A fully decoupled feed-forward control for low-voltage ride-through of DFIG based wind turbines

With the stator directly connected to the grid, doubly-fed induction generator is very sensitive to gird disturbance. However, wind turbines are required to stay connected to the grid for a given time duration during grid fault, according to the low voltage ride-through requirement. The key point of the low voltage ride-through solution is to depress high rotor current during grid fault. This paper proposes a fully decoupled feedforward control for the DFIG, enhancing the low voltage ride-through capability. When grid fault happens, the induced EMF is accurately estimated, resulting in minimum transient rotor current and minimum the occurrence of crowbar interruptions. Simulation results are included, demonstrating the viability of the proposed control.