Robust Voltage Control with Resonant Extended State Observer for Hybrid Fuel Cell System

The bus voltage regulation of the hybrid fuel cell system is very crucial. However, there exist various disturbances in the hybrid system, e.g., the excitation current introduced by the electrochemical impedance spectroscopy test, resulting in voltage fluctuation. To this end, a robust voltage controller based on resonant extended state observer (RESO) is proposed in this article. The proposed method integrates the resonant unit into the conventional extended state observer to construct the RESO, which is then used to estimate the disturbance. By rejecting it in the control law, robust voltage regulation can be achieved. The performance evaluation and stability analysis of the proposed controller are conducted theoretically, which provides a practical tuning guideline for controller parameters. Finally, both the simulation and experimental results are presented, and it is shown that compared with the conventional methods, the proposed one can achieve superior voltage regulation under disturbances.