Automated testing of communications based schemes in transmission line protection relays

Testing of modem microprocessor based transmission line protection relays with communication accelerated schemes requires excellent understanding of the logic of the particular scheme being tested. These-relays operate based on the state of multiple monitored signals, such as permissive signals, breaker status signals, and communication channel status signals. Time coordination of these signals and synchronization with the prefault and fault analog signals is. required in order to perform adequate testing of this type of schemes. The paper discusses the challenges in the testing of communication based schemes in transmission line protection relays. It introduces the concept of an automated "point-and-click" test process that allows a dramatic reduction in the time to test such complex logic.