6 frequency protection functions per protected net.
The Frequency protection function is used to detect frequency variations in a configurable amplitude and rate of change frequency range.
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7.6.8.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Outputs
Name
Type
Description
Start
Digital signal (active high)
Start signal
TRIP
Digital signal (active high)
Trip signal
BLOCK
Digital signal (active high)
Block output signal
The Start signal will be activated when the current exceeds 10% motor nominal current value IMn and within 100 ms the setting threshold value (Motor Start IMs).
The TRIP signal will be activated when the start conditions are true and the calculated
current-time integration (Is2 x Time) is exceed.
The Block Output (BO) signal becomes active at protection initialization until when the
current exceeds 10% motor nominal current value IMn
7.6.8.2 Configuration
7.6.8.2.1 General
Output Channel different from 0 means direct execution of the trip command (i.e.
skipping FUPLA cyclic evaluation).
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7.6.8.2.2 Trip Logic
7.6.8.2.3 Sensors
The protection functions can operate on any combination of phase or line voltages in
a triple, e.g., it can operate as single phase, double phase, three-phase protection on
voltages belonging to the same system. The default setting is to use the line voltage.
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7.6.8.2.4 Parameters
Start Value:
Delta frequency amplitude threshold, with respect to
rated network frequency fr. If set below fr it behaves
as under-frequency, otherwise as over-frequency.
Frequency gradient:
Rate of frequency change threshold.
Time:
Time delay for Trip condition detection.
Undervoltage threshold: Minimum voltage threshold to be exceed for protection enabling, otherwise it is blocked.
7.6.8.2.5 Events
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7.6.8.2.6 Pins
7.6.8.3 Measurement mode
Frequency protection functions evaluate the frequency and/or the frequency gradient
of voltage signals through the zero-crossing detection of the voltage measurement
quantity. The measure is performed on the first voltage measure available above the
minimum voltage amplitude (Undervoltage threshold).
7.6.8.4 Operation criteria
The start condition and trip logic is selected by user and can be
Frequency only (only frequency value is considered)
Frequency AND frequency gradient (both values must exceed thresholds to have
start and trip)
Frequency OR frequency gradient (at least one of the values must exceed threshold to have start and trip)
Depending on the set frequency threshold (Start Value) with respect to the network rated frequency, the protection function behaves either as under-frequency or
over-frequency protection. (e.g. if the set frequency threshold is below rated frequency value, the protection function behaves as under-frequency).
The condition on frequency gradient, when used, is in the same direction as the condition on frequency (e.g. if the protection function is set as under-frequency, then frequency gradient is significant only if it is negative and if actual frequency is below
rated value).
If the frequency cannot be measured,
OR the minimum voltage amplitude in the triple falls below 0.95 the preset
threshold value (i.e. Undervoltage threshold), then the protection function
is blocked and the Block signal is generated.
The protection function will exit Block status and clear the Block signal if minimum voltage amplitude rises above the setting threshold value
If the frequency can be measured,
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AND the minimum voltage amplitude is above the preset threshold (Undervoltage threshold),
AND the start condition is fulfilled (i.e. measured voltage frequency falls below
or rises above the setting threshold Start Value; AND/OR the frequency gradient is negative or positive and exceeding the setting threshold Frequency
gradient when the protection is set as under-frequency or over-frequency respectively), then the protection function is started and the start signal will be activated.
The protection function will come back in passive status and the start signal will be
cleared when at least the value of one of the needed conditions falls below 0.95 the
setting threshold value (Start Value AND/OR Frequency gradient).
After the protection has entered the start status, if the above conditions remain true
and the preset operating time (Time) has elapsed, function goes in TRIP status and
the trip signal is generated.
The protection function will exit the TRIP status and the trip signal will be cleared
when the all the start conditions fall below 0.95 the setting threshold value (Start
Value AND/OR Frequency gradient).
