Step-up converter for power factor control using soft switching technology

摘要

The present invention relates to a step-up converter for power factor control using a soft switching technique. Conventionally, diodes have a large loss due to reverse recovery characteristics, and this loss has a problem of increasing EMI generation. Accordingly, the present invention provides a soft switching unit in a boost converter, a resonant capacitor Cr connected between a positive end and a negative end of a rectifier, a first auxiliary switch Sa1, a first auxiliary diode Da1, and a second auxiliary diode connected to DC. The bidirectional switch composed of Da2 and the second auxiliary switch Sa2 is connected in parallel to the positive terminal of the rectifying unit, respectively, and two series of filter capacitors Co1 and Co2 connected in series are connected between the positive terminal and the negative terminal of the rectifying unit. A resonant inductor Lr is connected in series between the connection point of the first auxiliary diode Da1 and the second auxiliary switch Sa2 and the connection point of the two filter capacitors Co1 and Co2, and the first auxiliary switch Sa1 A soft switch for switching the switches and diodes of each part, consisting of a diode D connected in series with the positive terminal of the rectifying part between the connection point of the second auxiliary diode Da2 and the first filter capacitor Co1. The use to reduce the loss by switching in zero-current or zero voltage almost to zero, due to the EMI problem and soft switching is also considerably reduced, which is to compactly configure the entire system.