Traction inverter ratings for commercial electric vehicles (CEVs) are typically a) 1.3-1.6X higher in DC voltage, b) 3-5X higher in peak power, and c) 4-5X higher in lifetime compared to electric cars. Minimizing the size of such inverters without compromising their performance improves the CEVs’ drivable range and total cost of ownership. This paper presents the design challenges of high-power dense traction inverters using 1.7 kV SiC semiconductors rated for 300 kW peak, 1 kV DC bus, and 750k miles for medium- and heavy-duty CEVs. The inverter power density target of 100 kW/L is based on the US Department of Energy’s 2025 goals. In this paper, technological options and barriers in the design, manufacturing, integration and reliability of power modules, capacitors, bus bars, and heat sink for the inverter targets are discussed. Methods to overcome integration challenges of sub-components with different coefficients of temperature to achieve higher power density and design concepts of CEV traction inverter along with experimental results are presented.
