Design and practical implementation of efficient power-factor-corrected switching regulators based on reduced redundant power processing principle

Abstract

Power-factor-corrected switching regulators effectively eliminate the current harmonic distortions of the AC mains, associated with large non-linear loads, capacitive loads, and inductive loads from the electric machinery and electronic systems. Switching regulators with power factor correction (PFC) and fast voltage regulation are constructed by two simple converters with an energy storage element. Simple and typical power-factor-corrected switching regulators are connected with their the converters and the storage element serially. The main drawback of this approach is that the efficiency of these arranged switching regulators is inevitably reduced by the two power processing stages, the two simple converters. To solve the efficiency problem, non-cascaded switching regulators are proposed. Unlike the typical power-factor-corrected switching regulators, the non-cascaded power-factor-corrected switching regulators allow part of the input power to be processed by only one power stage, thereby reducing the amount of power redundantly processed by the two constituent power stages. Unfortunately, industry has been slow to appreciate and exploit the considerable advantages of the non-cascaded power-factor-corrected switching regulators. There seem to be the reason for that: the lack of detail, systematic comparison, and practical information on the non-cascaded power-factor-corrected switching regulators. The objective of this study is to fill this gap by providing a well-organized compendium of useful information for the switching regulator design engineers who want to understand the practical detail of the non-cascaded power-factor-corrected switching regulators for accomplishing an optimal in their designs. Two non-cascaded power-factor-corrected switching regulators have been constructed and tested for validating the reduced-redundant-power-processing (R2P2) principle. A rigorous and detail comparison of the switching regulators output power level, circuit complexity, components stress, and control methodological are reported.