| Wind turbine works in the natural environment all the year endured the role of different wind conditions which operation condition is very complex; the blades and tower components of wind turbine are flexible body structure, the flexible deformation has a great influence on the dynamic characteristics of wind turbines. Therefore, it’s essential to research the dynamics of different working conditions in order to ensure the high-efficiency and smooth operation of the wind turbines. This paper focuses on the dynamics of wind turbine carried out research, the specific content of the work is as follows:1) The time-domain dynamic load was solved under different design load conditions using BLADED software based on the wind turbine design certification standards IEC2005. It focuses on the calculation methods of extreme load extrapolation for the case of DLC1.1 using the method of maximum likelihood to obtain the desired load extrapolation extremes. The extreme loads of key position of wind turbine blades, hub and tower were obtained combined with the load calculation results for the cases of DLC6 and DLC7.2) A mechanical analysis model of the tower is established and the tower stiffness and static strength characteristics are analyzed by using the finite method which takes a 5MW wind turbine steel-concrete tower as the research object. It obtained the first six natural frequencies and mode shapes of tower by choosing Block Lanczos method. Selecting the hub dynamic load of wind turbine as the excitation load of tower under the different cases and using modal superposition method to calculate the displacement dynamic response and explored the vibration characteristics of wind turbines at different dynamic load excitation. Selecting a MW wind turbine gear box for the study to construct the multi-body dynamics analysis model and conducting a simulation based on different load input conditions, analysis of the dynamics characteristics of transmission system.3) The rigid-flexible coupling multi-body dynamic model of the whole wind turbine was constructed based on the designed machine kinematic topologies in the multi-body dynamics analysis software SIMPACK which a MW grade wind turbines was selected for the study. It calculates the top six natural frequencies and mode shapes of whole machines with modal analysis, results shows that the whole machines will not resonate at critical speed range. The displacement and acceleration dynamic response of wind turbine blades and towers, which includes the tip deflections of three coordinate direction were obtained with three different run conditions in 14m/s wind speed that simulation combined aerodynamic calculation software AeroDyn and control solvers through an interactive interface, analysis time varying changes of the key components of the wind turbine and explored its dynamics under different load cases.This paper focuses on the problem of wind turbine dynamics carried out research. Starting from the load calculation input conditions of dynamic analysis, it studies the dynamic properties of the wind turbine tower and gear box, the multi-body dynamics model constructing and dynamic characteristics of the whole machine, and then explores the dynamic variation of wind turbines under different input conditions. All those provide a theoretical reference for the design and analysis of wind turbine dynamics. |
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