Reconfigurable Full and Partial Power Processing GaN-FET-Based T-Type DAB DC–DC Converter

The multilevel dual-active-bridge (ML-DAB) converter offers enhanced performance and power density operation compared with conventional DAB counterparts. This article introduces a GaN-FET-based T-type DAB converter interface, designed to enable transition between full power conversion (FPC) and partial power conversion (PPC) modes. The proposed converter generates five voltage levels on both the primary and secondary sides of the high-frequency transformer (HFT), reducing voltage transitions (dvdt) and increasing the high power efficiency range. The main contribution of the proposed converter lies in the integration of an ML-DAB architecture with the capability to operate in PPC reconfiguration, enabling the processing of only a fraction of the total power with enhanced thermal performance. Output voltage regulation is achieved by a single-phase shift (SPS) between the primary and secondary sides, simplifying control and enhancing overall performance. Simulation and experimental tests under a scaled-down prototype to verify the proposed modulation method and control scheme implementation are performed.