The accurate tuning and controlling of arc-suppression coils is mainly depend on accurate measurement of phase-to-ground fault current. A new measurement method of phase-to-ground fault current is proposed, which can be used in cable networks or in mixed networks of cable and overhead line. The method can calculate the change of the phase-to-ground capacitive current and damp current by measuring the value and phase angle of the zero-sequence voltage of the normal operation power system on line. The measurement method can measure not only in a pre-resonant grounding power system, but also in a post-resonant grounding power system. Test and operation results indicated that the method is easy to use and has some advantages of measurement without accompanying operation, continuous calculation by measuring one signal only and high accuracy.%消弧线圈的准确调谐控制主要依赖于对电网对地电容电流的测量.提出一种适合于纯电缆电网或电缆架空线混合电网的接地电流在线测量方法.该方法只需连续监测电网正常运行时中性点位移电压的幅值和相位,就可在线算出电网对地电容电流和阻尼电流的变化.它既适用于“预调谐”,也适用于“随调谐”消弧线圈的调谐控制.模拟试验和挂网运行都证明它具有测量方法简单、测量时不需要任何伴随操作、仅需要一个测量信号、可连续重复测量、测量精度高等优点.
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