Modular DC Power Conversion System and Control Method for an Ultra-Wide Output Voltage Range of 5-500V Application

This paper proposes an ultra-wide output voltage range modular DC power conversion system composed of four dual active bridge (DAB) modules and a four-switch Buck-Boost (FSBB). Each output port of DAB module is connected through a control circuit. Through the control circuits, the output ports of these four DAB modules can be connected in parallel or in series. This expands the output voltage range of the DAB modules, without increasing the current stress on each module. The FSBB is connected to the output ports of the DAB modules as the post stage. It further extends the output voltage range of the system. Moreover, the series-parallel connection of the front-end DAB modules varies with the output voltage. It ensures a wide range of voltage regulation and low current stress. The phase-shifting control (PSC) and pulse width modulation (PWM) are applied to the DAB and FSBB models separately to regulate the wide-range output voltage. In this paper, a 1000W simulation model is built to verify the performances of the proposed DC power conversion system.