Behavior, Switching Losses, and Efficiency Enhancement Potentials of 1200 v SiC Power Devices for Hard-Switched Power Converters

Semiconductor power devices are the major constituents of any power conversion system. These systems are faced by many circumscriptions due to the operating constraints of silicon (Si) based semiconductors under certain conditions. The emergence and persistence evolution of wide bandgap technology pledge to transcend the restrictions imposed by Si based semi-conductors. This paper presents a thorough experimental study and assessment of the performance of three power devices: 1200 V SiC cascode, 1200 V SiC MOSFET, and 1200 V Si IGBT under the same hardware setup. The study aims to capture the major attributes for each power device toward determining their realistic potential applications. The switching performance of each power device is studied and reported. As the gate resistance is a crucial factor in a power device characterization, an extensive analysis of hard-switching losses under different separated turn-on and turn-off gate resistances is also performed and discussed. To appraise the fast switching capability, the switching dv/dts and di/dts are measured and analyzed for each power device. Furthermore, insights are provided about the dependency of switching energy losses on the power device current and blocking voltage. This paper also focuses on evaluating the operations and the performances of these power devices in a hard-switched dc-dc converter topology. While using of 1200 V SiC Schottky diode in the converter design with each power device, the high switching frequency operations and efficiency of the converter are reported and thoroughly explored. The SiC cascode exhibited superior performance when compared to the other two power devices. The results and analyses represent guidelines and prospects for designing advanced power conversion systems. © 2017 CPSS.