Multi-unit Control Strategy of Electrolyzer Considering Start-Stop Times

Hydrogen energy is one of the important new energy sources to realize energy transformation in the world today. Hydrogen production by electrolysis from renewable energy is an effective means to reduce the cost of hydrogen production and promote the development of hydrogen energy. However, due to the randomness and intermittence of renewable energy power generation (such as photovoltaic and wind power generation), the input of the hydrogen production system will be uncertain, and frequent random fluctuations, which will lead to frequent switching of electrolyzer arrays in hydrogen production stations and reduce the overall life of hydrogen production system. Therefore, a two-stage power hysteresis and cyclic switching control strategy are proposed in this paper. This strategy reduces the influence of fluctuating power on the switching changes of electrolyzer array by power hysteresis control and reduces the start-stop times of electrolyzers. The cyclic switching strategy is adopted to even the start-stop times of electrolyzers in the array at the same time. The proposed control strategy can improve the overall life of the hydrogen production system. Finally, a simulink model of photo-hydrogen coupling system is built to verify the effectiveness of the strategy in four different photovoltaic scenarios.