There exists a start-up inrush current problem during the grid-connection period within the three-phase voltage-source inverters（VSI）. Consequently

we propose a new method to suppress the inrush current effectively based on the virtual damping control. Firstly

a mathematical model is established based on the dq coordinate frame

and it is recognized that the primary cause of inrush current is the decrement in the damping ratio during the grid-connection period. Then

the detailed design process of the virtual damping control method is given

and the correctness and effectiveness of the proposed method are verified by simulation and experiments. The results show that the inrush current can be more than twice the rated current before adding virtual damping

the grid connection without inrush current can be realized after adding virtual damping

and it can also improve the robust stability of the system

the dynamic current quality

and equipment safety in operation.