山火对±800kV输电线路下电场影响的仿真分析

Simulation Analysis on Influence of Forest Fire on Electric Field Under ±800kV Transmission Line

特高压直流输电线路在山火中高温、高电导率火焰以及固体颗粒物等因素作用下,容易导致周围电场发生显著升高,从而引发输电线路跳闸。以云广特高压直流输电线路为例,采用Comsol软件,对山火中电荷数密度和颗粒物等因素对±800kV输电线路下电场的影响进行了仿真研究。研究表明,火焰稳定燃烧情况下,当火焰中电荷数密度达到1014m-3时,电场强度可达正常运行条件下的47倍,并且电荷数密度每增大10倍,合成电场也增大约10倍;颗粒物的存在会对背景电场产生畸变作用,当火焰中电荷数密度达到1014m-3时,畸变值可达正常运行条件下的7.5倍,同时固体颗粒物对电场的畸变作用随着颗粒长轴长度的增加及短轴长度的减小而增大。

Under the influence of flames with high temperature,high conductivity,solid particles and other factors,the electric field around UHVDC transmission lines increases significantly,which may cause trip of the transmission line. In this paper,taking YunGuang UHVDC transmission lines as the example,simulation studies are conducted to analyze the influence of charge density and particulates in forest fire on electric field under ± 800kV transmission line through Comsol software. Research shows that the maximum electric field strength increases significantly,up to 47 times higher than that under normal operating conditions when the flame charge density reaches 10^14m^-3 under stable combustion condition,the particles may cause distortion of the electric field,when the flame charge density reaches 10^14m^-3,the distortion value can reach 7. 5 times of which under normal operating conditions,the distortion of the electric field caused by solid particles increases with the increase of the long axis and the decrease of the short axis.