Bearing Damage Detection via Wavelet Packet Decomposition of the Stator Current

Abstract

Abstract-Bearing faults are one of the major causes of motor failures. The bearing defects induce vibration, resulting in the modulation of the stator current. In this paper, the stator current is analyzed via wavelet packet decomposition to detect bearing defects. The proposed method enables the analysis of frequency bands that can accommodate the rotational speed dependence of the bearing defect frequencies. The wavelet packet decomposition also provides a better treatment of nonstationary stator current than currently used Fourier techniques.

Bearing fault detection using motor current signal analysis based on wavelet packet decomposition and Hilbert envelope

“…In the first step, the stator current is decomposed into 11 levels for a good resolution. Therefore, we have 2 11 nodes at the ending level for which the frequency resolution is 11.72 Hz. In our case, the DMeyer wavelet was applied for better resolution [14].…”

“…We need to double the sampling rate for higher frequency analysis, which however involves more data and computation. Wavelet packet decomposition [11] is a generalization of wavelet decomposition at higher frequencies. In the wavelet packet decomposition, each approximate and detail coefficients are recursively decomposed.…”

A brief status on condition monitoring and fault diagnosis in wind energy conversion systems

“…In the case of rolling bearing fault diagnosis and apart from the well-established techniques developed for induction motor drives [18], a recently published paper seems to be convenient for wind turbine bearing fault detection [34]. Indeed, it uses the wind turbine generator stator current.…”

Simulation and Experiment study of ball defects of a two rotors-ball bearing-gear coupling system

“…Various numerical models have been developed to study the dynamic characteristics of rotor [3]- [9], many researches are focused with different on ball bearing faults. Changqing developed a bearing model considering the effects of distributed off-size rolling elements and waviness [5].…”

“…Lynagh [8] presents a detailed model of bearing vibration, including the effect of contact spring non-linearity in balls-toraceways' contacts. Eren [9] analyzed stator via wavelet packet decomposition to detect bearing defects. The proposed method enables the analysis of frequency bands that can accommodate the rotational speed dependence of the bearing defect frequencies.…”