www.ijastems.org Page 6 Zero current switching for Bidirectional dual boost DC-DC converter

Abstract- This paper presents a new bidirectional DC-DC converter with high conversion ratio for renewable energy systems. The coupled-inductor technique is used to achieve a high conversion ratio with very simple control circuits. In discharging mode, the converter acts as a two-stage boost converters, controlling one power switch to achieve high voltage step-up conversion. In charging mode, the converter acts as two cascaded buck converters that control two power switches simultaneously to achieve high voltage step-down conversion. The operating principles and analysis of the steady-state characteristics are discussed in great detail. Finally, a prototype24 V/200 V circuit with output power of 200 W is implemented to verify the feasibility of the proposed converter. The maximum efficiency levels in discharging and charging modes are about 94.3 % and 91.6%, respectively. I