Thermo-electrical performance of hybrid busbars: An experimental and numerical investigation

This paper is focused on hybrid busbars made from aluminum and copper with the purpose of analyzing the influence of temperature on the electric performance of the joints. The methodology involves the fabrication of fastened, friction stir spot welded, sheet-bulk compressed, and injection lap riveted unit cells that are representative of the different types of hybrid busbars joints, the development of a special purpose laboratory apparatus for thermo-electrical measurements, and numerical simulation with a finite element computer program developed by the authors. Results are a step forward in understanding the variation of the electrical resistance of hybrid busbars with temperature and allow concluding that an increase above 30% is expected when the temperature in service reaches the limiting value defined by the IEEE standard for metal-clad switchgear.