摘要
绝缘材料的表面电荷是诱发沿面闪络的重要原因。为了研究气体绝缘输电线路（gasinsulatedmetal-enclosed transmissionline,GIL）中盆式绝缘子表面电荷的积聚特性,搭建了一套高气压下绝缘材料表面电荷实验与测量系统,实现了密闭腔体内绝缘子表面电位的全自动测量。所设计的同轴圆柱电极结构模拟了实际的GIL,用静电探头法测量了直流电压下0.5MPaSF6气体中缩比型盆式绝缘子表面电位分布。根据表面电位分布,应用高分辨率的电荷反演算法计算了绝缘子表面实际的电荷密度分布,算法中考虑了静电探头的影响。实验结果表明,表面电荷分布可分为两类不同的形态,第一类为沿中心电极对称分布的同极性电荷,第二类为条纹状分布的异极性电荷以及点状分布的单极性电荷。分析认为气体电导、绝缘子表面电导以及绝缘子体积电导分别对不同形态的电荷分布起主导作用。表面粗糙处理可以抑制第二类电荷积聚,无法抑制第一类电荷积聚,研究结果可为直流GIL的设计优化提供参考依据。
The surface charge on insulating materials is an important factor to trigger surface flashover. In order to study the characteristics of surface charge accumulation on spacer in GIL, a surface charge experimental setup as well as measurement system under high gas pressure was built, which realized the fully automatic measurement of surface potential of spacer in a sealed chamber. A pair of coaxial electrodes was applied to model the real GIL. Surface potential distribution on a downsized cone-type spacer was measured by an electrostatic probe in 0.5MPa SF6 gas under DC voltage. According to the surface potential distribution, the actual charge density distribution of the spacer surface was computed by the charge inverse algorithm with high resolution, and the influence of electrostatic probe was considered in this algorithm. The results show that the surface charge distribution can be divided into two kinds of different patterns. The first class are homo-charges presenting a symmetrical distribution. The second one are hetero-charges showing a streak distribution, and singular polar charges displaying a random distribution on spacer surface. It is concluded that the gas conductivity, the spacer surface conductivity and the spacer volume conductivity contribute to the three different charge distribution patterns. The surface roughness can inhibit the second class of charge accumulation but cannot inhibit the first type charge accumulation. The results could provide the guidance for design ofDC GIL.
作者
薛建议
王涵
李科峰
樊晓锋
刘翔宇
刘彦琴
邓军波
张冠军
XUE Jianyi;WANG Han;LI Kefeng;FAN Xiaofeng;LIU Xiangyu;LIU Yanqin;DENG Junbo;ZHANG Guanjtm(State Key Laboratory of Power Equipment and Electrical Insulation（Xi＇an Jiaotong University）,Xi＇an 710049,Shaanxi Province,China;State Grid Sichuan Electric Power Company Chengdu Power Supply Company,Chengdu 010087,Sichuan Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第20期6164-6172,共9页
Proceedings of the CSEE
基金
国家自然科学基金(51577150)
国家重点基础研究发展计划(973计划)(2015CB251003)
国家电网公司四川省电力公司科技项目(521904160001)~~
关键词
气体绝缘输电线路(GIL)
直流电压
反演算法
静电探头
电荷积聚
电荷分布形态
gas insulated metal-enclosed transmission line（GIL）
DC voltage
charge inverse algorithm
electrostaticprobe
surface charge accumulation
surface charge distributionpatterns
