Effect of Component Unavailability on Power Distribution Feeder Reliability

Reliability of an electric power distribution feeder is affected by the availability of various components such as disconnecting switches, fuses and alternate supply. Depending on the restoration process of connected low voltage transformer, the outage duration can be changed. This paper presents the results of a range of cases to find the effect of unavailability of components on the feeder reliability. For this purpose, a simple distribution feeder from standard Roy Billinton Test System (RBTS) is selected as a test feeder. Analytical approach is used to evaluate the feeder reliability indices. A total of sixteen different distribution feeder design configurations are investigated to find the unavailability impact of individual and group of components. Both overhead and underground feeders are considered for comparison purposes. The results show that reliability of a distribution feeder is significantly decreased by the unavailability of components.