特高压直流换流站支柱绝缘子设计

特高压直流换流站的外绝缘设计是特高压直流输电工程的关键技术之一，直接影响工程的安全可靠运行，文章主要讨论特高压换流站支柱绝缘子的选型和设计。首先统计了 我国±500 kV换流站外绝缘的运行情况，总结了±500 kV换流站加强外绝缘和防污闪的主要措施，并分析了室温硫化硅橡胶(room temperature vulcanized silicone rubber，RTV)和长效室温硫化硅橡胶涂料的性能特点。然后根据积污站测试结果对特高压换流站站址的污秽水平进行了预测，根据预测的污秽水平和实验室污耐压试验结果推导出其所需的爬电比距。最后，分析了不同型式支柱绝缘子的经济技术特点，以及国内外厂家的制造能力，推荐瓷涂RTV方案作为特高压直流换流站外绝缘的首选方案，并对瓷涂RTV绝缘子使用过程中的相关问题进行了探讨。

Design of Post Insulator for UHVDC Converter Station

The external insulation design is one of the key technologies in ultra high voltage direct current (UHVDC) power transmission projects and may directly impact the secure and reliable operation of UHVDC transmission system. The type selection and design of post insulators for converter station in UHVDC project are the principal content of this paper. Firstly, the statistical data of operation situation of external insulation in domestic ±500kV converter stations is given, the main measures to enhance the external insulation of ±500kV converter station and prevent pollution flashover are summarized, the performance and features of room temperature vulcanized silicone rubber (RTV) and permanent RTV (PRTV) are analyzed and compared. Secondly, based on the test results of pollution accumulation station and the forecasted pollution level of the location where the UHVDC converter station will be constructed is forecasted, according to the forecasted pollution level and the results of laboratory pollution withstanding test the required specific cpeepage distance is deduced. Finally, based on the comparison and analysis on economic and technical property of different types of post insulators as well as the manufacturing capacity of manufacturers home and abroad, the RTV-coated porcelain insulator is recommended as the first choice scheme for external insulation of UHVDC converter station, moreover, the relevant problems in the usage of RTV-coated porcelain insulators are discussed.