High performance boost PFP (power factor pre-regulator) with an improved ZVT (zero voltage transition) converter

In this paper, the conventional ZVS PWM boost converter is improved to minimize the switching loss of the auxiliary switch using the minimum number of components. To reduce the switching loss and EMI noise, the saturable core and the parallel capacitor across the clamp diode (D2) are used in the auxiliary switching network. Using this technique, soft-switching for the auxiliary switch is guaranteed at wide line and load ranges. Since the active switches are turned on and off softly, the switching losses are reduced significantly and higher efficiency of the system is achieved. This paper proposes an improved ZVS PWM Boost PFP. A prototype of a 200 kHz 1 kW system was implemented to show the improved performance.