High power density and decoupled control of port power are important but generally difficult to be achieved at the same time for multi-port power electronic transformers (MP-PETs). This paper proposes a new MP-PET consisting of a common DC current bus, a grid-connected current-source converter (CSC) and several hybrid dual-active-bridges (H-DABs). The soft switching modulation method of the H-DABs is presented for different power flow directions, and the transmission power range is analyzed. The control methods of the different parts of the MP-PET are also proposed. The new MP-PET with the proposed control strategy requires fewer large capacitors and achieves flexible decoupling of the power control for each port. Simulation is carried out for the new MP-PET in an energy-storage system with multiple batteries. The simulation results verify the effectiveness of the proposed topology and its control method.