A Novel Control Method focusing on reactive power for a dual active bridge converter

This paper proposes a reactive current control method focusing on a copper loss reduction for a dual active bridge DC-DC converter. The proposed method controls the reactive current using the fundamental wave model of the primary and secondary voltages in the dual active bridge DC-DC converter. However, the total power factor reduced by the harmonic component of the output voltage of the each inverter in light load region. In order to keep the high total power factor, the pulse frequency modulation (PFM) is introduced to the proposed method. From the experimental results which the inductor current, total power factor, and the efficiency with the PFM compared without the PFM. The total power factor is over 0.88 from the 40% to the rated power with the PFM. In addition, the reactive power is controlled by adjusted switching frequency in order to achieve the minimum loss of a DAB converter prototype. As results, the efficiency of the prototype is improved 10% at 100 W. Therefore, it is confirmed that the proposed method achieves the minimum current value for the output power. In addition, the switching loss can be reduced by zero voltage switching with the reactive current control. Thus, the high efficiency can be achieved in wide load region.