Research On BESS Participating In AGC Auxiliary Service Based On Battery Life Characteristics

With the vigorous development of renewable energy technology,the traditional grid frequency control is facing increasingly pressure.AGC auxiliary service is widely used as a reliable and efficient frequency adjustment method,but the common thermal power frequency modulation unit can not achieve satisfactory frequency modulation effect.With the continuous development of energy storage technology,the lithium-ion battery energy storage system can be used to assist the thermal power unit to improve its frequency modulation effect.However,the current research on the control strategy and battery life decline model is not mature enough,which lead to the lack of economic analysis of the project.In this paper,the lithium-ion battery energy storage system is used to assist the thermal power unit to participate in the AGC auxiliary service.This paper analyzes many international power policies and China's assessment policy to get formulas for parameters of the frequency modulation effect.An evaluation compensation algorithm is established to measure the evaluation index and compensation amount according to the AGC set point command and the tracking output of the unit.After comparing the performance parameters and economic indicators of the commonly used batteries in the energy storage system,the ternary battery is selected as the energy storage component.In this paper,the aging experimental data of a certain type of ternary material battery in three different DOD are analyzed to find the best DOD and build a conservative but reliable battery energy decline model.Considering the power characteristics of the energy storage system in different energy intervals,the SOE centering control strategy based on Logistic function and the economic strategy based on evaluation indicators are established.There are both simulate with common operating conditions and continuous charging conditions,and the SOE centering control strategy is used to fit the daily adjustment model.The cost-benefit model is established by using the evaluation compensation algorithm,energy decay model and daily adjustment model.This model is used to analyze the project's life cycle net income,payback period and return on investment.The initial energy allocation scheme is obtained through the investment payback period and the return on investment,and there is a sensitivity analysis of possible policy updates and market changes.Investment solution can be obtain by using this economic model,which is more reliable and more compatible with policy and market changes.This article contains 53 figures,18 tables,and 57 references.