Implementation and real time test of an accelerated zone 2 trip scheme for non-communicated distance relays

This work describes an algorithm which allows the trip acceleration on zone 2 of non-communicated distance relays for cases where faults are located inside the protected line. The algorithm is based on the detection of remote breaker operation following a zone 2 fault detection by local distance relay and it uses as a basis the monitoring of changes on a proposed signal. This algorithm is evaluated using data from fault cases generated by an electromagnetic transients program for different fault and operation conditions of a test power system. Real time operation is validated by implementing the proposed algorithm into a distance relay model using generic data acquisition and signal processing hardware. This relay is then evaluated using a real time digital simulator RTDS and throughout the tests, the results show that proposed algorithm is able to provide accelerated zone 2 trips with reduced operating times than those issued by relays using conventional zone 2 trip.