A novel zero-voltage-switching PWM boost rectifier with high power factor and low conduction losses

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 new 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, and ZCS in the auxiliary switch. 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. Nine 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/sub rms/ and an output voltage 400 V/sub 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.