Research on the Influence of Ambient Temperature and Load Current on Surface Charge Accumulation of Basin Insulators in Extremely Cold Environments

One essential insulating element of the gasinsulated switchgears (GIS) is the basin insulator. Charge collection at the basin insulator's gas-solid interface is likely to happen under high-voltage direct current, which will lower the basin insulator's flashover voltage and impair the GIS's insulation performance. The accumulation of electric charges will be exacerbated in extremely cold conditions due to the basin insulator's surface temperature gradient in the GIS increasing. This study developed a simulation model for surface charge accumulation in extremely cold environments in order to investigate the properties of charge distribution in such settings. Simulation calculations were used to determine the charge distribution on the surface of basin insulators. The results show that the temperature of the basin insulator decreases, the surface electric field increases, and the maximum surface charge density increases by 8.5 % when the ambient temperature drops from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-20^{\circ} \mathrm{C}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-60^{\circ} \mathrm{C}$</tex>. The temperature of the basin insulator rises, the surface electric field increases, and the maximum surface charge density increases by 13 % when the load current increases from 1 kA to 4 kA. This work reveals the method by which load current and ambient temperature impact basin insulators' surface charge accumulation in extremely cold temperatures, offering a theoretical foundation for the subsequent design of GIS in high-cold regions.