Fault line Selection of Single Phase Grounding Fault in Small-Current Ground System Based on Reactive Current

It is difficult to select fault line accurate when single phase grounding faults occur in small-current ground system. The manuscript proposed a novel fault line selection scheme base on reactive current. According to theoretical analysis, the variation of current after the occurrence of single phase short circuit is mainly composed of capacitive current. The variation of capacitive current is induced by the change of line capacitor. For the line of faulty phase, the variation of reactive current is larger than that of normal line. Based on this principle, the novel fault line selection scheme is proposed. To research the reliability of the proposed scheme, a typical small-current ground system model is built in PSCAD. Effect of transmission line, arc suppressing coil and grounding resistance are researched in simulation. Simulation results show that the proposed scheme can select the fault line with a high reliability.