Composite Distribution System Reliability Evaluation - Effect of Interaction between Distribution Substation and Primary Distribution System

Abstract

This thesis examines the reliability analysis of distribution substation by using minimal cut set method and fault tree analysis (FTA). The five types of distribution substations are adapted from existing literature [2] to illustrate the detailed calculation of the substation reliability indices. The impact of the substation reliability on composite distribution system is also analyzed by using minimal cut set approach. The five types of primary distribution system are taken and modified from RBTS Bus 4 [2] and used for reliability assessment of composite distribution system. The substation reliability models, the interaction between the distribution substation and primary distribution system model and primary distribution system reliability model are adapted from literature [2] and conduct the detailed calculation by using Microsoft Excel software. In addition to load point reliability indices, system reliability indices of the composite distribution system are also analyzed by using minimal cut set method to illustrate the severity of system failures and the impact of substation reliability upon composite distribution system reliability. Fault tree analysis (FTA) approach is also used to analyze the same substation configuration with same reliability data for comparing with minimal cut set method and to provide as the alternative approach for reliability assessment of distribution substation.