An Improved ZVT PWM Three Level Boost Converter for Power Factor Preregulator

An improved ZVT PWM three level boost converter for power factor preregulator is proposed in this paper. Only one auxiliary switch is used in the active soft switching circuit. By using this ZVT converter topology, zero voltage turn-on and zero voltage turn-off of the main switches can be achieved and the reverse-recovery loss of boost diode can be reduced. In addition, the auxiliary switch is ZCS during the turn-on switching transition and zero voltage turn-off. A prototype of boost converter rated at 420 W has been built to confirm the effectiveness of the converter.