| With the steady growth of peak load demand and the large-scale use of intermittent renewable energy resources in recent years,the power grid has become more vulnerable,and the level of load fluctuation and uncertainty have increased significantly.High level of volatility and uncertainty will increase the cost of power system and increase the difficulty of peaking regulation.More and more renewable energy connected to the grid also leads to the inadequate consumption capaci ty of the power system,resulting in waste of resources such as wind and solar.In this context,the traditional mode which consider generate electricity as the only schedulable resource has been difficult to ensure the security,stability and economic of power system operation.In order to alleviate these problems,the research of distributed energy storage as a controllable resource participating in power system regulation has gradually attracted the attention of many scholars.Distributed energy storage can effectively alleviate the pressure on power grid caused by new energy generation and rapid load growth.Different from the traditional centralized energy storage power plants,distributed energy storage has the advantages of small space requirement and low investment cost,and can be flexibly installed in various locations on the user side.However,the charging and discharging power of single distributed energy storage is small and its capacity is limited,so it is not enough to participate in the operation of electricity market,and it is difficult to arouse the interest of power system regulation and management.In contrast,the aggregated distributed energy storage has flexible regulation and great potential for regulation.It is feasible to participate in the electricity market under reasonable regulation strategies.Therefore,it is necessary to aggregate the management of distributed energy storage so that it can serve the electricity market in an easy-to-control mode under the control strategy of refinement and individualization.This paper focuses on the aggregation modeling of distributed energy storage and its control strategy.The main work and research results are as follows:1.Considering the characteristics and research status of distributed energy storage,the concept of distributed energy storage aggregator is proposed.The regulation characteristics of the aggregator are described,the system framework of the aggregator is designed,the key technologies to be solved are analyzed,and the control structure,regulation mode and operation mechanism of the aggregator are emphatically analyzed.The distributed energy storage aggregator is chosen as the response platform,and the centralized-distributed structure is adopted to manage the distributed energy storage.Under this mode,aggregators sign contracts with energy storage users to optimize the regulation of distributed energy storage scattered throughout the power grid,so that they can better participate in the operation of the electricity market.2.The construction of distributed energy storage model is completed.Based on the daily operation curve of distributed energy storage,its operation characteristics and dispatchability potential are analyzed;combined with the capacity attenuatio n of distributed energy storage,its operation characteristics model is established;based on the life loss characteristics of distributed energy storage,the cost and benefits of distributed energy storage participating in power grid operation are analyzed,and the economic model of distributed energy storage is established;and the scheduling potentials of distributed energy storage is calculated.3.A new distributed energy storage control strategy is proposed,and its feasibility is verified by numerical simulation.A distributed energy storage control scheme based on improved K-means clustering is proposed.The scheme takes into account the parameter difference of distributed energy storage and optimizes the energy distribution within the aggregator without changing the total output of distributed energy storage.Aiming at the scenario of distributed energy storage participating in power grid operation in electricity market,an optimization model is constructed to improve economic returns and reduce operating costs.For the scenario of distributed energy storage providing ancillary services,an optimization model is constructed to reduce the fluctuation of daily load demand.By selecting hundreds of distributed energy storage with different parameters and referring to the daily load demand curve and time-sharing price of a city in China,a simulation example is designed to verify the feasibility and effectiveness of the proposed control strategy. |
PDF Full Text Request