Transformer partial discharge denoising method based on synchronous compression wavelet transform domain

Abstract

The invention discloses a transformer partial discharge denoising method based on a synchronous compression wavelet transform domain. The method comprises the following steps that: carrying out wavelet transform on an analog local signal to obtain a wavelet coefficient matrix; carrying out high-order statistics analysis on the wavelet transform coefficient matrix, utilizing a kurtosis threshold value criterion to carry out noise preliminary restraining on the wavelet transform coefficient matrix to obtain a corrected wavelet transform coefficient matrix; utilizing the corrected wavelet transform coefficient matrix to obtain a synchronous compression wavelet transform coefficient matrix, and adopting a generalized cross validation algorithm to obtain the noise threshold value level of the synchronous compression wavelet transform coefficient matrix; utilizing the noise threshold value level, and adopting a shear threshold value algorithm to carry out residual noise restraining on the synchronous compression wavelet transform coefficient matrix to obtain the synchronous compression wavelet transform coefficient matrix with small noise interference; and carrying out synchronous compression wavelet inverse transform on the synchronous compression wavelet transform coefficient matrix with small noise interference to obtain a pure partial discharge one-dimensional time domain signal. The method has the advantages of high denoising accuracy and short operation time, and is suitable for occasions of transformer partial discharge denoising.

Description

technical field [0001] The invention relates to the field of transformer partial discharge detection, in particular to a transformer partial discharge denoising method based on synchronously compressed wavelet transform domain. Background technique [0002] Partial Discharge (PD) is a highly localized microscopic discharge phenomenon. Due to the progressive deterioration of the insulation, PD can lead to complete destruction of the insulation leading to catastrophic failure of the transformer. Partial discharge one-dimensional time-domain signal is an important carrier for studying transformer partial discharge phenomenon, which is mainly interfered by narrow-band noise and white noise signal. This interference will affect the normal progress of follow-up work such as partial discharge detection and pattern recognition, so it is particularly important to suppress the interference signal. [0003] Traditional time-frequency analysis algorithms have low resolution and poor r...

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Problems solved by technology

However, the hard threshold scheme will cause the wavelet shrinkage coefficients to be discontinuous, while the soft threshold denoising scheme will cause the irrelevant wavelet coefficients to shrink together, resulting in a low signal-to-noise ratio of the denoised signal

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