Reducing Inductor Size and Current Ripple in an AC-AC Converter by Interleaved Switching Strategy

Bidirectional boost rectifiers are widely employed in high power factor correction (PFC). One of the disadvantages of the Full-bridge Boost Rectifier (FBR) is its need for a large size inductor to reduce the input current ripple, mainly at the half-cycle extremities while operating with bipolar voltage mode (BVM). When operating with unipolar voltage mode (UVM) that problem is reduced. On the other hand, One-Cycle Control (OCC) technique offers various advantages when compared to other control techniques for switching converters: overcomes nonlinearities; eliminates crossover distortion; does not use input voltage sensor and has stability in a large dynamic range while forcing the control variable to follow the reference in just one switching cycle. This paper proposes an extension of OCC strategy, here named interleaved switching strategy (ISS), which permits the FBR to operate with UVM. A two full-bridge ended AC-AC converter is built to verify the theoretical analysis of the ISS. Besides the theoretical analysis of ISS, the paper presents a quantitative study of the inductor size reduction resultant from UVM and BVM use.