微电网电-氢混合储能优化配置及协同运行特性分析OA

[Objective]Under the background of the"dual-carbon"goals and the development of new-type power systems,isolated microgrids with high renewable energy penetration face the coexistence of long-term source-load mismatch,short-term power fluctuations,and low-inertia operation risks.To address these issues,the optimal configuration and coordinated operation characteristics of electro-hydrogen hybrid energy storage in microgrids are studied.[Methods]Taking the capacity and power rating of electrochemical energy storage,as well as the capacities of the electrolyzer,hydrogen storage tank,and hydrogen fuel cell as optimization variables,a configuration model with the minimum comprehensive annualized cost as the objective is established.The model considers power balance,equipment operating limits,state continuity,and rate of change of frequency(RoCoF)constraints.An N-1 type extreme disturbance scenario with an instantaneous loss of 20%renewable energy output is adopted to verify the equivalent inertia support capability of the system.On this basis,a sensitivity analysis of hydrogen energy penetration is carried out,and the discrete Fourier transform(DFT)and Parseval's theorem are used to calculate the frequency-domain energy proportions of energy storage power sequences in intra-day,intra-week,and cross-week-to-seasonal fluctuation intervals.[Results]A case study of an isolated microgrid in Northwest China shows that the comprehensive annualized cost of the electro-hydrogen hybrid energy storage scheme is reduced by 83.38%compared with the pure electrochemical energy storage scheme.Under the extreme disturbance,the available effective inertia of the hybrid energy storage system is always higher than the minimum requirement under the RoCoF constraint.Frequency-domain analysis shows that hydrogen energy storage accounts for 77.7%of the action energy in the long-period interval,while electrochemical energy storage accounts for 88.0%in the intra-day fluctuation interval.[Conclusions]The proposed model can reduce long-period energy storage configuration costs and improve the operational economy of isolated microgrids with high renewable energy penetration while satisfying the RoCoF constraint in the initial stage of disturbance and the annual energy balance requirement.For isolated microgrids with significant seasonal source-load mismatch,hydrogen energy storage is more suitable for cross-period energy transfer,whereas electrochemical energy storage is more suitable for intra-day power smoothing and inertia support.