近年来，随着负荷密度区配电网规模的扩大和电缆线路的大量应用，配电网对地容性电流达到一个较高的水平。当配电网发生单相接地故障时，故障点流过过大的容性电流，导致故障点易于产生电弧，进而引起弧光过电压，弧光过电压会引起线路绝缘薄弱处损坏。在配电网中，当容性电流超过规定值时，为了使故障接地点电弧迅速熄灭，避免事故的扩大，需在配电网的中性点装设消弧线圈。因此，为了减小配电网容性电流的危害，确定配电网的运行方式，确定是否需要安装消弧线圈及确定消弧线圈的容量，准确的测量配电网的容性电流是十分必要的。 深入研究现有的配电网对地容性电流测量方法，并对各种测量方法进行了仿真，分析各种测量方法的测量精度、适用范围和优缺点。最终采用具有较多优点的注入信号向量法，进行进一步深入研究。对向量法注入信号的选择进行深入研究，研究表明合理地选择注入信号的强度和频率可减小测量误差，并最终确定选择注入“一高一低”的频率。其次，在仿真环境中搭建含有白噪声、电弧炉和变频器模型的不对称系统，仿真分析非线性负荷、系统不对称等对注入信号向量法的影响。最后，对注入信号向量法的信号提取进行研究，设计IIR滤波器，从含有噪声、50Hz工频干扰的信号中提取信号，仿真结果表明IIR滤波器能准确提取信号，能使容性电流测量结果具有较高的精度。

In recent years，the expansion of distribution power network and the large use of cables make the capacitive current reach a higher level.When the single-phase grounding occurs, the fault point exists large capacitive current.Excessive capacitance current easily generates arc which causes arc over-voltage.Arc over-voltage damages the insulation of the weak part.When the capacitive current exceeds the set value in the distribution network，arc suppression coil should be installed to make the grounding arc die out quickly and avoid the expansion of accident. Therefore, in order to mitigate danger the capacitance current of distribution network 、to determine the system operation mode 、to determine whether the arc suppression coil should be installed and the capacity of arc suppression coil,the capacitance current of distribution network needs to be accurately measured. The measuring methods of the existing capacitance current are studied and different measuring methods are simulated in this paper. Meanwhile the advantages and disadvantages of the methods mentioned above and the accuracy of measurement are analyzed.Vector method with more advantages is adopted and studied deeply.And the selection of the injected signal is analyzed.Research shows that the reasonable choice of the frequency range and injected signal strength can reduce the error of measurement.Based on the theoretical analysis,‘a high and a low’ frequency are chosen and injected.Asymmetric system with white noise、electric arc furnace and converter model is built in the simulation system.And the effects with nonlinear load and unbalanced system on vector methods are analyzed.Finally, the signal extraction of signal injection method is studied.An IIR filter is designed to be used to extract the signal from the signal containing noise and 50 Hz frequency interference.Simulation results shows that the IIR filter has high accuracy to extract the signal，which can make the capacitive current measurement results with high precision.