Project On
RECONFIGURATION AND
LOSS MINIMIZATION
OF A POWER DISTRIBUTION NETWORK
By
RITAM MUKHERJEE
UNDER THE GUIDENCE OF:
ANITA KHOSLA & RICHA KHERA
M

TECH (4THSEM)
MRIU
1
WHAT IS RECONFIGURATION
It is the process of operation that connection/disconnection of
switches to change the circuit topology.
Network reconfiguration is an operation in configuration management
that determines the switching operations for improvement of the
voltage stability with minimum loss condition.
System reconfiguration means restructuring of the power lines which
connect various buses in the power system.
2
INTRODUCTION
The
ideal
losses
in
an
electric
system
should
be
around
3
to
6
%
.
In
India,
collective
of
all
states
,
in
2011
the
total
losses
are
accounted
to
22
.
32
%
of
the
total
input
energy
.
So
it
is
necessary
to
use
effective
computational
tools
like
MATLAB,ANN
etc,
that
allow
to
reduce
the
loss
in
the
network
.
3
CLASSIFICATION OF NETWORK
RECONFIGURATION
It can be Classification as:
i
> The original power system network is changed by adding extra power
line to the present network by connection/disconnection the
switches.
ii> Another way of Network reconfiguration is to
connection/disconnection of already existing lines within the network.
4
LITERATURE
SURVEY
Merlin
and
Back
[
1
]
first
proposed
Network
Reconfiguration
.
It
is
a
process
of
operating
switches
to
change
the
circuit
topology
so
that
operating
costs
are
reduced
while
satisfying
the
specified
constraints
.
So
to
lighten
on
this
matter
distribution
system
reconfiguration
for
loss
reduction
.
Ray
Daniel
Zimmerman[
2
]
introduced
a
general
combinatorial
optimization
algorithm
known
as
simulated
o
f
a
balance
three
phase
system
.
It
states
that
a
solution
must
satisfy
Kirchhoff’s
voltage
and
current
laws,
which
in
a
three

phase
distribution
system
can
be
expressed
as
the
three

phase
power
flow
equations
.
In
1997
Hugh
Rudnick,
and
Raul
Sanhueza
[
3
]
introduced
a
heuristic
solution
algorithm
based
on
the
method
of
branch
exchange,
where
different
radial
configurations
are
generated,
improving
the
objective
function
and
originating
a
sequence
to
be
performed
on
the
network
.
5
Continued
…
Joon

Ho
Choi
and
Jae

Chul
Kim[
4
]
however
introduce
of
dispersed
generations
in
power
distribution
systems,
increases
the
complexity
and
solution
is
achieved
by
introducing
Genetic
Algorithms
approach
.
M
.
E
.
Hamedani
Golshan
and
S
.
A
.
Arefifar
[
5
]
was
another
to
find
the
solution
algorithm
based
on
tabu
search,
which
is
an
efficient
heuristic
method
to
a
combinatorial

optimization
problem
based
on
an
investigation
of
some
parameters
such
as
maximum
limits
on
size
of
distributed

generation
resources
.
R
.
Srinivasa
Rao
and
S
.
V
.
L
.
Narasimham
[
6
]
reported
a
simple
heuristic
rules
and
identified
an
effective
switch
status
configuration
of
distribution
system
.
P
.
V
.
V
.
Rama
Rao
and
S
.
Sivanagaraju
[
7
]
introduced
Plant
Growth
Simulation
Algorithm
which
has
emerged
as
a
useful
optimization
tool
for
handling
nonlinear
programming
problems
.
This
method
was
based
on
load
balancing
6
BENEFITS OF NETWORK
RECONFIGURATION
Efficient electrical transmission.
It improve the voltage stability of the system.
It
also
smoothens
out
the
peak
demands,
improving
the
voltage
profile
in
the
feeders
and
increase
network
reliability
.
Enhancement
of
voltage
stability
can
be
achieved
without
any
additional
cost
involved
for
installation
of
capacitors,
tap
changing
transformers
and
the
related
switching
equipment
.
7
OBJECTIVE
•
To
develop
a
6
bus
system
using
E

