Design of a single phase rectifier with switching on AC side for high power factor and low total harmonic distortion

A simple yet effective scheme for improving the power factor and waveshape of input current drawn by a single phase bridge rectifier is presented. A rectifier with filter capacitor draws current from the supply discontinuously, in short pulses. This introduces several problems including reduction of available power and increased loss. The scheme presented here uses a single MOSFET switch on the AC side to provide alternative path for the input current to flow and hence makes it continuous. The rectifier is connected to AC mains through a series combination of inductor and capacitor, which keeps the input current smooth and in-phase with the supply voltage. The simulated results reveal that the Total Harmonic Distortion (THD) of the scheme presented is below 2% with overall efficiency around 90%.