Transformer Partial Discharge Denoising Method Based on Synchronous Compression Wavelet Transform Domain

Abstract

The partial discharge denoising method based on the synchronous compression wavelet transform domain, including performing wavelet transform on the simulated local signal to obtain the wavelet coefficient matrix; performing high-order statistical analysis on the wavelet transform coefficient matrix, and using the kurtosis threshold criterion to perform noise on the wavelet transform coefficient matrix The preliminary suppression of the modified wavelet transform coefficient matrix is ​​obtained; using the modified wavelet transform coefficient matrix to obtain the synchronously compressed wavelet transform coefficient matrix, using the generalized cross-validation algorithm to obtain the noise threshold level of the synchronously compressed wavelet transform coefficient matrix; using the noise threshold level The shearing threshold algorithm is used to suppress the residual noise of the synchronously compressed wavelet transform coefficient matrix, and the synchronously compressed wavelet transform coefficient matrix with less noise interference is obtained; the synchronously compressed wavelet transform coefficient matrix with less noise interference is subjected to synchronously compressed wavelet inverse transform, A relatively pure one-dimensional time-domain signal of partial discharge is obtained. The method of the invention has the advantages of high denoising precision and short operation time, and is suitable for occasions such as denoising partial discharges of transformers.

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...

AI Technical Summary

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

Images