Mechanical Condition Assessment of Vacuum On-load Tap-changer for Converter Transformer based on time-frequency domain characteristics of Vibration Signal

2020 ◽  
Author(s):  
Zhicheng Pan ◽  
Jinyin Zhang ◽  
Haibin Zhou ◽  
Jun Deng ◽  
Chen Liang ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Vibration Signal ◽  
Condition Assessment ◽  
Mechanical Condition ◽  
Time Frequency ◽  
Tap Changer ◽  
Load Tap Changer

scholarly journals Application of the Acoustic Emission Method for Diagnosis of On-Load Tap Changer

2017 ◽  
Vol 42 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Henryk Majchrzak ◽  
Andrzej Cichoń ◽  
Sebastian Borucki
Keyword(s):  
Acoustic Emission ◽  
Frequency Domain ◽  
Time Domain ◽  
Operating Conditions ◽  
Time Frequency ◽  
Measurement Results ◽  
Tap Changer ◽  
The Time Domain ◽  
Load Tap Changer ◽  
Short Time

Abstract This paper provides an example of the application of the acoustic emission (AE) method for the diagnosis of technical conditions of a three-phase on-load tap-changer (OLTC) GIII type. The measurements were performed for an amount of 10 items of OLTCs, installed in power transformers with a capacity of 250 MVA. The study was conducted in two different OLTC operating conditions during the tapping process: under load and free running conditions. The analysis of the measurement results was made in both time domain and time-frequency domain. The description of the AE signals generated by the OLTC in the time domain was performed using the analysis of waveforms and determined characteristic times. Within the time-frequency domain the measured signals were described by short-time Fourier transform spectrograms.

scholarly journals Condition assessment of steel truss bridge using time frequency domain analysis

2016 ◽  
Vol 14 (2) ◽  
pp. 141-166
Author(s):  
Suresh Walia ◽  
Raj Patel ◽  
Hemant Vinayak ◽  
Raman Parti
Keyword(s):  
Frequency Domain ◽  
3D Visualization ◽  
Vibration Signal ◽  
Domain Analysis ◽  
Condition Assessment ◽  
Frequency Domain Analysis ◽  
Mode Shapes ◽  
Steel Bridge ◽  
Damage State ◽  
Time Frequency

In the present article the work is carried out on scaled modeled bridge for condition assessment due to seeded damage. The objective is to find the location of damage in the steel bridge using vibration signal. For the differentiation between damage and intact condition, time, frequency domain analysis has been used. Power spectral density has been applied to the vibration signal to extract the mode shapes and compare between healthy and damage state of the modeled. Further, Short Time Fourier Transform gives the 3D visualization of amplification in different mode of vibration which helps to identify the damage location. Using nodal energy approach, Wavelet Packet Transform has been used to determine the location of damage, which is superior than the frequency and time domain analysis parameters.

A Portable Detecting and Analytic Instrument of Vibration Signal

2012 ◽  
Vol 442 ◽  
pp. 305-308
Author(s):  
Jian Wei Li ◽  
Ling Wang ◽  
Hong Mei Zhang
Keyword(s):  
Frequency Domain ◽  
Virtual Instrument ◽  
Vibration Signal ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Time Frequency ◽  
Notebook Computer ◽  
Usb Bus ◽  
Data Acquisition Card

It is often needed in engineering that detecting and analyzing vibration signal of some equipment. To meet the requirement, a portable detecting and analytic instrument was designed using virtual instrument concept. In the instrument, notebook computer was used as the platform of hardware. Vibration signal was obtained by integrated piezoelectric acceleration sensor (DTS0104T), and was transferred to a notebook computer through data acquisition card (NI USB-6210) based on USB bus. The software, running on the notebook computer, was developed under LabVIEW. Vibration signal could be displayed on screen, recorded in disk or printed by printer, retrieved, and analyzed. The analysis functions of the instrument include: time-domain analysis, frequency-domain analysis, time-frequency domain analysis, and correlation analysis. The instrument is compact, portable, powerful, and with friendly interfaces, has broad application prospects.

Gear fault diagnosis based on time–frequency domain de-noising using the generalized S transform

2017 ◽  
Vol 24 (15) ◽  
pp. 3338-3347 ◽  
Author(s):  
Jianhua Cai ◽  
Xiaoqin Li
Keyword(s):  
Fault Diagnosis ◽  
Frequency Domain ◽  
Vibration Signal ◽  
Time Frequency ◽  
Transmission Modes ◽  
S Transform ◽  
Mining Machinery ◽  
Gear Fault ◽  
Generalized S Transform ◽  
Gear Fault Diagnosis

Gears are the most important transmission modes used in mining machinery, and gear faults can cause serious damage and even accidents. In the work process, vibration signals are influenced not only by friction, nonlinear stiffness, and nonstationary loads, but also by strong noise. It is difficult to separate the useful information from the noise, which brings some trouble to the fault diagnosis of mining machinery gears. The generalized S transform has the advantages of the short time Fourier transform and wavelet transform and is reversible. The time–frequency energy distribution of the gear vibration signal can be accurately presented by the generalized S transform, and a time–frequency filter factor can be constructed to filter the vibration signal in the time–frequency domain. These characteristics play an important role when the generalized S transform is used to remove the noise in the time–frequency domain. In this paper, a new gear fault diagnosis based on the time–frequency domain de-noising is proposed that uses the generalized S transform. The application principle, method steps, and evaluation index of the method are presented, and a wavelet soft-threshold filtering method is implemented for comparison with the proposed approach. The effectiveness of the proposed method is demonstrated by numerical simulation and experimental investigation of a gear with a tooth crack. Our analyses also indicate that the proposed method can be used for fault diagnosis of mining machinery gears.

Magnetic Bearing Rotor Vibration Analysis Based on the Harmonic Wavelet Package Algorithm

2012 ◽  
Vol 588-589 ◽  
pp. 152-155
Author(s):  
De Guang Li ◽  
Shu Qin Liu
Keyword(s):  
Frequency Domain ◽  
Vibration Analysis ◽  
Vibration Signal ◽  
Magnetic Bearing ◽  
Rotor Vibration ◽  
Time Frequency ◽  
Optimizing Design ◽  
Harmonic Wavelet ◽  
Frequency Map

Analysis of the magnetic bearing rotor vibration is the base of the optimizing design, supervise and diagnosis of the magnetic bearing. Harmonic wavelet package was used for the analysis of the vibration signal, and the 3 dimension time-frequency domain energy map was constructed, then the analysis of the rotor vibration became convenient. Via analysis of the time-frequency map, the vibration in each time and each frequency was obtained, and the supervise and the diagnosis of the rotor can be realized.

scholarly journals Fault Diagnosis of On-load Tap-changer Based on Vibration Signal

2019 ◽  
Vol 605 ◽  
pp. 012005
Author(s):  
Wenquan Huang ◽  
Changqing Peng ◽  
Liang Jin ◽  
Jiacheng Liu ◽  
Yuqi Cai
Keyword(s):  
Fault Diagnosis ◽  
Vibration Signal ◽  
Tap Changer ◽  
Load Tap Changer
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