An Unbalanced Duty Cycle Modulation for Dual-Bridge Resonant Converter

This paper proposes an unbalanced duty cycle mod-ulation (UDCM) strategy to optimize conduction loss and improve the overall efficiency for dual-bridge resonant converter (DBRC). Steady-state analysis is performed using fundamental harmonics approximation (FHA), and the ZVS conditions are given. Further, the minimum current trajectory (MCT) is presented, which makes the converter operates with minimum resonant current. Moreover, the ZVS range is extended and the circulating current is well suppressed. The theoretical analysis and calculation are validated through simulation and experimental test.