Abstract: The paper introduces, a high step-down bidirectional converter, utilizing one coupled inductor and two energy-transferring capacitors, is presented. The capacitor connected between input voltage and coupled inductor plays a role to step down the input voltage. The corresponding voltage conversion ratio is lower than traditional buck converter and tapped inductor buck converter. Moreover, the output voltage varies with the duty cycle linearly, making control easier. The output voltage not only depends on duty cycle but on number of turns in the coupled inductor. Furthermore, the leakage inductance energy can be recycled thereby reducing the switching losses and thus the efficiency can be improved.

Keywords: Step-down converter, coupled inductor, duty cycle, number of turns.