Abstract:
Two new topologies of single-phase Buck-Boost AC-DC converters with low input
current THD and high input power factor are proposed and presented. Instead of using a
single phase rectifier followed by a boost dc-dc converter, or using a bridge rectifier with
two diodes and two switches, the rectifier’s input is chopped at high frequency during
positive and negative cycles by a bi-directional switch in Buck-Boost conversion mode to
get step-up/step-down ac-dc conversion. Total Harmonic Distortion (THD) of the input
current of the proposed circuits with small input current filter is low. Input power factor
and the efficiency of conversion of the circuits are high. The circuits exhibit such
performance with variable loads at constant frequency switching. No additional control is
required to achieve the advantages.
Index Term- AC-DC power converters, bridge rectifier circuits, harmonic distortion,
passive filters, active power filters, power supplies, power harmonics, rectifying circuits,
harmonic standards.
