零序电流互感器，顾名思义，只要有零序电流产生的地方都可以进行保护。

Zero sequence current transformer, as the name suggests, as long as there are zero sequence current produced in the place can be protected.

产生零序电流，也只有在负荷不对称（目前所碰到的和要解决的不对称电流主要是三相电流）时才起到作用。

The generation of zero sequence current can only play a role only when the load is asymmetrical (the current and the asymmetric current is mainly three phase current).

测量到这个零序量，可以是中性点（最直接，零序电流互感器），也可以是三相电流矢量合成（三相电流互感器合成零序电流，电缆馈线回路常用）。

The zero sequence quantity can be neutral point (most direct, zero sequence current transformer), or three-phase current vector synthesis (three phase current transformer synthesis zero sequence current, cable feeder circuit commonly used).