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7.6.8.5 Setting groups
Two parameter sets can be configured for each of the frequency protection functions.
7.6.8.6 Parameters and Events
7.6.8.6.1 Setting values
Parameter
Values
Unit
Default
Explanation
Trip Criteria
f / f_AND_df/dt /
f_OR_df/dt
-
f
Definition of start/trip criteria.
Start value
40.00.. 75.00
Hz
49.95
59.95
Delta frequency amplitude threshold.
Frequency gradient
0.10 .. 1.00
Hz/s
0.50
Rate of frequency change threshold.
Time
0.10 .. 30.00
s
0.50
Time delay for Trip condition detection.
Undervoltage threshold
0.10 .. 1.00
Un
0.20
Minimum voltage threshold function
block/enabling
7.6.8.6.2 Events
Code
Event reason
E0
Protection started timing
E1
Timing cancelled.
E6
Trip signal is active
E7
Trip signal is back to inactive state
E16
Block output signal is ii active state
E17
Block output signal is back to inactive state
E18
Protection block signal is active state
E19
Protection block signal is back to inactive state
By default all events are disabled.
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7.7 Autoreclose
7.7.1 Autoreclose
The autoreclose function can be used to reclose the circuit breaker automatically after
a protection function has tripped. This function block can be applied to all protection
functions available in REF542plus.
7.7.1.1 Input/Output description
Input
Name
Type
Description
BS
Digital signal (active high)
Blocking signal
1 SHOT
Digital signal (active high)
AR only performing single shot
CB OK
Digital signal (active high)
CB drive ready for the following AR
EX. TRIG
Digital signal (active high)
Triggering of AR by an external signal
INCR.
Digital signal (active high)
Increment the number of shots
STOP AR
Digital signal (active high)
Immediate stopping of the AR cycles
TEST
Digital signal (active high)
Test of AR cycle (O-CO-CO…)
When BS signal becomes active, the protection function is reset (no matter its state),
i.e. all output pins go low generating the required events (if any) and all internal registers and timers are cleared. The protection function will then remain in idle state until
BS signal goes low.
Output
Name
Type
Description
CLOSE CB
Digital signal (active high)
CB close signal
OPEN CB
Digital signal (active high)
CB open signal
AR ACTIVE
Digital signal (active high)
High as long the AR is active
AR FAILED
Digital signal (active high)
High in case of unsuccessful AR
SHOT 1
Digital signal (active high)
1st Shot signal of the AR
SHOT 2
Digital signal (active high)
2
SHOT 3
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Digital signal (active high)
nd
Shot signal of the AR
rd
Shot signal of the AR
3
th
SHOT 4
Digital signal (active high)
4 Shot signal of the AR
SHOT 5
Digital signal (active high)
5 Shot signal of the AR
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7.7.1.2 Configuration
7.7.1.2.1 General
7.7.1.2.2 Parameters
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7.7.1.2.3 Events
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7.7.1.2.4 Pins
7.7.1.3 Operation Mode
The autoreclose function block can be operated in two different modes.
7.7.1.3.1 Start and Trip Controlled
In this operation mode the difference of the time duration between the start and the
trip signal of the related protection function is evaluated. Therefore different settings
of the specified time are provided. If the time difference between the protection start
and trip signal is within the specified time, the AR-cycle is released respectively continued. The corresponding CB shall be re-closed after the relating dead time is
elapsed. If the condition is not fulfilled, the AR function block will be blocked. To continue the operation of the feeder, the AR function block need to be released locally or
remotely via the station control system.
7.7.1.3.2 Start Controlled
This operation mode initiates the AR-Cycle only by a start signal of the related protection function. The tripping time for each shot can be delayed separately. This delayed
tripping is need in some application, e.g. to burn out a falling tree on the overhead
line. So the operation time of the protection function will now be controlled by the AR.
