A robust adaptive control strategy for oxygen excess ratio regulation in fuel cell systems with reduced control...

Proton exchange membrane fuel cells (PEMFCs) play a key role in advancing large-scale electrical energy applications for a carbon-neutral future. Ensuring reliable and efficient integration of the PEMFC-based energy systems requires advanced control strategies. This paper proposes a novel approach to regulate the oxygen excess ratio (OER) in PEMFC air supply systems. First, the system model is revisited from a control perspective, followed by the design of a reference controller using input-output feedback linearization. A clear presentation of state transformation and stability analysis is provided. Building on this, an innovative control strategy is developed that integrates sliding mode control (SMC) and model reference adaptive control (MRAC). The proposed strategy is validated through extensive numerical simulations based on real experimental data. Key evaluations include comparisons with conventional nonlinear methods, fault-tolerant control (FTC) under air leak scenarios, and robustness against uncertainty of parameters. In particular, the integration of SMC-MRAC achieves consistent OER regulation with significantly lower control input variation, represented by the reduced applied compressor voltage. These findings demonstrate the potential for reducing parasitic power loss and improving overall system efficiency. The results highlight significant advances in PEMFC control strategies, contributing to the broader goal of efficient and FTC-oriented health-aware energy management.