Resilient Regulation of PEM Fuel Cell Hydrogen Circulation: A Control-Barrier Function-based Adaptive Performance Approach

The hydrogen circulation system (HCS) with a circulation pump improves the percentage of hydrogen utilization, efficiency, and peak power of proton exchange membrane fuel cells by regulating the hydrogen excess ratio (HER) and the supply manifold pressure (SMP). However, achieving reliable synchronous control of HER and SMP remains challenging due to the inherent nonlinearities and uncertainties in the HCS. In this study, a multiple-input multiple-output (MIMO) resilient regulation strategy based on the control barrier function (CBF) is presented to address these challenges. Firstly, taking into account the MIMO coupling nonlinearities and parameter uncertainties of the circulation pump, two baseline adaptive controllers are designed, in which the controller gains and adaptive law are derived utilizing a bound estimation method to ensure stability. Subsequently, a prescribed performance control (PPC) approach formulated using the CBF guarantees the desired convergence rates and tracking error bounds for the HER and SMP. This is achieved by modulating the BACs-based control inputs via a quadratic programming policy. Finally, the robust safety of the CBF-based controllers is proved by quantifying the estimation-error bounds. Compared with the baseline controller, the proposed approach is validated through a hardware-in-the-loop experiment using a high-fidelity model, demonstrating reductions of 7% in HER overshoot and 79% in its root mean square error under varying load currents. © 2015 IEEE.