Research On Multifault Diagnosis Method For Gearbox Of Wind Turbine

With the rapid development of wind power industry in the world,the installed capacity of wind turbine is also increasing year by year.The structure of gearbox in wind turbine is complex,and many parts often fail at the same time.Different failure frequencies are coupled with each other,so it is difficult to distinguish the type of failure.In order to judge the type of fault accurately,it is very important to study the multi fault diagnosis method of wind turbine gearbox.The main contents of this paper are as follows:1.The main structure of the wind turbine,the main structure and failure reasons of the gearbox are studied.The main failures of the gear and rolling bearing in the gearbox are analyzed and introduced.The vibration characteristics of the gear and rolling bearing in case of failure are described and the failure signal simulation is completed.2.In view of the problem of composite fault feature separation of rolling bearing,which is limited to the lack of self adaptability in the parameter selection of variable mode decomposition(VMD),the correlation kurtosis which can highlight the periodicity of fault impact is selected as the optimization index,and combined with the 1.5D spectrum which has the advantages of suppressing Gaussian white noise and eliminating uncoupled harmonic components,a rolling shaft with 1.5D spectrum is proposed The method of feature separation for complex faults.Through the analysis of simulation,experiment and the measured signal of bearing composite fault of wind turbine,it shows that the method can separate the characteristics of rolling bearing composite fault to a certain extent.3.Aiming at the problem of multi fault diagnosis between gear and bearing in the gearbox,a multi-point optimal minimum entropy deconvolution(MOMEDA)combined with enhanced cepstrum is proposed for multi fault diagnosis of the gearbox of wind turbine,which can separate and accurately diagnose the features of multiple faults on the bearing and gear in the gearbox of wind turbine,and the method is proved by analyzing the experimental signals Effectiveness.This method is used to deal with the bearing at the non-driving end of the gearbox of the wind turbine generator,and the effect is obvious.At the same time,the effective reasons of the separation method of bearing composite fault feature based on parameter optimization VMD and 1.5D spectrum are analyzed.