A single-phase bidirectional dual active half-bridge converter

A bidirecitonal dual active converter with the power factor control capability is proposed for low-power on-board battery charger application. The source side half-bridge acts as a pulse-width modulation (PWM) converter that maintains the unity power factor. The battery side half-bridge converter acts as a dual active bridge (DAB) together shares the same DC link voltage with the PWM converter. Asymmetric duty cycle technique in which turn-on and -off time duration of primary switches in DAB converter are changed to control the charges of two capacitors is employed to eliminate imbalance voltage phenomenon. Thus, the input current can shape in phase with the voltage source and promising high efficiency of PWM converter. Simulation and experimental results are included to verify theoretical analysis.