Doubly-fed induction generator (DFIG) low voltage ride-through (LVRT) requires high response speed and robustness for grid side and rotor side PWM converters. In order to solve the problem of slow response and poor robustness of traditional PI control strategy under the condition of low voltage ride-through
a novel control strategy based on differential flatness theory is proposed for grid side and rotor side. In this paper
the mathematical model of the grid side and rotor side of the DFIG on the d-q axis is described
and the flatness of the system is proved according to the differential flatness theory. Secondly
a two-sided differential flat current controller with feedforward reference trajectory and error feedback compensation is designed. Finally
the system simulation model is built in MATLAB /Simulink. The simulation results show that the application of this control strategy improves the ride-through capablity of DFIG during the grid low voltage period
and the response speed is fast and the robustness is strong. The feasibility and effectiveness of applying differential flatness theory to DFIG are verified.
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