Research On Grid Connected Doubly Fed Wind Power Generator Based On Fuzzy Control

Due to the intermittent nature of wind energy, the doubly fed asynchronous wind power generation system has time-varying, multi variable, nonlinear and so on, which can not accurately measure the parameters of each motor during the grid operation. It increases the control difficulty and affects the grid connected process.In the grid connected voltage amplitude control, the traditional PI control method needs the model parameters, so the control effect is not good when the parameter changes. Although the fuzzy control does not need accurate mathematical model, the robustness is strong, but its control point error is big, there is blind area and dead zone, the control precision is poor. Through analysis on the mathematical model of generator. In this paper, fuzzy control and PI control combination, used in grid side converter control, outer ring by DC voltage PI control, ensure the grid side converter and normal work of the excitation current of sine wave, so as to control the input power factor. Inner loop adopts fuzzy PI control and the rotor current PI control, combined with grid voltage fuzzy control as a supplement, constructs the fuzzy PI control, control grid voltage amplitude, respectively under the ideal case and motor parameters changed the control method were analysis and verification, compared with the traditional fuzzy PI control. The system can be very good control of the stator voltage amplitude, fast response speed and high precision, and the variation of the parameters of the generator is very robust.In the power of the fan control, this paper in the traditional perturbation and observation method based on improved, using fuzzy perturbation and observation method, main idea for power curve in the fan from different observation points, according to each observation point of the slope. According to the fuzzy control to adjust the disturbance observation of step when the slope is larger by large step tracking coarse, when slope is small with small long after the track to achieve fine adjustment. Realization of maximum power tracking control of fan. This method not only can improve the speed of fan power adjustment, but also can improve the accuracy of the method.