Design and construction of a DAB using SiC MOSFETs with an isolation of 24 kV for PET applications

This paper analyzes the design and construction of a SiC-based Dual Active Bridge (DAB) converter for its use in a three-stage Power Electronic Transformer (PET) based on a Modular Multilevel Converter (MMC). The galvanic isolation between primary and secondary of the PET provided by the DAB High Frequency Transformer (HFT) is 24 kV. Challenges for the HFT design are discussed. A 5 kW DAB prototype using commercial 1.2-kV SiC MOSFETs is built to confirm the correctness of the design process. Parallelization of the DAB HFT to increase the power being transferred is also discussed.