Based on the summary on the characteristics of different energy storage techniques and their applications, the existing problems in large-scale grid-connected renewable energy sources are analyzed, and the research progress on the application of energy storage technique to solve such problems as system operation stability, power fluctuation, power quality and low voltage ride-through for wind power system are discussed. Furthermore, to meet the economic and technical requirements, the composition structure and optimal allocation method of energy storage system are mainly studied. In addition, control strategies of energy storage system in different operational situations are discussed. In the end, research direction and prospect of energy storage technology are forecasted.