With the wind power supply sharply increasing in some areas， the effects of large scale wind farms on the stability of regional power system are becoming very remarkable. Accordingly， more and more studies are focusing on the low voltage ride through（LVRT） technology used for doubly fed induction generators（DFIGs）. In this paper， the LVRT concept and relevant international standards are first introduced. And then it introduces various modeling methods， popular LVRT technologies and improved control strategies. In the end， the effects of wind farms with LVRT capability on the power systems are analyzed.