Bridgeless Cuk PFC Converter With Soft Switching in Full Input Voltage and Load Range

In this article, a new bridgeless Cuk power factor correction converter is presented. The proposed converter is capable of providing full soft switching operation for all semiconductor components in the entire line cycle and load variations, only by a single auxiliary switch. The converter operates in discontinuous conduction mode (DCM) that intrinsically provides low input current total harmonic distortion (THD) without any input filter. Despite imposing higher current stress on semiconductors in DCM, the proposed converter achieves high efficiency due to its soft switching operation. The theoretical analysis and operating modes are discussed in detail, and the validity of the analysis is verified by an implemented prototype operating at 200-W output power, 80-V output voltage, and 100-kHz switching frequency, yielding 95.83% efficiency and around 2% THD.