Transient modeling and control strategies for WT-PV integrated hydrogen production system

Abstract

This study delves into the critical control parameters of the proton exchange membrane electrolysis cell (PEMEC) within a wind-solar power integrated hydrogen production system, focusing on ensuring the long-term system operation with safety and stability. Key parameters including hydrogen in oxygen (HTO) content (globally monitored with a safety threshold of 2 %, with a corresponding current density boundary of 0.2 A cm^-2), water circulation system operation, and temperature control are analyzed under dynamic conditions. The study also examines the dynamic response of the PEMEC stack to varying operating conditions, emphasizing the need for temperature control strategies to manage thermal gradients and prevent local hot spots. Research shows that, under a constant water supply, when the circulating water temperature drops from 25 °C to 5 °C within the current density range of 0.2–3 A cm^-2, the average performance of the PEMEC decreases by 4.99–9.85 %, the voltage overshoot increases by 1.4–4.4 times, and the temperature fluctuation rises by 1.15–2.24 times. Conversely, when the temperature is adjusted from 5 °C to 25 °C, although the heat transfer power consumption increases by approximately 5 %, the performance of the PEMEC improves by about 5–10 % and the voltage overshoot decreases. A comprehensive control strategy is proposed, integrating these findings to optimize the system's performance under fluctuating renewable energy supply and load demands. The study concludes that the system can achieve efficient hydrogen production and reliable operation by applying these strategies, demonstrating adaptability to different environmental conditions and energy demands.