Bidirectional tapped-inductor-based buck-boost convertor and its circuit application

A novel Buck-Boost convertor based on tapped-inductor is presented in this paper. It can be provide wider voltage conversion ratio than conventional Buck-Boost convertor. When it running as boost-mode, recommended winding ratio setting (K_D=1, K_T<;1) helps to achieve larger conversion ratio; when it running as buck-mode, the smaller voltage conversion ratio can be realized by opposed winding ratio setting (K_T=1, K_D<;1). The detail analysis of this convertor is included in the paper. To meet the requirement of energy transfer bi-directionally in some special occasions, a bi-directional double-tapped inductor Buck-Boost conversion circuit based on former convertor is discussed in this paper. Running in alternating between motoring and regenerative braking manner is analyzed in detail. Finally, experimental results verify the correctness of theoretical analysis and the proposed convertor can provide wider conversion ratio with high efficiency.