A review of single-phase-to-ground fault location methods in distribution networks

Distribution network feeders are very different from transmission lines due to more complex structures and more branches. The phase-to-ground faults in distribution network will induce larger transition resistance than in transmission lines. The traditional single-phase-to-ground fault location methods for transmission lines are no longer suitable for the distribution feeders due to the transition resistance and the branches´ distributed capacitance. According to the investigation, single-phase-to-ground faults account for about 70% of all faults in distribution network. Therefore this paper surveys the singe-phase-to-ground fault location methods used both at home and abroad for distribution network, mainly including impedance method, traveling wave method, signal injection method, the zero-sequence component based method and compositive location method. The basic principles of the representative methods are present, and their advantages and disadvantages are analyzed. Then the main problems of the single-phase-to-ground fault location methods in distribution network are briefly expounded. Finally the future research ideas are proposed preliminarily.