IEEE PELS San Francisco Bay Area Chapter Seminar

In electric drivetrain architectures, including xEV and electrified aircraft applications, a boost dc-dc converter is often utilized to interface a battery system to variable-speed ac drives, thus enabling the system operation at increased dc bus voltages. It has been shown how wide bandgap SiC devices lead to improvements in efficiency and reductions in the size of magnetic components in standard boost converter realizations. We then show how further improvements can be achieved using composite architectures where stresses and losses on SiC devices and passive components are substantially reduced. Optimization of composite converters involves complex design tradeoffs in terms of losses, size, and reliability. To address these challenges, a systematic design methodology is presented, which involves selection of the converter architecture, magnetics design, control techniques, and electro-thermal co-design. The approach is illustrated by modeling, simulations, and experimental results on a 125 kW SiC composite dc-dc converter prototype featuring 22 kW/L power density and 99% drive-cycle weighted efficiency.