考 虑 单 相 断 线 坠 地 故 障 的 柔 性 电 压 消 弧 装 置 投 切 策 略

The zero-sequence voltage of single-phase line breaking and grounding fault in distribution network will make the flexible voltage arc-suppression device start up by mistake. The current at the fault point may increase after the device is put into operation. Firstly, the trajectory of zero-sequence voltage displacement under single-phase line breaking and grounding faults is analyzed. The reason why the typical phase selection method of grounding fault is not suitable for the single-phase line breaking and grounding faults and the mechanism of fault deterioration caused by mis-switching of flexible arc-suppression device are clarified. Secondly, a method for distinguishing between grounding faults and line breaking and grounding faults based on phase current mutation is proposed. An identification method of single-phase line breaking and grounding fault type based on zero-sequence differential current and phase difference of phase voltage is further proposed. A switching strategy of flexible voltage arc-suppression device considering single-phase line breaking and grounding fault is proposed. Finally, the correctness of the theoretical analysis is verified based on PSCAD simulation.