CN110749777A - Soil resistivity measuring method - Google Patents
Soil resistivity measuring method Download PDFInfo
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- CN110749777A CN110749777A CN201911213225.4A CN201911213225A CN110749777A CN 110749777 A CN110749777 A CN 110749777A CN 201911213225 A CN201911213225 A CN 201911213225A CN 110749777 A CN110749777 A CN 110749777A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/20—Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
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Abstract
The invention discloses a method for measuring soil resistivity, and the measuring method provided by the invention is used for reasonably arranging a grounding grid for ground grid designers and constructors. Firstly, a small earth screen is used for a grounding impedance test, and the test method can realize the measurement of the soil resistivity of a large plot, thereby obtaining the relatively real soil resistivity. The obtained impedance value is tested, the accurate soil resistivity is calculated by utilizing a ground resistance formula of a composite ground electrode with a horizontal ground electrode and a closed main edge, so that the size of the ground resistance is calculated by utilizing the composite formula again according to the size of the area of an actual engineering design drawing, the standard requirement of the ground resistance is accepted by referring to engineering, the size of the grounding grid is properly adjusted, resistance reduction measures are taken in advance to meet the acceptance criterion of the ground resistance, and the efficiency of designing the grounding grid is improved. The test method is suitable for testing in various environments, particularly for testing large-scale ground grid plots, and is simple in field operation.
Description
Technical Field
The invention relates to the technical field of lightning protection grounding, in particular to a soil resistivity measuring method applied to a transformer substation place.
Background
The soil resistivity is an important parameter in the calculation of grounding engineering, and directly influences the size of the grounding resistance of a grounding device, the ground potential distribution of a ground grid, the contact voltage and the step voltage. In order to reasonably design the grounding device, the grounding resistance value can be accurately calculated only by actually measuring the soil resistivity and carrying out actual measurement. However, the complex soil condition brings difficulty and limitation to the measurement of the soil resistivity, especially in a high mountain field soil environment with a complex environment, the accurate soil resistivity of each land can not be measured, so that the design and construction scheme of the grounding engineering can not be made reasonably, the great deviation between the measured value and the designed value exists after the engineering construction, the engineering can not achieve the ideal design effect, and a great amount of resources are invested in the later-stage transformation.
Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a method for measuring soil resistivity with less investment, simple operation and high accuracy, which reduces the manpower and material resources required for measuring soil resistivity in a grounding project, improves the efficiency and accuracy of ground resistance calculation in the grounding project, and helps to obtain a good grounding effect in the grounding project. The method is particularly suitable for measuring the resistivity of the soil in the ground screen construction design of a large-scale grounding system.
In order to solve the technical problems, the invention provides a soil resistivity measuring method, which adopts the technical scheme that the method comprises the following steps:
s1, burying the simulated land net 1 in a trench with a depth of 10-20 cm from the ground within the range of the soil to be detected, backfilling the soil, and thoroughly watering the soil in a dry environment.
The simulated ground screen 1 can be made of metal materials with good conductivity into rectangles with equal length and width and any equal grids.
And S2, vertically driving a current electrode 2 and a voltage electrode 3 into the ground to a depth of about 0.7-1.0 m.
Further defining the position C of the driving current electrode 2 and the position P of the driving voltage electrode 3:
firstly, according to the specification and size of a grounding grid designed according to a design drawing, taking 4-5 times of the longest diagonal length D of the grounding grid, and calculating the length D to be DCG(ii) a Starting from any point of the boundary line of the simulated ground net 1 by a distance dCGThe current pole 2 is driven into the position C; according to dCGThe length d is calculated to be 0.5-0.6 times ofPGStarting at G at a distance dPGThe voltage pole 3 is driven into the position P, the included angle α between the C and the P is 30 degrees, the GPS 5 is utilized to carry out accurate positioning in the implementation process, the installation position C of the current pole 2 and the installation position P of the voltage pole 3 meet the requirements, the distance tolerance is +/-3 m, and the included angle tolerance is +/-5 degrees.
The current pole 2 is a plurality of copper bars that equidistance was arranged and was linked together, the voltage pole 3 is a plurality of copper bars that equidistance was arranged and was linked together.
