The Comparison and Choice of Several Power Factor Correction Methods

At the input of AC-DC switching mode power supply, we often use a full wave rectifier and a parallel capacitor to get the direct voltage smooth and level. Because rectifier is non-linear and filter capacitor is an energy-stored component, the combination of those two will make the input alternating current distort greatly. The input pulse shape current contains a lot of harmonic waves. This will reduce the power factor greatly. Besides this, a lot of current harmonic emission will make the voltage shape distort and the circuit out of order. In order to reduce the pollution caused by input harmonic current of AC-DC converter and improve the input power factor, we must take measures to limit the input harmonic current. In this paper, I expect to compare several methods of power factor correction and introduce their usages