A soft-switching mode rectifier with power factor correction and high frequency transformer link

This paper presents a soft-switching mode rectifier (SSMR) consisting of a power factor correction zero-voltage-transition-pulse-width-modulated (PFC ZVT-PWM) converter and a high-frequency transformer-coupled dc/dc zero volt age switching clamped voltage (ZVS-CV) converter. An easily implemented ZVT soft-switching mechanism is developed to reduce the switching losses and s tresses of the power switches in the PFC ZVT-PWM converter, The operations of the proposed SSMR in various modes are analyzed in detail and the associ ated governed equations are derived. Then accordingly, a quantitative desig n procedure is developed to find the values of soft-switching circuit compo nents. In the control aspect, the dynamic model of the SSMR is derived and a current waveform controller is designed, such that sinusoidal line curren t with low harmonics and near unity power factor is obtained. Under this co ndition, a voltage controller is also designed for yielding good de output voltage control characteristics. Validity of the designed SSMR is verified experimentally.