In the field of energy storage charge and discharge of electric vehicles, the virtual synchronous machine (VSM) technology can be applied to the bidirectional converter of electric vehicles to achieve friendly interaction with the power grid and significantly improve the power quality. Therefore, the system simulation model is established according to the model of three-phase synchronous motor, and the power control method is adopted to effectively control the two-way converter of electric vehicle. The dynamic behavior of EV charger/discharger with traditional droop control strategy and virtual synchronous machine technology is studied in the case of grid voltage transient rise and fall fault and grid side power drastic fluctuation. The tolerance characteristics of EV chargers undergoing this process in charge/discharge mode were analyzed and verified. Simulation results show the effectiveness and correctness of the proposed method.