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。
Single-phase grounding transformer: Single-phase grounding transformer is mainly used for neutral point grounding resistance cabinet of generator and transformer, in order to reduce the cost and volume of resistance cabinet.
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) Intermittent extinguishing and reburning of single-phase grounding arc will result in arc grounding overvoltage, whose amplitude can reach 4U (U is the peak value of normal phase voltage) or higher, and its duration is long, which will cause great harm to the insulation of electrical equipment, breakdown in the weak insulation and cause great 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) Because of the dissociation of air caused by continuous arc, the insulation of surrounding air is destroyed and the short circuit between phases is prone to occur.
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) Ferromagnetic resonance overvoltage can easily burn the voltage transformer and cause the damage of the arrester, and may even cause the arrester to explode. These consequences will seriously threaten the insulation of power grid equipment and endanger the safe operation of power grid.