A Sensitivity Based Approach for Assessment of Reliability Indices of Electrical Distribution Systems.

In Nigeria, satisfactory degree of reliability has not been attained in the power system in recent times. The average duration of interruptions that customers experience is very high and the degree varies widely especially in urban and commercial cities of the country. This research paper therefore presents the sensitivity analysis of electrical distribution systems. Ten years of outage information from seven major distribution systems – Ibadan, Ilorin, Ikeja, Portharcourt, Kaduna, Kano and Benin were used as input data for computation of the mean and standard deviation for the system reliability indices using statistical analysis. The computed system reliability indices were used as input parameters in the analysis. A sensitivity analysis is performed to assess how the operation parameters could influence the numerical results. The results of the sensitivity studies indicate that Etete feeder of  Benin distribution system has the highest SAIDI sensitivity of 0.5478 because of prolonged customers‘ interruptions on the feeder while waterworks feeder of Ilorin distribution system has the least SAIDI sensitivity of 0.0019. Cocoa feeder of Ibadan distribution system has the highest SAIFI sensitivity of 1.0459 because of the frequent interruptions while waterworks feeder of Ilorin distribution system has the least SAIFI sensitivity of 0.0268. Ikpoba Dam of Benin distribution system recorded the highest CAIDI sensitivity of 0.8466 with waterworks feeder also recording the least CAIDI sensitivity of 0.0075. The results from this research paper provides baseline information for planning and managing distribution system on Nigeria national grid. Keywords: Sensitivity, Reliability indices, Distribution systems, SAIDI, SAIFI, CAIDI, Interruptions. DOI : 10.7176/APTA/77-07 Publication date :May 31 st 2019