Scalable Architecture of a 15 kW Multicell Interleaved M-Arm DC-DC Converter for High-Efficiency Power Processing in Green Hydrogen Electrolyzers

This manuscript presents a scalable architecture for a multicell interleaved M-arm DC–DC converter, offering a significant advancement in high-efficiency power conversion. The proposed topology integrates three interleaved converter cells, each comprising M interconnected arms, to ensure high performance with reduced complexity. Notably, only one inductor per cell is required to transfer power between the DC bus and the electrolyzer, enabling a compact and efficient implementation. Key features include an interleaved modulation scheme that ensures balanced current sharing among arms; inductor current ripple at a frequency equal to the switching frequency multiplied by the number of arms (f s × M); and voltage and current ripples at both the electrolyzer and DC bus occurring at a frequency of 3 × f s × M, enhancing system stability and dynamic performance. Moreover, the proposed converter enables a substantial reduction in the size and weight of passive components, such as inductors and capacitors, by improving current ripple distribution. Balanced current sharing among arms further enhances reliability and extends component lifetime. The converter’s ability to achieve high power density makes it especially attractive for high-power applications, such as green hydrogen production via water electrolysis. The paper details the steady-state operation in continuous conduction mode, design guidelines, and mathematical modeling, along with a comparison to state-of-the-art solutions. A 15 kW prototype was experimentally validated under open-loop control with a 600 V DC bus and 350 V electrolyzer output, achieving a peak efficiency of 98.14%, validated by experimental results and a demonstration video.