Improved Non-Isolated Bidirectional DC-DC Converter Assisted with an Active Resonant Network

This paper proposes a new non-isolated bidirectional dc-dc converter (NI-BDC) with an auxiliary resonant network (ARN) that is typically operated in both boost and buck modes. Regardless the direction of power flow, soft-switching capabilities such as zero voltage switching (ZVS) and zero current switching (ZCS) conditions has been obtained under light and heavy loads. This converter avoids the need of coupled inductors as against conventional converters thus reducing the size of the converter and minimizes the device count. The auxiliary resonant network mainly consisting of resonant inductor, capacitor, auxiliary switch and a diode. Furthermore, the zero voltage switching and zero current switching conditions have been achieved in both boost and buck modes that reduces reverse recovery conduction period of the body diodes of all the power switches. The proposed converter operates with soft-switching at constant switching frequency giving continuous inductor current. The detailed operating principles for boost and buck modes are described. The theoretical analysis and simulation results are presented.