# RECONFIGURATION ANDLOSS MINIMIZATION OF A POWER DISTRIBUTION NETWORK

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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

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

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

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

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

i
.
e
.

loss

was

1164
.
1
KW

which

created

congestion

of

line
.

So

to

avoid

this

problem

we

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

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

.

19

References

[
1
]

A
.
Merlin

and

H
.
Back
,

“Search

for

a

minimum

loss

operating

spanning

tree

configuration

for

urban

power

distribution

System,”

in

Proc
.

5
thPower

Syst
.

Computation

Conf
.

(PSCC),

Cambridge,

U
.
K
.
,

1975
,

Paper

1
.
2
/
6
.

[
2
]

Ray

Daniel

Zimmerman,

“NETWORK

RECONFIGURATION

FOR

LOSS

REDUCTION

IN

THREE
-
PHASE

POWER

DISTRIBUTION

SYSTEMS,

May,

1992
.

[
3
]

Hugh

Rudnick,

Ildefonso

Harnisch

and

Raúl

Sanhueza
,

“RECONFIGURATION

OF

ELECTRIC

DISTRIBUTION

SYSTEMS”,

Revista

De

Ingenieria
,

U
.
T
.
A
.

(CHILE),

VOL
.

4
,

1997
.

[
4
]

Joon
-
Ho

Choi

and

Jae
-
Chul

Kim

“Network

Reconfiguration

at

the

Power

Distribution

System

with

Dispersed

Generations

for

Loss

Reduction”,

IEEE,

0
-
7803
-
5935
-
6
/
00
/
\$
10
.
00

(c),

2000
.

[
5
]

M
.
E
.

Hamedani

Golshan

and

S
.
A
.

Arefifar
,”

Distributed

generation,

reactive

sources

andnetwork
-
configuration

planning

for

power

andenergy
-
loss

reduction”,

IEE

Proc
.
-
Gener
.

Transm
.

Distrib
.
,

Vol
.

153
,

No
.

2
,

March

2006
.

[
6
]

R
.

Srinivasa

Rao

and

S
.

V
.

L
.

Narasimham
,“A

New

Heuristic

Approach

for

Optimal

Network

Reconfiguration

in

Distribution

Systems”,

International

Journal

of

Engineering

and

Applied

Sciences

5
:
1

2009
.

[
7
]

P
.

V
.

V
.

Rama

Rao

and

S
.

Sivanagaraju
,”

Distribution

Network

Reconfiguration

for

Loss

Reduction

and

Balancing

using

Plant

Growth

Simulation

Algorithm”,

International

Journal

on

Electrical

Engineering

and

Informatics

-

Volume

2
,

Number

4
,

2010
.

20

Continued…

References

[
8
]

Balasim

Mohammed

and

Nesrullah

Salman,”

USING

NETWORK

RECONFIGURATION

AS

A

TOOL

FOR

MITIGATING

VOLTAGE

SAGS

IN

PRACTICAL

DISTRIBUTION

SYSTEMS”,

Diyala

Journal

of

Engineering,

Sciences

First

Engineering

Scientific

ConferenceCollege

of

Engineering

University

of

Diyala
,

pp
.

463
-
472
,

22
-
23

December

2010
.

[
9
]

Dr
.

Chen
-
Ching

Liu,

“Reconfiguration

of

power

networks

based

ongraph
-
theoretic

algorithms”,

Theses

and

Dissertations
.

Paper
11671
,

2010
.

[
10
]

V
.

Raj

Kumar,

B
.
Viswanath
,

D
.

Vijaya

Kumar

and

B
.

Venkata

Ramana
,“A

Heuristic

Based

Multi
-
Objective

Approach

for

Network

Reconfiguration

of

Distribution

Systems”,

nnovative

Systems

Design

and

Engineering

,

ISSN

2222
-
1727

(Paper)

ISSN

2222
-
2871

Vol

2
,

No

5
,

2011
.

[
11
]

Suman

Nath

and

Somnath

Rana
,

“Network

Reconfiguration

for

Electrical

Loss

Minimization”,

International

Journal

of

Instrumentation,

Control

and

Automation

(IJICA)

ISSN

:

2231
-
1890

Volume
-
1
,

Issue
-
2
,

2011

.

[
12
]

Jaydeep

Chakravorty
,

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RECONFIGURATION

OF

DISTRIBUTION

SYSTEM

USING

FUZZY

CONTROLLED

EVOLUTIONARY

PROGRAMMING”,

[IJESAT]

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OF

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-
Apr

2012
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[
13
]

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Lantharthong

and

N
.

Rugthaicharoencheep
,

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Reconfiguration

for

Balancing

in

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Distributed

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21

22

THANK YOU