A Nonisolated TCM Bidirectional Converter With Low Input-Current-Ripple for DC Microgrids

This article presents a new nonisolated dc-dc converter with bidirectional power flow capability. The proposed converter operates in triangular conduction mode (TCM). Consequently, reverse-recovery losses are completely eliminated, zero voltage switching characteristics are obtained, and the inductor size can be reduced. However, in comparison with other converters in TCM that suffer from a large input-current-ripple, the proposed converter benefits from very low input-current-ripple. Furthermore, in the proposed converter, the voltage stress of the main switches is reduced, the converter voltage-gain is increased, the output current is nonpulsating, the input and output sources share a common ground, and only a single magnetic core is required. The proposed power circuit topology is theoretically analyzed and experimental results are provided to verify its feasibility and demonstrate its superior performance.