In this paper has been evaluated the transient response of Dynamic Voltage Restorer (DVR) against voltage sags and the impact of these electronic devices to maintain the continuity of supply of wind farms against a three-phase voltage sag. The aim of these studies is to verify the influence of the DVR on the ability of wind turbines and wind farms to fulfill the more demanding grid connection requirements of power systems operators. Moreover, the simulations are performed in order to:• Analyse the impact of DVR device on the transient response of wind farm.• Evaluate the capacity of fixed speed wind farms to maintain the continuity of supply during three-phase voltage sags.