To analyze the effect of SF

6

/N

2

mixed insulating gas on the temperature rise of gas insulated metal-enclosed switchgear（GIS） bus bar

an electromagnetic-fluid-thermal multiphysics coupled simulation model was established for a single-phase GIS bus bar filled with 30%SF

6

～70%N

2

mixed gas.The finite element analysis method of fluid multi-component transmission is used to obtain the distribution of electromagnetic field and temperature field on the GIS bus bar.The results show that the temperature at the top of the GIS inner conductor and the

shell is higher than the bottom.The temperature is bilaterally symmetrical

it is distributed in a ladder shape with a higher top and a lower bottom.The temperature rise of the outer casing and the conductor increases with the increase of the load

and is linear with the ambient temperature.AS the gas pressure increases

the temperature rise gradually decreases

as the composition of the SF

6

gas increases

the decrease in the temperature rise of the conductor gradually becomes slower.So when the proportion of SF

6

gas in the mixed gas is constant

increasing the pressure of the mixed gas can effectively reduce the temperature rise of the GIS conductor.The simulation results are verified by setting up an experimental platform.The research results contribute to the early detection and prevention of GIS bus bar temperature rise.It can also provide a theoretical basis for the promotion and applic ation of mixed environmental protection gas in GIS.