Unified model for doubly-fed wind generator system and its application in controllers´ coordination

Recognizing the state-of-art of the control strategy for the double fed induction generator(DFIG) for wind power generation is designed with different subsystems with different references, which neglecting the mutual influence between the grid and rotor connected PWM(Pulse Width Modulation) converts and the corresponding PI controllers´ parameters are coordinated with field test, this paper proposes a unified model, which presenting a systematic viewpoint to the different PI controllers for the DFIG system with the same reference. The proposed the model for the general DFIG system, includes the mathematical description for the grid connected PWM converter(GCC) with PI controller, the generator´s rotor connected PWM converter(RCC) with PI controller with the same reference. The model describes the DFIG system with the PI controllers as a differential algebraic equation. Based on the proposed model, the application of determining the coordinated parameters of PI controllers is presented. The simulation results show the effectiveness of the proposed model.