An AC/DC PFC Converter with Active Soft Switching Technique

Need For Power Factor Correction

Power factor is the ratio of real power to apparent power both measured in Watts. From the voltage and current waveforms it can also be inferred as the phase shift between them. Power factor correction is shaping the input current of AC main synchronized with input AC voltage increasing the rectifier’s conduction angle. This is done to increase the amount of real power from the mains and to remove the harmonics present in the input current (Ahmad Mousavi & Gerry Moschopoulos, 2014; Chongming Qiao & Keyue Ma Smedley,2001). In older days, inductors and capacitors were used with low EMI but with reduced efficiency and increased component stress (Mishra, Ramteke & Suryawanshi, 2012). A lower capacitance can be added to the output capacitor but it will create ripples at the output voltage. Many researches have been developed in the area of power factor correction during recent years since electronic equipment with PFC converters are necessary to meet the standard and regulations involving harmonics.