Fault Ride-Through for Hydrogen Electrolyzers

This paper investigates the Fault Ride-Through (FRT) capability of a Proton Exchange Membrane (PEM) electrolyzer system supported by Supercapacitor (SC) energy storage under symmetrical fault conditions. Three configurations are analyzed: a baseline case without SC integration, SCs directly connected to the DC link, and SCs interfaced via a DC/DC converter. To evaluate the system behavior under these configurations, a dynamic model of the PEM electrolyzer is implemented to capture its transient response. Based on this model, analytical formulas are derived for sizing the energy buffer required to maintain continuous operation during grid disturbances. In parallel, a unified control strategy is proposed to coordinate power flow between the grid, SCs, and the electrolyzer. Time-domain simulations confirm that only the SC-supported configurations maintain uninterrupted hydrogen production during a severe grid voltage sag. The DC/DC-based layout reduces the number of SCs and offers greater control flexibility, while the direct connection provides a simpler solution. These results provide design insight for the robust integration of hydrogen systems into future power grids.