Bridgeless CUK power factor correction rectifier with reduced conduction losses

In this study a new bridgeless CUK power factor correction (PFC) rectifier is introduced. The output voltage of this converter is lower than its input voltage, which is preferred in low-voltage power supply applications. The conventional CUK PFC converter has three components in its power flow path. The proposed converter has lower conduction losses since the input rectifier is combined with the CUK converter and thus, there are two components in the power flow path. In the conventional PFC converters (continuous conduction mode boost converter), a voltage loop and a current loop are required for the feedback. This converter operates in discontinuous conduction mode and thus the control circuit is simplified and no current loop is required. Theoretical analysis and simulation results are provided to explain the converter operation. A 150-W prototype of the proposed converter is realised and the presented experimental results confirm the validity of theoretical analysis. The measured efficiency shows improvement in comparison to the conventional CUK rectifier. The measured power factor is 0.99 at full load and also satisfies the International electrotechnical commission standard on harmonics.