High-frequency AC-DC conversion with a silicon carbide power module to achieve high-efficiency and greatly improved power density

This paper presents a high-frequency bridgeless boost converter that implements power factor correction (PFC) and is a part of a two-stage on-board battery charger. The converter benefits from the advanced properties of silicon carbide (SiC) power devices to achieve a high-density and high-efficiency design. The advantages gained with SiC devices are maximized with a multi-chip power module (MCPM) that was designed specifically for this application. The operation and design of the converter are discussed and a hardware prototype is developed. The performance is verified with a peak efficiency of 98.7% and a peak output power of 6.3 kW at a switching frequency of 250 kHz. The operational limits are also investigated up to a switching frequency of 1.2 MHz where a peak efficiency of 96.5% is achieved for an output power of 3 kW. The resulting system volumetric power density was found to be 11.1 kW/L and the gravimetric power density was 8.1 kW/kg.