Laminated busbar design criteria in power converters for electrified powertrain applications

Stray inductance of the DC bus in switching power converters causes transient overvoltages across the power devices, creating a need for higher rated, more costly switches. Moreover, EMI filters become necessary to mitigate the high frequency noise generated by the inductive loop of the busbar. In automotive applications, due to low cost and improved power density requirements, low inductance busbars are critical to avoid these added component costs. This paper discusses the factors affecting parasitics of laminated busbars. A methodical approach to design and analyze a low impedance busbar using electromagnetic analysis tools has been presented and a busbar design is proposed for a bidirectional boost converter for an electrified powertrain application. The relationship between converter component selection, properties of its busbar and power density is also discussed.