| Large-scale energy storage is involved in active power balance control,and in the day-ahead plan formulation,it is necessary to determine the adjustable space that can be declared to participate in the day-ahead bidding on the basis of the monthly bilateral trading plan signed between it and new energy power plants.Due to the large error in the monthly new energy output forecast,determining the reserved space according to the monthly trading plan may sometimes result in some of the space for energy storage being idle,which is not conducive to giving full play to its capacity and causing waste of resources.Energy storage can be based on a more accurate day-ahead forecast,the possible idle space will be reported to participate in the day-ahead trading bidding,that is,to report additional space,in order to achieve further optimization of the bid capacity and gain excess revenue.In addition to weighing the risk of penalties caused by insufficient regulation margin due to wind power output forecast errors,it is theoretically difficult to consider the reasonable allocation of this capacity between two different services of peak and frequency regulation.Accordingly,this paper conducts a research on the optimization strategy of the day-ahead addition space for energy storage participation in auxiliary services.Considering the uncertainty of new energy output prediction,based on the historical data of new energy power plant output,a scenario generation method is used to establish the actual output prediction model of new energy power plant before the day,so as to provide data preparation for the subsequent optimization of energy storage output space reporting;considering the depth of discharge of energy storage battery and the number of charge/discharge cycles,combined with the research of existing energy storage battery aging model,a battery aging model based on the cost per unit of electricity is established to provide basic model support for the calculation of cost items in the optimization of energy storage output space reporting.To address the problem that scheduling call instructions are difficult to predict,we propose the index of scheduling call level coefficient,and use this index to decouple the scheduling instruction model and the addendum space reporting model to build a scheduling instruction decoupling model,so that the actual working conditions under different scheduling call levels can be distinguished and the actual benefits of reporting addendum space under different call levels can be obtained.Based on the aforementioned basic model,the benefits and costs of energy storage to participate in the peaking service only are analytically modeled,and on this basis,an optimization model of energy storage to participate in the peaking service is constructed.A stochastic planning method based on the optimal expectation scenario is selected,and the feasibility and practicality of the case of energy storage reporting additional space for peaking service only are solved through MATLAB by calling the CPLEX optimization toolbox,and the simulation results verify the rationality of the constructed model,which can effectively improve energy storage utilization and increase energy storage revenue.Combined with the FM auxiliary service market mechanism,we analytically model the benefits and costs of participating in the FM service with the reported additional space for energy storage,and on this basis,we construct an optimization model of the additional space for energy storage to participate in the dual auxiliary service,and simulate the feasibility and practicality of participating in peak-frequency regulation with the reported additional space for energy storage by calling the CPLEX optimization toolbox through MATLAB.The results are compared and analyzed with the results of only participating in peak regulation.The simulation results show that the participation in the two auxiliary services can further enhance the energy storage revenue and realize the full advantage of energy storage. |
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