Ripple Voltage Controlled in Two Switch PFC BuckConverters

Conventional single-phase power-factor-correction(PFC) rectifiers with active power decoupling capability typicallyrequire more than three active switches in their circuits. Byexploring the concept of power-buffer cell, a new single-stage PFCrectifier with two active switches, one inductor and one smallpower-buffering capacitor is reported in this paper. The proposedconverter can achieve high-power factor, wide output voltagerange, and power decoupling function without using electrolyticcapacitor. Additionally, an automatic power decoupling controlscheme that is simple and easy to implement is proposed in thispaper. The operating principle, control method, and designconsiderations of the proposed rectifier are also provided. A۱۵۰۰W prototype with ac input voltage of ۲۲۰ rms and a regulateddc output voltage ranging from ۳۰ to ۱۵۰ V has been successfullydesigned and simulated. The simulation results show that withonly a ۱۰۰ μF power-buffering film capacitor, the proposedconverter can achieve an input power factor of over ۰.۹۸, peakefficiency of ۹۴%, and output voltage ripple of less than ۵%, andTHD ۴% at ۱۵۰۰W output power.

کلیدواژه ها:

PFC rectifier ، Power decoupling ، Ripple Voltage ، Buck Converters