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Distribution Network Reconfiguration for Loss Reduction and Voltage

Profile Improvement using B-PSOPresented

by Gaddafi S. Shehu

Abdullahi B. Kunya, ABU Zaria-Nigeria

Adamu Y. Ilyasu, KUST Kano-Nigeria

Sunusi G. Mohammed, BUK Kano-Nigeria

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OUTLINES

• Introduction• Problems formulation• Test systems description• Results and discussions• Conclusion

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INTRODUCTION

• DN carry electrical power right from transmission system to consumers.• DN contributes at least 40% of the total power loss occurring in the entire system.• Most DNs are built meshed and operated radially.

Fig. 1 IEEE 16 bus test system section

S7 and S8 are tie switches

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INTRODUCTION• DN is vulnerable to outages due to its radial nature, as fault on a single line can result in

blackout to many customers.

• However, network modification is a non-linear, multi-objective, highly constrained problem.

• The complexity of the problem arises due to distribution network topology has to be radial.

• Power flow constraints are nonlinear in nature.

• Previous studies of DN reconfiguration focus on planning, and cost of construction minimization.

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BINARY PARTICLE SWARM

• Advantage of handling both discrete and continuous parameters.• Initializing search space with swarm particles, xi randomly.• The search space in this problem is the set of all the sectionalizing and tie

switches.• At each iteration, the position of ith particle is updated by its previous position in

the velocity vector, vi according (1)

• The velocity vector is updated according to the following equation (2)

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PROBLEMS FORMULATION

• The problem involves determining the optimal DNR, taking into account different technical constraints.

• The objective is to minimize power loss and voltage deviation as formulated in objective function.

first

and

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PROBLEMS FORMULATIONFor second OF

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PROBLEMS FORMULATION

• The following constrains are consider

3. Radial network structure are maintained, no loop are allow in the network

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TEST SYSTEMS DESCRIPTION

• Three IEEE standard test distribution networks are tested

Fig. 2 IEEE 16 bus test system

• The network has total loads of 28.125 MW and 13.53 MVAr on 12.65 kV substation voltage

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TEST SYSTEMS DESCRIPTION• The second test system used in the study is 33-bus distribution feeder with a total active and reactive

load demand of 3.72 MW and 2.30 MVAr respectively.

• It has 37 branches, 32 sectionalizing switches and 5 tie switches

Fig. 3 IEEE 33 bus test system

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TEST SYSTEMS DESCRIPTION• A 69 buses, 73 branches and 5 tie switches, is used. The network has a total load demand of

3.80MW and 2.70MVAr.

Fig. 4 IEEE 69 bus test system

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RESULTS AND DISCUSSIONS(16-bus test system)

• After reconfiguration

Fig. 6 16-bus test system voltage profile

Fig. 5 Optimized Configuration of 16 bus test system

16 Bus Test System Results

12.3364%

8.8903%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 160.965

0.97

0.975

0.98

0.985

0.99

0.995

1

Bus Number

Vol

tage

(pu)

Before ReconfigurationAfter Reconfiguration

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RESULTS AND DISCUSSIONS(33-bus test system)

• After reconfiguration

Parameters Before Reconfiguration

After Reconfiguration

Tie switches 33, 34, 35, 36, 37 7, 11, 14, 28, 32

Power loss 208.4592 kW 141.6346 kW

Voltage dev. 1.6610 pu 1.0991 pu

Min. Voltage 0.9108 pu 0.9413 pu

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 330.91

0.92

0.93

0.94

0.95

0.96

0.97

0.98

0.99

1

Vol

tage

(p.u

)

Bus Number

Before ReconfigurationAfter Reconfiguration

Fig. 8 33-bus test system voltage profile.

Fig. 7 Optimized Configuration of 33 bus test system

33 Bus Test System Results

32.0564%

33.8290%

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RESULTS AND DISCUSSIONS(69-bus test system)

• After reconfiguration

Parameters

Before Reconfiguration

After Reconfiguration

Tie switches

69, 70, 71, 72, 73

14, 58, 61, 69, 70

Power loss

224.9804 kW

98.5952 kW

Voltage dev.

0.2140 pu 0.1876 pu

Min. Voltage

0.9092 pu

0.9495 pu

69 BUS TEST SYSTEM RESULTS

Fig. 9 Optimized Configuration of 69 bus test systemPower loss reduced by 56.1761 %

Voltage deviation improved 64.6758%.

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RESULTS AND DISCUSSIONS(69-bus test system)• Fig. 10, 69-bus test system voltage profile

1 6 11 16 21 26 31 36 41 46 51 56 61 66 690.9

0.91

0.92

0.93

0.94

0.95

0.96

0.97

0.98

0.99

1

Vol

tage

(p.u

)

Bus Number

Before ReconfigurationAfter Reconfiguration

observed at bus 41- 46 due to introduction of loads at bus 15 – 27 and bus 62 – 65 by opening s14 and closing s71.

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CONCLUSIONS• The objective of the proposed technique is to minimize the active power loss and voltage

deviation.• The decision variables are the open/close status of the sectionalizing and tie switches.• IEEE multi-feeder 16-bus and single feeder 33-bus and 69-bus test distribution networks

are used for testing the proposed technique.• With the optimized reconfiguration, the radial nature is maintained, no mesh network is

formed.• While reconfiguring the networks, opening or closing some loads are transferring from

one feeder to another, hence overloading it.• Distributed generation is needed at those overloaded feeders to support its load carrying

capacity.• It is envisioned as future work to incorporate distributed generation to support the loaded

feeders.• Same technique will be used to determine their optimal siting and sizing.