Short-distance measurement method and structure of grounding resistance of grounding network

Abstract

The invention discloses short-distance measurement method and structure of the grounding resistance of a grounding network. A current pole used for measuring the grounding resistance of the grounding network is arranged near the grounding network to be measured, even inside the grounding network; the current pole is used as a small grounding network to be measured, and the grounding resistance R pole of the current pole is measured by the traditional long-distance measuring method; finally, a test voltage is applied between the grounding networking to be measured and the current electrode, a test current between the grounding network to be measured and the current pole is measured by an ampere meter, and the total grounding resistance R (total) of the grounding network to be measured and the current pole is calculated by using the Ohm's law; and the grounding resistance R pole of the current pole is subtracted from the R (total) to obtain the grounding resistance R (network) of the grounding network to be measured. The invention not only can avoid the problems of long wire pay-off distance, large work load, easy interference production and the like, but also can avoid the technical difficulty that the measurement precision of the traditional short-distance measurement method can not satisfy actual requirements.

Description

technical field [0001] The invention relates to a method for measuring ground resistance and a measurement structure thereof, and belongs to the technical field of indirect short-distance measurement of ground resistance. Background technique [0002] In the existing methods of measuring the grounding resistance of the grounding grid, it can be divided into the long-distance method and the short-distance method according to the distance of the current electrode. The basic measurement theory is briefly described as follows: [0003] as follows figure 2 As shown, when the test power supply is connected between the ground grid under test and the current pole, a closed loop is formed between the ground grid, the current pole, the earth and the wire, so a current i will flow in the earth, and the current will be The voltage distribution is generated on the ground surface. From the ground potential distribution curve in the figure, it can be seen that due to the existence of the ...

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Problems solved by technology

This approach itself is imprecise, because the so-called "equivalent" is actually for entities other than the equivalent, as follows image 3 As shown, after the soil structure in area A is equivalent to a double-layer structure, for point P outside area A, its surface potential will not change, but for point Q inside area A, it is different, and its surface potential is at It must be different before and after the equivalent, and all current short-distance measurement methods have equivalently treated the soil between the ground grid and the current electrode, so the calculated zero potential point must be located inside the equivalent soil model. This will inevitably lead to calculation errors

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