Prototype design and experimental verification of an isolated modular dc/dc converter system

This paper details design, development and control methods of an isolated modular DC/DC converter (IMDCC) system. A 10kW downscaled prototype is constructed to show the working principles, hardware design procedures, and control circuits implementation. In this prototype, there are two MMC stations, namely the inverter end and the rectifier end, each consisting of N half-bridge (HB) sub-modules (SMs). Each phase is controlled by an independent phase controller while both stations are controlled by a central controller. Moreover, the management and communication methods of these SMs are also illustrated. Further, the control principles for the single-phase and three-phase IMDCC system are presented respectively to achieve power regulation and balance all the SM capacitor voltages. Finally, experimental results are given to verify the validity of the circuit design and show the effectiveness of the control methods for both singlephase and three-phase IMDCC.