中性点接地电阻柜主要的作用是：当发电机运行中发生单相接地故障时，当故障电流达到一定值，其故障点出现电弧接地，使得接地过电压的出现具备了特定的“临界”条件，从而导致弧光接地过电压的产生；、由于发电机的耐压水平较弱，其绝缘容易遭受破坏。进一步扩大定子绕组绝缘损害范围，甚至烧损铁芯，并伴随产生高于正常状态时的机械压力作用于发电机及其回路。

The main function of neutral grounding resistance cabinet is: when single-phase grounding fault occurs in generator operation, when fault current reaches a certain value, arc grounding occurs at the fault point, which makes the occurrence of grounding overvoltage meet a specific "critical" condition, resulting in the generation of arc grounding overvoltage; and the insulation of generator is vulnerable to damage because of its weak voltage withstanding level. The damage scope of stator winding insulation is further enlarged, even the iron core is burned, and the mechanical pressure which is higher than the normal state acts on the generator and its circuit.

如不及时发现并快速切除故障，将发展成为相间或匝间短路。基于上述原因，国际广泛采用发电机中性点经高阻接地，当其回路发生单相接地时，以限制弧光接地过电压，减轻对铁芯的灼伤，减少对发电机及其回路的机械压力。

If faults are not detected in time and removed quickly, they will develop into inter-phase or inter-turn short circuit. For the above reasons, the generator neutral point is grounded by high resistance in the world. When single-phase grounding occurs in its circuit, it can limit arc grounding overvoltage, reduce the burning of iron core and reduce the mechanical pressure on the generator and its circuit.