Design of the feedback loop for single controller power factor correction converter

This paper presents the design of the feedback loop for single controller (SC) power factor correction (PFC) power converters which can regulate the output voltage tightly. In the SC PFC power converter, which needs a small size bulk capacitor for low cost, the loop gain design requires an input-to-output transfer function because the rectified input voltage has large harmonic components. Two design examples are used to illustrate that the capacitor size and corresponding loop gain affect the power converter performances such as THD, DCM conditions and output regulation. The proposed design procedures are verified for two-stage one-controller boost-forward PFC power converters using computer simulations and experimental results