A Three-Level Three-Phase Sextuple-Voltage Dual-Active-Bridge Converter for Medium Voltage DC Transformer

To improve the power density of DC transformer, this paper proposes a new three-level three-phase sextuple-voltage dual-active-bridge
$(\mathbf{T}^{\mathbf{2}}\mathbf{S}-\mathbf{DAB})$
converter, which can extend submodule port voltage of DCT to six times of the conventional full-bridge DAB, while ensuring the same device voltage stress. This paper presents the basic operation principle, parameter design scheme, and basic control strategy of the three-level three-phase sextuple dual active bridge converter. Finally, a 6kW, 900V/150V simulation model are constructed to verify the feasibility and rationality of the proposed topology.