A bridgeless CUK PFC converter with positive output voltage

The output voltage of the traditional CUK PFC converter is negative, and an additional inverting amplifier circuit needed, which increases volume cost converter. A new type bridgeless topology proposed in this paper, makes have a positive without need circuit, has advantages simple control, high efficiency, low cost. Through optimization, one input capacitor reduced, two diodes are converted from high-current working state frequency to low-current power frequency, ordinary rectifier can be selected instead fast recovery diodes, thereby reducing works DCM, so no current control loop required, simplifies circuit. In addition, main switch turned on under ZVS condition, diode off ZCS reduces switching loss improves efficiency simulation model was built PSIM, prototype with rated 150 W fabricated verify effectiveness superiority Experimental results show that PF 0.995 7, THD 3.78% conditions.