A Bidirectional Modular Multilevel DC–DC Converter of Triangular Structure

In this paper, a novel bidirectional modular multilevel dc-dc converter is proposed. The proposed topology, named the triangular modular multilevel dc-dc converter (TMMC), can achieve equal power sharing among its modules over a broad range of conversion ratios. The proposed control algorithm provides localized control of modules which enhances the converter´s dynamic performance and design flexibility. A 1.7-kW experimental implementation of the converter is shown to achieve an efficiency of 95.9% and 96.2% in step-up and step-down modes, respectively. Significant reductions in the input current and output voltage ripples are observed through the interleaved operation of the converter. The TMMC also provides multiple fixed voltage nodes which makes it suitable as a multiple-input multiple-output converter.