Analysis Of Noise Characteristic Of Large Wind Turbine Gear Box Structure

Large-scale wind turbines in service In wind,sand,rain,and other extreme environments,transient and frequency-varying fatigue loads are subject to severe degradation or even failure of transmission components such as the main shaft of the wind turbine and the speed increaser,and measures must be taken to ensure their safe operation.The operation status monitoring and fault diagnosis technology has become the main measure to improve the operational safety of the wind turbine drive system and is widely used,but the traditional time-frequency technology is difficult to adapt to the development needs of large-scale wind turbines.Therefore,there is an urgent need to study new methods for monitoring and fault diagnosis of transmission system operation,and in particular,detection and diagnosis methods for early failures.The structure noise of large wind turbines will exhibit different acoustic radiation properties under different operating conditions,that is,“structural noise utilization”.Therefore,it is necessary to study the structural noise characteristics of a large wind turbine drive system under typical operating conditions.This paper takes a large wind turbine gearbox as the research object,considers the fluctuation of the gear meshing during the operation of the gearbox,causes the overall vibration and noise radiation of the gearbox system,and calculates the time-varying meshing stiffness and error excitation of the gearbox.Using Solidworks software to establish the physical model of the wind turbine gearbox,and import it into ANYSYS,divide the grid and perform modal analysis to obtain the natural frequency and vibration mode of the wind turbine gearbox.The acoustic software ACTRAN was used to use the boundary element.Method for Solving Radiated Sound Fields of Acoustic-Solid Coupling Systems.Get its acoustic properties.Calculate the degree of acoustic contribution of each panel and analyze the influence of various parts of the gearbox system on the noise radiation of the gearbox.Acoustic software ACTRAN uses the boundary element method to solve the radiation sound field of acoustic-structure coupling system.Get its acoustic properties.Calculate the degree of acoustic contribution of each panel and analyze the influence of various parts of the gearbox system on the noise radiation of the gearbox.By calculation,the maximum noise of the wind turbine gearbox structure occurs at the meshing frequency of 1375 Hz.By analyzing the acoustic contribution of each plate,it isconcluded that the noise of the gearbox structure mainly comes from the upper side of the box body,the top plate and the front and rear plates.Increasing the rigidity of the box structure,using helical gears instead of spur gears,and adding damping layers can significantly reduce the noise radiation of the gearbox.