高海拔500 kV交流输电线路绝缘子片数选择研究

Research on Selection for Number of Insulators of 500 kV AC Transmission Line in High Altitude Area

国内外在海拔2000m以下高海拔地区已建设投运多回500kV输电线路,具有丰富的设计、运维经验。但在海拔2000m以上的高海拔地区,500kV线路绝缘配置经验及运行数据相对欠缺。伴随澜沧江、怒江、雅鲁藏布江流域水电资源的规划开发以及西藏、川西等高原地区骨干电力网架的规划建设,海拔2000m以上的高海拔区域将陆续建设多条500kV线路。依据国网电科院模拟高海拔条件下的低气压进行的全尺寸人工污秽闪络特性试验成果,对污秽条件下绝缘子选择的爬电比距法与污耐压法进行了对比,对双伞、三伞、钟罩等绝缘子的污耐压性能进行比较,探讨了低气压对绝缘子污闪特性的影响及污秽绝缘子海拔修正方法,推荐了高海拔地区500kV线路绝缘配置方案。

There are many 500 kV tranmission lines running in high altitude area below 2000 metres above sea level,which has accumulated rich experiences in design,operation and maintenance.However,in the areas over 2000 metres above sea level,there is a lack of experiences in insulation configuration and running data of 500 kV AC transmission lines.With the planning and development of hydropower resources in Lancang river,Nujiang river and Yarlung Zangbo river basin,and the planning and construction of backbone power grid in Tibet or western Sichua,many 500 kV transmission lines will be constructed in high altitude area above 2000 metres above sea level.According to the experiment results of artificial pollution flashover performance executed in low atmospheric pressure under imitated condition of high altitude by State Grid Electric Power Research Institute,the creepage distance method and the pollution withstand voltage method are compared which are often used to choose the insulators under pollution condition,and the pollution flashover performance of double-shed,triple-shed and anti-fog insulators are also compared.The influence of low atmospheric pressure on the pollution flashover performance of insulators and the altitude correction methods for flashover performance contaminative insulator are discussed,and the insulation configurations for 500 kV AC transmission line in high altitude areas are recommended.