SiC + Si three‐phase 48 V electric vehicle battery charger employing current‐SVPWM controlled SWISS AC/DC and variable‐DC‐bus DC/DC converters

Wide‐bandgap (WBG) devices such as SiC and GaN switches are regarded as next‐generation power semiconductors, due to their superior performance over conventional Si devices, for instance, a low switching loss and high thermal conductivity. Its bottleneck, however, is the high cost, which is critical for renewable energy and automotive industries. This study adopts SWISS AC/DC rectifier topology for the three‐phase 380–480 VAC along with an isolated DC/DC converter, indicating such topology can maximise the advantages of Si (low conduction loss) and SiC (high switching loss), altogether thereby yielding the high performance and low cost. A novel space‐vector pulse width modulation (SVPWM) was proposed to control such a current‐source power factor correction, where only two SiC devices were adopted for the DC‐bus voltage control. The closed‐loop control of the grid current is realised for the unity power factor. Such topology further allows the DC‐bus voltage to be varied with the output voltage, thereby minimising the system loss. A final prototype was built to charge a 48 V battery at 11 kW. Experimental results validated the effectiveness of such battery charger design.