Abstracto

Controllable Bridgeless CUK Rectifiers for PFC Applications

Nikhil Mohanan, Daisykutty Abraham, Geethu James

Power supplies with active power factor correction (PFC) techniques are becoming necessary to meet harmonic regulations and standards. Conventional PFC scheme has lower efficiency due to significant losses in the diode bridge. In an effort to maximize the power supply efficiency, considerable research efforts have been directed toward designing bridgeless PFC circuits, where the number of semiconductors generating losses is reduced by eliminating the full bridge input diode rectifier. A bridgeless PFC Rectifier allows the current to flow through a minimum number of switching devices compared to the conventional PFC rectifier. Accordingly, the converter conduction losses can be significantly reduced and higher efficiency can be obtained, as well as cost savings. Several bridgeless topologies, which are suitable for step-up/step-down applications have been introduced. The CUK converter offers several advantages in PFC applications. Unlike the SEPIC converter, the CUK converter has both continuous input and output currents with a low current ripple. Thus, for applications which require a low current ripple at the input and output ports of the converter, the CUK converter seems to be a potential candidate in the basic converter topologies. Due to the lower conduction and switching losses, the bridgeless CUK topology can further improve the conversion efficiency when compared with the conventional CUK PFC rectifier. To maintain the same efficiency, these circuits can operate with a higher switching frequency. It will reduce the size of the PFC inductor and EMI filter. The power factor value can be achieved up to 0.9136 using this circuit with a power of 166 W. It is proven by using MATLAB simulation.