Power factor correction circuit with a new modified SEPIC converter

This paper presents a new topology for a SEPIC converter used in power factor correction circuits. The conventional SEPIC converter was primarily designed to provide a nonpulsating input current, operating with both inductors in continuous current mode and only DC-DC conversion was considered. The modified SEPIC converter is designed to operate as an AC-DC converter and can be viewed as a cascade of a modified boost converter and a buck-boost converter. The boost converter operates in discontinuous current mode, while the buck-boost converter operates in continuous current mode. Since a high power factor is naturally achieved in this way, a simple feedback control technique is needed in order to regulate the output voltage. The paper also presents a calculus method for the power factor and total harmonic distortion factor for the proposed converter.