Abstract: The first virtual synchronous generator (VSG) demonstration projects applied to large power system were constructing in wind power, photovoltaic and energy storage station in Zhangbei in 2016 by State Grid Corporation of China. Technical feasibility and economic efficiency of multiple implementation methods and technical route of VSG are explored. Relying on this project, this paper analyzed in theory two kinds of frequency regulation control strategies, different damping coefficient control strategy and additional frequency regulation characteristics control strategy firstly, which were adopted by the demonstration project. The differences between two strategies in frequency modulation start-up time, oscillation risk, mode of supporting power, inertia response dead zone and so on were compared and studied. Then, relying on the recorded field data, paper showed the actual frequency modulation effect and characteristics of differences between the two strategies. Lastly, we optimized the VSG control strategies and proposed two new ones to make full ues of the available power of PV-VSG and coordination of photovoltaic and energy storage effectively to stable the grid frequency. The effectiveness of new control strategies was verified on a RT-LAB semi-physical simulation platform.