不均匀积污绝缘子雷电冲击闪络特性  

Lightning Impulse Flashover Performance of Non-Uniform Pollution Insulators

作　　者：蒋兴良[1] 王茂政 袁一钧 张志劲[1] 陈宇[1] Jiang Xingliang;Wang Maozheng;Yuan Yijun;Zhang Zhijin;Chen Yu(Xuefeng Mountain Energy Equipment Safety National Observation and Research Station of Chongqing University, Chongqing 400044 China;State Grid Hunan Electric Power Company Limited Research Institute, Changsha 410007 China)

机构地区：[1]重庆大学雪峰山能源装备安全国家野外科学观测研究站,重庆400044 [2]国网湖南省电力有限公司电力科学研究院,长沙410007

出　　处：《电工技术学报》2023年第23期6461-6470,6552,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金重点项目资助(51637002)。

摘　　要：自然条件下,绝缘子呈现不均匀积污状态,对绝缘子的雷电冲击闪络电压有较大影响。为此,该文以XP-70和LXY-70绝缘子为研究对象,在重庆大学雪峰山能源装备安全国家野外科学观测研究站进行不均匀积污绝缘子在预加交流电压后的雷电冲击闪络试验,并对其闪络特性进行分析。试验结果表明,在不均匀积污条件下存在非常明显的极性效应,且出现了极性反转现象。在相同等值附盐密度(ESDD)下,随着不均匀积污比(T/B)的减小,预加交流电压作用下的泄漏电流随之减小,而绝缘子串的闪络电压呈现上升趋势。此外,通过超高速摄像机拍摄的不均匀积污绝缘子的闪络过程发现,不均匀积污绝缘子下表面会率先形成非连续的局部电弧,局部电弧沿面快速发展最终导致闪络。最后,建立了普通瓷绝缘子和玻璃绝缘子的雷电冲击闪络电压梯度方程,并对其进行验证,结果表明计算值与试验值的相对误差在±6.56%之内。Flashover of pollution insulators is a serious threat to the safe operation of transmission lines,and most existing researches are limited to the AC and DC flashover performance of non-uniform pollution insulators and the lightning impulse flashover performance of uniform pollution insulators.The lightning resistance of pollution insulators is lower than that of clean insulators,and under natural conditions,insulators show non-uniform pollution state,which exacerbates the electric field distortion and has a greater impact on the flashover voltage.To address the shortcomings of existing researches,this paper carries out lightning impulse flashover tests on 7 pieces of XP-70 and LXY-70 suspension insulators with non-uniform pollution top and bottom surfaces after preloading AC voltage in Xuefeng Mountain Energy Equipment Safety National Observation and Research Station of Chongqing University.Firstly,the inert and conductive components of pollution are simulated using diatomaceous earth and sodium chloride,and the ratio of non-soluble deposit density(NSDD)to equivalent salt deposit density(ESDD)on the surface of insulators is maintained at 6.The top and bottom surfaces of insulators are coated separately using a quantitative painting method,and different non-uniform pollution accumulation ratios(T/B)are simulated by keeping the total amount of sodium chloride on the surface of insulators constant and only changing the salt density ratio on the top and bottom surfaces of insulators.After the test arrangements are complete,the lightning impulse circuit switch is disconnected,and the AC circuit switch is closed and preloading AC 70 kV voltage to insulators.After 3 minutes of preloading AC voltage,the AC circuit switch is disconnected and the lightning impulse circuit switch is immediately closed.The up and down method is used as the test voltage addition method,and the voltage step is set at about 3%of the expected lightning impulse flashover voltage U50%and 20 valid tests are conducted on the same sample.The results

关 键 词：不均匀积污 雷电冲击 闪络电压梯度 预加交流电压 

分 类 号：TM216[一般工业技术—材料科学与工程]