Power system cascading failure path searching under multiple failures based on probability estimation

Abstract

In the analysis of cascading failure, the multiple failures is necessary to take into account under a certain condition, and the occurrence probability and severity of multiple failures are varies with the change of operating mode caused by equipment maintenance. In this paper the event tree is used in the analysis on cascading failures and by use of probability approximation theory of rare event the probability order of multiple failures is divided, thus the screening process of multiple failures can be simplified. Applying this method to the analysis on cascading overload and from the case simulation results it can be seen that the proposed searching method can reflect the variation of failure probability caused by the change of operating mode well, and assess the risk of equipment maintenance better, thus the path searching of low-probabilistic and high-risk cascading failures can be further improved. The proposed method may be helpful for the research on cascading failures in depth.