Green hydrogen production from PV sources integrated into a modular multilevel converter

Hydrogen is increasingly recognized as a key element in future energy systems due to its potential to reduce carbon emissions and support the energy transition. To be a truly clean energy vector, hydrogen must be produced via electrolysis powered by renewable sources, resulting in so-called “green hydrogen”. Among available options, photovoltaic (PV)-driven electrolysis is particularly attractive, enabling zero-emission hydrogen production. This integration requires efficient, scalable power conversion systems capable of managing hybrid PV-hydrogen plants. Despite growing interest, the literature remains fragmented, with most studies focusing either on high-power converter designs for hydrogen electrolyzers (HEs) or on topologies aimed solely at maximizing PV generation. This paper proposes a novel power conversion architecture based on modular multilevel converters (MMCs), capable of integrating both PV arrays and HEs within a single system. Leveraging the intrinsic features of MMCs, the proposed solution enables high-efficiency local hydrogen production while reducing the impact on the electrical grid. The paper describes the converter topology, derives design criteria for converter and passive-component sizing, develops a control strategy for coordinated PV–HE operation, and presents the converter operating regions under various conditions. The system effectiveness is validated through a 5.2 MW processor-in-the-loop case study, in which the power conversion system is simulated in MATLAB/Simulink® while the proposed control strategy is executed on an embedded controller. The obtained results demonstrate stable converter operation, effective management of PV generation, hydrogen production, and grid power exchange, while confirming the feasibility of the proposed control strategy under realistic execution constraints and limited numerical precision.