Edohen O.M, Ike, S.A & Okhumeode, M.E
Unbalance loading in power distribution network has continued to pose a great threat to the electricity grid system due to phase load inequality, especially where large single–phase loads are used. The network configuration and length also have effects on the voltage unbalance in the feeder. In low voltage residential feeders, majority of the houses have single–phase power supply. This research focused on finding the revenue loss on JBS 1 Estate 11/0.415kV sub-station. Using direct calculation on established formulas, the values of the unbalance voltages and current were calculated using the real time field data obtained during the period under investigation. It was observed that the highest voltage unbalance of 4.13% was recorded in the month of May while low voltage unbalance figure of 1.05% was recorded in the month of January as depicted in Table 2 and Figure 1 respectively. The research further revealed that the annual revenue loss on JBS 1 Sub-station is quite high during the period under investigation which amounted to N4,688,759.90 (four million, six hundred and eighty-eight thousand, seven hundred and fifty-nine naira, ninety kobo) which is predicted to be a high revenue loss to the utility company. Read full PDF
Keywords: Voltage Unbalanced, Revenue Loss, NERC, Unbalanced Loading, Sub-Station
 Makoju, J. (2002): Nigeria Transmission Development Project (Distribution and Transmission). Report No. PID9541
 Lakshmikantha B.R., Dr Murugesh Mudaliar, Dr K.Balaraman, Dr R.Nagaraja (2008): Mitigation of Voltage Unbalance in Traction System, Proceedings of the World Congress on Engineering and Computer Science 2008 WCECS 2008, October 22 – 24, 2008, San Francisco, USA.
 Arobieke O, Osafehinti S, Oluwajobi O.O. (2002): Electrical power outages in Nigeria: History, causes and possible solutions. Journal of Energy Technologies and Policy.;2(6):18-23.
 Luis F. Ochoa, Rade M. Ciric, A. Padilha-Feltrin, Gareth P. Harrison (2005): Evaluation of distribution system losses due to load Unbalance, 15th Power Systems Computation Conference PSCC.
 Ahmadi G. and Shahrtash S.M (2009) : Neutral to Earth Voltage Reduction Methods in Three-Phase Four Wire Distribution Systems, 2009 International Conference on Electrical and Electronics Engineering, 5-8 Nov. 2009.
 Luma, N., & Manar, I. (2013): “Mathematical Model for Determination the Increase in Operational Cost Caused by Reactive Power Transmission in Electric Power System”. International Journal of Modern Engineering Sciences ISSN: 2167-1133 Vol.2 (1), p51-62.
 Davoudi, M. G., A. Bashian, J. Ebadi, (2012): “Effects of unsymmetrical power transmission system on the voltage balance and power flow capacity of the lines.” In IEEE 11th International Conference on Environment and Electrical Engg (EEEIC), Venice Austria, 860-863.
 Sahito A. A, Memon Z. A, Shaikh P. H., Rajper A. A., Memon S. A. (2015): Unbalanced Loading; An Overlooked Contributor to Power Losses in HESCO, Sindh Univ. Res. Journal. (Sci. Ser.) Vol. 47 (4) 779-782 (2015).
 Muljadi .E., Butterfield C.P., Batan T., and Yildirim D. (2000), Understanding the Unbalanced Voltage Problem in Wind Turbine Generation, IEEE Industry Applications Society Annual Meeting, NREL/CP-500-26338, page 117-121
 Gross C.A. (1986) “Power System Analysis” 2nd Edition 1986.