Effect of grid-connected DFIG wind turbines on power system transient stability

In some power systems, the penetration of wind power is increasing rapidly and starts to influence the overall system behavior and stability. Under this condition, it becomes necessary to require wind turbine generators (WTGs) to remain in service during grid faults to support network voltage and frequency. This paper investigates the effect of grid-connected wind turbines driving doubly-fed induction generators (DFIGs) on the transient stability of power systems. By using an uninterrupted operation scheme and the fast control of the DFIG converters, the DFIG wind turbines can successfully ride through grid faults and have no problem of angular stability associated with the conventional synchronous generators. Therefore, the integration of DFIG wind turbines can even bring some benefits on power system transient performance and stability. Simulation studies are carried out to demonstrate and compare the transient performance of the IEEE 10-machine 39-bus system with and without wind power integration during a severe grid fault. Results show that a better transient performance is achieved by the power system with wind power integration.