Current Sharing Analysis and Optimization for Full-Δ Three-Phase Interleaved LLC Circuits

The three-phase interleaved LLC (TP-LLC) circuit can effectively increase the power capacity, power density, and transmission efficiency, reducing the current ripple of the converter. Compared to the TP-LLC, the full-Δ TP-LLC exhibits notable advantages of lower current stresses and smaller passive component parameters, but it suffers from poor three-phase current balancing. To address this issue, this paper constructs a current-sharing analysis model and summarizes its current imbalance characteristics. Based on this model, two methods of safe operating region and phase-shifting correction technique are proposed to mitigate the imbalance characteristics of the full-Δ; type TP-LLC circuit. Finally, a2-kW prototype was developed for this study, and both simulation and experimental results have validated the effectiveness of these two methods.