Faulty line selection based on active-intervention-type arc suppression device via additional neutral resistance

The excessive arc current will damage electric equipment and threaten personal security when the single-phase-to-ground fault occurs in the distribution network. The active-intervention-type arc suppression device can effectively suppress the arc current by actively switching on the grounding switch of the faulty phase at the bus. However, in case of mis-selection, a more severe two-phase fault will be triggered. This paper studies the procedures of the active-intervention-type arc suppression device and proposes a faulty line and faulty phase selection method based on the neutral point additional resistance. The real-time line-to-ground parameters are calculated using the neutral point voltage changes before and after the additional resistance switching, and then the change of the line-to-grounding parameter is analysed to determine the faulty phase. The zero-sequence components of each line are analysed, and a mathematical formula is presented to determine the faulty line as the switching of the additional resistor will change the zero-sequence circuit of the faulty line. Simulation results show that the proposed method has high accuracy and reliability even for high-resistance-to-ground fault.