接地变压器简称接地变，根据填充介质，接地变可分为油式和干式；根据相数，接地变可分接地变压器为三相接地变和单相接地变。
The earthing transformer is called earthing transformer. According to the filling medium, grounding transformer can be divided into oil and dry type. According to the number of phases, the earthing transformer can be divided into three phase grounding and single-phase grounding.
三相接地变：接地变压器的作用是在系统为△型接线或Y型接线中性点无法引出时，引出中性点用于加接消弧线圈或电阻，此类变压器采用Z型接线，与普通变压器的区别是，每相线圈分成两组分别反向绕在该相磁柱上，这样连接的好处是零序磁通可沿磁柱流通，而普通变压器的零序磁通是沿着漏磁磁路流通，所以Z型接地变压器的零序阻抗很小（10Ω左右），而普通变压器要大得多。按规程规定，用普通变压器带消弧线圈时，其容量不得超过变压器容量的20%。Z型变压器则可带90%～100%容量的消弧线圈，接地变除可带消弧圈外，也可带二次负载，可代替所用变，从而节省投资费用。
Three-phase grounding transformer grounding transformer is the role of lead in the system for a given connection or Y connection not neutral, neutral point grounding for Petersen coil or resistor, such transformer with Z connection, different from ordinary transformer is divided into two groups, each phase coil respectively around the reverse the magnetic pole, the benefits of this connection is zero flux along the magnetic pole and zero flux circulation, ordinary transformer is leakage along the magnetic flow, so the zero sequence impedance of Z type grounding transformer is very small (10 or so), while the ordinary transformer is much greater. In accordance with the regulations, the capacity of an arc suppression coil with a common transformer shall not exceed 20% of the capacity of the transformer. The Z type transformer can be equipped with 90% to 100% capacity arc suppression coil. The grounding transformer can be carried out with the arc suppression coil, or with two loads. It can replace the used transformer and save investment cost.