Single-stage push-pull boost converter with integrated magnetics and input current shaping technique

This paper presents a novel single-stage push-pull boost converter with improved integrated magnetics and a better low-ripple input current. Most of the reported single-stage power factor corrected (PFC) rectifiers cascade a boost-type converter with a dc-dc converter. It is found that the push-pull converter, when the duty cycles are greater than 50%, can simplify the front end of the boost-type converter to a novel single-stage converter. Coupled inductor techniques provide a method to reduce the converter size and weight and to achieve a ripple-free current. All the magnetic components including the input filter inductor and the step-down transformer are integrated into a single EI core. The proposed integrated magnetic structure has a simple core structure, a small leakage inductance, and low core losses. The prototype is built to demonstrate the theoretical prediction.