含分布式电源的配电网单相接地故障精确定位方法  

A Method for Precise Location of Single-phase Grounding Fault in Distribution Network withDistributed Generation

作　　者：李卫国[1] 刘柏岑 卢广旗 LI Weiguo;LIU Baicen;LU Guangqi(Northeast Electric Power University College of Electrical Engineering,Jilin 132012,China;Tianshui Power Supply Company of State Grid Gansu Electric Power Company,Tianshui 741000,China)

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012 [2]国网天水供电公司,甘肃天水741000

出　　处：《供用电》2020年第9期58-63,共6页Distribution & Utilization

基　　金：国家自然科学基金项目(U1766204)。

摘　　要：分布式电源(distributed generation,DG)大量接入配电网,改变了配电网的结构和单相接地故障时的特征,给配电网的故障定位带来了困难。针对含DG的中压配电网故障定位困难且现有的故障定位方法准确度低的问题,提出一种新的故障定位方法。首先采集配电网故障前后电源节点处的零序电压、零序电流,根据含DG的配电网零序阻抗模型,计算出故障区段特征值,选择特征值最小的两节点作为故障发生区段的首末节点,建立两节点的线路零序阻抗模型,利用牛顿-拉夫逊方法计算出故障位置。算例表明,该方法具有较高的准确度和较强的鲁棒性,且不受过渡电阻和故障距离影响。With the distribution of DG(distributed generation)access to the distribution network,the structure of the distribution network and the characteristics of single-phase grounding fault have changed greatly,which brings difficulties to the fault location of the distribution network.In view of the difficulty of fault location in medium voltage distribution network with DG and the low accuracy of existing fault location methods,a new fault location method is proposed in this paper.First,the zero sequence voltage and current at the power node before and after the fault of the distribution network are collected.According to the zero sequence impedance model of the distribution network with DG,the characteristic value of the fault section is calculated.The two nodes with the minimum characteristic value are selected as the first and last nodes of the fault section.The zero sequence impedance model of the two nodes is established,and the fault location is calculated by Newton Raphson method.The example shows that the method has high accuracy and strong robustness,and is not affected by the transition resistance and fault distance.

关 键 词：配电网 分布式电源 单相接地故障 故障定位 零序电压 零序电流 零序阻抗模型 

分 类 号：TM71[电气工程—电力系统及自动化]