Analysis of Single-phase-to-ground Fault Based on Primary and Secondary Integration Circuit Breaker

Single-phase-to-ground fault (SPGF) in power distribution system (PDS) with neutral non-effectively grounded(NNEG) is a typical multiple fault, and long-term operation with faults may cause overvoltage problem of the entire system, resulting in equipment damage, etc. Based on the characteristics of SPGF, this paper theoretically analyzes the characteristics of SPGF in neutral ungrounded systems(NUS) and resonant grounding systems(RGS), and analyzes the threshold action value setting rules for zero sequence voltage and zero sequence current of primary and secondary integration circuit breaker(PSICB). Finally, based on a SPGF handling case, the application effect of PSICB in handling grounding faults was analyzed.