© ABB Group - 1 2-Jul-18
Protection Application
Handbook
Autoreclosing
© ABB Group - 2 2-Jul-18
Autoreclosing
Autoreclosing
Auto reclosing Cycle
OH-lines
High fault-rate
(80-90%)
Fast
simultaneous
© ABB Group - 3 2-Jul-18
Fault clearing
Autoreclosing
AUTORECLOSING CYCLE
OH-lines
Intermittent faults
(80-90%)
Successful
AR-rate :
© ABB Group - 4 2-Jul-18
High (80-90%)
Autoreclosing
Auto reclosing principles

95% of faults are transient type

3 Ph autoreclosing synchrocheck is used


1 Ph autoreclosing needs identification of faulty phase

© ABB Group - 5 2-Jul-18
Helps verify phase angles are not out of phase e.g: due to
heavy power swing
Phase identification is difficult for high resistance faults
Autoreclosing
© ABB Group - 6 2-Jul-18
Auto reclosing principles
Autoreclosing
Autoreclosure in a Line
bay
© ABB Group - 7 2-Jul-18
AR- Autorecloser
BFR- Breaker failure
relay
COM- Communication
COND-CB condition
DLC SC-Dead line check
and synchronism check
LP- Line protection
MAN- Manual CB control
PD- Pole discordance
relay
Autoreclosing
Auto reclosing principles

© ABB Group - 8 2-Jul-18

Protections that start autoreclosing

Main 1 protection

Main 2 protection
Protections that block autoreclosing

CB fail detected by Breaker fail relay & Pole discrepancy relay

CB not ready

Delayed tripping ( Zone2 or3 of distance relay , Back up relay)

Manual CB operation

Communication fail

Direct transfer trip receive , BB protection , O/V protection, Reactor
protection
Autoreclosing
Contact position
Circuit-breaker Contact Travel
t6
t2
Closed
Time
Open
© ABB Group - 9 2-Jul-18
t1
t3
Closed
t4
t5
Autoreclosing
Dead time for Automatic Reclosing Equipment
A
B
F
Contact position
t
© ABB Group - 10 2-Jul-18
t
1A
t
t2A
6A
Closed
Open
t
1B
t
2B
A
Dead time
Open
Closed
t
6B
B
Interruption time
0
Time
Autoreclosing
Single-pole Reclosing
Single-Pole Reclosing
© ABB Group - 11 2-Jul-18
A B C
A B C
Autoreclosing
Temporal Description of Automatic Reclosing
HSR = High-Speed Automatic Reclosing
DR = Delayed Automatic Reclosing
R = Automatic Reclosing
SR = Slow Automatic Reclosing
DR
HSR
R
SR
© ABB Group - 12 2-Jul-18
TD
0.1
1
3
10
100
s
Autoreclosing
Classical Three-pole Reclosing
A
t
F
1A
t2A
Contact position
© ABB Group - 13 2-Jul-18
t
B
Dead time
Closed
Open
A
t
6A
Interruption time
t
0
t2B
1B
Closed
Open
t
B
6B
Time
Autoreclosing
© ABB Group - 14 2-Jul-18
Factors affecting extinction of Primary Arc

Fault current magnitude

Fault clearance time

Coupling from energized conductors

Closing or opening of resistors

Magnitude of reenergizing voltage

Point of wave for reenergizing

Magnetic forces on the fault current

Length of insulating string

Weather conditions

Shape of grading ring
Autoreclosing
Minimum Dead Time (IEEE)
System Voltage
kV
© ABB Group - 15 2-Jul-18
23
46
69
115
132
230
345
400
500
Minimum deionization time [ms]
Based on Field and
Based on Operating
Laboratory Tests
Experience
110
120
130
150
160
210
260
280
330
180
200
210
230
240
280
340
370
420
Autoreclosing
Minimum Dead Time for Three-pole Reclosing
Minimum Dead Time
Three-Pole Reclosing
ms
500
400
Based on Operating Experience
300
200
© ABB Group - 16 2-Jul-18
100
Based on Field and
Laboratory Tests
100
200
300
400 500
System Voltage
600
kV
Autoreclosing
Double Fault on a Double-circuit Line
A B C
A B C
L1
R
L
© ABB Group - 17 2-Jul-18
L2
Autoreclosing
Capacitive Coupling and Single-pole Tripping
A B C
C
C
p
p
C
A B C
p
L
R
© ABB Group - 18 2-Jul-18
Ce
Ce
Ce
Autoreclosing
Secondary arc
© ABB Group - 19 2-Jul-18

Secondary arc is phasor sum of currents maintained by
capacitive and inductive coupling from the energised
phase conductors
Autoreclosing
Critical Line Lengths for Single-pole Reclosing
System Voltage
kV
© ABB Group - 20 2-Jul-18
230
345
500
765
Critical Line Length [miles]
Successful Range
Doubtful Range
0-300
0-140
0-60
0-50
300-500
140-260
60-100
50-80
Autoreclosing
© ABB Group - 21 2-Jul-18
Artificial extinction of secondary arc

Where high-speed automatic reclosing is to be implemented,
secondary arcs must be artificially extinguished since they would
otherwise last too long.

