Temperature rise prediction of EHV GIS bus bar by coupled magnetothermal finite element method

This paper presents a new magnetothermal finite element analysis for predicting the temperature rise of the extra-high voltage gas insulated switchgear bus bar. The power losses of a bus bar calculated by the magnetic field analysis are used as the input data to predict the temperature rise for the thermal analysis. The heat-transfer coefficients on the boundaries are analytically calculated by applying the Nusselt number considering material constant and model geometry for the natural convection. The temperature distribution in a bus bar by coupled magnetothermal finite element analysis shows good agreement with the experimental data.