Recently, more and more people realize the importance of environment protection. Electric power generation systems using renewable energy sources have an advantage of no greenhouse effect gas emission. Among all the choices, wind power can offer an economic and environmentally friendly alternative to conventional methods of power supply. As a result, wind energy generation, utilization and its grid penetration in electrical grid is increasing world wide. The wind generated power is always fluctuating due to its time varying nature and causing stability problem. Inserting energy storage system into large scale wind farm to eliminate the fluctuation becomes a solution for developing large scale renewable energy system connected with grid. The topology diagram and control strategy are presented in this paper. According to the simulation result, it could be indicated that embedding energy storage system into wind power system could improve the access friendly and extend system functions. This paper shows that integrating energy storage system into wind power system will build a more reliable and flexible system for power grid.