A Systematic Method for Reliability Index Evaluation of Distribution Networks in the Presence of Distributed Generators

This paper is aimed at evaluating the reliability indices of a distribution network (DN) considering the rerouting of the interrupted customers during outages. The DN is represented by its circuit graph that is used to analyze the effect of the failure mode (FMEA method) and compute the reliability of the system. To have a more accurate estimation, the capacity of the feeder and the voltage deviation when the rerouting occurs, are also considered. After the occurrence of an outage, the problem is finding the optimum tree by interchanging the status of normally open (NO) and normally closed (NC) switches to restore as many as interrupted customers subject to defined constraints. The proposed algorithm presents a systematic method to find the optimum solution of the restoration problem, and by decreasing the search space is suitable for analyzing the big size DN. To obtain the impact of each NC switches in the reliability improvement, a ranking method is also introduced.