The grid-structured energy storage converter can smooth the output of renewable energy and provide rotational inertia for the "double high" system(namely

high-efficiency and high-quality system)

which is regarded as the core equipment of the new power system. The accuracy of the energy storage configuration boundary and the design of key parameters determine the economy and stability of the system operation. Firstly

a unified grid-structured energy storage small-signal model is established from the two conditions of source and grid disturbance. Secondly

based on this model

the calculation method of energy storage configuration under different damping conditions is proposed

and the influence of damping coefficient

inertia time constant and sag coefficient on the power configuration

capacity configuration and adjusting time of energy storage units under the two conditions is quantitatively analyzed. Then

the boundary value of energy storage configuration under the tuning source and grid disturbance is optimized

and a key parameter design method of grid-structured energy storage is proposed. Finally

the accuracy and feasibility of the proposed model and control strategy are verified through case analysis.