The Control Strategy And Capacity Configuration Of Energy Storage System Participating In Automatic Generation Control

With the development of large-capacity power generation,long-distance power transmission and large-scale power grid interconnection,the frequency regulation task of the grid is very heavy.However,traditional resources have many problems such as slow response speed and response delay,which makes the automatic generation control(AGC)of energy storage system(ESS)urgent and necessary.At the same time,the promotion of energy storage technology and the development of demonstration projects at home and abroad make it feasible for ESS to participate in power system AGC.In recent years,the research results of ESS participation in AGC show that the ESS can be quickly regulated,with rapid and accurate response.Therefore,it is necessary to study the relative problems of ESS participating in AGC.Firstly,this paper introduces the performance,cost and technology maturity of fast frequency regulation resources,and discusses the feasibility to participate in frequency regulation.The technical parameters,cost and frequency regulation effect of the flywheel energy storage system and lithium-ion battery are analyzed in detail.The advantages and disadvantages of the two involved in frequency regulation are analyzed.Secondly,in order to avoid overcharge and overdischarge,the Logistic function is introduced to simulate the maximum output of the ESS.The area control error(ACE)of the grid and the state of charge(SOC)of the energy storage are dynamically corresponding,and a control strategy for coordinating ESS and conventional unit output is proposed.This strategy maximizes the life of the ESS while achieving frequency regulation.The simulation model of the ESS participating in the frequency regulation of the two-region system was built by using MATLAB/Simulink,and the validity of the model was verified.Finally,for cycle times of the ESS affected by the depth of discharge and the available capacity of the ESS affected by the number of cycles,the energy storage life model and the available capacity attenuation model are constructed respectively.This paper establishes a capacity allocation model based on climbing rate and revenue maximization from technology and economy.According to the cost and benefit of the ESS,the economic analysis model of the ESS is constructed.The capacity configuration of the ESS was carried out by an example,and the economics of the flywheel energy storage system for frequency regulation were verified.