Medium And Long-Term Generation Planning Considering The Evolution Law Of Flexibility Resources Supply And Demand

Renewable energy(RE),which feature is clean and low-carbon,is the key to the transition of power system in the future,meanwhile,the demand of power system flexibility soars due to the volatility and uncertainty.The power and flexibility which is supplied by conventional generation are coupled to each other.However,with the penetration of RE increasing,the demand of power system flexibility is also increasing,but the operation capacity of conventional generation is gradually compressed,the core constraints of generation planning will change from power and electricity balance to flexibility supply and demand balance in this scenario.Hence,this thesis dedicates to resolve the contradiction between the vision of the high penetration RE power systems in the future and shortage of flexibility resources.Firstly,this thesis takes the quantitative evaluation index of power system flexibility as the breakthrough point,then,on the basis of the currently research results,the multi-type flexibility resources of the system are modeled,and a set of quantitative evaluation indexes for evaluating the flexibility balance between supply and demand in the whole process of the system are builded to quantitatively asses the impact of RE integrated on the supply and demand balance of power system flexibility.Secondly,the influence mechanism of RE integrated on the flexibility demand of the system is analyzed,then,a two-layer structure is established by influence mechanism of flexibility demand—k-means clustering to generate a typical scenarios that are applied to analyze the evolution law of flexibility resources demand with different penetration ratio of RE.Results shows that supply shortage of flexibility increases and demand of flexibility resources type changes with the increasing of RE penetration ratio to the power system,by making full use of different flexibility resources about generation-load-storage,the inflection point of the system's absorption of RE is pushed back to varying degrees.On this basis,an optimal planning model of multi-type flexibility resources is established to accomplish special optimal planning at a given penetration ratio of RE.Lastly,based on above flexibility evaluation indices of supply and demand and evolution law of flexibility resources demand,an optimization framework of generation planning is put forward.Which can be used for correspondingly combining the medium and long-term generation planning and flexibility resources planning,coordinating the capacity of multi-type flexibility resources in future scenarios.At the same time,the impact of multi-type flexibility sources planning on economy,energy consumption and installed capacity compared to single-type storage planning is analysed,and the relationship between RE curtailment ratio(wind/solar curtailment ratio)and economy is studied.