高压开关柜裸露母线放电时的电磁辐射特性分析

Analysis of Electromagnetic Radiation Characteristics of Bare Busbar Discharge in High Voltage Switchgear

运行中高压开关刀闸、触点或接点发生故障时产生放电是主要现象,使用非接触的放电电磁测量法是实现状态监测的优选方法,因此研究高压开关柜中母线绝缘缺陷带来的放电电磁辐射具有重要的应用价值。本文利用天线原理和电磁场理论,采用HFSS仿真软件,建立母线的电磁辐射仿真模型,分析放电情况下,高压开关柜中裸露母线的电磁辐射场强分布和频率分布,以求得到母线发生故障时的辐射特性和频率特性。仿真结果表明:在非接触的测量点场强最大值对应的频率会随着母线宽度和长度的增加而逐渐减小;母线在垂直方向上的辐射最强,当母线宽度增加时,母线的辐射逐渐减弱;当裸露母线长度增加时,母线的辐射会逐渐增强;根据分析结果,给出了测量位置和频率选择的建议,为高压开关柜的状态检测设计提供了重要的指导方向和理论依据。

In the operation of high voltage switchgear, electrical discharge is the main phenomenon which occurs in the knife gate, contact or when contact failure happens. The non-contact electrical dis-charge measurement method is the preferred method to realize the condition monitoring. Therefore, it is of great value to study the electromagnetic radiation caused by busbar insulation defects in the high voltage switchgear. In this paper, based on the antenna principle and electromagnetic field theory, the electromagnetic radiation simulation model of busbar is established by HFSS. The electromagnetic radiation field strength and frequency distribution of the bare busbar in the high voltage switchgear are analyzed to obtain the radiation and frequency characteristics when the busbar failure happens. The simulation results show that the frequency corresponding to the maximum field strength at the non-contact measurement point will decrease with the increase of the width and length of the busbar. The busbar has the strongest radiation in the vertical direction. When the busbar width increases, the busbar’s radiation gradually weakens. When the length of the bare busbar increases, the radiation of the busbar will gradually increase. According to the analysis results, the recommendations for the measurement position and frequency selection are given, which provides an important guiding direction and theoretical basis for the state detection design of the high voltage switchgear.