TAP
.
•
To
find
the
reconfiguration
network
of
the
6
bus
system
.
•
To
find
a
suitable
solution
for
loss
minimization
of
the
6
bus
system
.
8
CIRCUIT ANALYSIS
A simple 6 bus Ring Distribution System is considered which has 2
generation units, 6 loads and 8 tie

switches. This distribution network is
shown in Fig. A.
Among 8 tie

switches, switch 1 and switch 2 were always kept in closed
condition and the remaining ones i.e. switches 3, 4, 5, 6,7and 8 were
controlled sequentially in on/off position.
So there are 2^6 i.e. total 64 conditions among which only 36 conditions
were found to deliver power to all loads. In this case load flow is performed
and power losses were observed for each case.
9
10
Fig . A : A Six

Bus System
Table . 1
The total 36 conditions with real power losses according to the different
conditions of switches being kept open and closed
.
Figure
Number
Switch Opened
Switch Closed
Total Line
losses (in
KW)
1
1
CB3
CB4,CB5,CB6,CB7,CB8
656
2
2
CB3,CB4
CB5,CB6,CB7,CB8
699.9
3
3
CB3,CB5
CB4,CB6,CB7,CB8
699.0
4
4
CB3,CB6
CB4,CB5,CB7,CB8
427.7
5
5
CB3,CB7
CB4,CB5,CB6,CB8
1035.6
6
6
CB3,CB8
CB4,CB5,CB6,CB7
303.7
7
7
CB4,CB5
CB3,CB6,CB7,CB8
351.0
8
8
CB4,CB6
CB3,CB5,CB7,CB8
962.3
9
9
CB4,CB7
CB3,CB5,CB6,CB8
1755.9
10
10
CB4,CB8
CB5,CB6,CB7,CB3
375.1
11
11
CB5,CB3
CB4,CB6,CB7,CB8
669.0
12
12
CB5,CB6
CB3,CB4,CB7,CB8
880.9
13
13
CB5,CB7
CB3,CB4,CB6,CB8
408.0
14
14
CB5,CB8
CB3,CB4,CB6,CB7
298.9
15
15
CB6,CB7
CB3,CB4,CB5,CB8
1711.8
16
16
CB6,CB8
CB3,CB4,CB5,CB7
500.8
17
17
CB7,CB8
CB3,CB4,CB5,CB6
749.0
11
12
18
18
CB4
CB3,CB5,CB6,CB7,CB8
708.9
19
19
CB5
CB3,CB4,CB6,CB7,CB8
553.1
20
20
CB6
CB3,CB4,CB5,CB7,CB8
847.2
21
21
CB7
CB3,CB4,CB5,CB6,CB8
1055.3
22
22
CB8
CB3,CB4,CB5,CB6,CB7
296.5
23
23
CB3,CB5,CB6
CB4,CB7,CB8
440.4
24
24
CB3,CB5,CB8
CB4,CB6,CB7
317.5
25
25
CB3,CB4,CB6
CB5,CB7,CB8
470.4
26
26
CB3,CB4,CB8
CB5,CB6,CB7
350.4
27
27
CB3,CB6,CB7
CB4,CB5,CB8
796.5
28
28
CB3,CB7,CB8
CB4,CB5,CB6
711.0
29
29
CB4,CB5,CB6
CB3,CB7,CB8
493
30
30
CB4,CB5,CB8
CB3,CB6,CB7
493
31
31
CB4,CB6,CB7
CB3,CB5,CB8
1653.6
32
32
CB4,CB6,CB8
CB3,CB5,CB7
962.3
33
33
CB4,CB7,CB8
CB3,CB5,CB6
1135.8
34
34
CB5,CB6,CB8
CB3,CB4,CB7
510.3
35
35
CB6,CB7,CB8
CB3,CB4,CB5
1164.3
36
36
CB6,CB7,CB8,CB4
CB5,CB3
1498
Continued…
DISCUSSION ON RESULTS
By
comparing
results
of
the
conditions
with
respect
to
line
losses
it
is
found
that
Condition
13
is
the
desired
condition
at
which
total
line
losses
is
minimized
i
.
e
.
408
KW
and
only
Tie