Normally, the first shot shall have a relatively short operation time in the range of 30
to 100 ms. The second and the following shot shall have longer operation time in the
range of 1 to 10s. If this mode is selected, the settings of the specified time are to be
used to control the operation time of the following shots.
The AR function can carry out maximal 5 shots. The corresponding scheme can be
configured using the General sheet, like shown in the following figure:
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Figure 33: Design of the AR scheme using the sheet General
As can be seen in above figure, the configuration can be done by a selection table. All
of the protection functions which can be connected are shown in table. The columns
is foreseen to define, which protection functions will activate a specific AR shots. By
selecting the related protection functions in each shot, the AR will be initiated according to the operation mode is defined previously. The protection function can be redefined after each shot. In above example the AR will operate as following:
Note
Due to dependency of the operation time on the fault current, the IDMT and Earth
Fault IDMT are not listed. If this protection shall be used to initiate the AR-cycle, the
relating trip signal shall be connected by a FUPLA wire to the input EX.TRIG of the
AR function block.
The number of the shots is limited to 3. The first shot can either be activated by the
Overcurrent High Set, the Earth fault high set or by the Overcurrent Instantaneous
protection function. The second and the third shots shall only be initiated by the Overcurrent Instantaneous. If after the first AR shot only the protection function Overcurrent High Set will trip and the function Overcurrent instantaneous remains inactive, no
AR will be carried out anymore. The AR function will be blocked, because the AR cycle is defined as not successful. As already mentioned before, a release command
from local – Alarm Reset Menu - or remote control is needed to have the AR in operation again.
The AR goes in ready condition again, if the CB is switch on and after the closed
command a 5 s fixed time has elapsed. In case of a protection trip, which is occurred
before the 5 s timer is elapsed, no AR cycle will be initiated. An unsuccessful AR will
be indicated and the AR function will be blocked again.
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Note
The distance protection can only be used in start and trip control mode. If the AR
status is ready, the overreach zone of the distance protection will be activated. After
the first shot, the overreach zone will not be activated anymore. The trip will be done
according to the setting of the related impedance zone.
Note
To ensure, the proper function of the AR, the trip of the protection shall be send directly to the so called 2-2 switch object, which controls and operates the CB. There is
no need to make a FUPLA wiring between the AR function block, 2-2 switch object
and the related protection functions.
The external trigger is to be selected, if the AR will be triggered by an external protection function. The trip must be connected to a binary input of the REF542plus. Afterwards the external trip signal need to be wired to the external trigger input EX. TRIG
of the AR function block.
Note
If the AR-cycle is initiated by the input EX. TRIG, the same wire of this input signal
must also be used to open the CB via the 2-2 switch object. Otherwise, in case of
blocking the AR by a blocking signal, no opening of the CB by the external protection
will be possible.
AR Ready
Mode:
Start and Trip Controlled
Protection x
Start
t < spec. time
Loop for n < nmax
Yes
Protection x
trip
Start dead time tp, at the
end of tp, CB on, then
start reclaim time trecl.
No
t < trecl.
If protection x trip,
CB definitively off,
AR blocked *
No
In case of Distance Protection,
the overreach zone is released,
if AR Ready. After the first
specified time is ellapsed, the
zone Z1 is deactivated.
Yes
If n = nmax. and
protection x trips,
CB def. off, AR
blocked
Figure 34: Flow chart of the start and trip control mode
The flow chart of the start and trip controlled mode is shown in above figure. With the
protection start signal the specified time is released, provided the AR function is
ready. Before the specified time is elapsed, the CB must be switched off by a protec1VTA10002 Rev02
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tion trip. Only in this case, the CB will be re-closed after the dead time has run out.
Otherwise the CB will be switched off definitively and an indication AR failed will be
generated. Simultaneously the AR function block is blocked, until the CB is switched
on again.
