Study On Load Characteristics Of Wind Turbine And Dynamics Of The Transmission System

With the fossil fuels becoming drying up and the environment getting worse, the renewable energy sources become more and more urgent, during the past 10 years the wind energy, which has the best economical prospect among all the renewable energy sources has been developed extensively. Wind energy is also very important and is becoming one of the most charming new energies in China.Of all the main parts of wind turbines, the reliability of gearbox on duty is always one of the puzzling questions. During the operation, the gearbox is not only enduring the bad conditions due to the temperature varying when season changes, but also enduring the dynamic loads caused by the random wind speed. Because of the above reasons, the characteristic of the loads and the dynamic performances of the transmission system are very important for improving the reliability of transmission of wind turbine.Supported by the NSFC (Natural Science Foundation of China), in this research the wind speed model of the wind farm was set up and the dynamic loads of the wind turbine blade which is caused by the wind crossing the blade were analyzed, and the dynamic behavior of transmission system of the wind turbines was investigated.The research in this thesis includes the following contents:â‘ Wind speed model of the wind farm is set up. The 4 order auto regressive model is set up and the auto regressive coefficient is obtained by the Yule Walker method, the time history of wind speed is got.â‘¡The load model of the wind turbine blade was established based on the aerodynamic and the blade element theory. And the dynamic loads of the wind turbine blade are obtained which is considered as the input loads of the transmission system. The statistical spectrum of the dynamic loads is drawn from the load data; the influences of the blade parameter on the dynamic loads are analyzed.â‘¢The dynamic model of the transmission system is set up and the dynamic equations of the transmission system are deduced. The dynamic responses are obtained by the numerical method.â‘£The effects that the wind turbine blade parameter (pitch angle, twist angle and attack angle) on the dynamic characteristics of the transmission system are analyzed under the condition of varying wind loads; The results lay a foundation for the pitch control of wind turbine blade and parameter optimization of the blade.