Evaluation of cascading failure in power system based on the operational reliability theory

According to the characteristics of the cascading failures in power grid, a lot of assessment methods based on the probability theory have been proposed in recent years. However, most of them ignore the influence of the changing operating conditions on the power system planning and operation. This paper assesses the risk of the cascading failure in the power system based on the operational reliability theory which considering the variation of operating states and environment of the power system. The operational reliability of the power system is calculated based on Markov Process which describes the transient probability of states. The key conception of this theory is that the failure rate and the probability of components are changing along with the life of the equipment, the operating states and the environment conditions. A new evaluation procedure is brought up to calculate the operational reliability indices which can provide the specific information of the cascading failure. The evaluating results of the test system confirm that this approach is applicable to analyze the cascading failures in real power system.