Design Considerations for PPS Controlled Current-Fed DAB Converter to Achieve Full Load Range ZVS with Low Inductor RMS Current

Current-fed dual active bridge dc-dc converters are suited for renewable energy systems such as solar photovoltaic and fuel cells, due to the advantages of small input current ripple and high voltage conversion ratio. In this paper, a current-fed dual active bridge dc-dc converter based on pulse width modulation plus phase shift (PPS) control is studied. The working principle and mathematical soft switching conditions of the converter are analyzed in depth. Based on the zero-voltage-switching (ZVS) conditions, maximum power transfer and root mean square (RMS) current analysis, optimal DC inductance and leakage inductance design to obtain low inductor RMS current and full load range ZVS is proposed. The effectiveness of the theoretical analysis has been verified by experimental results.