A Frequency Selection Method for Spatial Positioning and Receiving Frequency of Partial Discharge Signals

Abstract

The invention provides a frequency selection method for a partial discharge signal spatial orientation receiving frequency. The frequency selection method comprises the following steps that a time-domain signal is acquired in a full-band mode; Fourier analysis is carried out on sub-frequency-bands of the time-domain signal to obtain a frequency-domain signal; a 100-1200 MHz frequency band is divided into a 100-200 MHz frequency band, a 200-400 MHz frequency band, a 400-800 MHz frequency band and a 800-1200 MHz frequency band, the amplitudes of interference signals in the frequency bands are judged, the frequency band with the interference signals with the minimum amplitude is obtained, and if the amplitudes of the interference signals in two frequency bands are the same, the higher frequency band is selected as the frequency band with the interference signals with the minimum amplitude; the frequency point with the highest signal-to-noise ratio is selected from the frequency band with the interference signals with the minimum amplitude to serve as the receiving frequency of a partial discharge signal. According to the frequency selection method for the partial discharge signal spatial orientation receiving frequency, the method that firstly the appropriate frequency bands are screened, and then the frequency bands suitable for receiving the partial discharge signals of frequency points are screened out is adopted, some frequency bands not suitable for receiving the partial discharge signals can be eliminated, and therefore the clearest partial discharge signals can be obtained, and then positioning accuracy of the partial discharge signals can be high.

Description

technical field [0001] The invention relates to a frequency selection method, in particular to a frequency selection method for space positioning receiving frequency of a partial discharge signal. Background technique [0002] All kinds of power transmission and transformation primary equipment in conventional substations, including GIS outlet bushings, transformer high-voltage bushings, SF6 circuit breakers, transformers, capacitors, lightning arresters, insulators, etc., will generate partial discharge before insulation failure occurs. According to incomplete statistics, in the recorded accidents, the accidents caused by the failure of the primary equipment of power transmission and transformation account for a large proportion, and partial discharge is one of the main reasons for its failure, and it is also an important symptom of insulation deterioration. And the form of expression, so the in-depth study of partial discharge has gradually become an important topic for th...

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Problems solved by technology

[0005] The determination of some signals requires the frequency domain method, but the frequency domain method is an active receiving method, which uses a predetermined frequency for reception, but because the frequency range of partial discharge signals is wide, it is obviously not appropriate to use the frequency domain method for reception. less than clear partial discharge signal

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