SEPIC and BIFRED converters for switch-mode power supplies: A comparative study

The increased importance of power quality problem has attracted the attention towards power factor corrector (PFC) circuits for different power conversion systems. In this paper, a comprehensive comparison between single-ended primary inductance converter (SEPIC) and boost integrated flyback rectifier/energy storage DC/DC (BIFRED) converter, which are the two emerging PFC circuits, based on analytical relations, and simulation results are presented. All possible operating modes of SEPIC and BIFRED converters are also investigated. The authors also present equations for all operating modes. Furthermore, critical parameters for different operating modes to achieve very high efficiencies are discussed.