Research On Optimal Wind Power Capture Control Strategy Of Variable Speed WTGS

With the rapid development of human society and economy, the demand for energy increase continuely, the quantity of energy consumption of the conventional energy sources such as coal and oil is more and more, and the problem of environment pollution is growing severely, so human is paying more and more attention to the use of renewable energy. As a kind of pollution-free, cycling and green energy, wind energy has become the focus of the attention. Wind power generation is an effective method of use of wind energy. The development of wind power technology has being in progress, its economic performance has been close to the conventional energy sources. At present, the main wind power technology is Variable Speed and Constant Frequency (VSCF) wind power technology.This thesis first summarizes the situation of the development of wind power generation, and the state-of-arts of the research on the optimal wind power capture technology. Based on the fundamental of VSCF wind power scheme, an optimal wind power capture control strategy for variable speed WTGS is researched. To meet the need of research of VSCF doubly fed wind power generation technology, a simulation experiment platform is designed and built. A Y series three-phase asynchronous motor is used to simulate the wind turbine, by which the change of wind is simulated by changing speed of the motor. An Inverter is as a converter for both current and voltage to realize electric control. Then the stator field orientation vector control theory is used in the operation control of Doubly-fed induction generator (DFIG) to achieve feedforward decoupling control of stator side active and reactive power. An acquisition board of Advantech Industrial PC with supporting software is used to monitor the feedback control. And then, after the work principle and mathematical model of VSCF doubly-fed wind power generator is analysed, a neural network PID control strategy is proposed based on stator flux oriented vector control method, and the discrete model is established. Finally the control strategy is simulated by MATLAB and verified on the VSCF doubly fed wind power generation simulation system. The result shows that the result of theoretical operation proposed in this thesis almost is consistent with the actual operating effect, the system response is fast and overshoot is small. It should be concluded that the wind power control method proposed in this thesis can achieve the optimal wind power capture.