Identification of vulnerable branches considering spatiotemporal characteristics of cascading failure propagation

Abstract

A method of identification of a vulnerable branch considering the propagation characteristics of cascading failures is proposed. To determine vulnerable components that trigger or expand the propagation of cascading failures, a fault chain model of a power system is established by selecting the branch with maximum outage probability among all branches as the outage branch at the next step in a cascading failure process. The cascading failure process set can be compressed into a directed and weighted cascading failure graph by merging the repeated components in different cascading failure processes and accumulating the corresponding weight values between components: the cascading failure space–time graph can be generated according to the power grid partition. In terms of vulnerability cause and whether branch can promote the cascading failure process to spread across regions, vulnerable branches are classified and identified. The verification results show that the proposed method can accurately identify the vulnerable branches that trigger or expand the propagation of cascading failures and distinguish factors inducing different cascading steps.