Analysis Of Vibration Characteristics Under Environmental Excitation And Temperature Effect Of Wind Power Generation Structure

With the advance of global industrialization and mechanization,the development and utilization of new energy has become the focus of attention.The tower,as the load-bearing of wind power generation,its mechanical performance and dynamic characteristics for the safe operation of wind turbine is particularly important.In this paper,the finite element software ANSYS is used to establish the whole model of the tower and analyze its dynamic characteristics.The main tasks completed are as follows:1)Using modal analysis,the first 10 mode frequencies and modes of the tower tube are obtained,and the modal frequencies and blade excitation frequencies of the tower are compared to determine that the tower will not resonate during normal operation.The results show that the structural strength,stiffness and deflection of the tower meet the requirements.2)Vibration characteristics of wind power tower in Minqin wind power Plant under environmental excitation were measured,and the collected data were analyzed and processed to obtain the modal frequency and corresponding damping ratio of the tower.A good way to fit the true mechanical properties of the tower drum is found.The temperature variation rule of wind power tower is analyzed by using the real-time monitoring data of temperature in nearly one year.Various statistical methods,test hypothesis,extreme value analysis and least square estimation,are used to analyze the measured temperature and temperature difference of wind power tower,and the probability distribution model of the temperature difference between wind power tower and ambient temperature is established.The results show that the Gaussian distribution function can be used to characterize the probability distribution of wind turbine temperature.The Weibull distribution function can be used to characterize the probability distribution of the temperature difference between the cylinder and the environment.3)The response of the tower under the action of temperature is analyzed.The results show that the maximum displacement variation of the tower tube structure caused by temperature change under wind load reaches 6.3mm,and the influence of temperature should be considered in the static analysis of the tower structure.The influence of temperature on the modal frequency of the tower is very small,and the effect of temperature can be ignored in the analysis of its dynamic characteristics.This study provides reference for further study on the temperature effect of wind turbine tower.