Practical design considerations of a single-stage single-switch parallel PFC converter for universal voltage applications

In this paper, a single-stage single-switch power factor correction (PFC) converter with parallel power flow function is presented. By adding a secondary winding to the boost inductor, this topology will directly transfer some input power to the load, resulting in two flow paths for the load power. While still achieving high power factor, it will reduce the current stresses on power components and limit the maximum voltage across intermediate bus capacitors. Operational principle and practical design considerations are discussed in details. A 150 W prototype based on this topology has been built and tested in the lab with experimental results that show good performance.