Abstract: Unleashing the frequency support potential of energy storage devices will be the key to improving the grid-connected stability of wind and solar systems. This paper firstly compares and analyzes the inherent inertia of conventional generator sets, the virtual inertia of wind generator sets and the inertial support characteristics of energy storage. Then, according to the energy storage capacity configuration in the system, virtual inertia of the quantified energy storage is constrained to provide an evaluation basis for the system inertia demand to ensure frequency safety. On this basis, using the unique power support characteristics of energy storage, an active support control strategy of energy storage grid-connected frequency combining constant frequency control and frequency modulation state transfer control is proposed, breaking through the traditional control mode of virtual inertia and primary frequency modulation. Finally, a wind power high-penetration power grid simulation system is built to verify that the energy storage device can significantly improve the frequency stability of the system under the proposed control strategy and improve its active support performance for the power grid.