switches
5
and
7
(CB
5
and
CB
7
)
are
in
open
condition
.
It
is
also
noted
that
there
are
no
buses
which
are
in
under
voltage
condition
and
no
switches
(circuit
breaker)
are
at
overload
condition
.
13
Network
elements
Case Number
Losses in KW
Losses in
KVAR
Physical
Condition
Transformer
1
Case 13
4.2
59.0
Healthy
Condition
Transformer
2
0.2
3.4
Cable
1
4.2
0.5
Cable
2
0.0

2.0
Cable
3
0.0

4.8
Cable
4
70.6
17.7
Cable
5
30.5
7.0
Cable
6
298.3
85.4
Fig . C : Case 13
14
Continued…
DISCUSSION ON RESULTS
In
Case
9
when
Tie

switches
4
and
7
(CB
4
and
CB
7
)
are
in
open
condition
it
was
found
that
Cable
6
was
overloaded
i
.
e
.
loss
was
1164
.
1
KW
which
created
congestion
of
line
.
So
to
avoid
this
problem
we
had
to
redesign
the
cable
size
.
Otherwise
it
might
cause
mal

operation
of
relay
.
15
Network
elements
Case Number
Losses in KW
Losses in KVAR
Physical
Condition
Transformer
1
Case
9
18.9
264.5
Critical under
voltage condition
occurred at Bus4,
Bus3 & Bus5.Bus6
& CB8 are
operated at
marginal
condition.CB2 &
Transformer1 is
over loaded.
Transformer
2
63.2
885.0
Cable
1
61.1
23.2
Cable
2
0.0

2.0
Cable
3
296.8
82.8
Cable
4
0.0

2.5
Cable
5
151.8
42.8
Cable
6
1164.1
339.1
Fig . C : Case 9
16
LOSS MINIMIZATION
Cable size has a great impact in line losses, so by changing the cable
sizing the loss can be minimised in the system considering the
particular cases where the maximum losses are occurring
It was found that when the circuit breakers 1 and 2 were in closed
condition, Cable 6, that is the cable between Bus 2 and Bus 3 had
maximum amount of loss. It was assessed by using ETAP.
However, using ETAP it was noticed that by changing the cable size the
loss could be decreased. The tables is given below.
17
Continued…
Cable 6 which is 200 metre in length showed maximum amount of
loss.
18
Sl.
No
.
Cable
no
Case
no
Diamet
er
Change
in
diamete
r
Initial
Loss
in KW
Final
Loss in
KW
1
Cable 6
4
50
mm
2
75
mm
2
427
.
7
345
.
7
2
Cable 6
8
70
mm
2
95
mm
2
962
.
3
800
.
23
3
Cable 6
16
40
mm
2
48
mm
2
500
.
8
450
.
34
4
Cable 6
35
34
mm
2
60
mm
2
1164
.
3
985
.
32
5
Cable 6
20
15
mm
2
55
mm
2
847
.
2
569
.
32
CONCLUSION
If
we
compare
to
a
stander
result
the
loss
will
be
reduced
by
36
.
94
%
.
The
loss
can
be
minimized
if
we
changed
the
size
of
cable,
but
it
can
be
changed
within
certain
limit
other
wise
circuit
breaker
will
be
over
loaded
.
19
References
[
1
]
A
.
Merlin
and
H
.
Back
,
“Search
for
a
minimum
loss
operating
spanning
tree
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for
urban
power
distribution
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thPower
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/
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[
2
]
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FOR
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IN
THREE

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and
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Continued…
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[
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]
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Mohammed
and
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USING
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RECONFIGURATION
AS
A
TOOL
FOR
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VOLTAGE
SAGS
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THANK YOU
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