负极性球板电晕放电下绝缘表面电荷分布特性研究  

Study on Charge Distribution Characteristics of Insulation Surface Under Negative Corona in Sphere-plane Gaps

作　　者：易凡[1] 杜志叶[1] 黄从鹏 金颀 YI Fan;DU Zhiye;HUANG Congpeng;JIN Qi(School of Electrical Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072

出　　处：《高压电器》2020年第9期197-202,209,共7页High Voltage Apparatus

基　　金：国家自然科学基金资助项目(51477120)。

摘　　要：电晕放电是高压直流输变电工程运行和设计中重点关注的问题,其产生的空间电荷在直流电场的作用下积聚到设备绝缘表面上,引起绝缘表面局部电场畸变,降低设备的绝缘性能,目前尚无有效的数值方法考虑空间电荷对绝缘表面电场强度的附加影响。针对直流负极性球——板电晕放电,搭建了直流电晕下绝缘材料表面电荷测量试验平台,该试验平台采用了有源静电探头法的测量原理,选取了3种不同绝缘材料的圆形薄片和2种不同曲率的伞形圆盘作为试验的测量对象,测量其在负极性球——板电晕放电下绝缘表面各点的电位分布。通过电荷反演算法将试验所测得的绝缘表面各点电位值换算为表面各点电荷密度值,初步得到了负极性球——板电晕放电下绝缘表面电荷的分布特性,为深入研究高压直流设备在电晕放电情况下的绝缘表面电荷分布特性提供了参考,可进一步拓展到(特)高压直流电气设备绝缘表面合成电场数值计算和绝缘优化设计领域,具有一定的工程应用价值。Corona is the key issue in the design and operation process of high voltage DC transportation and transfer facilities.The corona space charges are accumulated to the equipment insulation surface under the action of DC electric field,which led to local electric field distortion of insulation surface and weakens the insulation performance of the equipment.At present,there is no effective numerical method to consider the additional effect of space charge on the electric field strength of insulating surface.Considering the negative corona in the sphere-plane gap,an experimental platform,based on the principle of active electrostatic probe,for measuring the insulation surface charge under DC corona is set up.Through this experimental platform,three kinds of round slices with different materials and two kinds of umbrella shaped discs with different curvature are selected to measure the surface potential under negative corona in the sphere-plane gap.Then the surface potential is converted to the density of surface charges using a kind of inversion algo-rithm.The distribution characteristics of the surface charge on the surface of the negative sphere-plate corona discharge are obtained preliminary,which provides references for the study on charge distribution characteristics of high voltage DC equipment insulation surface under the corona.Furthermore,it can be extended to surface composited electric field numerical calculation and optimization of insulation design of high voltage DC electrical equipment,which has a certain application value for projects.

关 键 词：负极性电晕 表面电荷 分布特性 合成电场 有源静电探头法 

分 类 号：TM851[电气工程—高电压与绝缘技术]