Anti-saturation Prescribed Time Control of PEMFC Air Feeding System With Flexible Performance

A rapid and reliable air supply is critical for the stable operation of proton exchange membrane fuel cells (PEMFCs). To prevent fuel starvation, the oxygen excess ratio (OER) must be maintained within an appropriate range. However, under input saturation from the air compressor and strong load variations, the OER error may fail to satisfy prescribed performance constraints. The singularity problem arising from the conflict between the OER error and constraint envelope can trigger instability in the control system. To address this singularity problem, an anti-saturation control scheme with flexible performance constraints and prescribed-time convergence is proposed. Adaptive auxiliary systems are introduced to adjust the performance boundaries in response to input saturation and large load transients, thereby compensating for adverse effects of input saturation and large load transients. The compensation signals generated by the adaptive auxiliary systems are dynamically linked to the saturation errors and system states. Experimental validation was conducted using a hardware-in-the-loop (HIL) platform based on Matlab/Simulink Real-Time and a PEMFC test system, including fuel cell controller (DSP28377D), air compressor, intercooler, humidifier, etc. The results demonstrate the effectiveness of the proposed control strategy under diverse operating scenarios.