Research On Joint Optimization Strategy Of Battery Energy Storage Participating In Peak Shaving And Frequency Regulation Of Power System

With the continuous expansion of the scale and capacity of new energy power generation,it directly affects the peak shaving ability,frequency stability and economic and reliable operation of the power grid.Because of its fast response speed and high control accuracy,it is a good choice to use battery energy storage to participate in peak shaving(PS)and frequency regulation(FR)control of power grid.Due to the different time scales of PS and FR control,in order to accurately distribute the output of battery energy storage participating in peak shaving and frequency regulation,it is necessary to study the joint nested model of objective functions of different time scales of battery energy storage PS and FR.The main research context is as follows:1.The control strategies of battery energy storage participating in PS and FR are summarized.The joint optimization of PS and FR is realized by nesting the objective functions of different time scales.In addition,the mechanism of PJM power market is analyzed,and the locational marginal price(LMP)of battery energy storage,the regulation price of FR market and the FR signal sources are determined,which lays a foundation for the establishment of the objective function.2.According to the rules of PJM power market in the United States,aiming at maximizing the benefits of battery energy storage participating in PS and FR,a joint optimization strategy aiming at maximizing the benefits of battery energy storage in PS and FR is proposed.Based on the dynamic programming,the long time scale of PS and the short time scale of FR are nested jointly.By comparing the results of joint optimization and simulation of only participating in frequency regulation,it is found that the joint optimization brings higher energy storage benefits,and realizes the joint optimization of PS and FR.3.In order to further study the influence of FR pricing on the output of battery energy storage PS and FR,in the case of the high renewables penetration,and a new FR pricing mechanism for battery energy storage considering the renewables penetration is proposed.The target tracking accuracy of battery energy storage is defined as the criterion to determine the optimal FR price.The simulation results show that the higher FR price can ensure the battery energy storage to participate in PS,and more effectively stimulate the battery energy storage to participate in FR at the same time,to ensure the tracking accuracy of the battery energy in FR.4.Considering that there is no additional FR performance compensation in the domestic FR market,only considering whether the battery energy storage can achieve the FR index,and to maximize the tracking accuracy in FR under the demand of PS and FR.A joint optimization of PS and FR aiming at maximizing the tracking accuracy of battery energy storage is proposed.The simulation results show that the control strategy can ensure the battery energy storage to complete the FR service and participate in FR as much as possible,so as to ensure the accuracy of battery energy storage to track the FR signal and maintain the frequency stability of power system.