Time synchronous end-to-end relay testing

The availability of precise time information via geo-stationary (GOES) or global positioning (GPS) satellites offers a valuable resource for synchronous control of remotely located protective relay test instruments, providing capabilities for end-to-end test of power system protection systems. The authors introduce a design for cycle-by-cycle control and synchronization of protection test instruments, illustrate a method for synchronizing and controlling protection tests instruments at remote locations using GOES/GPS satellite receivers, and suggest test methods suitable for end-to-end testing of protection systems