特殊污秽条件下电流互感器复合绝缘外套电蚀损缺陷机理分析  

Mechanism of Erosion Defect of Composite Insulation Jacket for Current Transformer Under Special Contamination Conditions

作　　者：贾志东[1] 曾智阳 陈灿[1] 王希林[1] 杨朝翔 闫振华[2] 

机构地区：[1]清华大学深圳研究生院,广东省深圳市518055 [2]国网宁夏电力公司电力科学研究院,宁夏回族自治区银川市750011

出　　处：《电网技术》2015年第10期2915-2922,共8页Power System Technology

基　　金：国家自然科学基金项目(51477086;51477085);高等学校博士学科点专项科研基金资助项目(20130002130009)~~

摘　　要：宁夏福祥变220 k V电流互感器因绝缘外套严重电蚀损缺陷而退运。福祥变地区气候干燥,降雨少,雾日少,互感器外套的电蚀损现象无法用常规污闪理论模型解释。从污秽分析、材料分析、电磁场计算3个方面,对互感器复合外套电蚀损缺陷进行了分析,并且在实验室中模拟出了材料表面放电及蚀损现象,验证了原因分析的结论:福祥变地区积污严重,污秽中含可导电颗粒;互感器绝缘外套硅橡胶材料憎水性良好,主要元素含量未发生明显变化;互感器护套低压端伞裙设计存在缺陷,低压端法兰与护套伞裙直接相连导致连接处液体硅橡胶材料运行场强过高诱发放电。特殊污秽条件以及伞裙设计缺陷是互感器外套缺陷的主要原因。The insulation jacket of Ningxia Fuxiang transformer substation 220 kV current transformer was returned for serious electrical erosion defects. The climate in Fuxiang transformer substation area is dry, with little rain or fog. Study found that the transformer jacket erosion phenomenon cannot be explained by conventional flashover theoretical model. From the contaminant analysis, materials analysis, and electromagnetic field calculation three aspects, the transformers composite jacket erosion defects were analyzed in this paper. And the surface discharge and erosion phenomenon was simulated in the laboratory, confirming the analysis conclusions. The results showed that the contamination in Fuxiang area was serious, and the contaminant contained conductive particles. The silicone rubber material of transformer insulation jacket had good hydrophobicity, and the main element content did not change significantly. There existed defects in current transformer low-voltage outer insulating sheath sheds design, where the low-voltage end flange connected to jacket sheds directly leading to distortion of the electric field. The high field strength of liquid silicone rubber material evoked discharge. Special contaminant condition and transformer sheds design defects was the main causes of the iacket erosion phenomenon.

关 键 词：互感器外套 液体硅橡胶 电蚀损 导电颗粒 模拟试验 

分 类 号：TM85[电气工程—高电压与绝缘技术]