The reclaim time is used to define an successful AR-cycle. After the CB is re-close,
the reclaim time is started. In case that another protection trip occurred during this
time, the AR-cycle will be continued. If the reclaim time is elapsed and no other protection trip is detected, the AR is define successfully and the AR-cycle will start again
from the status AR ready. If all number of shots has been performed and still a
protection trip is detected during the reclaim time, the AR function will be blocked and
AR failed will be indicated.
AR Ready
Mode:
Start Controlled
Protection x
Start
No
t > oper. time
Loop for n < nmax
Yes
Protection x
trip
Start dead time tp, at the
end of tp, CB on, then
start reclaim time trecl.
No
t < trecl.
Yes
If n = nmax and
protection x trips,
CB def. off, AR
blocked
Figure 35: Flow chart of the start control mode
The flow chart of the start controlled mode can be seen in above figure. The operation
principle is almost the same as the start and trip controlled. In this case, only the start
signal will operate the AR-cycle. The setting of the specified time is used to define a
delayed operation time of the protection, while the time setting in each protection
function blocks, which are connected to the AR function block, become during the
AR-cycle invalid.
Note
A delayed operation time is carried out, if the start signal during this delayed operation remains active.
7.7.1.4 Setting groups
Two parameter sets can be configured for the thermal overload protection function.
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7.7.1.5 Parameters and Events
7.7.1.5.1 Setting values
Parameter
Values
Unit
Default
Number of reclosure cycles
0 .. 5
Reclaim time
10 .. 30
s
30
Specific time first shot
0.04 .. 30
s
0.5
Dead time first shot
0,1.. 100
s
0.3
Specific time second shot
0.04 .. 30
s
0.5
Dead time second shot
0,1.. 100
s
0.3
Specific time third shot
0.04 .. 30
s
0.5
Dead time third shot
0,1.. 100
s
0.3
Specific time fourth shot
0.04 .. 30
s
0.5
Dead time fourth shot
0,1.. 100
s
0.3
Specific time fourth shot
0.04 .. 30
0.5
Dead time fourth shot
0,1.. 100
0.3
Explanation
1
7.7.1.5.2 Events
Code
Event reason
E8
AR active started
E9
AR active back
E10
General enable started
E11
General enable back
E12
Test enable started
E13
Test enable back
E14
AR failed started
E15
AR failed back
E18
Block AR started
E19
Block AR back
E20
AR 1. shot started
E21
AR 1. shot back
E22
CB OK started
E23
CB OK back
E24
CB OK internal drop delayed started
E25
CB OK internal drop delayed back
E26
External trigger started
E27
External trigger back
E28
Shot increment started
E29
Shot increment back
E30
Stop AR started
E31
Stop AR back
E32
Test started
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Code
Event reason
E33
Test back
E40
Close CB started
E41
Close CB back
E42
Open CB started
E43
Open CB back
E48
Shot 1 started
E49
Shot 1 back
E50
Shot 2 started
E51
Shot 2 back
E52
Shot 3 started
E53
Shot 3 back
E54
Shot 4 started
E55
Shot 4 back
E56
Shot 5 started
E57
Shot 5 back
By default all events are disabled.
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7.8 Fault recorder
7.8.1 Fault recorder
This function block allows the eight REF542plus analog input signals to be recorded
for a period of at least 1 second and for a maximum of 5 seconds. It is also possible
to record up to 32 digital signals simultaneously from the FUPLA.
7.8.1.1 Input/Output description
Inputs
Name
Type
Description
BL
Digital signal (active high)
Blocking signal
1 … 32
Digital signal (active high)
32 Input for recording binary signal
START
Digital signal (active high)
Start of the fault recording
OVERFLOW
Digital signal (active high)
Overflow signal indication
When BL signal becomes active, the fault recorder function is reset (no matter its
state), i.e. all output pins go low generating the required events (if any) and all internal
registers and timers are cleared. The fault recorder function will then remain in idle
state until BL signal goes low.
