Calculation of Temperature Distribution of GIS Bus Bar Under Multi-physical Field Coupling

The temperature rise of gas insulated switch-gear (GIS) bus bar is an important factor affecting its safe and stable operation. Based on the finite element method of electric-thermal-fluid multi-physical field coupling, the finite element simulation model of 252 kV GIS was established by considering the vortex loss of GIS bus bar, skin effect, heat conduction, heat convection, heat radiation and other complex heat transfer processes. The temperature distribution of GIS was calculated. The results show that when the ambient temperature is 293 K and 4 kA power frequency current is passed into the central conductor, the internal temperature of GIS distributes symmetrically along the central axis. The highest temperature in GIS is 324 K and the lowest temperature is 297 K. At the same height, the temperature of GIS decreases gradually along the radial direction from the conductor center, and the temperature difference between the top and the inside and outside is slightly larger than that at the bottom. The lower surface temperature of the basin insulator is greater than that of the upper surface, and the radial temperature difference between inside and outside is 23.5 K. Chamber height has great influence on gas temperature. The multi-physical field coupling simulation can effectively simulate the temperature rise of GIS under actual working conditions and provide theoretical support for GIS condition monitoring and maintenance.