In the control of virtual synchronous generator（VSG）

such phenomenon as fast fluctuation andbig offset of VSG output voltage is happened during the load variation due to limitation of linear sag charac-teristics. In view of this problem

a multiple loop virtual synchronous generator control method is proposedin this paper. Firstly

the virtual excitation is introduced in reactive power-voltage control of VSG to solvethe problem of fast voltage fluctuation caused by load variation. Secondly

a kind of variable coefficient re-active-voltage sag curve is designed by the improvement of the linear reactive-voltage sag curve so to assureVSG reactive power output and reduce voltage offset in case of sudden increase of load. Finally

combina-tion with voltage current double closed loop control can assure effectively power quality of VSG power sup-ply. Simulation model of micro-grid is set up by Matlab/Simulink simulation software and simulation is per-formed. The feasibility and effectiveness of the control strategy is verified by the simulation result.