Rotational inertia-based adaptive control strategy for grid-forming hydrogen fuel cell system

Hydrogen energy storage is a reasonable answer for problems caused by large-scale grid-connected renewable energy generation in power system. As they can enhance the stable operation of power system, owing to their extensive energy transfer capabilities over long cycles. However, disturbances in active command of hydrogen fuel cells and grid frequency often lead to active transient oscillations and frequency overshoots easily. This paper first examines the volt-ampere characteristics of hydrogen fuel cell and its grid-connected structure to ascertain the current density and corresponding DC side voltage necessary for achieving the maximum power output point. Then, Grid-Forming (GFM) control strategy is proposed for hydrogen fuel cell that incorporates a rotational inertia adaptive algorithm which adjusts rotational inertia of the GFM hydrogen fuel cell to ensure stable operation when facing frequency disturbances and active oscillations. Theoretical analyses and simulation results verifies that the rotational inertia-based adaptive control strategy significantly enhances the speed of system frequency recovery for GFM hydrogen fuel cells.