High Gain and High-Efficiency Bidirectional DC-DC Converter with Current Sharing Characteristics Using Coupled Inductor

Application of coupled inductor in designing nonisolated bidirectional dc-dc converter provides flexibility to attain high voltage conversion ratio both in buck and boost mode of operation. In this article, a new coupled inductor bidirectional converter is designed with low winding turns ratio (n = 1). The proposed topology uses two current path inductor structure which improves voltage conversion ratio and shares current in all operating modes. All the active switches in the proposed topology are soft switched utilizing synchronous rectification concept. Higher efficiency operation is possible as no extra circuit elements are required to achieve soft switching. Leakage energy of coupled inductor is successfully stored in a clamped capacitor which is utilized in the circuit topology. The voltage stress and current stress level of main active switches are low. The proposed circuit is simulated and performance parameters are verified through hardware results. Both simulation and experimental results performed on a 250 W prototype confirm to attain a high efficiency of the proposed converter with simple hardware requirement for practical implementation.