A Soft-Switching Solid-State Transformer Module

Abstract

This paper will study a fully soft-switching solid-state transformer (SST) module. The topology of the SST module is introduced and soft-switching operation principles are analyzed. To improve the system efficiency and power density, the magnetic components including the soft-switching resonant inductor and medium-frequency transformer (MFT) are designed. A 20kW SiC-MOSFET prototype is built up and tested for verification. The proposed two-stage SST module features a full load efficiency of 98.1% and a peak efficiency of 98.4% for bidirectional power flow.