Abstract: A new interleaved three-phase PFC AC-DC single stage multilevel is proposed in this paper. The proposed converter uses a flying capacitor structure with a standard phase shift PWM to improve efficiency, particularly at light load conditions. In the paper, the operation and its steady state characteristics are explained and its design is discussed. The feasibility of the new converter is confirmed with experimental results obtained from a prototype converter. 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 power factor correction and regulates the dc bus and an output controller that regulates the output voltage. The input controller prevents the dcbus voltage from becoming excessive while still allowing a single-stage converter topology to be used. The paper explains the operation of the new converter in detail and discusses its features and a procedure for its proper design.

Keywords: AC–DC Power Conversion, Three-Stage Power Factor Correction, static induction thyristor, single-stage power factor, Flying Capacitor.