This paper presents the development of the wind power system and low voltage ride through (LVRT) techniques for doubly -fed induction generator (DFIG) wind energy system. In recent years, wind power has been developing rapidly. As the wind power penetration from large scale wind turbines has been increasing rapidly in the transmission system, there is a higher requirement for the frequency stability and power generation efficiency of the wind power generation system, and the power grid puts forward higher continuous operation requirements for the grid connected wind turbine in the power grid fault and demand that the wind power generator has to ride through the grid faults, especially the grid voltage dips. This overview mainly introduces DFIG and low voltage ride through technology in the wind power generation system. This paper introduces respectively their development, control strategies and future trend.