单相接地变：单相接地变主要用于有中性点的发电机、变压器的中性点接地电阻柜，以降低电阻柜的造价和体积。 Change is mainly used for single-phase grounding: single phase grounding of the neutral point of generator, transformer neutral point grounding resistance cabinets, to reduce the cost of the ark of the resistance and volume. 1）单相接地电弧发生间歇性的熄灭与重燃，会产生弧光接地过电压，其幅值可达4U（U为正常相电压峰值）或者更高，持续时间长，会对电气设备的绝缘造成极大的危害，在绝缘薄弱处形成击穿；造成重大损失。 1) single phase earthing arcing intermittent out with renewed, can produce arc grounding overvoltage, its amplitude can be up to 4 U (U) as normal phase voltage peak or higher, duration is long, can cause great harm to electrical equipment insulation, the insulation breakdown is weak; In heavy losses. 2）由于持续电弧造成空气的离解，破坏了周围空气的绝缘，容易发生相间短路。 2) caused by continuous arc air dissociation, damage the insulation of the surrounding air, and prone to short circuit. 3）产生铁磁谐振过电压，容易烧坏电压互感器并引起避雷器的损坏甚至可能使避雷器爆炸。这些后果将严重威胁电网设备的绝缘，危及电网的安全运行。 3) produce ferroresonance overvoltage, easy to burn out voltage transformer, and cause the damage of the surge arrester and even may make arrestor explosion. The consequences will be serious threat to the insulation of the power grid equipment, endanger the safe operation of power grid.