Improved ADRC-based control of industrial alkaline electrolyzers for green hydrogen production in PV-battery microgrids

In the context of the global energy transition, alkaline electrolysis powered by renewable sources stands out as a promising solution for green hydrogen production. This paper investigates an improved Active Disturbance Rejection Control (ADRC) strategy applied to a 20 kW industrial alkaline electrolyzer (ATTAWEY model) integrated into a PV-battery microgrid. The system is modeled and simulated in MATLAB/Simulink under realistic operating conditions, including a constant DC bus voltage, ambient temperature, and a full drop and recovery of PV power. The study implements a dual-layer control architecture: one level ensures DC bus voltage regulation (using PI and ADRC), and the second manages the electrolyzer's dynamic response. Five control strategies are evaluated at the electrolyzer side, including classical PI, standard ADRC, and a proposed improved ADRC. While PI-based schemes are simple to implement, they exhibit weak disturbance rejection and limited dynamic performance. Standard ADRC improves responsiveness but results in minor overshoots and longer settling fluctuations. In contrast, the improved ADRC delivers fast and stable voltage recovery while keeping the electrolyzer within its rated power limits. The hybrid configuration combining ADRC for DC regulation and improved ADRC for electrolyzer control proves to be the most effective, ensuring robust system behavior and consistent hydrogen production even under fluctuating renewable conditions. • Framework integrates 20 kW alkaline electrolyzer into PV-battery microgrid system. • Evaluation of PI, ADRC, and improved ADRC strategies for electrolyzer control design. • Improved ADRC ensures stable and reliable green hydrogen generation from solar power.