Impact of Amperage Creep on Potroom Busbars: Thermal-Mechanical Aspects

The mechanical performance of pot-to-pot busbars is intimately linked to the temperature and thermal expansion of conductors. With amperage creep, busbars are typically running hotter than they were at start-up, so that adequate temperature fields for both standard and bypass conditions must be considered to accurately represent the thermal stresses acting over the system. To assist smelters to evaluate the performances of busbars systems under realistic operating conditions, a methodology was developed using ANSYS-based numerical simulation, where the temperature field obtained from a thermal-electrical model is applied as a load to a thermal-mechanical model. The bolted connections at the shunting-clamping stations, the weld plates and the contact mechanics between bars are taken into account explicitly. A test case based on a demonstration busbar system is presented and the typical impact of line current and selected operational procedures on thermal-mechanical performance and reliability of specific design features is discussed.