3D Thermal Analysis of a Power Supply Busbar Structure

Busbar technology is more and more used to realize connections within power supply systems in answer to the need of compactness. The integrated problem on heat conduction and radiation-convective heat exchange describes the temperature regime in current conductors and current carrying busbars of power electrical apparatus such as circuit breakers or high breaking capacity fuses. Beside steady-state conditions, the transient thermal regime of busbar has an important influence upon whole power supply system from thermal behaviour point of view. Hence, a 3D thermal analysis of a power system including fuse, low voltage circuit breaker and busbars connections, using a specific software package based on Finite Element Method, has been done. From 3D thermal modelling and simulations, the thermal transient impedance for the busbar has been computed. This allows a better correlation between protection characteristics of the fuse and circuit breaker and busbar design.