Fault identification method based on the neutral point medium resistance switching-on for the distribution network

It has long been a hot issue of the single-phase to ground fault identification technics for the distribution network with neutral un-grounded system (NUS), the neutral resonant grounded system (NES) and the neutral resistor grounded system (NRS). The fault detection and location could be very difficult since the faulted component in above scenarios is less pronounced, and meanwhile it becomes a less helpful by using conventional scheme if the arc suppression coil is equipped. In this paper, a novel method based on the neutral point medium resistance switching-on is introduced, and the faulted component of the lines in the distribution network is analyzed. By the comparison between the variations of the faulted phase-current before and after the medium resistance switching-on, the faulted location can thus be determined. Simulation results indicate that in most cases, the proposed method show great reliability and immune to the changes of the system conditions.