Development of a simple reliability model for reliability evaluation of redundant customer delivery systems

Abstract

This paper describes the reliability model developed recently for computing the reliability of one of the most commonly used customer delivery systems in transmission network systems (Jones station). The model is based on the minimal cut set approach and computes the frequency and duration indices of supply interruptions to the low voltage buses (delivery points) of the station. The developed model is simple to use, produces results quickly and avoids the detailed modelling of component failure modes. In addition, the model can handle radial and non-radial circuit supply to the station as well as some changes in the circuit supply network. The accuracy of the model was tested against the Hydro One's area reliability evaluation program (AREP). The application of the model to some of Hydro One's Jones stations shows that it produces very close results to those of the AREP program. The model has been used in recent reliability studies to evaluate the reliability benefits from various investment projects. The purpose of this paper is to describe in detail the reliability model and to illustrate some of its recent applications.