A Time-Domain Model for <i>CLLC</i> DAB Converter Considering Asymmetric Resonant Tank Parameters

The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLLC</i> dual-active-bridge (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLLC</i> DAB) dc–dc converter is usually designed only considering a symmetrical resonant tank, aiming to simplify the design and modeling procedures. Under asymmetric resonant tank parameters, the equivalent model composed of the five resonant elements cannot be solved. Therefore, a mathematical model with two individual resonant tanks is proposed in this letter. Compared with conventional modeling, the new modeling method for the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLLC</i> DAB converter significantly reduces the computational complexity, making the time-domain model with asymmetric parameters feasible. Furthermore, the zero voltage switching (ZVS) range under asymmetric resonant tank parameters is analyzed. Besides, the relationships between asymmetric resonant tank parameters and resonant capacitors’ voltage stress are analyzed. Finally, the accuracy of the proposed model and the theoretical analysis are verified through a 1.2-kW experimental prototype.