10 kV SiC MOSFET Based Boost Converter

Abstract

W kV SiC MOSFETs are currently under development by a number of organizations in the United States with the aim to enable their applications in high voltage high frequency power conversion applications. The aim of this study is to demonstrate their high frequency high temperature operation capability in the application of a DC/DC boost converter. A DC/DC boost converter based on a 10 kV 10 A SiC MOSFET and a 10 kV 5A Junction Barrier Schottky (JBS) diode is designed and tested for continuous conditions up to a switching frequency of 25 kHz, an output voltage of 4 kV, an output power of 4 kW and a junction temperature of 174degC for the SiC MOSFET. In the steady state of the 20 kHz boost converter operation, the input power is 4335 W, the output power is 4030 kW and the efficiency is 93%. The power loss analysis shows the total power loss in the 30.45 mm2 SiC MOSFET is 115 W, and the operating junction temperature of the SiC MOSFET is 140degC at the 20 kHz switching frequency. The power losses and the junction temperature of the SiC MOSFET as a function of the switching frequency, load current and input voltage in the boost converter are investigated extensively. The fast switching, low loss and high temperature operation capability of 10 kV SiC MOSFETs demonstrated in the DC/DC boost converter make them attractive in high frequency high voltage power conversion applications.