陡波下500kV GIS隔离开关室的暂态电场特性  

Transient Electric Field Characteristics for Disconnector Room of 500 kV GIS Under Steep Wave

作　　者：杨瑞[1] 贺恒鑫[1] 何俊佳[1] 

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院),武汉430074

出　　处：《南方电网技术》2017年第8期49-54,共6页Southern Power System Technology

基　　金：国家工程实验室开放基金资助项目(NEL201604)~~

摘　　要：为准确指导500 kV隔离开关室的绝缘设计,必须研究同时考虑隔离开关室结构引起的电场畸变和不同电压波形下的电场动态分布特性。基于时域有限差分法对500 kV隔离开关室在特快速暂态过电压(VFTO)下和雷电波下的暂态电场特性进行了研究。计算结果表明:隔离开关在合闸和分闸时,在VFTO作用下,各节点电场存在高频振荡,不同时刻的电场分布不断变化;在电压波头时间为4 ns和20 ns时,各节点电场均存在高幅值的振荡,严重威胁到设备的绝缘,尤其在施加4 ns斜角波电压时,电场最大值约为稳态值的4~5倍,振荡频率比母线的更高,因此必须计算其暂态电场以便校核绝缘设计;雷电波下,各节点电场几乎无折反射,因而可用静电场计算结果进行校核。To accurately guide the insulation design of 500 kV disconnector room of GIS,it is necessary to study the dynamic distribution characteristics of electric field caused by structure and voltage waveform. The transient electric field characteristics of 500 kV disconnector room under very fast transient overvoltage（ VFTO） and lightning wave are studied based on time domain finite difference method. Results show that no matter the disconnector is closed or opened,high frequency oscillations will occur in the electric field of each node,moreover,the electric field distribution will change constantly under VFTO. Oscillations have a high amplitude under 4 ns and 20 ns wavefront voltage time,which may seriously threaten equipment insulation. Especially,when the 4 ns ramp wave voltage is applied,the maximum value of electric field is about four ~ five times of the steady-state value and the oscillation frequency is higher than that of coaxial bus duct. So transient electric field must be calculated to check the insulation design. Under lightning wave,electric field of each node in the disconnector is almost non-reflex,and can be verified by the calculation result of electrostatic field.

关 键 词：隔离开关室 暂态电场 雷电波 特快速暂态过电压 时域有限差分法 

分 类 号：TM154.1[电气工程—电工理论与新技术]