In this paper, a control-type ZVS technique for GaN-Based three-port quasi single-stage AC/DC converter is studied. The AC/DC converter consists of a ZVS totem-pole PFC rectifier and a CRM Buck converter. Two DC bus ports, exchange power with AC gird alternatively within line cycle. ZVS technique based on reverse recovery characteristics of Si diode is proved to be simpler and more effective than traditional methods. Three-mode mixed working mode is adopted based on the distribution of switching frequency and multi-level characteristic. ZVS switching modes and the distribution of ON time and OFF time are analyzed. DC-port voltage design is studied based on the natural ZVS region. A voltage outer loop and a current inner loop is adopted to control PFC rectifier and a single voltage loop is adopted to control Buck converter, mode switching strategy is also studied. The theory and control strategy are verified both in simulation model and a GaN-based prototype.
 

control-type ZVS, three-port AC/DC converter, CRM, DCM