Guiji Tang

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Vibration problems in rotors can be extremely frustrating and may lead to greatly reduced reliability. By utilizing the proper data collection and analysis techniques, the faults because of vibration can be discovered and predicted. The time-frequency analysis by Hilbert-Huang transform (HHT) plays on a significant role in the analysis of singularities,(More)
—Under the interactions between the power network and mechanical system, torsional vibration, of large turbine-generator rotor strings, has occurred. Taking a 300MW turbine-generator as the subject of study, simulation tests, of electrically-mechanically coupled sub-synchronous vibration of the rotor strings, have been performed. The results show that: in(More)
The time-frequency analysis by Hilbert-Huang transform (HHT) plays on a significant role in the analysis of singularities, which hide in the signal, and is an effective method for non-stationary signal. Based on empirical mode decomposition (EMD), the Hilbert-Huang method can obtain a true instantaneous frequency representation of a signal. The analytical(More)
In order to extract the fault features of rolling bearing effectively, a new improved enhanced kurtogram method is proposed. Improved enhanced kurtogram is calculated based on harmonic wavelet packet composition and the node whose kurtosis value is maximum is selected after calculating the improved enhanced kurtogram of the original fault signal, then(More)
A novel method of fault diagnosis for rolling bearing based on variational mode decomposition (VMD), permutation entropy (PE), and support vector machine (SVM) is put forward in this paper. Firstly, the original vibration signals of bearings are adaptively decomposed into a series of band-limited intrinsic mode function (BLIMF) components using VMD.(More)
To process the vibration signal fault diagnosis automatically and effectively, a method to calculate the generalized fractal dimension (D q) based on the traditional G-P correlation dimension algorithm is presented. First, the vibration signal, a kind of random fractal that meets the statistical self-similarity, is reconstructed according to the phase space(More)
The application of wavelet analysis in fault diagnosis is growing rapidly. This paper examined the advantages of harmonic wavelets and realized the capability of analyzing harmonic wavelet on arbitrary detail of frequency section. The simulating signal can be extracted effectively in frequency domain by harmonic wavelet packet transform and can easily be(More)
To analysis the effect of noise in signal to correlation dimension, the correlation dimension of the noised Lorenz signal was calculated. Morphological filter is introduced for de-noising the vibration signal. The correlation dimensions on the noised and de-noised vibration signals of rotor system at various states were analyzed. The result showed that the(More)
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