Busbar heating during transient conditions

Busbar technology is more and more used to realize connections within power supply systems as an answer to the problem of compactness. The integrated problem on heat conduction and radiation-convective heat exchange describes the temperature regime in current conductors and busbars of power electrical equipments 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 the thermal behaviour point of view. Hence, in this paper, a mathematical model is proposed for the transient conditions of the busbar heating. The busbar lengthwise heating with two different electrical contacts at its end terminals has been obtained. The influence of current on the heating distribution has been investigated. To validate the thermal model some experimental tests have been done. It observes a good correlation with the calculations.

► A mathematical model for busbars thermal behaviour during transient conditions has been established.
► The mathematical model includes data about busbar material, current density and both end terminals electrical contacts.
► The heating distribution lengthwise the busbar can be computed.
► Using the proposed thermal mathematical model the busbar designing can be improved.