Performance Considerations of PFC Switching Regulators Based on Non-Cascading Structures

This paper discusses the characteristics of power-factor-correction (PFC) switching regulators of non-cascading structures in terms of efficiency, input current harmonic distortion, and load transient response. The discussion begins with simplified power flow diagrams of the non-cascading PFC switching regulators and describes their essential features for achieving power factor correction and tight voltage regulation. Based on these diagrams, the various configurations of switching regulators can be classified into three categories, each offering a different possibility of performance tradeoffs. The first category permits tradeoff between efficiency and input current harmonic contents, the second permits tradeoff between efficiency and load transient response, and the third allows tradeoffs among all performance areas. The paper briefly reviews the non-cascading structures of PFC switching regulators in terms of the three categories. Simulation and experimental results are provided to illustrate the performance tradeoffs in these PFC switching regulators.