A review of dynamic modeling and control of grid-connected hydrogen production units using water electrolysis

As key enablers of the energy transition, water electrolysis units are increasingly expected to provide grid support services in addition to producing green hydrogen. However, their dynamic behavior and control present significant challenges to power system stability and efficiency. This review provides a critical assessment of the state-of-the-art in dynamic modeling and control for grid-connected electrolyzers. We identify a fundamental gap in current research: system-level transient models for grid analysis almost universally neglect the inherent and tightly coupled thermo-electrical dynamics of the electrolyzer, leading to an overestimation of its true response capabilities and potential risks to equipment health. Furthermore, we highlight that existing control systems are fragmented, managing power electronics, electrolyzer thermal states, and auxiliary equipment independently. This paper argues for the necessity of a unified control architecture to overcome these limitations. We introduce the concept of a state-aware frequency response strategy, where an electrolyzer’s grid support is dynamically adjusted based on its internal state (e.g., temperature, health) to balance performance with long-term reliability. By systematically analyzing the modeling hierarchy from material to system levels, this review exposes critical scientific challenges and provides a theoretical and technical roadmap for the optimized and stable grid integration of water electrolysis systems.