Power transformer vibrating separation method and system based on time-frequency ratio distribution

Abstract

The invention discloses a power transformer vibrating separation method and system based on time-frequency ratio distribution. The method comprises: screening a first group of mixed signals and a second group of mixed signals from vibrating mixed signals by using a preset mixed signal screening condition; calculating the time-frequency ratio of the two groups of mixed signals; respectively calculating an optimal amplitude estimated value and an optimal phase estimated value of the time-frequency ratio; constructing a mixed matrix estimated value by using the optimal amplitude estimated value and the optimal phase estimated value, and inversing the mixed matrix estimated value to obtain a corresponding inverse matrix; performing Fourier transform on the vibrating mixed signals, multiplying the corresponding result by the inverse matrix to obtain a Fourier transform result of winding vibrating source signals and core vibrating source signals, and performing inverse Fourier transform on the result to correspondingly obtain time-frequency signals of winding vibration and core vibration. The method and the system fulfill the aim of separating winding vibrating signals and core vibrating signals from surface vibrating signals of an oil tank.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to a vibration separation method and system for power transformers based on time-frequency ratio distribution. Background technique [0002] Large power transformer is one of the most important and valuable key equipment in the power grid system, and its safe operation is crucial to ensure the safety and reliability of the power grid. In order to avoid major accidents of transformers caused by mechanical structure defects, it is necessary to analyze and deal with the vibration of power transformers during their work. [0003] Windings and cores are the main components of transformers, and they are also the main fault components of transformers. Windings and cores are also the main source components of transformer vibration. When the transformer is in operation, the magnetostriction of the silicon steel sheet produces the vibration of the iron core, and the electromagnetic...

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Problems solved by technology

[0004] At present, the vibration analysis methods for power transformers usually only stop at the detection of the vibration signal on the surface of the oil tank, and the vibration signal on the surface of the oil tank only reflects the overall vibration status of the transformer, but fails to reflect the vibration status of the winding and the vibration status of the iron core.

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