Stability analysis of an off-grid hybrid power plant for hydrogen production

A 500 kW off-grid hybrid system based on renewable energies (PV and Wind) is designed to produce green hydrogen. This energy system includes a Battery Energy Storage System (BESS) to improve the grid stability. To control the power plant two strategies are assessed. First, a variable-load control is applied to the electrolyser, while the BEES control (with hysteresis) ensures that the power is not less than the minimum admissible in the electrolyser. A second control is developed to minimize electrolyser degradation. In this case, the electrolyser operates at constant power, allowing only very slow voltage variations. Key words. Off-grid hybrid system, grid stability, power plant control.