环境湿度对输电线路下方空间电场测量结果的影响

为了研究高湿度地区工频电场强度测量值偏大的问题,本文从环境湿度对测量系统的绝缘木支架电气特性参数的影响入手,用复介电常数描述木支架的电气特性,建立了准静态场的求解模型,应用有限元法求解了输电线路下方的空间电场分布,以数值模拟的方法获得了环境湿度对空间电场测量结果的影响规律。研究表明,在实际工况中环境湿度通过改变木支架含水率影响了支架的导电特性,导致支架附近的空间电场发生畸变,是引起电场强度增大的主要因素。提出了为高湿度地区的紧急工频电场强度测试时利用金属支架测量并修正结果的方法。

Influence of Environmental Humidity on the Measurement Results of Space Electric Field Under the Transmission Line

In order to study the problems that the measured value of the intensity of the power field in high humidity area is larger than the actual value,this paper starts from the influence of environmental humidity on the electrical characteristic parameters of wood insulating brackets in measurement system,describes the electrical characteristics of wood insulating brackets using complex permittivity,and builds quasi-static field solution model.Finite element method(FEM)is applied to solve the spatial electric field distribution under the transmission line,and the influencing law of environmental humidity on the measurement results of space electric field is obtained by numerical simulation.The research shows that under the actual working conditions,the environmental humidity affects the electrical conductivity of the insulating brackets through changing the moisture content of wood,which distort the spatial electric field near insulating brackets,which is the main factor leading to the increase of electric field strength.Based on the results of calculation and experiment,a method for measuring the intensity of emergency power frequency electric field using metal brackets in high humidity area and correct the results is proposed.