In order to reduce the influence of frequent start-stop of alkaline electrolyzer and frequent power fluctuation on the economy and stability of islanded wind power hydrogen production system under intermittent and fluctuating wind speed

a hierarchical energy management strategy of islanded wind power hydrogen production system considering the start-stop of electrolyzer is proposed. The upper energy management adds the start-stop penalty function of the electrolyzer to the objective function of the system

and establishes an optimal energy management model for the start-stop of the electrolyzer. In order to improve the daily income

the improved grey wolf algorithm is used to optimize the start-stop state of the electrolyzer

and the operation plan of each unit of the system is obtained. According to the basic working characteristics of alkaline electrolyzer

an intra-day rolling optimization model based on the power grading energy management strategy of electrolyzer is established. According to the dayahead optimization results and the latest forecast information

the system operation plan is re-optimized with the goal of maximizing the daily income of the system. The underlying energy management proposes a real-time energy management strategy based on system operation state recognition

which can adjust the system operation mode in real time according to the system operation state. The simulation results show that the proposed hierarchical energy management strategy can reduce the downtime of the electrolyzer

reduce the power fluctuation of the electrolyzer

effectively maintain the system power balance

and improve the system economy.