High-resistance grounding fault line selection method and system based on passive voltage regulating device

The invention provides a high-resistance grounding fault line selection method and system based on a passive voltage regulating device. The method comprises the following steps: acquiring real-time zero-sequence voltage of the system and real-time zero-sequence current of each feeder line through measurement; under two conditions of a normal operation state and a single-phase earth fault state of the system, the zero-sequence voltage of the system is regulated and changed through a passive voltage regulating device, the zero-sequence current of each feeder line is recorded, and the zero-sequence admittance before and after the fault of each feeder line of the system is solved; and judging the fault feeder line according to the zero-sequence admittance phase angle difference before and after the grounding fault of the non-fault feeder line and the fault feeder line. The line selection method provided by the invention is high in line selection accuracy, can solve the problem of fault line misjudgment during sma