Isolated bidirectional AC/DC converter is adopted to realize the connection between battery and single-phase power grid.The analyzed structure is a dual active bridge single-phase AC/DC converter which can control the power flow of microgrid composed of renewable energy

battery pack and single-phase power grid.The analysis of the converter mainly focuses on the connection structure and control method

which suppresses the fluctuation of bus voltage.A single-phase phase-locked loop(PLL) with improved second-order generalized integrator(SOGI) is adopted.In order to overcome the problem that the loop filter of traditional PLL is difficult to completely filter out the harmonics of the input signal and produce phase shift in the output signal of PLL

a vector control strategy for current regulation of grid-connected voltage source converter is proposed.Finally

the voltage and current signals are simulated by PLECS software.The simulation results show that the PLL based on the second-order bandpass filter can suppress the DC component and high-frequency component

effectively eliminate the phase shift caused by unreasonable parameter setting

and verify the feasibility of the control strategy of bidirectional AC/DC converter.