Topology and Control Strategy of Multi-port DC Transformer Based on Dual-Active-Bridge

This paper presents a topology of multiport DC transformers and its control strategy, which uses dual-active-bridge (DAB) as submodules. Firstly, the structural characteristics and control methods of the DC transformer with ISOP structure are analyzed. On this basis, the topology of the traditional ISOP DC transformer is improved so that it can output up to three different voltage levels. Then the control strategy was designed for the modified DC transformer. Finally, the simulation results verify the rationality of the topology and control strategy.