Research on frequency stability control method of multi-energy system considering grid-connected parameters of electric hydrogen energy coupling equipment

Renewable energy coupling hydrogen production technology can overcome the weakness of randomness and intermittence for renewable energy to a certain extent. However, due to the long-distance and reverse distribution of renewable energy generating units and the main network, there will be a risk of oscillation instability when a high proportion of power electronic hydrogen production system is interconnected with the power grid. Firstly, the impedance model of the electric hydrogen production system is established. The oscillation characteristics of hydrogen production system interconnected with power grid are analyzed. Secondly, the influence of electrolytic hydrogen system on the stability of multi-energy system is analyzed. The instability problems caused by input power fluctuation and hydrogen production rate change are studied. Then, an oscillation suppression strategy for renewable energy hydrogen production system based on power allocation is proposed. It is used to enhance the stability of the multi-energy system of the electrolytic water hydrogen production system. Finally, through the establishment of renewable energy electrolysis hydrogen experimental simulation system. The system frequency stability under different renewable energy output fluctuations and different impedance conditions of the system is verified. The simulation results show that the proposed multi-energy hydrogen production control method based on power allocation can ensure the stability of the system under the fluctuation of renewable energy output.