Urban medium-voltage distribution cable partial discharge signal denoising method

Abstract

The invention discloses an urban medium-voltage distribution cable partial discharge signal denoising method. In order to suppress periodic narrowband interference, a K-means clustering algorithm is used to classify noisy partial discharge signal spectrums. In order to suppress white noise interference, an improved empirical Wavelet Transform (EWT) algorithm based on an Order Statistic Filter (OSF) is provided, and the method comprises the following steps: firstly, estimating an envelope line on a signal frequency spectrum by using the OSF, reasonably segmenting the signal frequency spectrum, then, carrying out adaptive decomposition on a signal by using the EWT, introducing a kurtosis criterion to select a useful modal component, and finally, carrying out adaptive decomposition on the signal by using the EWT. And finally, reconstructing a partial discharge signal through threshold denoising. In combination with the K-means clustering algorithm and the empirical wavelet transform, the method provided by the invention does not need to modify algorithm parameters, can perform adaptive denoising on white noise and periodic narrow-band interference at the same time, can effectively reserve signal details while having a high denoising signal-to-noise ratio, and is relatively high in algorithm efficiency.

Description

technical field [0001] The invention relates to the field of electric equipment fault diagnosis and identification technology and partial discharge technology, in particular to a method for denoising the partial discharge signal of urban medium-voltage power distribution cables. Background technique [0002] With the continuous development of urban medium-voltage distribution networks, medium-voltage distribution cables are widely used. When a line fault occurs in an urban power distribution cable, because the cable line is mostly laid underground and has a complex structure, it is impossible to visually see the fault location and find the cause of the fault, which will be more difficult to troubleshoot than the overhead line. [0003] Insulation defects have a greater impact on the safe operation of distribution network equipment. Statistics show that partial discharge is the main cause of insulation defects, and it is also an important symptom and manifestation of insulat...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the existing technical difficulties and provide a method for denoising the partial discharge signal of urban medium-voltage distribution cables, which can simultaneously perform self-adaptive denoising on white noise and periodic narrow-band interference

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