Virtual synchronous generator(VSG)technology is widely concerned because it can help renewable power generation equipment equipped with frequency and voltage support capabilities similar to synchronous machines. The models and control strategies of VSG are now focused on and VSG is mainly applied in the microgrid. Started with the difficulties encountered in the demonstration project of the large-capacity grid-connected renewable VSG

combined with the relevant technical problems of renewable energy development

the safe and efficient operation problems of the grid-connected VSG in the complex conditions are summarized as the grid-connected adaptability of VSG

including grid-connected stability

fault ride-through

and frequency support based on rotor inertia of wind power VSG. For various aspects of grid-connected adaptability problems

the existing research results and limitations are summarized

relevant research progress is specially introduced

and the future research directions are prospected.