Dual-Output Ac-Dc Converter With Three-Port Bridgeless Pfc And Non-Isolated Dcx

This study proposed a dual-output AC-DC converter based on three-port bridgeless power factor corrector (TPB-PFC) and a non-isolated resonant DC-transformer (Ni-DCX) for dual-output DC voltage applications. A constant DC output voltage and a variable DC output voltage are provided simultaneously by the proposed AC-DC converter. Based on the TPB-PFC converter, a stacked power conversion structure with reduced power conversion stage is presented. Therefore, lower power losses and higher efficiencies are achieved. Meanwhile, soft switching of all the power devices in the Ni-DCX is achieved with open-loop controlled and optimised operation of the Ni-DCX, resulting in easy control and higher efficiency. In addition, switching losses of the TPB-PFC are reduced thanks to the three-level characteristic. Operation principles and characteristics of both TPB-PFC and Ni-DCX converter, and modulation and control strategies of the proposed AC-DC converter are analysed in detail. Feasibility and effectiveness of the proposed solutions are verified experimentally with a 2 kW dual-output AC-DC prototype.