Method for extracting characteristics of mechanical state signal of on-load tap changer

Abstract

The invention discloses a method for extracting characteristics of a mechanical state signal of an on-load tap changer, and relates to the field of measuring electrical variables. The method for extracting the characteristics of the mechanical state signal of the on-load tap changer comprises the steps that a vibration signal during on-load tap switching process is measured through an accelerationsensor; noise component in an original signal is removed by wavelet denoising; then an envelope line of time domain waveform of the vibration signal after noise reduction is calculated by a Hilbert amplitude demodulation method; an amplitude mutation method is used for dividing the envelope line of the vibration signal into a stationary section and a non-stationary section; then an empirical modedecomposition method is used for decomposing the non-stationary segment signal to extract the feature quantity, and the fast Fourier transform is used for decomposing the stationary section to extract the vibration characteristic quantity so as to establish a vibration feature database of the on-load tap changer. The method for the extracting characteristics of the mechanical state signal of theon-load tap changer can improve the accuracy of the vibration signal feature extraction of the on-load tap changer without increasing the calculation cost, and provides an effective method for realizing on-line monitoring and diagnosis of the mechanical state of the on-load tap changer.

Description

technical field [0001] The invention relates to the field of measuring electric variables, in particular to a method for extracting mechanical state signal features of an on-load tap changer. Background technique [0002] During the operation of the on-load tap-changer (abbreviated as OLTC), the collision or friction between the parts of the mechanism will generate vibration signals, which contain rich equipment status information. At present, the analysis based on vibration signal has become an important means of mechanical fault diagnosis of on-load tap-changer. The existing vibration signal analysis methods include fast Fourier transform, EMD (empirical mode decomposition) and wavelet packet. Most of these methods decompose the non-stationary signal into the sum of several simple stationary signals, and then process each component to extract time-frequency features. However, studies have shown that the switching process of on-load tap-changers includes main stages such ...

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Problems solved by technology

However, studies have shown that the switching process of on-load tap-changers includes main stages such as selection, shifting and contact collision, and its vibration signa

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