弧光接地过电压的危害 The damage of an arc to earth voltage ⒈弧光接地产生的高幅值的过电压加剧了电缆等固体绝缘的积累性破坏。对于中性点非直接接地系统，我国现行规程笼统地规定允许带单相接地故障运行2小时，并未区分是架空线路还是电缆线路，也没有明确是弧光接地还是金属接地。在高幅值的弧光接地过电压的持续作用下，加剧了电缆等固体绝缘的积累性破坏。最终在非故障相的绝缘薄弱环节造成对地击穿，进而发展成为相间短路事故。 The over-voltage of the high amplitude of the arc grounding amplifies the cumulative damage of solid insulation such as cable. For neutral indirect grounded system, allowed in the current procedures in general provisions of single-phase earth fault running for 2 hours, does not distinguish between overhead line or cable line, is also no clear arc grounding or metal. The cumulative damage of solid insulation such as cable is exacerbated by the continuous effect of the voltage of the high amplitude arc. Finally, the insulation of the non-fault phase is caused by the failure of the insulation, and the development becomes a short-circuit accident. ⒉弧光接地过电压导致烧PT或保险熔断，普通的电压互感器饱和点一般为1.6～1.8倍，在弧光接地过电压作用下，使电压互感器严重饱和，激磁电流剧烈增加。另一方面，电压互感器饱和，也很容易激发铁磁谐振，导致电压互感器过载。上述两种情况，都将造成电压互感器烧毁或高压保险熔断。 Lead to burn this over-voltage of arc light earthing PT or safety fuse, common voltage transformer saturation point average of 1.6 ~ 1.8 times, under the influence of arc grounding overvoltage, serious saturation voltage transformer, dramatic increase excitation current. On the other hand, the voltage transformer is saturated and it is very easy to excite the ferromagnetic resonance, causing the voltage transformer to overload. Both of these conditions will cause the voltage transformer to burn or the high-pressure insurance to fuse. ⒊弧光接地过电压导致避雷器爆炸 The voltage of the arc is caused by the voltage of the arc 弧光接地时，过电压的能量由电源提供，持续时间较长，能量很大。当过电压的能量超过避雷器所能承受的400A/2ms的能量指标时，就会造成避雷器的爆炸事故。 When the arc is ground, the energy of the overvoltage is provided by the power supply, which lasts longer and has a great energy. When the overvoltage energy exceeds the 400 a / 2ms energy target that the arrester can withstand, the explosion accident of the lightning arrester is caused.