Fault Diagnosis Of Wind Turbine Gear Box Based On VMD And Wavelet

With the rapid development of modern science and technology,the modernization level of modern industry and equipment is continuously improved,and high efficiency,high performance,high automation and high reliability have become the development direction of mechanical equipment.Gear transmission is one of the most common transmission methods in mechanical equipment.To ensure the normal operation of mechanical equipment and reduce the maintenance time and maintenance cost when the fault occurs,it is necessary to make a faster and more accurate diagnosis of the gearbox failure.Variational Mode Decomposition(VMD)mainly includes two aspects: the construction and solution of the variational problem.The variational mode decomposition algorithm can simultaneously estimate the modes of different center frequencies,and its essence is a set of adaptive Wiener filter banks.Different from Empirical Mode Decomposition(EMD),Variational mode decomposition uses non-recursive mode decomposition to effectively avoid modal aliasing caused by recursive mode decomposition,and can overcome the end effect.Therefore,the VMD-based fault analysis method has great research value.Based on the VMD decomposition and wavelet principle,the theoretical research and experimental verification of gearbox fault diagnosis are carried out.Taking the gearbox of a wind power plant in Zhangjiakou of Datang as the experimental research object,according to the actual working condition of the gearbox,first selects the appropriate wavelet base for the fault vibration signal,performs wavelet denoising preprocessing and VMD decomposition,and explains the VMD after signal denoising.The effect of decomposition is better than directly decomposing the signal.Then,the modal component with decomposed significance is selected for Hilbert transform.Finally,the transformed spectrogram is analyzed to find the gearbox fault and complete fault diagnosis.The above experiment was repeated by EMD method.The results show that the proposed method can effectively analyze and diagnose the gearbox fault.