This document presents a technique for distribution network reconfiguration to reduce power losses and improve voltage profiles using Bacterial Particle Swarm Optimization (B-PSO). The technique was tested on three IEEE standard test networks - a 16-bus system, 33-bus system, and 69-bus system. For each test system, the proposed technique optimized the open/closed status of sectionalizing and tie switches to minimize losses and voltage deviations while maintaining radial network topology. Results showed reductions in power losses of 12-56% and improvements in voltage profiles for all three test systems. Future work could incorporate distributed generation to support overloaded feeders from load transfers during reconfiguration.

1. Distribution Network Reconfiguration for
Loss Reduction and Voltage Profile
Improvement using B-PSO
Presented
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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2. • Introduction
• Problems formulation
• Test systems description
• Results and discussions
• Conclusion
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3. • 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
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S7 and S8 are tie switches

4. • 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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5. • 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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6. • 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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7. For second OF
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8. • The following constrains are consider
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3. Radial network structure are maintained, no loop are
allow in the network

9. • 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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10. • 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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11. • 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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12. 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 16
0.965
0.97
0.975
0.98
0.985
0.99
0.995
1
Bus Number
Voltage(pu)
Before Reconfiguration
After Reconfiguration
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13. 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 33
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1
Voltage(p.u)
Bus Number
Before Reconfiguration
After 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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14. 69-bus test system
• After reconfiguration
Paramete
rs
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 system
Power loss reduced by 56.1761 %
Voltage deviation improved 64.6758%.
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15. 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 69
0.9
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1
Voltage(p.u)
Bus Number
Before Reconfiguration
After 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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16. • 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.
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