GIS金属环小孔外UHF信号特征的研究  

Study on the UHF signals radiated out of the small hole in mental ring

作　　者：陈金法[1] 胡文堂[1] 徐华[1] 郑书生[2] 詹花茂[3] 

机构地区：[1]国网浙江省电力公司电力科学研究院,浙江杭州310014 [2]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206 [3]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《华北电力大学学报（自然科学版）》2014年第1期66-71,共6页Journal of North China Electric Power University：Natural Science Edition

摘　　要：运行中的大多数气体绝缘开关设备（Gas Insulated Switchgear,GIS）上未安装内置式特高频（Ultra High Frequency,UHF）传感器,并且盆式绝缘子被金属环覆盖,检测金属环小孔处辐射出来的UHF信号成为实现GIS局部放电UHF带电检测的唯一方法.研究UHF信号通过金属环小孔的传播特性对于改进UHF检测系统和提高检测灵敏度具有指导意义.根据导行电磁波理论分析了UHF信号通过小孔传播的电场结构和截止频率;基于时域有限差分法仿真了局部放电UHF信号的传播过程,分析小孔处的电场强度的方向性和频谱特性.研究表明,小孔处UHF信号的电场方向平行于小孔短边,其主要能量集中在1.2～1.6 GHz之间.此结论对改进UHF检测系统提供了重要的指导方向和理论依据.Internal ultra-high-frequency （UHF） coupler has not been installed on most of gas insulated switchgears （GISs） in service. Insulators are surrounded by mental rings. In this condition, detecting UHF signal at the hole in mental ring is the only way to measure partial discharges （PDs） in GIS on site. Working on the propagation of UHF through the hole has instructive function for improving UHF detecting system and its sensitivity. The field pattern and cut off frequency of electromagnetic （EM） wave passing through the hole are analyzed according to guided EM wave theory. The propagation of UHF signal are simulated by using finite difference time domain method, and the direction and spectrum are analyzed. According to research, the direction of electric field is parallel to the short side of hole, and the energy is mainly on the frequency band of 1.2 - 1.6 GHz. These conclusions give important direction and theo- retical basis for improving UHF detecting system.

关 键 词：特高频 金属环小孔 时域有限差分 

分 类 号：TM595[电气工程—电器]