Contact Temperature Prediction in Three-Phase Gas-Insulated Bus Bars With the Finite-Element Method

Degradation of the electric contact in gas-insulated bus bars (GIBs) is closely related to the overheating phenomenon occurring at the contacts. This paper employs the finite-element method to solve the 3-D coupled eddy current, fluid, and thermal problems in a three-phase GIB. In the model, the contact resistance is measured and described as a resistor between the conductor and the contact. Computational fluid dynamics is used to predict the temperature rise of the components in the GIB. The temperature-dependent thermal properties of SF6 gas and air are considered in the thermal analysis. The developed methodology is implemented on a 126 kV three-phase GIB prototype and validated with the experimental temperature rise results.