Direct identification of Multi-Hidden failures in main distance relays of transmission systems

Hidden failure of protective relays is one of the major causes of outages and eventually cascading failures in power systems. Owing to the fact that hidden failures cannot be detected until their effects are exposed to abnormal conditions, the proposed “direct identification method” provides detection and localization of single as well as multi-hidden failures according to the issues from the main distance relays of the transmission system. This novel analytical model gets the information of the recorded outputs of starters, trip signals, and relay resets as inputs, and by comparing these inputs with the reference data for the outputs of the main distance relays, the presence of hidden failures in distance relays are directly revealed. The whole process ends in one round and there is no need of optimization methods and complicated algorithms. The proposed method was simulated with the supposed data on 14-bus IEEE system and the results showed its high accurate performance.