A ZVS-PWM voltage-doubler rectifier with high power factor

This paper proposes a new single-phase high power factor rectifier, which features regulation by conventional PWM, soft commutation and instantaneous average line current control. A zero-voltage-switching pulse-width modulation (ZVS-PWM) auxiliary circuit is configured in the presented ZVS-PWM rectifier to perform ZVS in the main switches and the passive switches. Furthermore, soft commutation of the main switch is achieved without additional current stress by the presented ZVS-PWM auxiliary circuit. A significant reduction in the conduction losses is achieved, since the circulating current for the soft switching flows only through the auxiliary circuit and a minimum number of switching devices are involved in the circulating current path, and the proposed rectifier uses a single converter instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter. Seven transition states for describing the behavior of the ZVS-PWM rectifier in one switching period are described. A prototype rated at 1 KW, operating 80 kHz, with an input AC voltage of 220 V_rms and an output voltage 400 V_dc has been implemented in laboratory. An efficiency of 96.7% and power factor over 0.99 has been measured. Analysis, design, and the control circuitry are also presented in this paper.