Comparison of conducted RFI emission from different unity power factor AC/DC converters

Low frequency harmonic injection into AC power supply and small power factor are the main disadvantages of conventional AC/DC converters. Using current mode control, converter input current can have a sinusoidal form in phase with the power supply voltage. By solving the problem of power factor with high frequency switching current mode control, another problem arises-high frequency harmonics generated in the radio-frequency (RF) range from the converter. In this paper, an AC/DC converter with fixed topology (diode bridge+boost converter) is used and various current control methods are applied to it. After simulating the converter behavior, by using a standard network "line impedance stabilization network" between the AC power supply and the converter, conducted RF noise is calculated. Finally laboratory results are compared with simulation results.