A Seamless Switching Control Method of DAB Converters for Photovoltaic Microgrids

This paper proposes a seamless switching control method for dual active bridge (DAB) converters applied in islanded photovoltaic microgrids to suppress bus voltage drops and achieve voltage self-recovery. First, the voltage and current on both sides of the converter are selected as the control objectives, and a parallel proportional-integral (PI) controller is presented to obtain multiple quasi control signals. Secondly, a two-stage decision-making scheme is proposed to obtain the optimal control signal based on the multiple loop outputs. To improve the dynamic performance of the system, a synchronous updating method is adopted to improve the conventional PI control structure. Combined with the application scenarios in the photovoltaic microgrids, the impact of the proposed method on the system stability is analyzed. Finally, compared with the conventional switching control method, the effectiveness of the proposed method is verified through simulations.