Design of a Single-Stage Single-Switch Power-Factor-Corrected (S4-PFC) AC/DC Converter

This paper presents the design of a single-stage single-switch power-factor-corrected (S⁴PFC) AC/DC converter. The converter under study is an integration of boost and flyback converters. The converter operation is equivalent to its two-stage counterpart with switches in the PFC and DC/DC converter stages turned on and off at the same time. Based on this observation, power circuit and control loop design of the converter can be carried out using standard design equations and methods, after the bulk capacitor voltage has been determined. This design concept is applied to design a 120 W (12 V, 10 A) S⁴PFC AC/DC converter. Experimental results are given to confirm validity of the proposed design method.