Using Monte Carlo simulation for overall distribution system reliability worth assessment

This paper describes a Monte Carlo simulation approach to overall distribution system reliability worth assessment and illustrates it by application to the distribution systems of all the five load buses associated with a complex test system. The paper presents the results of a series of simulations studying the impacts of various probability distributions for restoration times on the two reliability worth indices, namely load point expected cost (ECOST) and interrupted energy assessment rate (IEAR). Different radial system operating philosophies are incorporated and their impacts are analysed. Furthermore, the contributions from radial segment and subtransmission failure modes, such as first-order active failures, first-order total failures and all the possible second-order overlapping failures, to overall distribution worth indices are analysed. All the information generated by the simulation studies can provide useful reference to the electric power utilities and planners in the decision-making stage.