With the growth of wind power and photovoltaic generation, and the increasing of electric vehicle application, the balance characteristics have been furtherly affected between renewable energy and electric load, several resources are used as flexible regulation for the safety and stability of power system, such as energy storage system（ESS）and flexible interconnection（FI）. It is focus on the typical topology and application scenarios wind generation （WG）- photovoltaic（PV）-ESS- electric vehicle（EV）FI, combined with the randomness and disorder of electric vehicle load and the constraints such as energy balance, operation balance, reliable power supply, power fluctuations, the configuration method of the ESS is proposed, meanwhile, the proposed control optimization method leads to the configuration of the energy storage system can be greatly reduced by optimizing the control strategy. Under the same control and operational effect, the optimal configuration of the ESS is established.