The objective of the present work is to study the dynamic behavior of Grid-connected Doubly Fed Induction Generator (DFIG) based wind turbine during balance and unbalance grid operating conditions. A 1.5MW grid-connected DFIG based wind turbine is molded and analyzed in this study. This study includes the implementation of a Flexible A.C Transmission System (FACTs) to protect DFIG based wind turbine interconnected power systems from isolating during and after the disturbance. It is found that FACTs devices improve the transient performance and therefore help the wind turbine
generator system to remain in service during grid faults. This grid connected wind energy conversion system (WECS) is
composed of DFIG and two back-to-back Pulse Width Modulation (PWM) voltage-source converters in the rotor circuit. A mathematical model of the machine; derived in an appropriate dq reference frame, is established. The grid voltage-oriented vector control is used for the grid side converter (GSC) in order to maintain a constant DC bus voltage and to compensate for reactive power at the power network. The stator voltage-orientated vector control is adopted in the rotor side converter (RSC) control strategy, providing efficient handling of active and reactive power at the stator. The proposed system is simulated for different operating conditions to illustrate the reliability of the control techniques.