换流站复合外绝缘应用及雨闪事故分析

Application of Composite Insulators and Analysis of Rain Flashover in Converter Stations

为了全面掌握换流站复合外绝缘大规模应用和雨闪的相关性,首先从电压等级、设备类型和使用环境等方面详细统计了南方电网直流换流站复合绝缘的应用情况和外绝缘雨闪事故;其次,从交直流绝缘子伞形参数的角度分析了伞间距与外绝缘伞裙雨闪的关系;最后,分析了围脖伞和包覆伞等复合防雨辅助伞裙的技术特点和存在的主要问题。统计结果表明,南方地区换流站设备复合化趋势明显,发生雨闪事故复合绝缘子的伞间距均≤48mm,伞间距不足是换流站发生外绝缘雨闪的主要原因。新建直流工程建议采用伞间距≥70 mm的复合绝缘子,在运工程建议完善辅助伞裙的粘接质量控制和验收方法。

In order to get a full grasp on the application of composite insulators used in the converter stations and the failure of rain flashover, the application and rain flashover accidents of polymer insulators provided in the converter stations of China Southern Power Grid, an investigation and statistics was carried out from aspects of voltage level, equipment types, and application environment. Then the relationship of shed distance and rain flashover was analyzed from the view of shed profiles. In the end, the technical characteristics and main problems in the use of auxiliary sheds were also analyzed. Statistics show that more composite insulators have been used in converter stations of South China, and the distance between two adjacent big （small） sheds is no more than 48 mm, which is the main reason of rain flashovers occurring in the converter stations. The composite insulator with the shed distance larger than 70 mm is recommended in the new DC project to improve the supervision of adhesive bonded quality, and an acceptance method of auxiliary sheds is also suggested.