Optimal locations for protection system enhancement: a simulation of cascading outages

Recent studies have shown that hidden failures in the protective devices have a great impact on the power system reliability. In this paper, we provide the definitions of vulnerability and reliability of protection system 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 limited budget. Finally, we present the result of a case study on New York Power Pool (NYPP) 3000-bus system.