Research on line selection method of single-phase grounding fault in small current system based on percentage restrain differential amplitude-phase plane
amplitude-phase plane,high impedancegrounding fault,percentage restrain differential,zero-sequence current
In small current systems, there are some limitations in selecting fault lines only by using zero sequence current characteristics of single-phase grounding fault. Based on the analysis of the amplitude-phase relationship between the zero sequence current and the neutral point current of the fault line and the non-fault line after the single-phase grounding fault occurs in the small current system, a method of selecting the high impedance grounding fault circuit based on the percentage restrain differential amplitude-phase plane is proposed. The simulation results show that the proposed method has high accuracy and high fault tolerance.