Temperature Distribution Simulation in an MV Switchgear Bus Bar Chamber

Temperature is one of the main contributors for the decrease of switchgear insulation withstand capability and life expectancy. Unattended temperature rise can lead to overheating of switchgear insulation causing insulation breakdown and hence switchgear outage. This work presents a simulation investigation of how temperature hot spots may be detected by studying the surface temperature distribution along a switchgear bus bar chamber wall. A three-dimensional (3-D) finite element method (FEM) MV switchgear bus bar chamber is created. The heat dissipation caused by bus bar load currents and thermal localized hot spots caused by increased contact resistances is investigated. It is shown that it may be possible to detect inner hot spots on the surface of switchgear chamber walls. It is also shown that the coating and the emissivity factor of the walls have a significant influence on the detected surface temperature.