Enhancing operational resilience of standalone photovoltaic-electrolyzer systems: A comparative analysis of single- and dual-stage power interface architectures

Off-grid power delivery from photovoltaic (PV) systems to electrolyzers serves as a key pathway toward sustainable green hydrogen production, with the PV output voltage adapted to the electrolyzer operating voltage by dc/dc converters. However, a systematic understanding of the performance trade-offs between different converter architectures and their associated control strategies is still lacking, particularly for ensuring robust operation under intermittent solar conditions. This paper presents a systematic comparative study of single- and dual-stage dc/dc converter architectures for standalone PV-electrolyzer (PVEC) systems. The study investigates the fundamental control trade-offs, comparing the single-stage’s rigid electrolyzer-following operation with the dual-stage’s superior flexibility in providing direct electrolyzer current regulation. To enhance operational resilience, two distinct low power ride-through (LPRT) strategies are proposed and analyzed for the dual-stage configuration, ensuring stable power delivery during significant solar power reductions. The feasibility and performance of the proposed architectures and control strategies are validated through both 5 kW system simulations and experiments on a 200 W GaN-based hardware prototype. The results demonstrate that while the single-stage architecture is viable for small-scale systems, the dual-stage configuration’s enhanced control flexibility and scalability are essential for large-scale, storage-ready PVEC applications.