Voltage recovery of grid-connected wind turbines with DFIG after a short-circuit fault

The fast development of wind power generation brings new requirements for wind turbine integration to the network. After the clearance of an external short-circuit fault, the voltage at the wind turbine terminal should be re-established with minimized power losses. This paper concentrates on voltage recovery of variable speed wind turbines with doubly fed induction generators (DFIG). A simulation model of a MW-level variable speed wind turbine with a DFIG developed in PSCAD/EMTDC is presented, and the control and protection schemes are described. A new control strategy is proposed to re-establish the wind turbine terminal voltage after the clearance of an external short-circuit fault, and then restore the normal operation of the variable speed wind turbine with DFIG, which has been demonstrated by simulation results.