Abstract: During the operation of current grid-side electrochemical energy storage stations，the main controlling constraint is the maximum chargeable and dischargeable power of the whole station.To make a more sufficient consideration for energy efficiency of the stations，an optimized power control strategy based on battery energy efficiency curve is proposed. Targeting at the output power and energy efficiency，the operation optimization model of grid-side electrochemical energy storage stations considering the dynamic efficiency of energy storage is established.The model considers the variation of energy storage efficiency changing with different power during the charging and discharging，and incorporates the dynamic efficiency into the energy storage station optimization model in the form of an approximate linear function.The simulation analysis is carried out based on the actual operation data on grid side. Comparing the effect of different charging and discharging control strategies on grid operation control，it is proved that the dynamic efficiency characteristics will impact the comprehensive energy efficiency of the energy storage station to some extent and should be take into considering in operation optimization of grid-side electrochemical energy storage power station.

Key words: dynamic efficiency, electrochemical energy storage, power control, lithium iron phosphate battery, renewable energy, energy efficiency of battery, control strategy, source-grid-load-storage