Zero Common-Mode Voltage Three-Level Buck DC-DC Converter using 1.2 kV SiC MOSFET Neutral-Point-Clamped (NPC) Modules for UPS Applications

摘要

As wide-bandgap technologies become more readily available for commercial applications, there are still a few key limitations of the technology which need to be addressed, such as the high levels of electromagnetic interference generated by the faster switching speeds attained by these devices. The topology proposed in this paper is able to address this concern so that the benefits of SiC MOSFETs, such as high switching frequency and efficiency, are maintained while the common-mode voltage profile of the converter is significantly reduced, leading to a reduction in the overall EMI profile of a UPS system. The high efficiency, low EMI profile, and voltage balancing capabilities of the converter are demonstrated first through simulation, then by experimental verification using a 20 kW UPS hardware prototype.