Dynamic Characteristics Simulation of Medium Voltage DC Off-grid Hydrogen Production System

On the premise of ensuring safety of large power grid, in order to maximize the utilization of wind power and photovoltaic for green hydrogen production, this paper proposes a system solution of off-grid wind-solar complementary hydrogen production. Firstly, the models of wind turbine, photovoltaic, electrolyzer cell and other equipment in the wind-solar complementary hydrogen production system are studied. The electromagnetic transient simulation model of the off-grid wind-solar complementary hydrogen production system is established. Then, energy storage system is controlled by introducing power outer loop to solve the voltage support problem in the main grid of the system. Secondly, in order to make full use of new energy for power generation, combined with the characteristics of hydrogen production equipment that can absorb fluctuating power, a coordinated control strategy of constant current output was proposed it to realizes the cooperative control of the interaction of sources and loads. Finally, aiming at the typical operating conditions of the system, the validity of the mathematical model and its control strategy system is verified by simulation. The method proposed in this paper can effectively improve the utilization rate of renewable energy and provide a complete set of solutions for green energy to participate in hydrogen production.