Variable Speed Control Analysis of Direct-Drive Wind Turbines Incorporating the Variable Gain Pitch Knowledge Identification Algorithm

Abstract

For direct-drive wind turbines, effective methods can be adopted to reduce the generator speed fluctuation under the rated wind speed. However, there is a nonlinear relationship between the change of pitch angle of wind turbine and wind speed. In order to obtain the maximum power of the wind turbine, under the working condition of wind gust, this paper takes the principle of prior action of the pitch control and uses the variable gain pitch knowledge identification algorithm to achieve the effective control of the motor speed by designing the power pitch generator on the pitch controller to ensure that the pitch angle can be operated quickly under the rated power, and at the same time, the nonlinearities are added to the speed control process of the pitch angle generator. The gain factor of the pitch angle generator speed control process can ensure that the pitch control can work in advance under the wind gust environment. Finally, the simulation results show that the two gust control methods can achieve effective suppression of wind turbine generator in the case of overspeed, which can effectively increase the power generation of wind farms, reduce the load of wind turbines, and improve the operating stability of the system.