And S3, connecting the measuring device by using a lead: the analog ground grid 1 is connected to the C1 and P1 ports of the ground impedance tester 4 by wires, the current pole 2 is connected to the C2 port of the ground impedance tester 4 by wires, and the voltage pole 3 is connected to the P2 port of the ground impedance tester 4 by wires.
S4: measuring and calculating the grounding resistance of the simulated ground net 1: the grounding resistance of the simulated grounding grid 1 is measured by adopting a pilot frequency (45 Hz, 55 Hz) current method, the applied current in a measuring circuit is 3A-5A, the measuring times can be more than or equal to 2, the deviation of the result of each test is not more than 5%, and the average value of the measured data is taken as the grounding resistance of the simulated grounding grid 1.
S5: calculating the resistivity of the soil:
the simple calculation formula of the power frequency grounding resistance of the composite artificial grounding grid is utilized:
calculating the resistivity of the soil;
in the formula: r represents the ground impedance of the analog counterpoise 1,
denotes the soil resistivity and S denotes the area of the simulated counterpoise 1.
According to the calculated soil resistivity
Then according to the design area S of the grounding grid0Calculating the grounding resistance R of the grounding grid0。
The invention has the beneficial effects that the rapid and accurate soil resistivity measurement value is constructed by taking the test method for optimizing the grounding resistance as a main purpose in construction. Therefore, the construction progress and efficiency of the grounding resistance of the substation are improved, and the ground screen design and construction scheme of the substation are further optimized according to the soil resistivity testing method, so that construction meets the standard requirements. The method can meet the requirements of design and specification by laying the ground screen once under different geographical geology, namely the success rate of laying the ground screen once is 100%, and the finally obtained test value of the grounding resistance value is smaller than the specification requirement and the theoretical design value.
Drawings
FIG. 1: a diagram of the arrangement and wiring of the devices provided for an embodiment of the present invention;
FIG. 2: the embodiment of the invention is a schematic positioning diagram of a measuring device.
Detailed Description
An embodiment of the present invention will be described in detail with reference to fig. 1 and 2.
Fig. 1 is a diagram of arrangement and wiring of a device provided in an embodiment of the present invention, and fig. 2: the embodiment of the invention is a schematic positioning diagram of a measuring device.
The selected places in the embodiment are as follows: the Huaishao railway traction substation selects the Huaishan south traction substation with better grounding test wiring conditions as a research object.
As shown in fig. 1, the apparatus required for implementing the present invention is prepared, and comprises an analog earth mat 1, a current pole 2, a voltage pole 3, a ground impedance tester 4 and a GPS 5.
The simulated ground net 1 is a copper woven net with the size of 20 x 20 meters; the current pole 2 is 3 round steel that the head was connected with the wire equidistance, the voltage pole 3 is 3 round steel that the head was connected with the wire equidistance.
S1: digging a trench with the size of 10cm, which is equal to the size of the simulation ground screen 1, in an open and flat place of the substation, burying the simulation ground screen 1 in the trench, and backfilling soil.
S2: as shown in fig. 2, in the implementation process, the mounting position C of the current pole 2 and the mounting position P of the voltage pole 3 are located by using the GPS 5, and the locating methods and requirements of the C point and the P point are as follows:
the Huai south traction substation occupies a floor area of 77m by 65m, namely a diagonal line is about 100m, a current-voltage method arranged on the opposite north side of a railway of the substation is selected to measure the grounding resistance of the grounding grid according to the field topography condition, any point of a boundary line of a simulated grounding grid 1 is used as a starting point G, round steel with 3 head connecting wires is vertically and equidistantly driven into a position C with a distance of 500 m, and the depth is about 1.0m and is used as a current electrode 2. 3 round steel with heads connected with conducting wires are vertically and equidistantly arranged at a P position which is 300 meters away from the G as a starting point, the depth is about 1.0m, the round steel is used as a voltage electrode 3, and a current electrode-ground net edge connecting line and a voltage electrode-ground net edge connecting line are arranged in the same direction. And the C point and the P point are positioned by using the GPS 5, and the included angle degree is 30 +/-5.
