In power system, it is a comprehensive problem that whether generator neutral point grounds or how to ground, refering to technology, economy, safety and so many fields. Usually relative neutral point treatment is adopted according to various coperation requirements. In order for safety of people and machine. it is necessary to strengthen research of neutral point treatment of electrical equipments for determining a good neutral grounding technique based a safe and economic oepration.
In the case that generator grounds unsolidly, when generator stator winding has single-phase grounding fault, grounding fault current would be much lower than load current due to not forming loop short-circuit, which is called small grounding current system. Current flowed throungh grounding point is equal to capacitance current towarding earth of connected device for generator drawing forth loop circuit. When it excesses allowable value, stator core would be burned and moveover the stator winding insulation would be damaged, causing turn-turn or phase-phase short-circuit. Therefore, we need to apply protective measurements of arc-suppression coil or high-resistance grounding to generator neutral point avoiding destroying of generator.