Single-Stage Isolated Bidirectional Soft-Switched AC-to-DC Converter with Active Power Decoupling

In this paper, a single-stage (SS) isolated bidirectional AC-to-DC converter with active power decoupling and reduced switch count is presented. The presented single-phase AC-to-DC converter is derived from H-bridge converter, buck based active power decoupling (APD) converter and dual active bridge (DAB). With the ability to transfer the double-line frequency ripple (DLFR) from the output to the auxiliary capacitor, the presented converter prompts a design with low-valued capacitance. To ensure soft-switching for secondary side connected APD converter, a variable switching frequency (VSF) modulation strategy is implemented. The control and modulation for the presented single-stage (SS) AC-to-DC converter are designed in a manner that ensures jinput power quality and desired output power, while keeping the low DLFR at the output. Finally, the effectiveness of presented single-phase SS bidirectional soft-switched AC-to-DC converter along with its control is verified by simulation and experimentation.