Comparison of SiC MOSFETs and GaN HEMTs based high-efficiency high-power-density 7.2kW EV battery chargers

As two exemplary candidates of wide-bandgap devices, SiC MOSFETs and GaN HEMTs are regarded as successors of Si devices in medium-to-high-voltage (>1200V) and low-voltage (<;650V) domains, respectively, thanks to their excellent switching performance and thermal capability. With 650V SiC MOSFETs coming into being the direct competition of SiC and GaN in <;650V domains is inevitable, such as Level-2 battery chargers for electric vehicles. This paper applies 650V SiC and GaN to two 240VAC/7.2kW EV battery chargers, respectively, aiming to provide a head-to-head comparison of these two devices in terms of the efficiency, power density, thermal and cost, with the same control strategy of varying the phase-shift and switching frequency to cover the wide input range (80VAC~260VAC) and wide output range (200V~450VDC).