Enhanced Voltage Regulation of Dual-Stack Hydrogen Fuel Cell Hybrid System Under Multi-Frequency EIS Disturbance

The fast electrochemical impedance spectroscopy (EIS) measurement is increasingly integrated into the hydrogen fuel cell (FC) hybrid system to enable state monitoring for optimized operation. However, the injected multi-frequency EIS signal from the fast EIS measurement would cause bus voltage fluctuation in the system. To solve this problem, in this article, an enhanced voltage regulation is proposed for the dual-stack FC hybrid system under EIS disturbances. In the proposed method, the extended state observer is utilized to compensate for the inherent modeling imperfection, and the multiple resonant control is applied to suppress the multi-frequency EIS disturbance. Furthermore, the optimized injection strategy of EIS signals is proposed to further improve the bus voltage quality and reduce the control force. The parameter tuning procedure and stability analysis of the proposed controller are presented in detail. The efficacy of the proposed method is verified by both the simulation and experimental results.