Study on Electric Field Distribution of 500kV AC GIL Tri-post Insulator Affected by Metal Particles

Gas insulated transmission line (GIL) is of crucial importance in special transmission scenarios and plays an important part in the large AC/DC hybrid power grid. Metal particles generated during transportation and operation could seriously affect the internal insulation performance of the equipment, which may cause surface flashover, breakdown and other discharge faults. In this paper, the sources of metal particles in GIL are analyzed, and a 500 kV AC GIL 1:1 finite element model is established. The change of electric field distribution on the surface of tri-post insulator caused by suspended metal particles in GIL is studied. Also, the influence on electric field distribution on the surface of tri-post insulator with different metal particle shapes is analyzed. The conclusion can provide guidance for the suppression of metal particles in GIL.