Study On Single-Stage Power Factor Correction Converter

For AC/DC power supply ,in order to compliance with IEC 1000-3-2 harmonic regulation and realize low-cost ,high-performance ,the single-stage power factor (PFC) techniques have gained much attention these years,especialy in low power applications. A single-stage PFC converter combines the PFC stage and a DC/DC converter into one stage with a shared switch and controller . implements the input current shape and provide tight output regulation.The advantages and disadvantages of PFC approachs are analyzed and compared . and where sigle-stage PFC converter is more adapted to low power applications .A topological study of representative single-stage PFC converters are presented.In sigle-stage PFC approach, there are two important issues of concern. One issue is how to implement the input current shaper (ICS). Another one is how to control the energy-storage capacitor voltage below 450V. The single-stage PFC converters of Boost type can be classified as 2-terminal ICS cell and 3-terminal ICS cell. Several new PFC topologies were derived from some existing ones using the translation rule of the 2-terminal and 3-terminal ICS cell.Two single-stage PFC converters with the negative feedback of engergy-storage capacotor voltage by transformer windings are analyzed. The two converters have similar performances, and they can be translated each other,which verified the translation rule. The analysis and simulation show that with the negative feedback of energy-storage capacitor voltage by transformer winding have good performances. then develop a design process to optimize the converter design. In the last chapter, it is analyzed that by using the doubel-volgage recitifer front end of the transformer ,the problem of the capacitor voltage in single-stage PFC can be solved very well.