In this paper, a three-dimensional numerical analysis model of GIL subsection with a basin insulator inside is established. The temperature distribution in steady state is calculated by finite volume method. The temperature distribution of the insulator under different gas pressure is calculated. With the increase of gas pressure, the maximum temperature of insulator gradually decreases, and the minimum temperature of insulator barely changes. The results show that higher load current will result in higher insulator temperature, and the linear relationship between the ambient temperature and the insulator temperature is obtained.

basin insulator, gas insulated transmission lines, multi-physics, temperature distribution