A Novel High-Frequency Inverter With ZVT in a Wide Range of Duty Cycles and PFs

This article presents a wide-range zero-voltage-transition high-frequency single-phase inverter. The proposed inverter consists of a full-bridge inverter and two auxiliary switches that are magnetically coupled to the output filter inductor via an additional winding. The auxiliary circuit provides zero-voltage switching for the full-bridge converter switches, while the auxiliary switches are turned
on
and
off
with zero-current switching. A combination of unipolar and bipolar modulation is used as the modulation technique to ensure soft switching over a wide range of duty cycles and power factors. The proposed auxiliary circuit has a simple structure and does not require floating gate drives for the auxiliary switches. A 1.5 kW–400 kHz prototype has been developed to verify the theoretical analysis, demonstrating a significant increase in efficiency for both unity and nonunity power factors.