Unified Boundary Control With Phase Shift Compensation for Dual Bridge Series Resonant DC-DC Converter

In this paper, the triple-phase-shift (TPS) control with certain unified boundary conditions is applied to a dual-bridge series resonant converter (DBSRC) for applications needing bidirectional energy flow ability. The control strategy is unified for the whole variation range of load, input/output voltage and with simple calculation. By using this unified boundary control, the circulating energy is minimized significantly. A wide soft switching operation range can be achieved as well. Furthermore, based on the analysis results of unified boundary conditions, an improved unified boundary control with duty cycle compensation is also proposed. The ZVS operations of all sides switches can be maintained for wide converter gain and load with high efficiency. The procedure of design for important parameters is given. Finally all works are verified through actual experimental tests on a 500W laboratory prototypes successfully.