MV NETWORK
MANAGEMENT
Amit Sharma
Anil Kadam
MV Public Distribution Network
20MVA
33/11kV
Public Distribution
Primary Substation
Primary
Distribution
20MVA
33/11kV
Process
Industry
Farm (rural
distribution)
kWh
kWh
Urban Distribution
kWh
Medium Industrial
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Large Commercial
2
Radial network
33kV
Load
Centre 11
Primary
1
20MVA
11kV
Load
Centre 2
Load
Centre 3
Load
Centre 11
Load
Centre 1
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Open ring network
33kV
Primary
1
20MVA
Load
Centre 11
11kV
Load
Centre 3
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Open ring network
33kV
Primary
1
20MVA
Load
Centre 11
11kV
Load
Centre 3
NOP
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- Why improve MV distribution?
●
To obtain the best possible power
quality
The main issue is to reduce
outage time and cost to the utility
and its customers
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- How can outage time be reduced?
● By improving
MV networks:
● By improving the MV
networks management:
 Large number of short
sections
 With Fault Passage
Indicators (FPI’s)
 Redundant networks
 Or with remote controlled
load break switches
 Reliable components…
 Or with fully automated
reclosers and sectionalizers
 Or Ring Main Units with
FPI’s
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- Different types of devices
R
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R2
8
- overhead networks: types of faults
● Temporary
faults
80%
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● Permanent
faults
20%
9
- temporary faults
● Temporary faults can be cleared by the
use of Automatic Circuit Reclosers
(ACRs)
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- temporary fault: one recloser
R
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- temporary fault: one recloser
O
15
s
C
R
100%
Time
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- temporary fault: one recloser
O
15
s
15
s
C
R
100%
Time
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- temporary fault: one recloser
O
15
s
15
s
C
R
100%
Time
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- temporary fault: one recloser
O
15
s
15
s
15
s
C
R
100%
Time
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- temporary fault: one recloser
O
15
s
15
s
15
s
C
R
100%
Time
2
mn
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- temporary fault: TWO reclosers
R1
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R2
17
- temporary fault: TWO reclosers
R1
Network A50%
R2
Network B50%
Network
B
Time
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- permanent faults
Permanent faults cannot be cleared by
automatic reclosing
To manage “permanent faults”, the
best solution is to add some
“sectionalizers”
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- case 1: no network automation
Permanent fault
R
100%
5H – 6H
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- case 1: no network automation
Permanent fault
R
100%
95%
5H – 6H
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- case 2: addition of non-communicating fault
passage indicators (FPI)
An FPI for each branch of the network
R
Add an FPI around
each major
«obstacle»…
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- case 3: addition of communicating FPIs
R
Put several
communicating
FPIs in strategic
locations
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- case 4: addition of communicating FPIs and remote
controlled load break switches
T
T
R
T
T
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remote controlled load break
switches
Communicating FPI
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- case 5: recloser and sectionalizer load break
switches
R
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- case 5: recloser and
sectionalizer load break switches Permanent fault
S3
R
S4
S3
1
1
1
S2
S2
S1
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- case 5: recloser and
sectionalizer load break switches
Permanent fault
S3
R
S4
S3
2
2
2
S2
S2
S1
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- case 5: recloser and
sectionalizer load break switches
Permanent fault
S3
R
S4
S3
2
2
2
S2
S2
S1
2’
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- case 5: recloser and
sectionalizer load break switches
Permanent fault
S3
S4
R
S3
S2
S2
S1
95
%
75
%
2’
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60’
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- summary of overhead networks 1/2
Permanent fault
95%
Case 1
A recloser
6h
95%
Case 2
A recloser
+ FPIs
3h
95%
Case 3
A recloser
+ FPI with Com
1h30
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- summary of overhead networks 2/2
Permanent fault
95%
Case 4: A recloser,
70 %
remote controlled
switches
and FPI with Com
10
’
1
h
95%
Case 5
75 %
A recloser
and sectionalizers
2’
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1
h
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SAIDI/SAIFI variations – Quality Power
● SAIDI (System Average Interruption Duration Index) can vary from a
few minutes to several hours,
● SAIFI (System Average Interruption Frequency Index) can vary from
1 to 10 and more, depending on :
● population density (rural or urban area)
● proportion between underground and overhead distribution
● maximum accepted costs for non distributed energy
Urban area
Rural area
Excellent
Average
< 10 mn
30 mn
< 30 mn
2 hrs
Poor
>2 hrs
>10 hrs
Permanent Interruptions (>1 mn)
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OPEN RING SYSTEM
MAIN SUBSTATION
51/51N
51/51N
What would happen to this network
if a fault occurred here ??
OPEN POINT
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OPEN RING SYSTEM
MAIN SUBSTATION
51/51N
What would you do to get the
customers back on supply ??
OPEN POINT
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OPEN RING SYSTEM
MAIN SUBSTATION
NEW OPEN POINTS SHIFTED FROM
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Thank You!!
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