As an effective carrier of distributed generators

microgrid is an independent power grid by parallel connection of distributed generators. However

the conventional droop control has a fast dynamic response speed to output frequency and is easily disturbed by frequent fluctuation of load. In order to improve the dynamic stability of the microgrid frequency

this paper proposes a control strategy of synchronous generator based on adaptive virtual inertia. The proposed method simulates the behavior of synchronous generator

constructs the relationship between the frequency change rate and the virtual inertia

and adaptively changes the inertia of the control of virtual synchronous generator. Thus the capacity of the microgrid in resisting disturbance and overload is improved. Compared with the conventional alternating inertia method

the proposed method does not require sampling frequency differentiation terms

which avoids the introduction of system noise. Meanwhile

it achieving flexible adjustment for smooth inertia coefficient

and has strong robustness. In addition

the convergence and stability of the proposed algorithm are analyzed and proved by Lyapunov stability theory. Simulations and experimental results show that the proposed method can improve the dynamic stability of microgrid frequency

and the feasibility and effectiveness of the proposed control strategy are verified.