POLLUTION FLASHOVER PERFORMANCE OF INSULATORS FOR DC LINES IN HIGH ALTITUDE AREAS

摘要

Pollution flashover performance of insulators is one of the key factors to be considered in the selection of external insulation for transmission lines at high altitude areas. Many HVDC electric transmission projects such as Qinghai-Tibet +400 kV power transmission project and other UHVDC projects will be constructed soon in China are at more than 4000 m altitude someplace. So it's important for researching on the pollution flashover performance of the insulators used for HVDC electric transmission projects. At present, most related researches are performed in artificial simulation environments. In this paper, firstly achieved in the highest artificial pollution chamber (a part of the Tibet High Altitude Test Base of SGCC) in the world, DC artificial pollution tests were carried out on different insulator types in various typical kinds in the actual high altitude (4300 m). Relationships between 50% pollution flashover voltage (U50%) and ESDD in high altitude, the relations between the U50% and the altitude were obtained. The research would provide a basis for the design of HVDC transmission lines.