Research On MTMD Vibration Control Of Megawatt Wind Turbine Tower

Since the beginning of the 21st century,with the rapid development of the global economy,the demand for energy around the world has increased sharply.Environmental degradation,political tension and regional conflicts caused by energy supply problems are not uncommon.Energy has become a top issue concerning political security,economic development and social life,and is crucial to our production,life,scientific and technological development.Among the available energy sources,wind energy is a safe,environmentally friendly and renewable green energy with advantages such as low development cost and convenient operation and maintenance.Countries all over the world attach importance to the development and utilization of wind energy.With the progress of science and technology level and continuous accumulation of technology,wind power generation is increasingly developing towards the direction of high power,tower barrel is getting higher and higher,more and more flexible.The problem of tower instability caused by vibration is becoming more and more prominent.It is of great significance to study the dynamics,control and suppression of large MW wind turbine tower.In this thesis,the vibration control and suppression of Multiple tuned mass dampers for large megawatt wind turbine tower are studied.By means of theoretical analysis,fine modeling and simulation,the dynamic parameter modeling and dynamic response analysis of the tower barrel of an actual wind turbine in service were completed.On the basis of systematic analysis of the vibration mechanism of the tower barrel,TMD and MTMD vibration reduction solutions were proposed.Specific research contents are as follows:Firstly,based on the idea of finite element parameterized modeling,APDL language and Python environment were used to study the construction of a parameterized rapid modeling script that included the wall thickness,diameter,height,engine room,wind turbine weight,center of gravity and other variables.The vibration characteristics of a wind turbine tower under various engine room weight,foundation stiffness,platform height and weight conditions were studied by orthogonal experiment method.The influences of the natural frequency and vibration mode of the tower with engine room weight,foundation stiffness and other parameters were sorted out and mastered.Secondly,the MTMD dynamic design of the wind turbine drum is carried out to avoid the resonance risk.The optimal parameter values and MTMD azimuth design are given by using the fixed-point theory,optimal damping and optimal adjusting conditions.On this basis,the harmonic response analysis of the tower barrel under harmonic load is completed,and the frequency characteristics when the peak displacement of the tower top is sorted out.Finally,from the point of view of digital prototype,the wind-vibration response characteristics of the tower under complex wind conditions under random load are studied.The transient response characteristics of displacement and acceleration before and after the introduction of MTMD optimization design are analyzed.Taking the maximum displacement amplitude of the top of the tower barrel as the index to evaluate the vibration control effect,the sensitivity analysis of TMD and MTMD parameters was carried out respectively,and the influence of MTMD parameters on the vibration control of the tower barrel was studied.The results show that MTMD system has a good effect on vibration control and stability of tower barrel.This study provides a reference for the vibration reduction design of a kind of tall and flexible structures represented by wind turbine tower.