Control Strategy of Single-Stage DAB Based on Synchronous Rectification

Microinverters serve as pivotal components in photovoltaic (PV) power generation systems. The single-stage dual-active-bridge (DAB) converter has gained widespread adoption owing to its structural simplicity, good controllability, and superior conversion efficiency. When actually controlling the turning on and off of the power devices in a single-stage DAB converter, the turn-off loss of the secondary-side metal-oxide-semiconductor (MOS) tube can reduce transmission efficiency. To address this issue, a variable-frequency control method based on synchronous rectification is proposed. By detecting the secondary-side current of the transformer and controlling the zero-current turn-off of the secondary-side MOS tube, a linear relationship between input and output is achieved, simplifying the algorithm and facilitating control. A converter model is built in MATLAB/Simulink simulations to verify the effectiveness of the control strategy.