| At present,the installed capacity and grid-connected scale of distributed photovoltaics,wind power and other renewable power sources are constantly expanding,showing a trend of high penetration.However,the randomness and volatility of renewable energy power pose a great challenge to the safe and stable operation of distribution networks.Utilizing bidirectional power adjustment capability and fast response characteristics of battery energy storage system can effectively solve the problem of distributed generation and grid connection,so the role of energy storage in high-penetration distributed generation has become a research hotspot.At present,there is a lack of quantitative description of the problems caused by high-penetration photovoltaics in distribution networks,and there is no strong evidence for the role of energy storage systems in solving network-side safety problems.In addition,the application form of energy storage in the existing research is only limited to one of centralized or distributed,and it does not optimize and innovate from the viewpoint of effectively combining advantages and disadvantages of distributed energy storage and centralized energy storage.Besides,it can not clearly distinguish the differences between distributed energy storage and centralized energy storage in the process of energy storage layout and configuration.Based on the application background of high-permeability photovoltaic power distribution network,this paper builds a hierarchical and distributed application of hierarchical energy storage system.At the same time,this paper fully considered the mass storage capacity of centralized energy storage,and the flexible layout of distributed energy storage,and proposed a cross-time-scale layout configuration method for hierarchical energy storage systems,which mainly includes the following contents:(1)Demand analysis of hierarchical energy storage system.This paper introduces the concept of PV penetration,and analyzes the influence of high-penetration distributed photovoltaic(PV)on the power flow,voltage and network loss of the regional distribution network,and quantifies the influence of distributed PV on the stability of the network side under different penetration,different access points and access modes.(2)Location and capacity configuration of hierarchical energy storage system.To study the topological structure and function of the hierarchical energy storage system that is used in conjunction with distributed and centralized energy storage;to achieve the goal of peak load filling and power fluctuation,and considering the balance of power flow,voltage fluctuation range,and other constraints,to optimize the location and capacity configuration of hierarchical energy storage system.And compare and analyze the advantages and disadvantages of centralized energy storage,distributed energy storage and hierarchical energy storage system.(3)Economic analysis of hierarchical energy storage system.From the economic point of view,the cost components of the hierarchical energy storage system are analyzed.Based on the capacity configuration results,the economic differences of energy storage systems in centralized,distributed,and hierarchical applications are compared and analyzed.. |
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