Partial discharge ultrahigh-frequency signal initial time determination method based on difference energy function

Abstract

The invention discloses a partial discharge ultrahigh-frequency signal initial time determination method based on a difference energy function. The method comprises the steps of (1) arranging a ultrahigh-frequency sensor on to-be-tested equipment, acquiring and sampling an ultrahigh-frequency signal waveform generated by the partial discharge by high-sampling-rate digital testing equipment; (2) calculating a cumulative energy function of the ultrahigh-frequency signal waveform generated by the partial discharge; (3) optimally selecting the length WL of a data window, and calculating the difference energy function of the cumulative energy function from a first data window based on the sliding window algorithm; (4) determining a moment corresponding to the first significant peak value of the difference energy function, and adopting the moment corresponding to the first significant peak value of the difference energy function as an initial moment for ultrahigh-frequency signals. According to the technical scheme of the invention, by the difference energy function, the rapid growth position of the cumulative energy function is strengthened and the slow growth part of the cumulative energy function is weakened. Meanwhile, the white noise and the low-frequency and narrow-band noise in ultrahigh-frequency signals are corresponding to the slow growth part of the cumulative energy function. Therefore, the level of the white noise and the level of the narrow-band white noise are effectively reduced by the difference energy function.

Description

Technical field: [0001] The invention relates to the field of partial discharge detection of power equipment, in particular to a method for determining the initial moment of a partial discharge UHF signal based on a difference energy function. Background technique: [0002] Partial discharge is one of the main causes of major accidents in power equipment. Quickly and accurately locating the source of partial discharge is crucial to the maintenance of power equipment and the safe operation of the power system. Partial discharge monitoring is of great significance to the safe operation of power equipment. Because the UHF method has the advantages of high detection sensitivity, high signal-to-noise ratio, and the ability to locate partial discharge sources, it has been widely used in partial discharge detection of power equipment, and the location of partial discharge sources is one of the research hotspots. . [0003] Due to the complex structure of large equipment such as g...

AI Technical Summary

Problems solved by technology

When the noise of the UHF signal is large, the determined time difference of the signal has a large error; (2) When there is interference on the scene that distorts the waveform of the UHF signal, the time difference of the UHF signal will also be determined by using the above method large error

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