LAUSR

Summary This paper presents a new algorithm for discrimination of short-circuit faults from power system stressed conditions. The proposed algorithm is based on the combination of distance relay zone-3 operation and traveling waves generated by either the fault or circuit-breaker switching. By pick-up of the distance relay zone-3, the algorithm looks for traveling waves arriving from the fault point in the first stage. If a fault generated traveling wave is detected, it would be concluded that a fault has occurred. Otherwise, the algorithm enters the next stage and waits for arriving traveling waves caused by open-switching of the faulted line remote circuit-breaker. If any traveling wave is detected, the system is under fault condition. Otherwise, the reason of zone-3 pick-up is due to a stressed condition. Training a decision tree-based classifier with the proposed features and simulating the method demonstrate that the proposed algorithm is able to provide a reliable remote back-up scheme for protection of transmission lines.