Design of a 10 kV SiC MOSFET-based high-density, high-efficiency, modular medium-voltage power converter

Abstract

Simultaneously imposed challenges of high-voltage insulation, high <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{d}v/\mathrm{d}t$</tex> , high-switching frequency, fast protection, and thermal management associated with the adoption of 10 kV SiC MOSFET, often pose nearly insurmountable barriers to potential users, undoubtedly hindering their penetration in medium-voltage (MV) power conversion. Key novel technologies such as enhanced gate-driver, auxiliary power supply network, PCB planar dc-bus, and high-density inductor are presented, enabling the SiC-based designs in modular MV converters, overcoming aforementioned challenges. However, purely substituting SiC design instead of Si-based ones in modular MV converters, would expectedly yield only limited gains. Therefore, to further elevate SiC-based designs, novel high-bandwidth control strategies such as switching-cycle control (SCC) and integrated capacitor-blocked transistor (ICBT), as well as high-performance/high-bandwidth communication network are developed. All these technologies combined, overcome barriers posed by state-of-the-art Si designs and unlock system level benefits such as very high power density, high-efficiency, fast dynamic response, unrestricted line frequency operation, and improved power quality, all demonstrated throughout this paper.