配电网电容电流测量的改进信号注入法研究  

Research on improved signal injection method for capacitance current measurement in distribution networks

作　　者：虎俊 张智 田浩 HU Jun;ZHANG Zhi;TIAN Hao(Wuzhong Power Supply Company,State Grid Electric Power Co.,Ltd.,Wuzhong Ningxia 751100,China)

机构地区：[1]国网宁夏电力有限公司吴忠供电公司,宁夏吴忠751100

出　　处：《宁夏电力》2024年第4期63-68,共6页Ningxia Electric Power

基　　金：国网宁夏电力有限公司科技项目(5229WZ220009)。

摘　　要：信号注入法是测量配电网接地电容电流的常用方法,注入信号的频率选择会直接影响到测量精度,因此,提出了适用于测量配电网电容电流的改进信号注入法。首先,通过注入高频信号获得电压互感器的漏感值;其次,通过扫频法确定配电网接地电容的谐振频率,从而计算出配电网的接地电容电流值;最后,通过电网额定电压除以接地容抗,求得接地电容电流值。利用串联电容对实验系统总电容的削减效应,有效提升电容电流的测量精度。仿真和实验室的模拟实验结果证实了所提电容电流测量方法的可行性及有效性。The signal injection method is a common approach for measuring the ground capacitance current in distribution networks.The choice of the injected signal’s frequency directly affects the measurement accuracy.This paper presents an improved signal injection method for measuring capacitive current in distribution networks.Firstly,the leakage inductance value of the voltage transformer is determined by injecting a high-frequency signal.Then,the resonant frequency of the ground capacitance in the distribution network is identified through a frequency sweeping method,enabling the calculation of the ground capacitance.Finally,the current value of the ground capacitance is obtained by divi-ding the rated voltage of the network by the ground capacitive reactance.By leveraging the reduction effect of series capacitance on the total system capacitance,this study effectively enhances the precision of capacitance current mea-surement.Both simulation and laboratory experiments validate the feasibility and efficacy of the proposed capacitance current measurement method.

关 键 词：配电网 信号注入法 电容电流测量 接地电容谐振频率 

分 类 号：TM933[电气工程—电力电子与电力传动]