±500 kV换流站直流分压器外绝缘闪络事故分析及处理措施  

Analysis and Treatment on External Insulation Flashover of DC Voltage Divider of ±500 kV Converter Station

作　　者：叶廷路[1] 吴光亚[2] 吴巾克[3] 李建建[3] 陈原[4] 宋福如[5] 林国强[5] 

机构地区：[1]国家电网公司生技部,北京市100031 [2]国网电力科学研究院,武汉市430074 [3]国家电网公司运行分公司,北京市100045 [4]华北电力科学研究院有限责任公司,北京市100045 [5]河北硅谷化工有限公司,河北省邯郸市057151

出　　处：《电力建设》2010年第12期56-60,共5页Electric Power Construction

摘　　要：对±500 kV江陵和龙泉换流站直流分压器的外绝缘闪络事故进行了分析,指出该分压器发生闪络事故的原因:一是复合套管的憎水性完全丧失;二是复合套管的均压环结构不合理;三是复合套管的伞裙形状参数特性较差。发生闪络事故的主要原因是复合套管的憎水性完全丧失,其次是均压环结构不合理。在此基础上,针对分压器的结构和事故性质,提出从根本上解决问题的思路:应按所要求的电气、机械和憎水性能来选用复合套管外绝缘材料;按上下均压环中心距离和均压环直径能保证复合套管的爬电距离和干弧距离的有效性与设计值接近这一主要原则来重新设计均压环;建议复合套管的伞伸出大于或等于70 mm,伞间距至少为70 mm来重新设计伞形。同时,建议可以采取在复合套管的外绝缘表面上涂覆防污闪涂料PRTV(permanent room temperature vulcanizedanti-contamination flashover composite coating)来提高外绝缘强度处理措施。The external insulation flashover of DC voltage divider in Jiangling and Longquan ± 500 kV DC converter stations was analyzed.Reasons for the occurrence of flashover voltage divider were propposed： First,the hydrophobic property of composite bushing is completely lost;Second,the grading ring structure of mean composite bushing is irrational;Third,the characteristics of shed shape parameters of the composite bushing are undesiarble.On this basis,and with respect to the structure of the voltage divider and the nature of this accident,fundamental solutions to the problem was proposed.The external insulation materials of the composite bushing should be selected in accordance with the electrical,mechanical and hydrophobic requirements;the grading ring should be re-designed on the conditon that the center distance between the top and down grading rings and the diameter of both grading rings guanrantee the approximation of design values and the effectiveness of creepage distance and dry-arc distance of composite bushing;it is also suggested that the shed extension of composite bushing should be bigger than or equal to 70 mm,and the shed pitch of bushing be at least 70 mm.Moreover,the outer insulation suface of the composite bushing should be painted with the permanent room temperature vulcanized anti-contamination flashover composite coating（PRTV） to enhance the external insulation ability.

关 键 词：直流 换流站 分压器 外绝缘 氟硅橡胶 闪络 事故 

分 类 号：TM854[电气工程—高电压与绝缘技术]