A Compact 250 kW Silicon Carbide MOSFET based Three-Level Traction Inverter for Heavy Equipment Applications

A sustained effort is required to realize the aggressive targets of electrification of heavy equipment, e.g., the heavy-duty off-road vehicles, due to numerous emerging challenges, which are different from those in the automotive industry. Heavy equipment manufacturers are increasingly investing in new generation of power electronics technology to fulfill the high performance and reliability targets under harsh environments while reducing fuel consumption and staying cost competitive. In this work, a holistic power electronic circuits design is proposed to achieve 4× power density at 98% peak efficiency for a compact 250 kW three-phase three-level (3-L) T-type traction inverter. The proposed T-type inverter is designed using the best in class silicon carbide (SiC) power modules. Most importantly a multi-objective optimization approach to trade the volumetric power density (kW/l) against SiC device type (650, 900 and 1200 V), dc bus voltage, switching frequency, the size of the passives components. T-type inverter system design guidance is given in this work, including loss calculation, dc-link capacitor selection, thermal management solution, and bussing structure. In addition, the hardware-in-the-Ioop simulation study is performed to validate the performance of the control system designed for the traction inverter.