一种基于改进阻抗法的直流微网故障定位方法  

A fault location method for DC micro-grid based on the improved impedance method

作　　者：高传薪 陈皓[1] 郑思琦 闫重熙 Gao Chuanxin;Chen Hao;Zheng Siqi;Yan Chongxi(School of Electrical Engineering,Sichuan University,Chengdu 610000,China)

机构地区：[1]四川大学电气工程学院,成都610000

出　　处：《电测与仪表》2021年第5期151-158,共8页Electrical Measurement & Instrumentation

基　　金：四川省重点研发项目(21ZDYF3753)。

摘　　要：直流配电网故障定位是排查故障、保障线路安全和保证供电质量的关键。文中研究了现今直流微网中的故障定位技术,在基于电压源换流器的直流微网中分析了单极故障和极间短路故障时的故障响应特性,提出了一种利用换流器出口侧电容放电过程,提取其中的故障电压电流信息计算线路电感值从而确定出故障位置的新方法。根据电压关系将故障过程分段,利用暂态电流的变化率进行故障选线,再根据故障电路的二阶响应过程,确定出故障位置。在PSCAD/EMTDC中进行了仿真验证,结果表明,定位算法能够准确识别出故障类型以及故障线路并精确定位出故障位置。极间短路故障的定位误差在0.5%以内,单极接地故障的定位误差在3%以内。Fault location of DC distribution network is the key to fault diagnosis,line safety and power supply quality.This paper firstly studied the fault location techniques in DC micro-grid,and then,based on the voltage source inverter DC micro-grid,the failure response features of the single-electrode fault and inter-electrode short-circuit fault were analyzed,finally,a new method was proposed to determine the fault location by extracting the circuit inductance value of fault voltage and current information from converter outlet side capacitance discharge process,The fault process is segmented according to the voltage relationship,and the fault line selection is carried out by using the change rate of transient current.Finally,the fault location is determined according to the second-order response process of the fault circuit.Simulation results in PSCAD/EMTDC show that the location algorithm can accurately identify fault types and fault lines and locate the fault location.The positioning error of inter-electrode short-circuit fault is within 0.5%and that of single-electrode grounding fault is within 3%.

关 键 词：直流微网 故障定位 电压源换流器 微分算法 大电阻 

分 类 号：TM727.2[电气工程—电力系统及自动化]