Continuous-current mode operation of a semi-dual-bridge resonant converter

Originated from the dual-bridge resonant converter, a semi-dual-bridge resonant converter is proposed for unidirectional applications in this paper. The single phase-shift modulation is adopted for power regulation. It is proved that the proposed converter is capable to work in either continuous-current mode or discontinuous-current mode. Compared with the dual-bridge resonant converter with single phase-shift modulation, the high circulation energy in output bridge is eliminated and the zero-voltage switching range of all switches is extended in the proposed converter. Steady-state analysis of the converter in continuous-current mode is performed using fundamental harmonics approximation. A design example based on the analysis results is presented and then verified through both simulation and experimental test on a lab prototype converter.