Research On Planning And Benefit Analysis Of Long-Duration Energy Storage For High Proportion Of New Energy

Environmental problems have put forward strict requirements for the clean process of power system.New power system with renewable energy such as photovoltaic and wind power as its main form is the main trend of future development.The randomness and fluctuation of renewable energy output bring challenges to the reliable supply of power.Long-duration energy storage(LDES),as a new energy storage technology with long-term and large capacity,provides an effective way to solve the seasonal imbalance between supply and demand in high-proportion new energy power system and has a good application prospects.However,LDES is still in the ascendant,and mature analysis methods and general research conclusions have not been formed.How to make overall planning for LDES and flexible resources at multiple time scales,fully explore the flexibility potential of LDES,and finely analyze the configuration requirements and cost-effectiveness of LDES are of great significance for effectively guiding the development of LDES.Therefore,this paper studies the planning and benefit analysis of LDES for high proportion of new energy.Firstly,the modeling method of LDES parameters decoupling is studied,to model techno-economical characteristics of different types of LDES uniformly.Based on the analysis of LDES technology economic characteristics and parameter differences,decouple the configuration of LDES discharge power capacity,charge power capacity and energy storage capacity,and set five independent dimensions of performance parameters covering the technical economy of each link of LDES,establish the technical space covering the comprehensive performance range of all types of LDES technology,and reflect cost and efficiency performance of each link of LDES technology.On this basis,a flexible operation model for the generalization of LDES is established.Secondly,the quantitative analysis model of multiple time scales energy storage collaborative planning is studied.Modeling multi-class flexible regulation resources,considering the coordination of multiple time scales flexible resources including LDES,embedding the hour-by-hour time series operation simulation for 8760 hours a year,quantifying the low-carbon requirements and operation constraints of the system,accurately describing the time series coupling characteristics and system operation state of long-term and short-term storage energy at different time scales,and establishing a multiple time scales energy storage coordination and optimization planning model.A general generation function based method is used to simulate the randomness and fluctuation of new energy output according to the statistical characteristics of the historical series of new energy generation,taking full account of the spatial correlation of new energy.To solve the problem of high computational complexity caused by the coupled operation of multiple time scales energy storage,a time clustering algorithm suitable for LDES transfer characteristics is adopted,which ensures sufficient accuracy while meeting the requirements of reasonable computational efficiency.The optimal LDES capacity allocation scheme is explored through an example of a region in Northwest China,and the feasibility of LDES participating in the construction of high-proportion new energy power system is demonstrated.Finally,the LDES benefit evaluation and cost guidance mechanism are studied.Based on the LDES technology space,the LDES cost-effectiveness is measured finely and sensitivity analysis is made.The relationship between different combinations of LDES technology and economic parameters and LDES system value level,optimal configuration structure and short-term energy storage substitution is evaluated through an example.The results show that the cost-effectiveness of LDES is most affected by the energy storage capacity cost and discharge efficiency,and the introduction of LDES can reduce the total cost of power system by up to 40%under the background of lowcarbon transformation.Based on the application background of LDES,the formation mechanism of LDES price in different stages is established,and the corresponding cost guidance methods are analyzed.Combined with specific examples,the cost recovery and allocation of LDES stations are calculated,and the necessity of new market mechanism adapting to high proportion of new energy resources for Rational Recovery of investment costs of flexible resources such as LDES is demonstrated,which provide a reference path for the market development of LDES.