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Modern electric power protection, monitoring, and control systems rely on the availability of high-accuracy time. Precise time enables technologies like synchrophasors, IEC 61850 Process Bus, and highly accurate, wide-area power system event reporting. Today, high-accuracy time is generally provided by Global Positioning System (GPS) clocks. However, if GPS is the only source of accurate time, it becomes the single point of failure in systems that rely on precise time. GPS may become unreliable due to solar activity, intentional or unintentional jamming, or the U.S. Department of Defense (DoD) modifying GPS accuracy or turning off the satellite system. (5 pages)

In this paper, we first review backup protection concepts and analyze the impact of breaker failure protection on power system stability. We then show the importance of having different breaker failure operating times for different types of faults. Finally, we discuss the effect of fault detector reset time and describe fast-reset instantaneous overcurrent elements. (5 pages)