Accurate prediction of GIS temperature-rise and analysis of the heat flux distribution are very important for the design of GIS. Using the 3-D multi-physics coupling method

we established a 3-D electromagnetic-thermal-flow coupled model to analyze the electromagnetic field

temperature field and gas flow field of 126 kV three-phase-in-one-tank type GIS. Firstly

the Ohmic losses of GIS which were calculated to be 1 107.8 W by Ansys Maxwell 3 D were introduced into Ansys Fluent as heat source to calculate the temperature distribution and velocity distribution

and the highest temperature-rises of electrical contact area and shell were about 52.5 K and 20 K

respectively. Then the distribution characteristics of convection and radiation heat flux were analyzed

which lays a foundation for the future heat transfer analysis method. Finally

the temperature-rise test results were compared with the simulation results and the maximum error was 3.601 K

which verifies the correctness of the simulation results. Thereby

the multi-physics calculation of GIS can provide a theoretical basis for the optimal design of the product.