Branched DC-Busbar Wirings to Reduce Inductance of Double-Sided-Cooling Inverter for xEV Traction

New configurations of the DC busbar are proposed, to reduce the total inductance of double-sided-cooling inverter. These include two low-inductance configurations of the DC wiring plates and DC terminals in the DC busbar. In configuration 1, the positive and negative DC terminals are branched, alternately arranged, and connected to the power module. In configuration 2, the DC wiring plates are branched and connected to the power module in parallel. Because the inverter has high dI/dt, the proximity effect fixes the distribution and flow of the commutating transient current during switching. Thus, it is difficult to reduce the inductance of the inverter even if the width and thickness of those wirings are changed. The proposed configurations overcome the influence of the proximity effect by utilizing parallel connection of the branched DC terminals or DC wiring plates. To estimate the low-inductance performances of these proposed configurations, the inductance equations were derived and their performances were evaluated. To validate the low-inductance performance, the prototype of the proposed inverter with configuration 2 was simulated and tested. These validation results indicate that the proposed inverter reduced the inductance to less than 15 nH (from that of the conventional inverter 20 nH) and achieved high efficiency in conjunction with high cooling performance.