基于偏置阻抗法的配电网电容电流测量新方法  

A new capacitive current measurement method of the distribution network based on bias impedance

作　　者：李晓波[1] 苗晓鹏[1] 桑振华[1] 蔡旭[2] 

机构地区：[1]中国矿业大学信息与电气工程学院,江苏徐州221116 [2]上海交通大学电子信息与电气工程学院,上海200240

出　　处：《电力系统保护与控制》2014年第4期22-26,共5页Power System Protection and Control

基　　金：国家自然科学基金(51107143)~~

摘　　要：分析了目前配电网电容电流测量方法所存在的问题,提出了一种偏置阻抗法测量电容电流的新方法。该方法通过在配电网中任意一相与地之间串入一固定电阻和可调电抗,调节电抗器,同时观察和测量中性点电压与偏置相对地电压的相角差,来配合电抗器的进一步调节,当该相角差接近90°时,即可精确地测量出电网对地参数。通过Matlab仿真和理论计算得到了一致的结果,同时验证了该方法能够取得比较精确的测量效果。该方法具有操作简单,测量精度高,不会引起中性点过电压等优点,可以应用于配电网电容电流的测量。A new capacitive current measurement method of the distribution network is proposed based on the analysis of the problems existed in the current capacitive current measurement methods. First, a fixed resistance and an adjustable inductor are installed in series between any one phase and the ground; second, the adjustable inductor is regulated, and at the same time, the phase angle difference between the neutral voltage and the bias phase voltage is observed; then the system ground capacitance and resistance can be calculated when the phase angle difference mentioned above is close to 90 degrees. The corresponding simulation is carried out by using Matlab, which obtains the same results with the theoretical calculation. The results show that this method is feasible. Apart from these, this method is operated simply, of high measurement accuracy, and not leading to neutral overvoltage. This method can be used in the capacitive current measurement in the distribution network.

关 键 词：配电网 偏置阻抗法 相角差 对地参数 测量效果 

分 类 号：TM933.1[电气工程—电力电子与电力传动]