Prediction of temperature rise in gas insulated busbar using multi-physics analysis

This paper describes the coupled magneto-thermal analysis technique to calculate the temperature rise in the gas insulated switchgear (GIS) bus bar. Harmonic eddy current analysis is carried out and the power losses are calculated in the conductor and shield tank. Two methods are presented to analyze the temperature distribution on the conductor and tank surface. The one is to solve the thermal conduction problem with the equivalent natural convection coefficient and applied to the analysis of single phase GIS system. The other is to employ the computational fluid dynamics technique which directly solves the thermal-fluid equations inside the tank. The method is applied to the analysis of a three phase GIS problem. The accuracy of the developed technique is verified through the comparison of the measured and simulated temperature rise in a single phase and three phase GIS system.