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

A simulation model of a MW-level wind turbine with dynamic slip control and pitch control is developed in the simulation tool of PSCAD/EMTDC and stability investigations are carried out with respect to a short circuit fault in the external power system. After the fault has been cleared, the voltage at the wind turbine terminal has to be re-established, and the wind turbine should restore its normal operating condition. Controlling the generator slip and pitch angle can adjust the electromagnetic torque and the aerodynamic torque of wind turbine, which helps to rebuild the voltage at the wind turbine terminal. Simulation results prove that dynamic slip control and pitch control are effective methods to improve the voltage and maintain power system stability.