Optimal Locations for Protection System Enhancement: A Simulation of Cascading Outages

Recent studies have shown that hidden failures in protective devices have a great impact on power system reliability. In this paper, we provide the definitions of vulnerability and reliability of protection systems to numerically characterize this impact. A random search algorithm based on power system heuristics is given for fast rare-event simulation of consecutive relaying malfunctions in bulk power systems. We also propose an economical system upgrading strategy that can best enhance the protection system reliability under a limited budget. Finally, we present the result of a case study on the New York Power Pool (NYPP) 3000-bus system.