| As a branch of active power factor correction (PFC) techniques, the single-stage single-switch (S4) technique receives particular attention because of its low cost implementation. Using DCM converter in front of the line to achieve high power factor operation can further reduce the power supply cost. The performance of such kind of AC/DC converter strongly depends on the complexity of its circuit topology. However analysis and design of the DCM-S4 converter is yet to be formulated. In this dissertation, new methods to analyze and design the S4-PFC converters have been developed. These methods are generally suitable for all kinds of DCM-S 4 converters. This dissertation also gives an overview of recent active PFC techniques. Based on the general study and review of the S4-PFC technique, four converter topologies have been proposed with emphasis on different applications. Analysis and design of these converter topologies are presented with simulation and experimental verifications. For all these converters, high input power factor and acceptable efficiency have been achieved. The low voltage stresses on the storage capacitors for these converters result in low cost implementation of the proposed topologies. |
