Optimal sitting and sizing of shunt capacitor for real power loss reduction on radial distribution system using firefly algorithm: A case study of Nigerian system

ABSTRACT

Geometrical increase in power demand and high load density at the distribution ends of modern power systems have key consequential problems of high power loss and poor voltage profile, as a result of which the integrity of radial distribution networks to faithfully account for the energy received from transmission subsystems has been seriously undermined. This challenge is, however, being overcome by placement of shunt capacitors to supply the reactive power required for compensation; hence, optimal sitting and sizing of compensators has been intensively researched. As efficient as the use of meta-heuristic algorithms for joint optimal placement and sizing of the shunt capacitors are, employment of the approach on the Nigerian radial distribution system (RDS) is not yet popular as most of the earlier works reported rather used analytical and numerical programming approaches. In this study, therefore, the use of firefly algorithm (FA) on a Nigerian 11-kV feeder is presented as an approach to optimally site and size shunt capacitor for real power loss reduction on such network. Backward-forward sweep load flow technique, with voltage stability index (VSI), is employed to find the candidate buses where the shunt capacitors would be installed, then FA is employed to determine the optimal size required. This approach is implemented on a 34-bus 11-kV feeder and it is found out that the system’s real power loss reduced from 762.6419 to 597.7486 kW, while the minimum bus voltage magnitude was raised from 0.8295 to 0.8456 p.u. and the minimum system VSI was improved from 0.4741 to 0.5121 p.u. Based on these results, the proposed approach is, therefore, considered a promising technique for sitting and sizing shunt capacitor optimally in real practical RDS.

KEYWORDS:

• Backward-forward sweep
• firefly algorithm
• loss minimization
• voltage profile
• voltage stability index

Additional information

Notes on contributors

Olabode E.o.

Olabode E.o. received B.Tech. and M.Tech. degrees in Electronic and Electrical Engineering from the Ladoke Akintola University of Technology, Ogbomoso, Nigeria. He is a registered Engineer with the Council for the Regulation of Engineering in Nigeria.

Ajewole T.o.

Ajewole T.O. obtained B.Eng. degree in Electrical and Computer Engineering from the Federal University of Technology, Minna, Nigeria, while his M.Sc. and the  PhD degrees were obtained in Electronic and Electrical Engineering from the Obafemi Awolowo University, Ile-Ife, Nigeria. He is currently with the Osun State University, Osogbo, Nigeria.

Okakwu I.k

Okakwu I.K. has B.Eng. in Electrical and Electronic Engineering from the Ambrose Alli University, Ekpoma, Nigeria. His M.Sc. were obtained in Electrical and Electronic Engineering from the University of Lagos, Lagos, Nigeria and the  PhD obtained  from the University of Benin, Benin-City, Nigeria. He is currently with the University of Benin, Benin-City, Nigeria.

Ade-Ikuesan O.o.

Ade-Ikuesan O.O. obtained B.Eng. and M.Sc. from the Ondo State University, Ado-Ekiti, Nigeria and the University of Lagos, Lagos, Nigeria respectively. At present, she on her PhD at the Federal University of Agriculture, Abeokuta, Nigeria where she is also an academic staff.