Advancement of SiC High-frequency Power Conversion Systems for Medium-Voltage High-Power Applications

High voltage (HV) silicon-carbide (SiC) MOSFET has multiple advantages over its silicon (Si) counterpart including lower losses, higher blocking voltage, and improved thermal performance. SiC-based high-frequency power conversion solutions start to penetrate into medium voltage (MV) high-power areas due to high-density and high-efficiency. However, faster SiC switching transitions in MV lead to electromagnetic emissions, insulation degradation, and system-integration challenges. This paper provides several examples of using SiC high-frequency power conversion solutions in medium-voltage high power areas to illustrate the challenges and recent advancements. SiC device in series for MV two-level converters, HV PD-free PCB bus structure, SiC solid-state transformers, and MV insulated auxiliary power supply system are discussed.