Optimal Shunt Capacitor Placement for Voltage Profile Improvement in an 11kV Distribution Network: A Marine Base Feeder Case Study
Keywords:
Distribution network, ETAP, Improved voltage, Marine base, Optimal capacitor placementAbstract
The study examines the degradation of voltage profiles in the marine base 11 kV distribution network in Port Harcourt, Rivers State, Nigeria, caused by increased load demand and insufficient reactive power support. Using operational data obtained from the Port Harcourt Electricity Distribution Company (PHED), the network is modelled and analysed in ETAP 19.1 software. A Newton–Raphson load flow method is employed to assess the steady state operating condition of the feeder and to identify weak buses that violate the statutory voltage limits of 0.95–1.05 per unit. Results from the base case analysis reveal that several downstream buses experience unacceptable voltage drops, with minimum voltage levels reaching as low as 94.15 percent. To address this deficiency, an optimal shunt capacitor placement strategy is applied. The analysis identifies bus 16 as the most effective location for compensation, and a capacitor bank rated at 3 × 300 kVAr is optimally sized and installed. Post compensation simulations demonstrate a significant improvement in voltage profile across the entire feeder, with all buses operating within permissible limits and the maximum voltage drop reduced from 5.85 percent to 1.79 percent. The novelty of the paper lies in its practical, utility-driven application of optimal capacitor placement on a real Nigerian 11 kV distribution network using field data, providing clear quantitative evidence of voltage enhancement through targeted reactive power compensation. The findings offer actionable guidance for distribution utilities seeking cost-effective solutions for improving power quality and system reliability.
References
A. Hamouda and K. Zehar, “Improvement of the power transmission of distribution feeders by fixed capacitor banks,” Acta Polytechnica Hungarica, vol. 4, no. 2, 2007.
A. Subramanian, S. Jaisiva, R. Swathana, and S. Neelan, “Optimal allocation of FACTS devices for voltage profile enhancement,” International Journal of Enhanced Research in Science, Technology & Engineering, vol. 4, no. 8, pp. 187–193, 2015.
S. Reza, M. Azah, and S. Hussain, “Heuristic optimization techniques to determine optimal capacitor placement,” Dept. of Electrical and Systems Engineering, Universiti Kebangsaan Malaysia, 2012.
P. Mohan and P. Aravindbadu, “A novel placement algorithm for voltage stability enhancement in a distribution system,” International Journal of Electronics Engineering, vol. 1, pp. 85–87, 2019.
J. N. Onah, “Contingency evaluation of the Nigerian 330 kV transmission grid,” M.Eng. Thesis, University of Nigeria, Nsukka, Nigeria, pp. 33–39, 2019.
U. O. Emmanuel, N. N. Samuel, and K. I. Gerald, “Electric power transmission enhancement: A case of the Nigerian electric power grid,” American Journal of Electrical and Electronic Engineering, vol. 4, no. 1, pp. 33–39, 2016.
V. Srividya, “Optimum capacitor placement in a radial distribution system using Dijkstra algorithm methods,” Enriching Power and Energy Development, pp. 1–9, 2013.
M. Begovic, B. Milosevic and D. Novosel, “A novel method for voltage instability protection,” Proceedings of the 35th Annual Hawaii International Conference on System Sciences, Big Island, HI, USA, 2002, pp. 802–811.
A. Chandra and T. Agawal, “Capacitor bank designing for power factor improvement,” International Journal of Emerging Technology and Advanced Engineering, vol. 4, 2014.
I.O. Akwukwaegbu and G.I. Okwe, “Concepts of Reactive Power Control and Voltage Stability Methods in Power System Network,” IOSR Journal of Computer Engineering (IOSR-JCE), vol.11, no 2, pp.15-25, 2013.
R. S. Reddy and T. Q. Manohar, “Review of the voltage stability phenomenon and importance of FACT control in power system environment,” Global Journal of Researches in Engineering: Electrical and Electronics Engineering, vol. 12, 2012.
