With the continuous increasing penetration of distributed energy in isolated microgrid

the inertia of system is getting lower gradually. Virtual synchronous generator(VSG)

which can simulate the inertia of synchronous generator and plays a vital role in damping dynamic frequency variations

has been gradually applied in microgrid. Frequency of island microgrid will oscillate severely and even may exceed its safety constraints when the power imbalance caused by fluctuations of renewable energy output or loads switching happens. To deal with these problems

a virtual synchronous generator control method based on model predictive control is proposed. Firstly

the predictive model

which aims at optimizing the weighted combination of frequency deviation and VSG output with frequency change rate as the constraint is established. Then

the systematic control strategy is designed according to physical quantities

such as frequency

VSG output voltage and current

the increment of active power needed is calculated for changing the power reference of VSG. Meanwhile

the solution of the predictive model is given

and the convergence of the algorithm is analyzed

which provides the basis for selecting key parameters. The correctness and effectiveness of the proposed control strategy are verified by the simulation results of two typical cases.