Improving Dynamic Response of PEMFC Anode Pressure in Droped Load Scenarios through Split Range Control

The dynamic response of proton exchange membrane (PEM) fuel cells’ anode pressure and the pressure difference between the cathode and anode significantly influence the performance and durability of fuel cells. To address the slow dynamic response of the anode pressure during rapid load drops, this study proposes a split range control strategy by introducing the hydrogen purge valve into the anode pressure control. By rational planning the split range block, the hydrogen purge valve is opened at appropriate times during load drops. To validate the effectiveness of the split range control, simulations are conducted under load drop conditions using an 80 kW fuel cell hydrogen and air supply subsystem model. The simulation results demonstrate that the split range control reduces the setting time of the anode pressure during load drops by half, with the most significant improvement observed at 67% load to idle condition, where the setting time is reduced from 2.6 s to 1.1 s. Furthermore, the pressure difference between the cathode and anode decreases from 67 kPa to 44 kPa. The impact of hydrogen purge valve frequency is investigated by comparing simulations using a 1 Hz low-speed hydrogen purge valve and a 100 Hz high-speed hydrogen purge valve. The results show that both valves effectively improve the dynamic response of the anode pressure during load drops, with identical maximum pressure differences between the cathode and anode. The findings indicate that the combination of a 1 Hz low-speed hydrogen purge valve and split range control can improve the dynamic response of the anode pressure during load drops.