Design and experimental analysis of a 1 kW, 800 kHz all-SiC boost DC-DC converter

This paper presents the design, prototype development, operation and testing of a 1 kW, 800 V output all-SiC boost DC-DC converter using SiC MOSFET and SiC Shottky diode chips. The switching frequency is raised up to as high as 800 kHz and a 230 °C junction temperature has been reached by switching-loss dominant self-heating. High frequency switching characteristics of the proposed converter are evaluated in detail. Based on those evaluations, the Critical Conduction Mode (CrCM) Zero Voltage Switching (ZVS) soft-switched experiments are carried out on the same SiC module. The switching loss of SiC MOSFET is dramatically reduced, thus significantly improving the converter overall efficiency and relieving the high temperature stress induced on the switching devices. This work will provide useful information for the high frequency and high temperature applications of SiC devices.