In this article, a control strategy combined with expanded phase shift (EPS) and frequency conversion for a single-stage dual active bridge (DAB) AC/DC converter is proposed. The control strategy is adopted to realize Zero Voltage Switching (ZVS) under a wide load range without operating mode switching and achieve power factor correction (PFC). A control algorithm for the DAB AC/DC converter is fitted on this basis, which ensures that the dual active bridge AC/DC converter works in the optimal operating mode. The variation of efficiency and total harmonic current distortion with power transfer in the converter is also analysed. A 1 kW experimental prototype was built to verify the effectiveness of the control strategy. The experimental results verify the operating mode, soft-switching performance and high efficiency.