Research On Wind Turbine Active Power And Reactive Power Control Strategy

Energy and environment problem has become the key factors influencing the human and social sustainable development. The development of new energy is receiving more and more attention. With the rapid development of wind power generation, power capacity is increasing. Concerning the volatility and unpredictable for wind power, studying the modeling and the power control strategy of wind power system has important theoretical significance and practical values for power system safe and stable operation.By analyzing doubly-fed wind power generation system principle, structure and composition, the mathematical model is deduced in detail in this paper, including wind turbine model, model of doubly-fed wind power generator, and the relations between double-fed induction wind generator and power. Combining with the actual and expert experience, the mathematical model of DFIG at any given speed rotating d-q coordinate system is fixed.In the aspect of control method, this paper puts forward the corresponding improvement control strategy, in order to realize the maximum wind power tracking and the low voltage power grid failure through running, including:(1)Applying a pulse width modulation scheme with the switch in the complex plane vector and the relationship between voltage to control on and off of the power electronic devices, which can realize the modulation of the grid wind power converter system;(2) Grid side converter and rotor side converter control strategies are improved based on the stator voltage oriented which are able to control wind turbine and converter effectively, in order to realize the active and reactive power decoupling control and the maximum wind power tracking.(3) Power grid voltage fault low voltage ride through control strategy is proposed that can inhibit the rotor current fluctuations and dc bus over-voltage to make wind turbine network operation.Aimed at above the proposed control scheme, a 1.5 MW doubly-fed wind power system simulation model is built in the Matlab/Simulink simulation platform. The simulation results verify the correctness and the effectiveness of the proposed control strategy.