A novel location method for single-phase grounding fault in small current grounding distribution network based on difference of phase current fault component between fault and non-fault phases

Abstract

Single-phase grounding fault is the most frequent fault in distribution network small current grounding systems. But the misjudgment ratios of existing location methods are always high, which influences the power distribution stability. This is due to a series of problems such as insignificant characteristics of steady-state electrical quantities and short duration of transient zero-sequence fault characteristics. After studying a typical fault characteristic called phase current fault component, the experiments show that when single-phase grounding fault occurs, the phase current fault component waveforms of fault and non-fault phases are significantly different in fault upstream sections. On the other hand, in downstream and non-fault sections, the waveforms are basically the same. With this conclusion, a new fault section location scheme for single-phase grounding fault in distribution networks is designed based on difference of phase current fault component between fault and non-fault phases. And the reliability and sensitivity of this method are proved under multiple conditions in the PSCAD simulation environment.