当配电网发生单相接地故障时，故障点会流过电容电流。随着城市发展，配电网不断扩大、延伸，使得配电网对地电容电流也随之增大，导致故障点易于产生间歇性接地电弧，引起幅值过高的弧光接地过电压，若弧光过电压持续时间长、影响面积大，可能导致绝缘击穿使故障扩大。为了避免事故的扩大，需在配电网的中性点装设消弧线圈，而配电网电容电流的测量是装设消弧线圈、确定消弧线圈容量和进行消弧线圈调谐的重要参数。因此，本文就如何准确测量配电网的电容电流进行研究。 针对低压配电网电容电流测量模型，利用对称分量法对于对称系统进行理论分析，揭示了系统中对地电容、绝缘电阻与系统零序电压之间以及支路零序电流之间的关系，使配电网电容电流测量得到了量化的估计。基于理论分析的基础上，本论文提出了利用最小二乘参数辨识法进行对地电容以及对地绝缘电阻的辨识，进而求得各个支路以及系统的对地电容电流、对地绝缘电阻电流的大小，当系统对称时的仿真模型验证表明：应用于对称系统时该方法可靠、有效。 针对三相电源不对称系统分析参数辨识法电容电流测量的影响，理论分析表明，用于检测电容电流的零序信号中含有50Hz工频信号，为了保证参数辨识法对于不对称系统电容电流的辨识精度，利用优化设计法设计了一个FIR带通数字滤波器。 论文给出了不对称系统的电容电流测量方法，首先测取系统零序电压和各个支路的零序电流信号，再对测取信号利用设计的滤波器进行信号处理，通过最小二乘辨识获得对地电容和绝缘电阻的大小，得到测量的对地电容电流和绝缘电阻电流大小，通过仿真验证表明，针对不对称系统参数辨识的检测方法同样精确、可靠、有效。

When the distribution network occurssingle-phase ground, impaired point flows capacitive current. With the city development, distribution network continue to expanding, making the distribution network to ground capacitive current also increased,leading to the impaired point are prone to producing intermittent arcing ground, causeing excessive amplitude arc grounding overvoltage. If the arc overvoltage durats long time and affects a large area, it may lead to insulation breakdown,the failure expanding. In order to avoiding the expansion of the accident, the neutral point of distribution network need to installe arc suppression coil. Measuring capacitive current is the important parameters of installation of arc suppression coil, determining. Petersen Coil capacity and processing Coil tuning. Therefore, this article mainly research on how to accurately measure the distribution network capacitive current. For low-voltage distribution network capacitive current measurement model, The symmetrical components method was utilized to analyze the symmetric Systems. The relationship between capacitance, insulation resistance and system zero-sequence voltage and branch zero sequence current were invetigated . Quantitative estimates was obtained for the distribution capacitive current measurement. In this thesis, Least Squares Parameter Identification method was utilized to investigate the identification of ground capacitance and insulation resistance and obtained the ground capacitance and insulation resistance of each branch as well as the current system. The simulation results showed that this method was reliable and effective when the system is symmetrical. For asymmetric three-phase power system analysis impact of parameter identification method of capacitive current measurement. Theoretical analysis shows,zero-sequence signal used to detecting capacitive current contains a 50Hz frequency signal. In order to guarantee the asymmetry parameter identification method for system identification precision capacitive current. Using the optimized method to design a band-pass digital FIR Filter. Paper gives measurement methods to asymmetric system. First, measuring the system zero-sequence voltage and zero-sequence current of each branch signal. Then the measured signal is taken advantage of filters designed for signal processing. Gain ground capacitance and insulation resistance of an identification by least squares. It is measured capacitance to ground current and insulation resistance of the current size. The simulation results shows,to asymmetric system detects parameter identification also accurate, reliable and effective