Location for single‐phase grounding fault in distribution network based on equivalent admittance distortion rate

Abstract

Abstract To solve the problem of difficult location (especially high grounding resistances) for single‐phase grounding faults in distribution networks, a fault location method based on equivalent admittance distortion rate is proposed in this paper. The equivalent admittance distortion rates are first obtained by measuring the pre‐fault and post‐fault equivalent admittances of each phase, each feeder and each section. Then the phase with the largest equivalent admittance distortion rate in each phase is determined as the fault phase, the feeder with the largest equivalent admittance distortion rate in each feeder is determined as the fault feeder, and the section with the largest equivalent admittance distortion rate in each section is determined as the fault section. Moreover, a fault identification strategy for single‐phase grounding faults is proposed to improve the robustness of this method. By measuring bus voltages and currents before and after faults, the fault type with only one‐phase in which voltage decreased and current increased is identified as single‐phase grounding faults. Compared with the existing methods, simulation results show that the proposed method is simple to implement and has strong robustness to high grounding resistances, long grounding distances and interference harmonics.

Keywords

• Distribution networks
• Power system protection