Pollution measurement technology of insulators for UHVDC

In recent years, HVDC transmission project is developing greatly in China and the ±800 kV UHVDC project prepares for construction in the future. This paper introduce the oversea and domestic research situation of pollution performance and withstand voltage at pollution condition for insulators used under ultra voltage direct current (UHVDC). The design method of environment pollution station and insulators experimented in the station are recommended with the requirement of UHVDC project. Several pollution experiment methods used in domestic and overseas for DC pollution has been analysed and compared so as to summarize a new principle which DC and AC special insulators for contrasting experiment in the article. Via gathering the surface dirt accumulated at insulators, several viable pollution measurements such as measure salt deposit density (ESSD) and dust deposit is put forward on the basement of experiment data collected by the station operating. In the experiments, the problem that how to measure the pollution rate of direct current and alternating current are also discussed. Considering the experiment error, a corrected measure that setting a DC insulator without electricity to accumulated dirt for contrasting the insulators with electricity is designed. At last, the usage of the DC and AC pollution rate under UHVDC is preliminarily researched in the paper.