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7.8.1.2 Configuration
7.8.1.2.1 General and setting parameters
Name:
User defined Analog Input meaning.
Factor:
Analog input scaling factor, used for display.
time before fault: Recording duration before recorder start input trigger.
Recording time:
Total allocated duration, it limits the number of records
(from 5 to 1) in the ring buffer.
time after fault:
Recording duration after recorder start input trigger.
7.8.1.2.2 Pins
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7.8.1.3 Operation
The fault recorder is started within the application. The recording time of the fault recorder is a combination of the time before the fault and the time after the fault. The
time before the fault refers to the period recorded before the fault recorder is actually
started from a protection start signal. The time after the fault is the period after the
fault recorder has started. Dynamic recording of the fault record e.g. from start signal
to signal CB OFF) is not possible.
The ring buffer process saves the specific fault record, i.e. the oldest fault record is
always overwritten with a new one. The number of saved fault records depends on
the record time. The total duration of all saved fault records is 5 seconds maximum, if
it is set to a lower value it limits the number of records in the buffer:
n=int((recording time/(time before + time after).
For example, 5 fault records can be saved with a record time of 1 s, that is the minimum settable record time (time before the fault + time after the fault).
The fault records are exported with the configuration software and then converted to
the COMTRADE format. The fault records can also be exported via the bus of the station control system. The conversion to the COMTRADE format has to be carried out
in the station control system.
Note
The following limitations must be taken into account on the use of the fault recorder:
At least one protective function must be configured and
The start signal for the fault recorder must be implemented in the FUPLA.
The analog signals are digitized and processed with a 1.2 kHz sampling rate, because they are decisive for the protection trips. They therefore within a time grid of
0.833 ms. Start and trip signals from protection functions are recorded and sent to the
binary outputs immediately.
In contrary, the digital signals are processed in accordance with the FUPLA cycle
time. The cycle time depends on the application in this case. The digital signals are
therefore in a grid that is significantly larger than the analog signal grid.
The fault recorder is dedicated for recording fault data during a short circuit in the
network. The data can be exported from the REF542plus later and displayed with
suitable program.
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Figure 36: Example showing the graphic display of fault record data of a two-pole short circuit
with the WINEVE program
7.8.1.4 Parameters and Events
7.8.1.4.1 Setting values
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Parameter
Values
Unit
Default
Explanation
Time before fault
100 .. 2000
ms
100
Recording duration before recorder start.
Recording time
1000 .. 5000
ms
2500
User defined limit to total duration
of the buffer, i.e. to records number.
Time after fault
100 .. 4900
ms
1000
Recording duration after recorder
start.
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7.9 Appendix A – Connection Diagram
7.9.1 Directional protections Connection Diagram
In the following figures are reported as an example the typical connection diagram of
current and voltage transformers for a generic feeder and the convention used to define Forward and Backward direction of the power flow.
The connection of earth current sensor and of residual voltage sensor (Analog Input 7
and 8) may be required depending from the directional protection used.
Figure 37: Generic feeder connection, directional earthfault (67N, 67S) and overcurrent protections can be instantiated, residual current can be directly measured
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Figure 38: Generic feeder connection, directional earthfault (67N, 67S) and overcurrent protections can be instantiated, both residual current and residual voltage (open
delta) can be directly measured
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7.9.2 Differential and Restricted differential protections
Connection Diagram
Figure 39: Differential transformer feeder connection, restricted differential protection
on grounded star side winding can be instantiated.
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Multifunction Protection and Switchgear Control Unit Model REF542plus
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7.9.3 Synchro Check Connection Diagram
Figure 40: Syncro Check feeder connection, network 2 line 1-2 voltage connection on
Analog Input 8
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7.10 Appendix B –IDMT Protection Curve Characteristics
7.10.1 IDMT Protection Functions
The REF542plus makes available two Overcurrent IDMT and Earth fault IDMT protection functions.
