Design of a High-Frequency DC-DC Converter with a Custom Power Module and Integrated Cooling Structures

The packaging of wide band gap devices for high-frequency operation is an ongoing research topic. While current packaging research optimizes either for electrical or thermal characteristics, both are relevant for the successful design of DC-DC converters. This paper presents a synchronous boost DC-DC converter with a switching frequency of 333 kHz on the basis of a custom power module and an optimized inductor. The custom power module with silicon carbide MOSFETs is designed for minimized stray inductances. The power module includes dc-link capacitors to achieve fast switching transients and, thus, lower losses even on a planar module layout. An integrated micro-channel structure cools the power module with a fluid. Despite the high switching frequency and ensuing high losses per chip, no double-sided cooling technique is required. The converter reaches a maximum efficiency of 97.3%. With a maximum power output of 15 kW, it achieves a power density of 25.4 W/kg.