A two-stage control scheme for a dual-bridge series resonant converter

High frequency (HF) isolated dual-bridge converters are featured with high power density, high efficiency for bidirectional applications, such as distributed generation systems. In this paper a high-frequency isolated dual-bridge series resonant converter (DBSRC) with a novel two-stage control scheme is proposed for an application with a wide variation of voltage gain. The dual-phase-shift control is adopted for the DBSRC. The steady-state analysis of the DBSRC is performed by means of the fundamental harmonics approximation. A novel control scheme is presented for the converter with a 40% variation in converter gain. It can be seen that zero-voltage switching is kept for all switches on the low-voltage side and half of switches on the HV side. Also, there is no circulation energy on the LV side for full load operation. Verification of the analysis and design are performed through simulation and experimental test at last.