New ZCS turn-on and ZVS turn-off unity power factor PWM rectifier with reduced conduction loss and no auxiliary switches

A ZCS turn-on and ZVS turn-off unity power factor PWM rectifier, which feat ures soft switching with no auxiliary switches and reduced conduction losse s is presented. Thc ZVS and ZCS switching are achieved by using a simple co mmutation circuit with no auxiliary switches, and reduced conduction losses are achieved by employing a single converter instead of a typical front-en d diode rectifier followed by a boost rectifier. Furthermore, thanks to fea tures such as simple PWM control at constant frequency, low switch stress a nd low VAR rating of commutation circuits, it is suitable for high-power ap plications. The principle of operation is explained and analysed, and the d esign considerations and experimental results of the new converter are incl uded.