Fault Diagnosis Of Wind Turbine Gearbox Based On Synchrosqueezing Wavelet

With the rapid development of the world wind power industry and the higher requirements of reliability,security,maintainability of wind power system,condition monitoring and fault diagnosis technology of wind turbine system have aroused widespread concern of experts and scholars at home and abroad.As an important part of the mechanical transmission system of wind turbine,the real-time monitoring and accurate analysis of gearbox running status are of great significance both to the fault diagnosis and operation and maintenance of the whole wind turbine.In this paper,it aimed at the problem of vibration signal feature extraction in the fault diagnosis of wind turbine gearbox.By using Synchrosqueezing Wavelet Transform(SWT),synchrosqueezing wavelet ridge,cross wavelet transform and order analysis,in view of the two states of constant speed and variable speed,the theoretical research and experimental verification of the vibration signal characteristic extraction method of wind turbine gearbox are carried out,which provides an effective theoretical method for condition monitoring and fault diagnosis of wind turbine gearbox.The specific research ways are as follows:Firstly,Analyzing the structure characteristics,failure mechanism and vibration fault characteristics of the gearbox.Furthermore,aiming at the problem that the vibration signal of the wind turbine gearbox is non-stationary,non-linear and difficult to extract in different states,the time-frequency analysis technique based on SWT and the feature extraction of variable speed signal based on order analysis are proposed to realize the effective extraction of the vibration signal characteristics of wind turbine gearbox.Secondly,the time-frequency analysis method of vibration signal based on SWT and cross wavelet transform is used to describe the time-frequency characteristics of the vibration signal of gearbox bearing under different fault conditions,and compared with continuous wavelet transform,cross wavelet transform and SWT.Simulation analysis and bearing diagnosis experiment verify that the proposed method has better fault diagnosis effect.Finally,in order to solve the problem that the rotational speed information of tacholess order analysis is difficult to be extracted,a order analysis method based on current-aided is proposed,and it is used in variable speed feature extraction of the gear vibration signal.This method effectively utilizes the current signal to extract the speed information,and achieves the fault diagnosis of the gear teeth broken under the variable speed.The fault diagnosis experiment of wind turbine gearbox verifies the effectiveness of the method.