CN-121994882-A - Multi-lateral-line-based grounding grid conductor defect position positioning method

CN121994882ACN 121994882 ACN121994882 ACN 121994882ACN-121994882-A

Abstract

The invention discloses a multi-lateral line-based grounding grid conductor defect position positioning method, relates to the technical field of grounding grid defect identification, and solves the problems that multi-lateral line corrosion judgment depends on manual subjective experience and lacks objective quantification standards in the prior art. According to the invention, by constructing a mathematical quantization model of the upward-convex intensity index CIn, triple physical information, namely, quantitatively describing the convexity degree of a curve by the second derivative in the depth direction, reflecting the corrosion severity degree relative to the abnormal value of resistivity, strengthening the response contribution of the depth of a target burial depth by a depth weight function, forming a unique numerical judgment standard, and realizing objectification and automation of the whole corrosion positioning process. Meanwhile, the three-dimensional confidence level field C (x, y, z) mechanism provided by the invention establishes a mathematical framework for scientific fusion of multi-line data, so that not only is artificial subjective interference eliminated, but also a repeatable and verifiable quantization result is provided, and the recognition capability and positioning accuracy of early weak corrosion under complex working conditions are obviously improved.

Inventors

BIAN MEIHUA
LU ZHANQIANG
DENG SHANQUAN
HE YUYIN
ZHU JUNWEI
CHEN HENG
PENG JIANING
ZHANG XINGSEN
LIU GUICHAN
LI JUNHUA

Assignees

广西电网有限责任公司电力科学研究院

Dates

Publication Date: 20260508
Application Date: 20260119

Claims (9)

1. The method for positioning the defect position of the grounding grid conductor based on the multiple side lines is characterized by comprising the following steps of; arranging N measuring lines in a grounding grid detection area, wherein M measuring points are arranged on each measuring line at equal intervals; The transient electromagnetic method is adopted to collect the induced voltage attenuation curve of each measuring point ; Converting induced voltage into apparent resistivity-time curve ; Based on smoke ring theory, establishing a time-depth correspondence, and converting apparent resistivity-time data into an apparent resistivity-depth sequence ; Calculating the upward convex intensity index of each measuring line The said Quantization calculation by the following formula: in the formula, Representing the second derivative in the depth direction; Representing the reference resistivity of the intact ground network; representing a depth weight function; comparing all the lines Value, choose The measuring line corresponding to the maximum value is used as a target measuring line closest to the corrosion center; extracting plane position coordinates of defects on the target line And depth coordinates ; Space cross-validation using multiple line data to construct a three-dimensional confidence field When (when) And when the current is larger than the preset threshold value, confirming that the region has the conductor defect and outputting a final positioning result.
2. The method for locating a defect in a grounded network conductor based on multiple sidelines according to claim 1, wherein the three-dimensional confidence field is represented as follows: in the formula, For the plane coordinate of the nth measuring line, To influence the radius for the line, An exception indication function is binarized.
3. The method for positioning a defect position of a grounding grid conductor based on multiple lateral lines according to claim 1, wherein the arrangement of the measuring lines satisfies the following conditions: Wherein D is the distance between the measuring lines, D is the width of the detecting area, and h is the buried depth of the grounding grid.
4. The method for positioning a defect position of a grounding network conductor based on multiple lateral lines according to claim 1, wherein the apparent resistivity value is calculated as follows: in the formula, Indicating apparent resistivity; Indicating vacuum permeability; Representing a sampling time; representing the emitted magnetic moment; representing the equivalent area of the receiving coil; Representing the induced voltage.
5. The method for locating a defect in a ground network conductor based on multiple sidelines according to claim 1, wherein the time-depth correspondence is established based on the following formula: in the formula, Representing a detection view depth; The apparent resistivity is indicated by the expression, Indicating the magnetic permeability of the vacuum, Indicating the diffusion time.
6. The method for positioning a defect position of a grounding network conductor based on multiple lateral lines according to claim 1, wherein the depth weight function is as follows: in the formula, For the depth of the object to be achieved, Half width is affected for depth.
7. The method for locating a defect in a multi-sidetrack based ground network conductor according to claim 1, wherein the planar position coordinates of the defect are extracted on the target sidetrack And depth coordinates The process of (2) is as follows: after the target line is determined, the coordinates are determined ; Then, identifying the measuring point corresponding to the second derivative integral maximum value on the target measuring line : Measuring point The horizontal coordinate of (a) is the defect plane position Defect depth coordinates And determining the peak position by the second derivative of the depth direction of the measuring point.
8. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored program, wherein the program, when run, controls a device in which the computer-readable storage medium is located to perform the multi-sidetrack based ground network conductor defect location method according to any one of claims 1 to 7.
9. A processor for running a program, wherein the program is run to perform the multi-sidetrack based ground network conductor defect location method of any one of claims 1 to 7.

