Coupled Inductor Based Buck PFC Converter for Elimination of Dead Zones

In buck converters, which are indispensable for AC-DC power conversion applications, dead zones naturally occur when the input voltage is lower than the output voltage. These converters can never adjust the input current to be pure sinusoidal because of their dead zones. Therefore, they have difficulty meeting the current harmonic limits of IEC61000-3-2. In this paper a coupled inductor based buck power factor correction (PFC) converter proposed to achieve elimination of dead zones, high power factor (PF) and low total harmonic distortion (THD) with a simple construction. Proposed converter not only eliminates input current dead zones by adding extra circuit, but also minimizes the turn-on and turn-off switching losses in both switches. A simulation study is performed with PSIM to verify the performance of proposed topology. The results obtained from couple inductor based buck PFC converter under various conditions are presented.