Summary of research on hidden failures in protection systems

With the development of power market, power systems are forced to be operated closer to their limits. To achieve high security in such an environment is a challenging task. In most cases, collapse of power system often begins with small fault; the misoperation of protection system spreads the affected area of fault, while hidden failure of protection system always results in its misoperation. Aiming at hidden failure in relay protection, the paper presents a comprehensive review and summary of its research history, current progress and its associated application in power system, the paper also presents its future prospect.