For each protection one at the time of the four current-time characteristics can be activated:
Normal inverse,
Very inverse,
Extremely inverse,
Long-term inverse.
7.10.1.1 Overcurrent IDMT
IDMT protection function evaluates the RMS value of phase currents at the fundamental frequency.
S L1-3 are the start signals phase selective. The phase starting signal will be activated when respective phase current start conditions are true (phase current value is
above 1.2 times the setting threshold value, Base current Ieb).
The TRIP signal will be activated when at least for a phase current the start conditions are true and the calculated operating time has elapsed.
7.10.1.2 Earth fault IDMT
Earth fault IDMT function evaluates the measured or calculated amount of residual
current at the fundamental frequency.
When the measured or calculated earth current exceeds the setting threshold value
(Base current Ieb), by a factor 1.2 then the protection function is started and the
start signal will be activated.
The protection function will come back in passive status and the start signal will be
cleared if the earth current falls below the 1.15 the setting threshold value.
The TRIP signal will be activated when the start conditions are true and the calculated
operating time has elapsed.
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7.10.1.3 Operating time calculation
The operating time depends on the measured current and the selected current-time
characteristic.
The formulas for the trip time according to British Standard (BS 142) and IEC 60255-3
are the following:
t =
kß
(I I EB )
α
−1
t =
BS142
k
(G GS )α − 1
IEC60255-3
where:
t:
Time to trip
k:
Time multiplier to vary time delay (BS 142, 0.05 ≤ K ≤ 1.5)or time value
(IEC 60255-3, see table)
α:
Constant according to the list below
ß:
Constant according to the list below (BS 142)
I/I EB :
Fault current factor
I = G:
Actual measured current
IEB = GS : Base current setting value
The following table shows the two constants α and ß for the different current-time
characteristics.
Current-time characteristic
α
ß (BS142)
k (IEC 255) [s]
Normal inverse
0.02
0.14
0.14
Very inverse
1.0
13.5
13.5
Extremely inverse
2.0
80.0
80.0
Long time inverse
1.0
120.0
120.0
REF542plus implements the formula in accordance with BS 142 and the k-factor
ranges from of 0.05 to 1.50. When the time multiplier k in the “parameters” dialog
window is set to one (k=1) the REF542plus IDMT protections operate in accordance
with IEC 60255-3.
The tripping characteristic of the four different IDMT-curves are shown in the next figures. According to the standard the characteristic is only defined for G/Gs or I/IEB in
the range up to 20. If the values of the mentioned ratio G/GS or I/IEB is higher than 20,
the operating time remains constant as the operation time at the border value of 20.
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IDMT IEC60255-3
1000
1
t=
(G GS )α − 1
Time [ s ]
100
10
Long time Inverse
Normal Inverse
1
Very Inverse
Extremely Inverse
0.1
1 1.2
10
G/Gs
20
100
Figure 41: Tripping characteristic according to the IEC 60255-3 curve definition.
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Protection Functions: Configuration and Settings
IDMT Normal Inverse
100
t=
k × 0.14
(I I EB )0.02 − 1
Time [ s ]
10
k=1.5
k=1
k=0.5
1
k=0.1
k=0.05
0.1
1 1.2
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I/Ieb
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100
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IDMT Normal Inverse
100
t=
k × 0.14
(I I EB )0.02 − 1
Time [ s ]
10
k=1.5
k=1
k=0.5
1
k=0.1
k=0.05
0.1
1 1.2
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I/Ieb
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Protection Functions: Configuration and Settings
IDMT Extremely Inverse
1000
t=
Time [ s ]
100
k × 80
(I I EB )2 − 1
10
1
k=1.5
0.1
k=1
k=0.5
k=0.1
k=0.05
0.01
1 1.2
1VTA10002 Rev02
Valid beginning since version V4D02
10
I/Ieb
PTMV, 2003.12.10
20
100
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
IDMT Long time Inverse
1000
k ×120
t=
(I I EB ) − 1
Time [ s ]
100
k=1.5
10
k=1
k=0.5
1
k=0.1
k=0.05
0.1
1 1.2
1VTA10002 Rev02
Valid beginning since version V4D02
10
I/Ieb
PTMV, 2003.12.10
20
100
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
7.11 Appendix C: Product Information
Product Information
ABB Australia Pty Limited
Medium Voltage
Power Technology Products Division
Bapaume Road, Moorebank NSW 2170,
Australia
ABB Secheron SA
Medium Voltage
Rue des Sablieres 4-6
CH – 1217 Meyrin
Switzerland
Phone: +61 2 9821 0111
Fax: +61 2 9602 2454
E-mail: abbptmv.aus@au.abb.com
internet: http://www.abb.com/au
Phone: +41 22 306 2646
Fax:
+41 22 306 2682
E-mail: info.secheron@ch.abb.com
Internet: http://www.abb.ch
ABB Xiamen Switchgear Co. Ltd.
