Verification of the DAB loss model at different frequencies

This study comprehensively validates the loss modeling of dual active bridge (DAB) converters under varying switching frequencies, with particular focus on their performance in single-phase shift (SPS) and extended-phase shift (EPS) control modes, while identifying optimal frequency operating points. A comprehensive analytical loss model was developed, encompassing MOSFET and diode conduction/switching losses, as well as transformer core losses and inductor copper losses. Through systematic simulation and experimental validation, the impact of switching frequency (80 kHz to 180 kHz) on total power dissipation was investigated. The results indicate that under SPS control, minimal total losses occur at 160 kHz (light-load conditions) and 100 kHz (full-load conditions), whereas under EPS control, optimal frequencies shift to 180 kHz (800 W) and 150 kHz (1000 W). Experimental results demonstrated strong congruence with simulation data, exhibiting deviations below 5 W across all test scenarios. The proposed loss model exhibits exceptional operational fidelity in predicting prototype behavior, thereby confirming its practical utility for efficiency optimization and optimal switching frequency selection in real-world DAB converter design.