Investigation of control for grid integrated doubly fed induction wind generator

In this paper, a doubly fed induction generator (DFIG) wind turbine controller which consists of two control loops is introduced. In steady state, the main control loop ensures that the wind power generators without wind speed measurement can perform active power control tasks below the nominal wind speed while the auxiliary stability control loop restraining the wind power system oscillations by eliminating the system unbalancing energy during system disturbances. The impacts of DFIG operation that limits on the controller are also discussed in this paper. In the simulation study, a testing system including a DFIG-based wind farm implemented in DIgSILENT/Power Factory is conducted to demonstrate the effectiveness of this strategy. The simulation results show that the control strategy can adjust the power of the DFIG wind generator accurately under wind speed fluctuation. In addition, when a disturbance occurs in the system, the strategy is effective in improving the power system transient stability in different operation statuses without deteriorating the system voltage stability.