| With the increasing depletion of traditional fossil fuels and the proposed "double carbon"goal,the transformation of energy utilization towards low-carbon and clean direction and the acceleration of the deep decarbonization of high-carbon-emitting industries have become a social consensus.Currently,the new power system has been developed towards high-proportion renewable energy.However,the intermittent and random output characteristics of renewable energy have led to the increasingly prominent problem of wind and solar curtailment in the new power system.At the same time,hydrogen energy with its high efficiency and clean characteristics has become an important mediator connecting power and terminal energy utilization.The electro-hydrogen coupling system using renewable energy to produce hydrogen plays an important role in wind and solar power utilization,flexible operation,low-carbon emission reduction,and has attracted extensive attention.However,the hydrogen production system for electricity-to-hydrogen energy conversion has a complex structure and variable operation conditions.Therefore,how to construct a dynamic model that accurately reflects the system’s dynamic operational characteristics and how to optimize the operation status of the electro-hydrogen coupling system based on these operating characteristics are crucial issues that need to be addressed to make breakthroughs in the field of electro-hydrogen coupling.This paper aims to accurately reflect the operation characteristics of the hydrogen production system and improve the optimal operation of the electro-hydrogen coupling system.It conducts research on the construction of the hydrogen production system dynamic model and the analysis of its operation characteristics,as well as the modeling and optimization of the electro-hydrogen coupling system considering various factors.The main work and innovation points are as follows.(1)To meet the modeling requirements for dynamic characteristics of electrolytic hydrogen production systems,a bottom-up modeling approach incorporating the differences in the principles of hydrogen production process is proposed to accurately model and analyze the operating characteristics of each subsystem and the overall hydrogen production equipment.Specifically,the hydrogen production process is analyzed using the most technically mature and widely applied alkaline electrolysis as an example,and the hydrogen production system is decomposed into subsystems,including electrolysis,temperature control,pressure control,and hydrogen storage,based on the differences in electrochemical,thermodynamic,and fluid dynamic principles.Subsystem models are constructed using a bottom-up approach and interconnected to form the overall hydrogen production system model.A dynamic model simulation program is developed based on MATLAB environment to realize the refined simulation and analysis of the operation status of the alkaline electrolysis system under different working conditions and working condition changeover scenarios.The efficiency characteristics,regulation characteristics and start-stop characteristics of the hydrogen production system are simulated and analyzed with the MW-class system as an example,which provides technical parameters and safety constraints reference for the subsequent optimization of the electrohydrogen coupling system.(2)To meet the optimization and scheduling requirements of electro-hydrogen coupling system,an operation optimization method of electric-hydrogen coupled system considering the detailed operation characteristics of hydrogen production system is constructed,and the impact of different modeling methods on the optimization results is analyzed.Specifically,based on the refined simulation results of the hydrogen production system,a hydrogen production system operation characteristic model covering start-stop characteristics and non-linear efficiency features is established.An electro-hydrogen coupled system powered by multiple power sources is used as the object,and an optimization model of the electro-hydrogen coupled system satisfying constraints such as multi-state start-stop and segmented linear dynamic efficiency is constructed with the lowest system operation cost as the goal.Based on MATLAB development environment,Yalmip+CPLEX toolkit is used to program the electro-hydrogen coupled system optimization model program,and the optimized operation strategy of electro-hydrogen coupled system under different scenarios such as general energy storage model/detailed operation characteristics model of hydrogen production system is compared and analyzed with IEEE30 node modification system as an example.The analysis showed that using the adjustability of the electrolytic hydrogen production power could reduce the cost of power supply and better integrate renewable energy.Modeling the electrolytic hydrogen production system using classical energy storage models may lead to overly optimistic analysis results,while considering the start-stop characteristics and variable efficiency characteristics of the hydrogen production system may affect the flexibility of the hydrogen production equipment to a certain extent.(3)To meet the dual requirements of operation optimization and information protection for electro-hydrogen coupling systems in a market environment,a one-master-multi-slave game model that considers maximizing the interests of the electric trading center(ETC)and hydrogen energy suppliers(HES)is constructed based on the minimal information exchange.And a distributed optimization method is designed to realize the operation optimization of the electrohydrogen coupling system in a market environment.Specifically,starting from the dual requirements of maximizing the interests of HES and protecting corporate privacy in a market environment,a double-layer transaction structure containing HES-ETC is designed,and a onemaster-multi-slave game model with the goal of maximizing the interests of each stakeholder is constructed.In order to solve the problem that the game model has a large number of participants and is difficult to solve,a distributed optimization algorithm that exchanges information through the price curve and the energy use curve is proposed.CPLEX is used to solve the operating strategies of ETC and each HES in a single game.And the iteration of master-slave game subject’s decision is performed by the interaction of tariff curve and energy consumption curve information until the interaction information satisfies the convergence condition.Taking a multi-subject electro-hydrogen coupling system with 8 HESs and 1 ETC as an example,it is verified that the game model can achieve distributed iterative solution.The analysis of the optimization results of each layer shows that the proposed game model can take into account the multilateral interests while ensuring the privacy of each subject,and converge to the optimal operation of the system in an iterative manner. |
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