A Bare-die SiC-based Isolated Bidirectional DC-DC Converter for Electric Vehicle On-board Chargers

This paper discusses electrical design aspects of a cooling system-integrated, high power-density, 800 V to 600-800 V, bare-die SiC-based, 1 MHz, dual-active-bridge (DAB) dc-dc converter for three-phase onboard charging systems of electric vehicles. The primary emphasis is on maximizing power-density while maintaining sufficient conversion-efficiency. A wire bondless approach towards integration of the bare-die switches is discussed, which enables reliable high switching-frequency operation. Further, details of the used adjustable leakage-inductance planar transformer and simulation-derived loss breakdown of the converter are also provided, which demonstrate a projected maximum efficiency of 97%. Finally, preliminary experimental results on a scaled-down laboratory prototype, having a power density of 18.2 kW/litre are presented.