Research On Optimal Operation Method Of Integrated Electricity-Hydrogen Systems Considering Working Characteristics Of Electrolyzer

With the proposal of carbon neutrality and carbon peaking goals,developing new power systems and hydrogen energy industry chains has become an inevitable choice to promote the transformation of energy structure.However,the large-scale access of new energy poses challenges to the stable operation of power systems.The green development of hydrogen energy systems requires breaking away from dependence on fossil fuels for hydrogen production and solving the supply problem.The development of electrolytic hydrogen production technology provides a bridge for energy flow between power systems and hydrogen energy systems.Electrolyzers can be used as a flexible resource in power systems to promote the absorption of new energy,provide green and low-cost hydrogen as a hydrogen generation source in hydrogen energy systems,and promote the mutual support and integration between new power systems and hydrogen energy systems.However,the operation of the electrolyzer is limited by its own structure and operating rules.The coupling between systems can change the operational characteristics of power systems and hydrogen systems,affecting the relationship between supply and demand.Currently,the coupling characteristics and collaborative methods between power systems and hydrogen systems are not clear.Current research mainly focuses on scheduling and controlling electrolyzers as controllable resources from the perspective of power systems,while ignoring the internal constraints in the operation of electrolyzers and the interaction between power systems and hydrogen systems.Therefore,this paper focuses on the operating characteristics of the electrolyzer and the coupling system,and carries out research on the optimal operation method of the integrated electricity-hydrogen system based on the actual situation.To address the problem that the electrolytic hydrogen production model is difficult to simultaneously take into account the characterization and calculation requirements.This paper comprehensively considers the energy conversion laws,temperature safety constraints,and the impact of startup and shutdown processes on electrolytic hydrogen production,and constructs an electrolyzer model.This model can reflect the relationship between the input and output quantities of the electrolyzer and related influencing factors,and can reflect the operating characteristics of the electrolyzer during operation.Then,we constructed a hydrogen energy system model from the four aspects of production,storage,transportation,and utilization,considering the development trend of the hydrogen energy industry chain.Provide a theoretical basis for system modeling for hydrogen energy research.To address the challenge that the operation strategy of hydrogen energy system in the scenario of power-to-hydrogen is difficult to carve out,this paper establishes a hydrogen energy system model with power-to-hydrogen as the main hydrogen source and pipeline network as the transmission path.Considering the impact of flexible electricity prices on the cost of hydrogen production and the operational characteristics of the system,an optimal operation model for the hydrogen energy system is constructed.To address the non convexity brought by the pipeline transmission model,a progressive second-order cone algorithm is adopted to improve the accuracy.The effectiveness of the proposed model and algorithm is verified through case studies.The impact of electricity prices on the operating of the hydrogen energy system and the strategies for improving system stability and economy the are analyzed.To address the problem of the cooperative operation of integrated electricityhydrogen system,this paper constructs a structural framework of the integrated electricity-hydrogen system and analyzes the internal characteristics of the subsystems.The stochastic scenario generation method is used to simulate the uncertainty of renewable energy output,and then an integrated electricity-hydrogen system model is constructed.With the goal of minimizing system operating costs,a two-stage stochastic optimization model for the integrated electricity-hydrogen system is constructed.The analysis of case studies shows that the constructed model and method can promote the optimization of the operation curve of the electrolyzer,achieve the optimal allocation of resources,and effectively improve the renewable energy consumption rate and the operational efficiency of the integrated electricityhydrogen system.