Evaluation of reliability indices accounting omission of random repair time for distribution systems using Monte Carlo simulation

This paper describes a methodology for reliability assessment of electrical distribution system accounting random repair time omission for each section. A distributor segment in a distribution system has failure rate and repair time which decide mean up time (MUT) and mean down time (MDT) at load points. Usually the reliability analysis is based on exponential failure and repair laws. The repair time is a random variable. Certain values of repair times are smaller which may be neglected based on the tolerance time of consumers at each load point. Complete reliability analysis with repair time omission has been presented. Modified mean up time, mean down time and unavailability (h/year) have been obtained at each load point using state transition sampling technique. These have been obtained accounting outage due to random repair time omission. The methodology has been implemented on two distribution systems. (C) 2012 Elsevier Ltd. All rights reserved.