800-V SiC Traction Inverter Key Design Considerations forImproved Efficiency and Power Density

Abstract:
Traction inverter is the heart of the drivetrain system. It is critical not only to meet full vehicle performance, reliability and safety; it is also key to enable longer drive range with the highest possible efficiency. The 800-V powered, SiC power switch based inverters bring significant engineering efforts, new semiconductor IC feature requirements and design optimization. This paper presents the required key technology enablers, including power module selection, the isolated gate driver and bias supply design, micro-controller, sensing and signal chain circuit considerations. The key features for improving the efficiencyand reliability of the inverter are discussed, such as adjustable gate drive strength, protection and state-of-health monitoring for SiC power modules. The bias supply design is optimized for 800-V inverter withhigh CMTI and EMI performance. In this paper, A 300 kW, 800-V SiC based inverter that is using Automotive leading techniques is developed and introduced. Key waveforms are measured to prove thesystem level performance. A 2.85% of power losses saving can be achieved at 32 kW/L power density.