M. M. Aman, G. B. Jasmon, A. H. A. Bakar, and M. Karimi, “Optimum shunt capacitor placement in distribution system: A review and comparative study,” Renewable and Sustainable Energy Reviews, vol. 30, pp. 429–439, 2014.
A. A. Abou El-Ela, R. A. El-Sehiemy, A.-M. Kinawy, and M. T. Mouwafi, “Optimal capacitor placement in distribution systems for power loss reduction and voltage profile improvement,” IET Generation, Transmission & Distribution, vol. 10, no. 5, pp. 1209–1221, 2016.
A. Askarzadeh, “Capacitor placement in distribution systems for power loss reduction and voltage improvement: A new methodology,” IET Generation, Transmission & Distribution, vol. 10, no. 14, pp. 3631–3638, 2016.
D. Jana, C. Biswas, A. Bera, and R. Chowdhury, “Optimal capacitor placement and sizing by controlling reactive power in distribution networks,” Proc. 2025 8th Int. Conf. on Electronics, Materials Engineering & Nano-Technology (IEMENTech), Kolkata, India, 2025, pp. 1–5.
M. A. El-Sayed Mohamed El-Saeed, A. F. Abdel-Gwaad, and M. A. AbdEl-fattah Farahat, “Solving the capacitor placement problem in radial distribution networks,” Results in Engineering, vol. 17, 2023.
E. S. Abraham and I. Oluwafemi, “Power loss minimization and voltage profile improvement on electrical power distribution systems using optimal capacitor placement and sizing,” Int. J. Adv. Electr. Eng., vol. 3, no. 1, pp. 1–8, 2022.
O. C. Peter, O. I. Benedict, O. U. Chinweoke, and O. K. C, “Power quality improvement of a distribution network for sustainable power supply,” Int. J. Integrated Eng., vol. 14, no. 1, pp. 363–373, 2022.
J. P. Mahato, Y. K. Poudel, R. K. Mandal, and M. R. Chapagain, “Power loss minimization and voltage profile improvement of radial distribution network through the installation of capacitor and distributed generation,” Arch. Adv. Eng. Sci., vol. 3, no. 4, pp. 265–273, 2025.
M. A. Kamarposhti et al., “Optimizing capacitor bank placement in distribution networks using a multi-objective particle swarm optimization approach for energy efficiency and cost reduction,” Sci. Rep., vol. 15, Art. no. 12332, 2025.
M. O. Okelola, O. W. Adebiyi, S. A. Salimon, S. O. Ayanlade, and A. L. Amoo, “Optimal sizing and placement of shunt capacitors on the distribution system using whale optimization algorithm,” Nigerian J. Technol. Develop., vol. 19, no. 1, Mar. 2022.
M. J. Tahir, M. B. Rasheed, and M. K. Rahmat, “Optimal placement of capacitors in radial distribution grids via enhanced modified particle swarm optimization,” Energies, vol. 15, p. 2452, 2022.
C. Zangpo, T. Jamtsho, W. Tshering, S. Nethagani, and T. Tobgay, “Optimal capacitor placement for minimizing power losses and improve voltage profile on distribution system of Dewathang feeder,” Zorig Melong: A Technical Journal of Science, Engineering and Technology, vol. 8, no. 2, 2025.
D. Das, Electrical Power System. New Delhi, India: New Age International (P) Ltd., 2016.
B. W. Stevenson, Electric Power Systems Basics. Houston, TX, USA: Wiley-Interscience, 2018.
A. F. Agbetuyi, “Voltage stability investigation of power systems with grid-connected wind turbine generators: A case study of Nigerian distribution system,” Ph.D. dissertation, Covenant Univ., Canaan Land, Ota, Ogun State, Nigeria, 2014.
U. Dorji, “A review on load flow studies,” Master’s seminar, Kumamoto Univ., Kumamoto, Japan, 2019.
H. Saadat, Power System Analysis. New Delhi, India: Tata McGraw-Hill, 2016.
A. Elsheikh, Y. Helmy, Y. Abouelseond, and A. Elsherif, “Optimal capacitor placement and sizing in a radial electric power system,” Alexandria Engineering Journal, vol. 53, pp. 809–816, 2014.