There are several methods to extinguish artificially the secondary
arc:

Fixed Four-Reactor Scheme

Switched Four-Reactor Scheme

High speed Earthing Switch Scheme
Autoreclosing
Fixed Four-reactor Scheme
ABC
ABC
L
R
Lp Lp Lp
© ABB Group - 22 2-Jul-18
Ln
Autoreclosing
Secondary Arcing Time (Haubrich)
Secondary Arcing Time
s
T sa
Haubrich 1971
2.0
1.5
1.0
0.5
© ABB Group - 23 2-Jul-18
Is
50
100
150
A
© ABB Group - 24 2-Jul-18
Autoreclosing
Autoreclosing
© ABB Group - 25 2-Jul-18
Auto reclosing in one and a half breaker
system
Autoreclosing
© ABB Group - 26 2-Jul-18
Auto reclosing in one and a half breaker
system
Autoreclosing
© ABB Group - 27 2-Jul-18
Special problems

Memory Circuit

Priority circuit

Autoreclosure out of service
© ABB Group - 28 2-Jul-18
Autoreclosing
Autoreclosing
Synchronism and Energizing check
UBus
ULine
UBus
FreqDiff < 50-300 mHz
o
PhaseDiff < 5-75
UDiff < 5-50% Ur
UHigh > 50-120% Ur
U Bus
1-ph
U Line
3-ph (or 1-ph)
ULow < 10-100% Ur
© ABB Group - 29 2-Jul-18
SYNC-BLOCK
Fuse fail
ULine
Autoreclosing
© ABB Group - 30 2-Jul-18
DLC and SC at Auto reclosing
© ABB Group - 31 2-Jul-18
CBIP manual on Protection
of Generators, generator
transformers and 220kV
and 400 kV networks
Auto Reclosing
Autoreclosing
1.0 GENERAL
• The auto-reclosing of power lines has become a generally accepted
practice.
• Reports from different parts of the world show that in
certain networks in region subject to a high lightening intensity only
about 5% of the faults are permanent.
• Auto reclosing therefore provides significant advantages.
• Outage times will be short compared to where station personnel
have to re-energize the lines after a fault.
© ABB Group - 32 2-Jul-18
• In interconnected networks auto-reclosing helps in maintaining
system stability
Autoreclosing
1.1 Recommendations for provisions of auto-reclosing
• Presently 1 phase high speed auto-reclosure (HSAR) at 400kV and
220kV level is widely practised including on lines emanating from
Generating Stations and the same is recommended for adoption.
© ABB Group - 33 2-Jul-18
• If 3-phase auto-reclosure is adopted in future the application of the
same on lines emanating from generating stations should be studied
and decision taken on case to case basis.
Autoreclosing
2.0 SETTING CRITERIA
2.1 Dead Time
• Auto- reclosing requires a dead time which exceeds the de-ionising
time
• Time required for the de-ionising of the fault path depends on:- arcing
time, fault duration, wind conditions, circuit voltage, capacitive
coupling to adjacent conductors, etc.
© ABB Group - 34 2-Jul-18
• Single phase dead time of 1.0 sec is recommended for both 400kV
and 220kV system.
Autoreclosing
2.2 Reclaim Time
• The time during which a new start of the auto-reclosing equipment is
blocked.
• If reclosing shot has been carried out and the line is energized and a
new fault occurs before the reclaim time has elapsed, the auto-reclosing
equipment is blocked and a signal for definite tripping of the breaker is
obtained.
© ABB Group - 35 2-Jul-18
• After the reclaim time has elapsed, the auto-reclosing equipment
returns to the starting position and a new reclosing sequence can occur.
• The reclaim time must not be set to such a low value that the intended
operating cycle of the breaker is exceeded, when two faults incidents
occur close together.
Autoreclosing
• If the breaker is closed manually, the auto reclosing equipment is
blocked and cannot start again until the reclaim time has elapsed.
© ABB Group - 36 2-Jul-18
• For the breaker to be used for auto-reclosing, it is essential that it
has the operating mechanism and breaking capacity necessary for
it to be able to perform the auto-reclosing sequences required.
Autoreclosing
2.3 Circuit Breaker Requirement
• According to IEC Publication 56.2, a breaker must be capable of
withstanding the following operating cycle with full rated breaking
current:
O + 0.3 s + CO + 3 min + CO
• The recommended operating cycle at 400kV and 220kV is as per the
IEC standard.
© ABB Group - 37 2-Jul-18
• Reclaim time of 25 sec is recommended.
© ABB Group - 38 2-Jul-18
Autoreclosing