摘要
直流分压器由于内部阻容单元与外绝缘结构电压分布不同,不可避免地使阻容单元与空心绝缘子之间形成径向电位差。为研究直流分压器径向电位与大气环境条件的关系,以具有复合外套的±800 kV直流分压器为例,采用有限元分析计算干燥、均匀湿污、非均匀湿污和大雨等条件下直流分压器内部的径向电位分布。计算结果表明,干燥条件下径向电位最高处位于分压器高压端附近第二节阻容单元处,最高径向电位差约为60 kV;湿污条件下,分压器最大径向电位略微升高,约3 kV;雨量较大并桥接部分伞裙时,最大径向电位会有不同程度的提高,与雨帘的长度和位置有关。直流分压器内部径向电位的抬升易引发内部电极径向放电的风险,因此直流分压器内部绝缘裕度设计过程中应考虑不同工况下的径向电位变化。
As the different electrical potential between internal resistance-capacitance unit and outdoor insulation,the radial potential difference between resistance-capacitance unit and Hollow insulator is inevitable.In order to find out the relationship between the internal radial potential of DC voltage divider and the surrounding environment,a FEM(Finite Element Method)analysis are carried out by the example of ±800 kV DC voltage divider with composite housing.The internal radial potential of DC voltage divider under the dry condition,uniform wet pollution,non-uniform wet pollution and heavy rain conditions are calculated.The simulation results show that the maximum radial potential of the DC divider subjected to dry condition is about 60 kV located at the second resistance-capacitance unit near the high voltage terminal.For the case of wet and polluted condition,the radial potential is about3 kV larger than that in the case of dry condition.When heavy rain and part of the sheds of the composite housing are bridged by the rain,the maximum radial potential increases,and the displacement is related to the length and location of the sheds bridged.With the increase of internal radial potential,the voltage divider will run the high risk of radial discharge.Thus then the radial potential under different environment conditions are strongly recommended to consider in the insulation design of DC voltage divider.
作者
韦晓星
刘婉莹
孙勇
夏谷林
楚金伟
卢文浩
WEI Xiaoxing;LIU Wanying;SUN Yong;XIA Gulin;CHU Jinwei;LU Wenhao(EHV Power Transmission Company Maintenance &Test Center,CSG,Guangzhou 510663,China;EHV Power Transmission Company,CSG,Guangzhou 510620,China)
出处
《高压电器》
CAS
CSCD
北大核心
2019年第2期14-20,30,共8页
High Voltage Apparatus
基金
国家自然科学基金项目(51477086)~~
关键词
直流分压器
阻容单元
径向电位
非均匀湿污
雨帘长度
DC voltage divider
resistance-capacitance unit
radial potential
non-uniform polluted and wet condition
rain curtain length
