A thermal-mechanical approach for the design of busbars details

Abstract

The mechanical behavior of busbars is a complex, displacement-controlled problem intimately linked to the conductors’ temperature. Thermal stresses are generated between two bodies submitted to differential thermal expansion, such as a pair of busbars at different temperatures that are mechanically connected at multiple locations. It can also occur to a single busbar circuit if the system lacks the required flexibility to accommodate the hot conductors-to-cold supports differential thermal expansion. An approach for the thermal-mechanical design of busbars was developed using ANSYS™-based numerical simulation. Special attention is given to specific design features such as weld plates, flexible joints, sliding supports and fixed points positioning for they play a major role on both the thermal expansion’s preferential direction and system’s ability to accommodate it. A test case based on a demonstration busbar system is presented and the impact of geometry and temperature on the thermal-mechanical performance of those specific features is discussed.