Oxygen excess ratio control strategy for fuel cell dynamic response optimization

Abstract

Precise regulation of the oxygen excess ratio (OER) is crucial for ensuring both the efficiency and durability of proton exchange membrane fuel cells. Conventional proportional-integral (PI) control and first-order active disturbance rejection control face limitations in simultaneously achieving rapid dynamic response and robustness under complex disturbances. To overcome these challenges, a second-order active disturbance rejection controller (2-ADRC) is proposed for a nonlinear cathode gas path model. Unlike conventional ADRC, the 2-ADRC incorporates disturbance-derivative estimation into both the extended state observer and nonlinear state error feedback. This design improves the controller’s ability to compensate for rapidly varying disturbances and enhances transient performance. Simulation studies under multi-step load and OER commands, as well as in the presence of measurement noise, show that 2-ADRC outperforms PI and ADRC. Compared with PI, the integral of absolute error, integral of squared error, and total variation are reduced by 44.03 %, 7.27 %, and 42.40 %, respectively. Under noisy conditions, relative to ADRC, the reductions reach 64.5 %, 58.3 %, and 27.7 %. These results indicate the proposed method shortens rise and settling times, suppresses oscillations, and achieves smoother actuator responses. With millisecond-level real-time performance, 2-ADRC offers enhanced robustness and accuracy, making it promising for embedded ECU applications in fuel cell vehicles.