A Variable Switching Frequency Control Method for a Dual-Active-Bridge Single-Phase AC-DC Converter with an Active Energy Buffer

This paper proposes a new control method for a dual-active-bridge (DAB) single-phase ac-dc converter with an active energy buffer circuit. The proposed control method realizes continuous-current-mode (CCM) operation of the DAB converter by adjusting a switching frequency according to the phase angle of the single-phase line voltage, and thus, makes it possible to improve the power conversion efficiency. Experimental results verified the CCM operation with the proposed control method and demonstrated an improved power conversion efficiency of 92.8% at the 220-V, 5.4-kW output.