Abstract:The battery energy storage system has a fast and accurate power response capability and is beneficial for the power plant to better track the automatic generation control (AGC) command and complete the grid AGC control target more efficiently.Since the construction cost of the energy storage system is relatively high,it is of great significance to establish an effective method for economic evaluation of energy storage batteries.A control strategy for auxiliary thermal power units to participate in frequency modulation and a control strategy for subsection frequency modulation are proposed.Then a gray model algorithm is used to establish the attenuation model for battery capacity,and a prediction method for the health of energy storage systems is derived.Finally,two control methods are used.The strategy completed the research on the economic evaluation of energy storage system participation in FM.