Hybrid high-frequency-SiC and line-frequency-Si based PEBB for MV modular power converters

A phase-shift isolated DC-DC converters are expected to be the key elements of modern medium voltage (MV) modular power converters. By comparing to the conventional MV modular power converters including bulky line-frequency transformers, the isolated DC-DC converters enable significant volume reduction and flexible bidirectional power flow control. The isolated phase-shift DC-DC converter with integrated gate drivers and interface module can be recognized as the power electronics building block (PEBB). The present paper further extends the concept of PEBBs dedicated for MV modular power converters. A hybrid high-frequency SiC- and line-frequency Si-based isolated AC-DC-DC PEBB is proposed in the paper. It provides galvanic isolation, voltage transformation capability and requires fewer transistors and diodes than multistage multilevel H-bridge AC-DC-DC converter with the same number of voltage levels. Experimental results of the SiC-based phase shift DC-DC converter and simulation results of the proposed AC-DC-DC PEBB are presented to confirm the validity of the system.