Research on Optimization Strategy for Maximum Current Stress in Single-Stage DAB Microinverters

This paper proposes an optimized control strategy for single-stage dual active bridge (DAB) microinverters, aiming to minimize the peak current stress. The core of this strategy lies in jointly regulating two key parameters: the virtual input voltage V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dcmin</inf> and the phase-shift coefficient k. To achieve global minimization of the maximum inductor current i<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Lmax</inf> throughout the fundamental period, a control equation for dynamically adjusting k based on grid voltage is derived. This control strategy not only reduces control complexity but also effectively lowers current stress while ensuring full-range zero-voltage switching (ZVS) and maintaining a low RMS leakage current. Experimental results validate the feasibility of the proposed control strategy.