Assessment of critical events corridors through multivariate cascading outages analysis

Massive blackouts of electrical power systems over the past decade has focused increasing attention to cascading events that may lead to widespread network collapses. It is important to be able to identify places in the system where the cascading events are most likely or/and lead to the most severe consequences. Based on this information, transmission planning decisions can be made that minimize the risk of blackouts in the most efficient way. This paper addresses all these issues. First, it outlines a method to simulate cascading failures resulting from multiple extreme initiating events. The method is currently confined to analyzing steady state power-system responses to extreme events and uses a simplified model of protection system. The second goal is to determine parts of the network vulnerable cascading failures. The hypothesis of critical events corridors is proposed to represent repeating sequential outages that can occur in the system for multiple initiating events. The new concept helps to identify system reinforcements that planners could engineer in order to “break” the critical events sequences and therefore lessen the likelihood and consequences of cascading outages. This hypothesis has been successfully validated with a California power system model.