Large-scale renewable energy participates in the power grid through power electronic equipment, which cannot provide stable and effective inertia support for the power system. Based on the rate of change of frequency at the time of disturbance and the virtual inertia control of the energy storage system, the supporting effect of the energy storage on the inertia of a high-proportional renewable energy system is analyzed in this paper. Then an energy storage capacity configuration calculation method is proposed considering the equivalent inertia time constant and virtual inertia control parameters. Next, the quantitative analysis index is proposed based on the supporting effect of inertia, which provides analysis methods for renewable energy participating in the power grid and energy storage capacity configuration. Finally, the IEEE 30-bus system is used to analyze system frequency response characteristics under different energy storage capacity configuration scenarios. The effectiveness of the proposed method is verified.