Design And Testing of 1 kV H-bridge Power Electronics Building Block based on 1.7 kV SiC MOSFET Module
The Power Electronics Building Block (PEBB), as a concept to construct modular converters, was originally proposed by the Office of Naval Research in 1997. A PEBB is defined as a universal power processor that uses a systematic approach and has features of modular configurations, scalable voltage, and current ratings, as well as low inventory and maintenance cost. As a result of the booming technology associated with wide-bandgap semiconductor devices and packaging, silicon carbide (SiC) MOSFETs have demonstrated their superior performance to silicon (Si) insulated-gate bipolar transistors (IGBTs) in terms of higher breakdown voltage, faster switching speed, lower switching loss, and higher operating temperature. Historically, in power electronics, high switching frequency and low switching loss have always been the driving forces for reducing the size of passive and thermal management components. It is highly likely that SiC MOSFETs will change the game of developing high density medium voltage (MV) PEBBs and power converters. However, SiC MOSFETs bring harsh challenges to power stage, gate driving, protection, and control circuitry designs for a SiC-MOSFET-based PEBB, as shown in Fig. 1. This paper tackles those challenges and ensures the best performance for the SiC PEBB. Fig. 2 shows the PEBB1000. All of the parts are integrated to build the modular converters, including the controller, smart gate driver, busbar, inductors, dc-link capacitors, switches, different sensors, etc. A novel switching-cycle control (SCC) is proposed to minimize capacitor size and to enable the DC-DC operation of the modular multilevel converter (MMC). The basic modular multilevel buck converter (MMBC) was built with the PEBB1000 to validate the SCC approach. The PEBB DC capacitance was Cdc = 58 μF, and the PEBB inductance was Ldm = 4 μH, which is a significant reduction in size, compared to the conventional MMC and conventional MMC control schemes.