An extended minimal cut set algorithm applied into overall power system reliability assessment

An Electric power system is a complex system in which a failure either in generation, transmission, substation or distribution will cause an outage. It is necessary to evaluate the power system all together to obtain a complete and accurate reliability index. The existing reliability assessment studies mainly investigate reliability hierarchically, neglecting effects occurring over different levels. Therefore the interaction between breakers, disconnectors and fuses are not analyzed in detail. This paper proposes an overall electric power system reliability assessment method, consisting of two parts: Firstly, an extended minimal cut set algorithm is proposed based on the analysis of the correlations of the switches outages. Secondly an idealized model of the substation is derived from the reliability parameter matrix and expected contingency set. The reliability index calculated with this method accurately captures the operation of the system. This in turn provides the planner and system manager with valuable information.