Analysis and Design of a New Three-Level PFC AC-DC Converter

In this paper, a new integrated three-level ac-dc converter is presented. The proposed converter integrates the operation of the boost power factor correction and the three-level dc/dc converter. The converter is made to operate with two independent controllers - an input controller that performs PFC and regulates the dc bus and an output controller that regulates the output voltage. The input controller prevents the dc bus voltage from becoming excessive while still allowing a single-stage converter topology to be used. In the paper, the operation of the new converter is explained in detail and analyzed, and its steady-state characteristics are determined. The main focus of the paper is on the design of the converter as a procedure for its proper design is developed in the paper and is demonstrated with a detailed design example. The feasibility of the new converter is confirmed with experimental results obtained from a prototype converter.