Abstract：A bidirectional isolated resonant converter with variable mode and wide voltage range was

proposed. The proposed converter has the advantages of BOOST circuit and flyback current feed topology. By

reusing the pre-storage and flyback energy feedback of the resonant inductor，it can improve the gain from the

battery side to grid side and the power density of the converter，while also reducing the current circulation. The

converter adopts fixed frequency pulse width modulation and has multiple working modes，which is suitable for

wide range output. the working principle of the converter was first introduced and the output gain when the energy

flows in different directions was analyzed. Finally，on the premise of meeting the charge and discharge of the

battery in the home distributed energy storage system，the devices and control parameters were designed to verify

the correctness of the theoretical analysis.

      Key words：DC-DC converter；voltage gain；soft switch；wide range；variable mode