基于参数识别的小电流接地故障选线定位研究  

Study of Fault Line Selection and Fault Point Location in Small Current Neutral Grounding Fault Based on Parameter Identification

作　　者：刘哲 吕鹏[2] 孙建东[2] LIU Zhe;LV Peng;SUN Jian-dong(State Grid Nanjing Power Supply Company,Nanjing 210019,China;State Grid NARI Technology Co.,Ltd,Nanjing 210061,China)

机构地区：[1]国网南京供电公司,江苏南京210019 [2]国电南瑞科技股份有限公司,江苏南京210061

出　　处：《电工电气》2018年第8期34-39,50,共7页Electrotechnics Electric

摘　　要：针对小电流接地故障选线定位存在的难题,建立了基于线路集中参数下的单相接地故障零序等效模型,通过分析各线路电气量特征,把其等效为电容模型,根据求解的线路对地电容值判断是否为故障线路。同时建立故障线路数学模型,利用零序电压、电流数据求解模型参数,依据所得参数计算故障点至母线的距离,从而实现接地点的精准定位。经RTDS故障仿真和MATLAB数据处理验证该方法正确可靠,选线定位精度高,且不受中性点接地方式和不稳定电弧的影响,有较强的耐过渡电阻能力,满足集故障识别、选线和定位为一体的自动化要求。Aiming at the problem existing in the route selection location of small current neutral grounding fault,this paper established the single-phase grounding fault zero-sequence equivalent model.Through analysis of the electrical characteristics of each line,it was equaled to a capacitance model.Based on the solution circuit,the judgment of grounded capacitance value would be made on whether it was a fault line.At the same time the mathematical model of fault line was established.The model parameters for fault lines could be solved with the zero sequence voltage and current.Based on the parameters of the fault,the distance from the fault point to bus bar could be calculated to realize the accurate location of the fault.This principle has been verified via a RTDS simulator and MATLAB data processed tool.The method above has higher reliability and better capability of the fault resistance endurance,which is free from the impact of neutral grounding modes and unstable fault arc.Particularly,it can be combined with fault identification,fault line selection and fault location,which is satisfying the automated requirements.

关 键 词：小电流接地故障 单相接地故障 选线定位 电容模型 参数识别 区段定位 

分 类 号：TM711[电气工程—电力系统及自动化] TM862