A Method for Analyzing Connection Direction of Grounding Grid Down-conductor Based on Magnetic Field Method

Abstract

The invention discloses a method for analyzing the connection direction of the down lead of the grounding grid based on the magnetic field method. The method comprises steps of selecting two down leads to inject and discharge current respectively on the ground surface of a grounding grid branch; taking a to-be-tested down lead as a base point to establish a to-be-tested area A; first determining aconnection mode; then determining the horizontal arrangement direction of the to-be-tested down lead and the connection point of the to-be-tested down lead and the grounding grid branch according tothe measured synthetic magnetic induction intensity and the horizontal magnetic induction intensity of the earth surface; and finally determining the connection direction of the to-be-tested down lead. The method can accurately determine the connection direction of the down lead of the grounding grid, the whole analysis process is simple to operate, and the connection directions of the down lead of different connection modes can be accurately determined, so as to provide the accurate reference basis for topology detection and corrosion diagnosis technology of the grounding grid. The detectionprocess is simple, the amount of data calculation is small, and the analysis efficiency of the connection direction of the down lead is improved.

Description

technical field [0001] The invention relates to the technical field of analyzing the connection direction of grounding grid branches, in particular to a method for analyzing the connection direction of grounding grid downconductors based on a magnetic field method. Background technique [0002] As an important part of the power grounding system, the grounding grid mainly exists in power plants and substations, and is used for rapid discharge of large currents such as lightning currents to reduce ground potential rise and prevent dangerous voltages. Therefore, the performance of the grounding grid determines the safety and reliability of the power system operation to a large extent. [0003] The grounding grid will be corroded under long-term operation, which will affect the safe operation of the power system. Therefore, it is necessary to detect and repair the defects of the grounding grid in time. One of the main technical means of diagnosing grounding grid corrosion at th...

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Problems solved by technology

[0003] The grounding grid will be corroded under long-term operation, which will affect the safe operation of the power system. Therefore, it is necessary to detect and repair the defects of the grounding grid in time

One of the main technical means for the corrosion diagnosis of the grounding grid at this stage is to use the principle of the electrical network, regard the grounding grid as a pure resistance network, and use the down-conductor as a wire to inject current and collect voltage into the grounding grid, so the down-conductor is in the The determination of the connection direction of the horizontal ground grid greatly affects the accuracy of the measurement results

[0004] It is easy to identify the connection direction of the grounding down-conductor above the ground surface by observation, but it is difficult to identify the direction of the grounding down-conductor below the ground surface and determine the location of its connection to the grounding network branch

Due to historical reasons and limitations of some technical conditions, the grounding grid design drawings of many old substations in operation are missing or damaged, resulting in the unknown connection direction of the grounding down conductor; there are also some substation grounding grid design drawings and grounding grid The actual direction of the down-conductor cannot correspond, which brings a lot of inconvenience to the electric power department in the state detection of the substation grounding grid, and will bring large errors to the corrosion diagnosis results.

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