Robust Bus Voltage Control for Hybrid Fuel Cell System Considering EIS Measurements

The hybrid fuel cell (FC) system encounters various disturbances, including load disturbances and those related to electrochemical impedance spectrum (EIS) measurements. These disturbances can significantly degrade the quality of the bus voltage. To address this challenge, this paper proposes a robust voltage controller for the hybrid system based on the refined active disturbance rejection control algorithm. Compared to conventional methods, this approach improves the system's anti-disturbance ability from three aspects: 1) enhancing disturbance estimation capability with an improved disturbance observer; 2) strengthening disturbance suppression through enhanced feedback control law; and 3) alleviating the burden of disturbance suppression. The design process of the proposed controller is described in detail, and its performance is evaluated comprehensively in terms of disturbance rejection and system stability based on theoretical analysis. Additionally, guidelines for tuning the controller parameters are provided. Finally, the effectiveness of the proposed controller is demonstrated by both simulation and experimental results.