A Novel Topology of Three-Port DC-DC Converter with Improved Carrier Phase-Shifted Control for MVDC Applictions

With the rapid advancement of DC/DC power transmission technology, various DC/DC topologies are proposed, efficiency in power delivery and energy conversion should be promoted dramatically, for example, Dual-Active-Bridge(DAB) converter. Aiming at the MVDC applications, this paper proposes a novel topology of DC/DC converter which is composed of modular multilevel converter on the primary side and double full bridges on the secondary side. Based on carrier phase-shift modulation, the primary side produces a five-level waveform to reduce the instant voltage impact on switches and realize the stable power transmission. In order to retard the losses brought by circulating current, the individual capacitor voltage is chosen for outer loop to produce reference value. Eventually, the effectiveness and correctness of this topology and corresponding control methods are verified by the results in MATLAB/Simulink.