Evaluation of high voltage 15 kV SiC IGBT and 10 kV SiC MOSFET for ZVS and ZCS high power DC -DC converters

The advent of Silicon Carbide (SiC) devices has made possible high switching frequency operation of PWM power converters. In this paper, SiC devices are compared in detail with Si devices in a high power (1 MW) DC -DC converter application. The converter is designed as the building block for traction drives which requires it to operate at high power, high input voltage (11 kV) and low output voltage (800 V) levels. A dual active bridge (DAB) and a series resonant converter (SRC) topology are compared to achieve highly efficient operation. The performance and efficiency of these converters are compared by simulations using two different combinations of switches; the SiC combination consists of 10 kV/10 A SiC MOSFET at High Voltage (HV) side and 1200 V/100 A SiC MOSFET at Low Voltage side (LV), and the Silicon combination consists of 6.5 kV/10 A Si IGBT at HV side and 1200 V/100 A Silicon IGBT at LV side. For further understanding, efficiency analysis using the newly developed 15 kV/20 A SiC IGBT on the HV side is also carried out.