A Single-Stage 99% Efficient All-SiC Medium Voltage DC Transformer (GR-20-04)

Principal Investigator: Dr. Yue Zhao

The goal of this project is to develop a 99% efficient single-stage all SiC medium-voltage (MV) dc transformer (DCX), which is the most critical building block in a solid-state transformer (SST). Compare to the state-of-the-art SSTs, where series connection of multiple cells on the MV ac side is usually required, in this project, 10 kV SiC MOSFET modules are utilized on the primary side to enable a single-stage DCX from 7.2 kV to 400 Vdc. This design concept leads to higher reliability, higher efficiency and higher power density compared to the state-of-the-art SST.

When circuit topology is simplified, the design challenges are shifted to the design of the medium frequency (MF) transformer, which is the key task in this project. A Pareto-front analysis based multi-objective optimization approach for transformer design is utilized in this project to identify the optimal operating conditions of the transformer. Both single-phase and three-phase integrated magnetics are investigated in this project.