In this paper, the author researches on a fast energy storage and energy conversion system for electric vehicle. This paper analyses and studies several main energy storage technologies and expounds the energy storage principle, advantages and disadvantages which also presents the application status quo. This paper introduces the current situation of China's power system and the concept and connotation of smart grid in the future. Based on the background of the development and construction of smart grid in China, the application and development direction of energy storage technology are studied. In this paper, the structure of the battery energy storage system is introduced, and the mathematical model of the battery energy storage system is given. The power control strategy of converter is researched and designed. Combined with the development of wind power in China, the application and effect of battery energy storage system in wind power generation in China are studied and analysed.