电力线路电场强度测量代替电压测量的量化误差分析  

Quantitative Error Analysis of Voltage Value Obtained by Measuring Electric Field Intensity of Overhead Power Line

作　　者：张海 刘宗杰 王继文 韩建伟 徐国强 杨鹏 ZHANG Hai;LIU Zongjie;WANG Jiwen;HAN Jianwei;XU Guoqiang;YANG Peng(Jining Power Supply Company of State Grid Shandong Electric Power Co.,Ltd.,Jining,Shandong 272000,China)

机构地区：[1]国网山东省电力公司济宁供电公司,山东济宁272000

出　　处：《广东电力》2023年第6期85-93,共9页Guangdong Electric Power

基　　金：国网山东省电力公司科技项目(520600200R4)。

摘　　要：配电线路故障指示器采用电场强度测量来替代真实的电压测量,易受到环境、测量点等多因素影响,存在较大误差,目前研究尚缺乏针对该误差的量化分析,使得实际应用中基于该估算电压值的故障启动和判别,易发生误动和拒动。从电磁场理论层面分析通过电场强度测量获取线路电压的可行性,得出输电线路单相接地故障条件下电压测量和电流测量完全解耦的结论。建立基于镜像法的电磁模型,给出空间电场强度与线路电压之间的关系公式,并根据物理场有限元分析,绘制杆塔存在情况下的空间电场强度分布图和波形曲线簇,明确误差来源。结果表明,无论是相电压还是零序电压,电场强度测量均有相当大的偏差,难以用来准确判断实际电压数值。The fault detection technology implementing distributed measurement along power lines or on poles and towers is widely used in high-voltage and low-voltage distribution network lines.However,due to the inability to install voltage transformers,only measuring electric fields can be used to replace the real voltage measurement.Because of the influence of environment,weather,measuring points and other factors,there is a large error.Aiming at this problem,the quantitative error analysis of the voltage value obtained from the electric field measurement of power lines has not been seen for the important issues,resulting in the current application of the estimated voltage value can only be used as a starting threshold and other relatively preliminary applications.Therefore,this paper analyzes the feasibility of obtaining line voltage by measuring electric field from the perspective of electromagnetic theory,and draws a conclusion that voltage measurement and current measurement are completely decoupled under single-phase short circuit fault conditions of transmission lines.At the model level,this paper establishes the electromagnetic model based on image method and gives the relationship between space electric field and line voltage.It also builds the finite element analysis model based on the physical field and draws the spatial electric field distribution diagram and waveform curve cluster when the tower exists so as to clarify the source of error,which lays a foundation for the subsequent accurate layout of electric field measurement points and the subsequent fault judgment calculation of alternative voltage.

关 键 词：电场强度测量 电压测量 误差分析 有限元建模 

分 类 号：TM744[电气工程—电力系统及自动化]