Method for extracting amplitude-frequency characteristic quantity of transformer vibration signal based on cross wavelet

Abstract

The invention discloses a method for extracting amplitude-frequency characteristic quantity of a transformer vibration signal based on a cross wavelet. The method comprises the following steps of: 1, acquiring vibration signals at two different positions of each phase of a transformer on the surface of a transformer oil tank, and marking the signals as x(t) and y(t) respectively; 2, subjecting the vibration signals to cross wavelet transform to obtain power spectrum density; 3, determining a transformer vibration signal characteristic frequency; and 4, determining a transformer vibration signal characteristic amplitude value. The method solves a technical problem that most methods in the prior art carry out analysis based on a vibration signal on one test position on the surface of the transformer oil tank and do not take account of the characteristic difference of vibration signals at different measuring points of the transformer so as to cause a case that the characteristic quantity is not universal when the test position is changed.

Description

technical field [0001] The invention belongs to the detection technology of transformer signals, in particular to a method for extracting amplitude-frequency feature quantities of transformer vibration signals based on cross wavelets. Background technique [0002] The transformer vibration signal contains the state information of the transformer, and the transformer state diagnosis technology based on the vibration signal has a good application prospect in the field of transformer state detection. The vibration signal generated by the core and winding of the transformer body is transmitted to the surface of the oil tank through insulating oil and structural parts. The vibration signal measured on the surface of the oil tank contains the interference caused by the propagation path in addition to the vibration signal of the transformer body. The vibration signals collected by two different test positions of the same phase, due to the different transmission paths, the signals c...

AI Technical Summary

Problems solved by technology

Existing research technologies are mostly based on the analysis of the vibration signal of a test position on the surface of the transformer oil tank, without considering the difference in the characteristics of the vibration signal at different test points of the transformer, resulting in the fact that when the test position is changed, the characteristic quantity is not universal.

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