Protection system misoperation analysis

This paper provides a summary of more than 2,200 protection system misoperations and associated leading causes. Approximately 65% of the misoperations occurred due to three leading causes. Suggestions for improvement were developed to reduce the most frequent causes of protection system misoperations. The observations, conclusions, and recommendations in this paper can serve as technical input to the industry and help increase bulk power system reliability by reducing relay misoperations that could otherwise cause, or contribute to, a larger system disturbance.