Multiphysics Coupling Simulation and Analysis of Influencing Factors on Temperature Rise Characteristics of Tri-Post Insulator GIL

In this paper, a 1100 kV GIL thermal–mechanical-electrical multi-physics coupling simulation model was established, the evolution characteristics of the internal temperature field of the tri-post insulator GIL with external factors were investigated. The results show that the temperature of the GIL tri-post insulator gradually decreases from the conductor to the enclosure, and the internal temperature is slightly lower than the surface; the maximum thermal stress occurs at the edge of the insulator wrapped around the conduct. Under rated conditions, the maximum stress inside the insulator can be up to 180 MPa, and the thermal expansion difference between the upper and lower surfaces of the enclosure hardly changes with temperature. This study provides an important guarantee for the safe operation of GIL.