Single-Stage Resonant AC-DC Dual Active Bridge Converter with Flexible Active and Reactive Power Control

A new single-stage ac-dc resonant DAB converter and modulation scheme is proposed. The resonant network is based on a tuned ������ structure that ensures unity-power-factor operation at both ports. Due to the immittance characteristic of the tuned resonant network, the low-frequency ac input current of the DAB converter is directly controllable by means of modulating the dc-side switches according to a prescribed current reference generated by a closed-loop ���� current control. The proposed modulation scheme achieves soft switching for all acside switches and at least half of the dc-side switches. It also results in reduced rms bridge current and conduction loss.