Description

Multi-lateral-line-based grounding grid conductor defect position positioning method Technical Field The invention relates to the technical field of ground network defect identification, in particular to a multi-lateral-line-based ground network conductor defect position positioning method. Background With the large-scale development of the ultra-high voltage alternating current-direct current hybrid power grid, the grounding grid is used as a key facility for guaranteeing the safe and stable operation of a power system, and conductors of the grounding grid are buried underground for a long time, so that defects such as break points, corrosion thinning and the like are very easy to occur under the effects of factors such as soil corrosion, electrochemical corrosion and fault current impact. The traditional grounding grid detection method such as a heavy current method, a potential distribution method and the like needs to perform power failure operation in an operation transformer substation, and only the whole grounding resistance of the grounding grid can be obtained, so that the specific position of the hidden defect cannot be accurately identified. Transient Electromagnetic Method (TEM) is based on Faraday's law of electromagnetic induction, transmits a pulse magnetic field to underground through a transmitting coil, utilizes the remarkable electrical difference between a grounding grid conductor and soil, induces the secondary field attenuation characteristic generated by eddy current to identify low-resistivity abnormal bodies, has the advantages of non-contact, strong interference resistance and high resolution, and is particularly suitable for the diagnosis of grounding grid corrosion in complex electromagnetic environment of transformer substation. However, a single measuring line can only acquire one-dimensional information of the cross section direction, and it is difficult to accurately position the corrosion body in the three-dimensional space, so that multi-measuring line fusion detection becomes an inevitable direction of current technical development. The existing research proves that the corrosion area shows a 'protruding' trend in the apparent resistivity profile, and the trend is more remarkable when the test line is closer to the corrosion center, but interpretation of multi-test line data still depends on the morphological difference of the profile compared with the artificial experience, and the lack of objective quantification standard leads to serious limitation of the accuracy and consistency of the detection result on the artificial subjective factors, and is difficult to meet the urgent requirements of the smart grid on standardization and automation of the detection equipment. The core of the prior art is the qualitative and subjective problems of corrosion abnormality discrimination. The method is characterized in that engineering personnel need to observe the apparent resistivity profile of a plurality of measuring lines by naked eyes, judge which measuring line has more obvious upward convex trend according to subjective experience, and further infer the corrosion position. The method has three serious defects that firstly, the upward convex trend lacks mathematical definition, the judgment of different personnel on the same profile is possibly divergent, especially in the early stage of corrosion or under the uneven background of soil resistivity, weak abnormality is easy to misjudge or miss-detect, secondly, the comparison of multiple measuring lines lacks a quantitative weight mechanism, the relative contribution degree of abnormal response of each measuring line cannot be scientifically estimated, when the measuring lines all present a certain degree of abnormality, the measuring line closest to the corrosion center is difficult to accurately identify, thirdly, the manual interpretation efficiency is low, the rapid automatic processing of mass data cannot be realized, and the practical popularization of the method in the periodic inspection of a large-scale grounding grid is restricted. This deficiency directly leads to an increased uncertainty in the positioning results, possibly masking early corrosion hazards, leaving a serious operational risk for the substation. In view of this, there is a need for a method for positioning a defect position of a ground network conductor based on multiple side lines. Disclosure of Invention Aiming at the problems that multi-measuring line corrosion discrimination depends on manual subjective experience and lacks objective quantification standard in the prior art, the invention provides a multi-lateral line-based grounding grid conductor defect position positioning method, which can fundamentally solve the problem that the prior art depends on subjective experience discrimination by constructing a mathematical quantification model of an upward convex strength index CI n. The specific technical scheme is as follows: The method for positi