With the large-scale access of new energy sources (such as wind power, photovoltaics, etc.) in the power system, the inertia and voltage stability of the system decline, resulting in weakening of power grid regulation capabilities and anti-interference capabilities, and risks to system safe operation. Aiming at the lack of understanding of the response characteristics of energy storage in current transient simulation, this paper proposes to accurately simulate the response characteristics of energy storage controller and its impact on the power grid through electromagnetic transient simulation. In this paper, the basic principle of grid energy storage system is studied, the difference between grid energy storage system and energy storage technology is compared, and the simulation model of grid energy storage system is established. On this basis, an optimal configuration of grid energy storage based on iterative linear programming is proposed. Combined with the CEPRI-VC case released by China Electric Power Research Institute and the 10-machine 39-bus test system, it is verified that grid energy storage can improve transient voltage. Effectiveness in stability. The results show that grid energy storage can effectively solve the problem of system instability caused by interference, and the optimal configuration scheme can improve voltage stability while taking into account the economy.