Case studies in facility-wide time synchronization

Time synchronization of protective LEDs can be critical for analyzing events, compensating for channel asymmetry in distance protection and streaming synchro-phasors. Satellite-based IRIG-B time can be used to provide a precise time signal but still has limitations. This paper examines some of the limitations of IRIG-B as a time source and discusses solutions to many issues as well as alternate timing signals. Case studies examined include: time synchronization across a large industrial facility using IEEE 1588 with multiple vintages of devices, distance limits of IRIG-B signals and time offset coordination for local times.