Performance of high-impedance fault detection algorithms in long-term field trials

Researchers at Texas A&M University's Power System Automation Laboratory have tested the long-term performance of high-impedance fault detection algorithms at five utilities. During the test period, prototype units were installed on feeders with a wide variety of load types. They were exposed to long-term load variations, switching events, and naturally occurring faults. One unit was also exposed to 62 staged fault tests. None of the prototype units experienced any false indications. Sensitivity to staged faults was very good. Finally, during the test period, one of the prototypes experienced a non-staged high-impedance fault; it successfully detected this fault.