Design and Performance Considerations of PFC Switching Regulators Based on Noncascading Structures

This paper systematically explores the performances of power-factor-correction (PFC) switching regulators based on noncascading structures in terms of efficiency, input-current harmonic distortion, and load voltage regulation. The investigation begins with simplified power-flow diagrams, which represent the noncascading PFC switching regulators and describe the essential features of the noncascading PFC switching regulators to achieve PFC and voltage regulation. Based on these diagrams, the noncascading PFC switching regulators can be classified into three categories, each offering a different set of performances. The first category permits a tradeoff between the efficiency and the input-current harmonic distortion, the second permits a tradeoff between the efficiency and the size of the storage element for the load voltage regulation, and the third allows a tradeoff among all the performances. With detailed analyses through analytical approaches, simulation results illustrate the performances of these three categories of noncascading PFC switching regulators. An experimental prototype of the third category has been built to validate the analyses.