Soft-Switching Bridgeless Buck–Boost PFC Converter Using Single Magnetic Core
Mohammad Mahmoodsaleh, Ehsan Adib
Abstract
In this article, a new bridgeless single-phase buck-boost power factor correction (PFC) converter with one magnetic core is introduced. The proposed converter is designed to operate in discontinuous capacitor voltage mode (DCVM) to achieve low total harmonic distortion (THD) and continuous input current with a simple structure. The DCVM operation gives additional advantages, such as inherent PFC, low turn-off losses, and reduced complexity of the control circuitry. Unlike the buck converter, the proposed converter eliminates the dead angle of input current without adding any extra circuits. Also, by eliminating two input diodes in power flowing path, the efficiency is further improved. Due to achieved almost zero current switching at the turn-on and almost zero voltage switching at the turn-off, the switching losses are eliminated. In this article, theoretical analysis and principal operation of the converter are discussed. An experimental prototype is implemented to verify the performance of the proposed converter. Experimental results are presented for a 120-W prototype at 110-V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> input and 48-V output.