连接于变压器中性点与大地之间的一种限流电气保护设备,在电网正常运行时不工作,当电网线路出线故障时,变压器中性点电压将产生偏移,如果变压器中性点接有接地电阻装置,它可以将配电网中性点强制接地,并限制其故障电流,使继电保护设备有足够的时间进行检测,实现跳闸和备用切换,避免配电网和电气设备遭到破坏。

A limit is connected between the neutral point of the transformer and earth flow electrical protection equipment, does not work in the normal operation of the power grid, when the grid line outgoing line fault, transformer neutral point voltage will produce offset if the transformer neutral grounding resistor, it can be the distribution network neutral point grounding force, and limit the fault current, the relay protection device has enough time for testing, realize tripping and standby switching, to avoid the destruction of electrical equipment and power distribution network.