Research On The Dynamic Characteristics Of Doubly-fed Wind Power System Based On The Imitate Of Wind Turbine

In the process of the research of wind power technology, wind turbine usually can not be directly connected with generator and there is no physical environment of wind farms in preliminary research of laboratories. Therefore, the establishment of a wind turbine simulation system means great significance to wind generation technology research and development. A DC motor is used to imitate the characteristic of wind turbine in this article, on this basis the wind power generation system based on the simulation of wind turbine is established.First of all, the operating characteristics of DFIG in VSCF wind power generation is analyzed, Mathematics model of DFIG in the synchronous rotary coordinate is established by the thought of coordinate transformation. The characteristic of dual PWM converter is used for DFIG excitation. The voltage oriented vector control strategy is used in grid-side, which makes the unit power factor operation at grid-side converter achieved, and which also guarantee DC voltage's stability; the stator flux oriented vector control is introduced, decoupling control of active power and reactive power at stator port of DFIG are achieved.Secondly, the operate characteristics of wind turbine and the operate principle of wind turbine under maximum wind energy capture are researched, and so is the power regulation characteristics of wind turbine. The characteristic of wind turbine and DC motor are contrasted, and the mathematical model of mechanical shaft is established. The control method of imitation characteristics of wind turbine use DC motor is studied, in this article the impact on the simulation system the torque control was provided, which imitates the torque characteristics of wind turbine by controlling the armature current of DC motor, then imitate the wind turbine torque characteristics under different wind speeds.Finally, the wind power generation system based on the imitate of wind turbine is established by the means of Matlab software. The validity of control strategy of the wind turbine simulation system based on the torque control and the control of DFIG is simulated by this simulation. Not only for the wind turbine operating characteristics under the different wind speeds and the grid-connection of DFIG are analyzed, but also the dynamic effects of DFIG by the wind turbine simulation system under the transient condition is researched. Through the comparative analysis, the rationality and validity of the simulation system are verified.