A RELIABILITY IMPROVEMENT PROPOSAL (RIP) MODEL FOR RELIABILITY ASSESSMENT OF ELECTRICAL DISTRIBUTION SYSTEMS
G.A. Ajenikoko
Department of Electronic & Electrical Engineering
Ladoke Akintola University of Technology, Ogbomoso
E-mail: ajeedollar@gmail.com
ABSTRACT
In Nigeria, the average interruptions that customers experience are very high and the degree varies from place to place, thus making it impossible to achieve a satisfactory degree of reliability in the power system. The need for an effective planning tool to evaluate alternative reliability improvement proposal in order to establish and prioritize reliability improvement recommendations for optimization of reliability performance of a power delivery system has necessitated the development of a Reliability Improvement Proposal (RIP) model. The model uses quantitative processes to optimize reliability performance expectations of both customers and regulatory authorities. This research paper focuses on a Reliability Improvement Proposal (RIP) model for reliability assessment of electrical power distribution systems. Seven major distribution systems-Ibadan, Ikeja, Ilorin, Port Harcourt, Kano, Kaduna and Benin were used as case studies. The development of the model started with identification and computation of major system reliability indices before and after the proposal. The changes in the system reliability indices and the weighting coefficients were then estimated using appropriate mathematical relations. The weighting coefficients show the extent to which the system reliability indices change when a RIP is suggested. The results of the RIP model showed that the system reliability indices has changed from 0.3433, 0.1198, 0.2291, 0.2629, 0.2352, 0.1964 and 0.0.4032 before the proposal to 0.9772, 0.9855, 0.9863, 0.9858, 0.9905, 0.9860 and 0.9793 after the proposal for Ibadan, Ilorin, Ikeja, Port Harcourt, Kaduna, Kano and Benin distribution systems respectively. The highest CAIDI weighting coefficient of 5.158 was recorded on Kano distribution system while the least SAIFI weighting coefficient of 0.0009214 was recorded on Ibadan distribution system as a result of the level of industrial activities of the city. Kano distribution system has the least RIP value of -5.589 while Kano distribution system has the highest RIP value of 8.87 because of the level of power requirement of the city compared to any city in the case study.The results of this research paper will assist electrical power system engineers in making effective planning policies and prioritize reliability improvement recommendations so as to optimize reliability performance of electrical power system.