A new nonisolated bidirectional DC-DC converter with ripple-free input current at low-voltage side and high conversion ratio

In this paper, a new nonisolated bidirectional dc-dc converter is proposed. In this converter, a 4-winding coupled inductor is used. The second winding of coupled inductor, which is connected in series with a capacitor, is applied to eliminate input current ripple at low-voltage side for whole range of duty cycles in both boost and buck operations. Working of this converter is in such a way that increasing or decreasing turns ratio of third and fourth windings of coupled inductor increases the voltage conversion ratio. This paper has analyzed the value of current and voltage stresses of all switches, required condition for canceling input current ripple at low-voltage side and the voltage conversion ratio for boost and buck operations. Finally, the accuracy and precision of analytic results are justified through experimental results for both boost and buck operations.