CN-122016616-A - Method for testing axial distribution unbalance degree of biochemical erosion of cable outer sheath

CN122016616ACN 122016616 ACN122016616 ACN 122016616ACN-122016616-A

Abstract

The invention discloses a cable outer sheath biochemical erosion axial distribution unbalance test method which comprises the following steps of (1) inputting a test excitation signal to a cable to be tested, (2) collecting test signal reflected waves, (3) calculating a time domain reflected energy spatial distribution ratio, (4) calculating time domain reflected energy spatial distribution unbalance, and (5) evaluating the cable outer sheath biochemical erosion axial distribution unbalance. The method has the advantages that the method is simple and efficient, and can well evaluate the axial distribution unbalance of the biochemical erosion of the cable outer sheath by injecting excitation test signals into the cable sheath and the cable core loop to be tested at the head end and synchronously collecting reflected wave signals and calculating the spatial distribution unbalance of the time domain reflection energy of the reflected wave signals.

Inventors

CHEN BANGFA
LI HENGZHEN
HE ZILAN
CHEN BAIQUAN
CHEN SIXIANG
HUANG JING
LIANG JIASHENG
WANG JUNBO

Assignees

广东电网有限责任公司佛山供电局

Dates

Publication Date: 20260512
Application Date: 20251215

Claims (1)

1. A cable outer sheath biochemical erosion axial distribution imbalance testing method comprises the following steps: the first step is to inject excitation test signals into the cable to be tested and collect reflected waves Injecting a linear frequency modulation pulse excitation signal into a cable sheath to be tested and a cable core loop at the head end, and synchronously collecting reflected wave signals ; Second step, calculating the space distribution ratio of each time domain reflection energy of the reflected wave signal Based on the time length of the signal The method comprises the steps of equally dividing the system into 100 areas, guaranteeing the dominance and sensitivity of biochemical erosion fault reflection pulses in a noise environment, and calculating the normalized time domain reflection energy space distribution ratio of each area: Wherein, the , , Is the maximum value in the original signal, Is the minimum value in the original signal, As an average value of the original signal, For the length of the cable to be tested, For the wave speed of the signal in the cable, For each of the areas the energy value is reflected, The spatial distribution ratio of time domain reflection energy for each region; third step, calculating the spatial distribution unbalance of the time domain reflection energy Wherein, the In order to divide the number of areas into which the area is divided, The time domain reflection energy space distribution ratio average value is obtained; fourth, according to the time domain reflection energy space distribution unbalance degree Judging the condition of unbalanced axial distribution of biochemical erosion of cable outer sheath Spatial distribution of energy according to time domain reflection To judge the unbalance degree of the biochemical erosion of the cable outer sheath in the axial distribution of the cable to be tested, And is also provided with Smaller means less balanced.

Description

Method for testing axial distribution unbalance degree of biochemical erosion of cable outer sheath Technical Field The invention belongs to the field of testing and evaluating biochemical erosion of a cable outer sheath, and particularly relates to a testing method for axial distribution imbalance of biochemical erosion of the cable outer sheath. Background Since 21 st century, the economic rapid development of China promotes the continuous expansion of the power grid scale, and the power cable gradually replaces an overhead line due to the advantages of reliable power supply, small influence on urban environment and the like, and becomes core equipment of an urban power transmission and distribution network. However, the cable is at risk of insulation damage caused by various factors during operation. In the coastal areas of south, the cable is easy to suffer biochemical erosion, so that the cable outer sheath is broken by faults. Biochemical attack refers to the act of damaging the cable matrix by biological or chemical factors. Under the condition of buried laying, the outer sheath of the cable is in direct contact with soil, and is easy to be eroded by organisms. Termites are main hazard sources, and bite through a cable sheath in the foraging or nesting process, so that formic acid, microorganisms and moisture further corrode a metal sheath and a water blocking tape in the cable, original performances of the cable are damaged, an insulating layer is aged, and insulation breakdown and power failure are caused seriously. In addition, the damage to the sheath can be caused by the biting of mice, so that the aging and insulation faults of the cable are accelerated, and the operation safety of the cable is threatened. At present, no testing method related to the axial distribution imbalance of the biochemical erosion of the cable outer sheath exists. Therefore, it is needed to find a test method for evaluating the axial distribution imbalance of the biochemical erosion of the cable outer sheath, and provide scientific basis for the operation and maintenance management and control measures for the biochemical erosion state of the cable outer sheath. Has important significance for guaranteeing safe and reliable operation and prolonging the service life of the power cable. Disclosure of Invention The method is simple and convenient to operate, and can effectively evaluate the axial unbalance degree of the cable outer sheath damage and corrosion by calculating the time domain reflection energy spatial distribution unbalance degree of the cable to be tested. The technical scheme of the invention is as follows: 1. A cable outer sheath biochemical erosion axial distribution imbalance testing method comprises the following steps: the first step is to inject excitation test signals into the cable to be tested and collect reflected waves Injecting a linear frequency modulation pulse excitation signal into a cable sheath to be tested and a cable core loop at the head end, and synchronously collecting reflected wave signals; Second step, calculating the space distribution ratio of each time domain reflection energy of the reflected wave signal Based on the time length of the signalThe method comprises the steps of equally dividing the system into 100 areas, guaranteeing the dominance and sensitivity of biochemical erosion fault reflection pulses in a noise environment, and calculating the normalized time domain reflection energy space distribution ratio of each area: Wherein, the ,,Is the maximum value in the original signal,Is the minimum value in the original signal,As an average value of the original signal,For the length of the cable to be tested,For the wave speed of the signal in the cable,For each of the areas the energy value is reflected,The spatial distribution ratio of time domain reflection energy for each region; third step, calculating the spatial distribution unbalance of the time domain reflection energy Wherein, the In order to divide the number of areas into which the area is divided,The time domain reflection energy space distribution ratio average value is obtained; fourth, according to the time domain reflection energy space distribution unbalance degree Judging the condition of unbalanced axial distribution of biochemical erosion of cable outer sheath Spatial distribution of energy according to time domain reflectionTo judge the unbalance degree of the biochemical erosion of the cable outer sheath in the axial distribution of the cable to be tested,And is also provided withSmaller means less balanced. The method has the advantages that the method is simple and efficient, and can well evaluate the axial distribution unbalance of the biochemical erosion of the cable outer sheath by injecting excitation test signals into the cable sheath and the cable core loop to be tested at the head end and synchronously collecting reflected wave signals and calculating the spatial distribution unbalance of the