Objective The regulation principles and methods of energy storage power plants to maintain the steady state of the power system in the case of wind and solar power generation were investigated and on this basis an active support control strategy of virtual synchronous generator three-level model assisting thermal power units to maintain the frequency stability of the grid with active support control was designed. Methods Using the characteristics of the fast response of energy storage batteries an energy storage system was established to improve the control of the energy storage converter. The conventional control architecture was improved by adding an outer-loop regulator with virtual impedance in the voltage and introducing a current inner-loop control based on a quasi-PR controller. The principle of the control strategy and the correspondence of the synchronous generator were analyzed in depth. Results With the increasing penetration of new energy into the grid the number of frequency fluctuations becomes less when energy storage power stations are connected to the grid to participate in frequency regulation. Conclusion This control method can bring a certain amount of inertia and damping to the new energy power generation system thereby enhancing the stability of the system. It also provides the necessity and feasibility of energy storage stations participating in grid frequency modulation and provides a certain practical reference significance for the distribution of energy storage stations and the capacity allocation of energy storage batteries.