ABB Industrial Park
Torch Hi-tech.Development Zone
Xiamen, Fujian, P.R.of China
ABB s.r.o.
MV Switchgear
Videnska 117
61900 Brno
Czech Republic
Phone: +86 (0)592 6026033
Fax:
+86 (0)592 6030505
Phone: +420 5 4715 2413
Fax:
+420 5 4715 2190
E-mail: info.ejf@cz.abb.com
Internet: http://www.abb.com
Internet: http://abbcndmx.com.cn
ABB Calor Emag Mittelspannung GmbH
Product Management
Oberhausener Straße. 33
40472 Ratingen
Germany
ABB Arab S.A.E
Medium voltage department
Industrial Zone - B1,
10 th of Ramadan City ,
Egypt.
Phone: +49 2102 12 1901
Fax:
+49 2102 12 1808 1901
E-mail: calor.info@de.abb.com
Internet: http://www.abb.de/calor
Phone: +20 15 36 1288
Fax:
+20 15 36 1642
Internet: http://www.abb.com/eg
ABB Limited - Design & Development
MV Switchgear Division
plot No. 79 Street No. 17
Nashik -PIN- 422007
India
Phone: +91 0253 2351095
Fax: +91 0253 2350644
Internet: http://www.abb.com
1VTA10002 Rev02
Valid beginning since version V4D02
ABB T&D S.p.A, Unita’ Operativa
SACE T.M.S.
Product Management
Via Friuli 4
I-24044 Dalmine (BG)
Italy
ABB Ltd.
Power Technology Medium Voltage
513 Sungsung-dong (Chonan Foreign Invested-Enterprises Industrial Park)
Chonan, Chungchong-namdo, Post 330-300
Korea
Phone: +39 035 395 710
Fax:
+39 035 395689
E-mail: sacetms.tipm@it.abb.com
Internet: http://www.abb.com
Phone: +82 41 529 2458
Fax:
+82 41 529 2500
E-mail: swgr.info@kr.abb.com
Internet: http://www.abb.com.kr
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Multifunction Protection and Switchgear Control Unit Model REF542plus
Protection Functions: Configuration and Settings
Product Information
ABB Transmission & Distribution Sdn. Bhd.
Manufacturing
Lot 608, Jalan SS 13/1K
47500 Subang Jaya, Petaling Jaya
Selanggor Darul Ehsan
Malaysia
Phone: +603 5628 4888
Internet: http://www.abb.com
1VTA10002 Rev02
Valid beginning since version V4D02
PTMV, 2003.12.10
ABB Elektrik Sanayi A.S.
Medium Voltage Technology
Power Technology Products Turkey
Design&Order Handling
Organize Sanayi Bölgesi 2. Cadde No:16
Yukar Dudullu 81260 Istanbul
Turkey
Phone : +90 216 528 20 00
Fax :
+90 216 365 29 43
Internet: http://www.abb.com
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