S3: and (3) wire connection:
6mm is used between the current pole 2 and the C2 port of the grounding impedance tester 42Connecting a copper wire;
the voltage electrode 3 is used as a test grounding electrode and is used for testing grounding impedance2.5mm between the P2 ports of instrument 42Connecting a copper wire; the analog ground grid 1 is used as a tested grid and is connected to the ports C1 and P1 of the grounding impedance tester 4.
S4: the grounding resistance of the analog grounding grid 1 is measured by adopting a pilot frequency (45 Hz, 55 Hz) current method, the applied current is 3.5A, the instrument adopts frequencies of 45Hz and 55Hz for measurement, the equivalent impedance under 50Hz is calculated, and the results of the two measurements are respectively: 12.50 Ω and 12.71 Ω, and the average of the two measurements was taken as the test result: 12.6 omega.
S5: and (3) calculating the soil resistivity of the position of the transformer substation:
according to a calculation formula of the grounding resistance:
in the formula, rho is the soil resistivity, R is the ground resistance of the simulation ground net 1, S is the area of the simulation ground net 1, and the soil resistivity of the position of the transformer substation can be calculated as follows:
given that the soil resistivity of the substation is rho =504 Ω. m, the area S of the grounding grid designed by the substation0=65m × 77m, in terms of ground resistance:
in the formula:
rho is the resistivity of the soil
S0Designing ground grid area for transformer substation
R0For calculated grounding resistance of transformer substation grounding grid
To obtain
After the project is finished, the actual measurement value of the grounding resistance of the transformer substation is 3.3 omega through measurement of a design institute, and the soil resistivity is calculated to be 467 omega. The error is within 10%.
Claims (3)
1. A soil resistivity measuring method is characterized by comprising the following steps: the method comprises the following steps:
s1: in the range of soil to be detected, the simulated land net (1) is buried in the soil with the depth of 10 cm-20 cm from the ground, and the soil is backfilled;
s2: vertically driving a current electrode (2) and a voltage electrode (3) into the ground surface to a depth of about 0.7-1.0 m;
s3: the analog grounding grid (1) is connected to C1 and P1 ports of the grounding impedance tester (4) through leads, the current pole (2) is connected to C2 port of the grounding impedance tester (4) through leads, and the voltage pole (3) is connected to P2 port of the grounding impedance tester (4) through leads;
s4: measuring the grounding resistance of the simulated grounding grid (1) by adopting a pilot frequency (45 Hz, 55 Hz) current method, wherein the applied current in a measuring circuit is 3A-5A, the measuring frequency can be more than or equal to 2, the deviation of the result of each test is not more than 5%, and the average value of the measured data is taken as the grounding resistance of the simulated grounding grid (1);
s5: the simple calculation formula of the power frequency grounding resistance of the composite artificial grounding grid is utilized:
calculating the resistivity of the soil;
in the formula: r represents the grounding impedance of the simulated grounding grid (1), rho represents the soil resistivity of the soil to be measured, S represents the area of the simulated grounding grid (1), and the grounding resistance of the actual grounding grid can be calculated according to the calculated soil resistivity rho and the actually designed area of the grounding grid.
2. A soil resistivity measurement method according to claim 1, characterized in that: the simulation ground screen (1) can be made of metal materials with good conductivity, is equal in length and width and comprises rectangles with any equal grids.
3. A soil resistivity measurement method according to claim 1, characterized in that: the S2 further includes the steps of:
firstly, according to the size specification of a grounding grid designed according to a drawing, taking 4-5 times of the longest diagonal length D of the grounding grid, and calculating the length DCG(ii) a Starting from any point of the boundary line of the simulated ground net (1) by a distance dCGA current electrode (2) is arranged at the position C; according to dCGThe length d is calculated to be 0.5-0.6 times ofPGStarting at G at a distance dPGThe mounting position C of the current pole and the mounting position P of the voltage pole form an angle α of 30 ° ± 5 °.
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| CN201911213225.4A CN110749777A (en) | 2019-12-02 | 2019-12-02 | Soil resistivity measuring method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111641096A (en) * | 2020-04-27 | 2020-09-08 | 国网辽宁省电力有限公司电力科学研究院 | Construction process of conductive polymer material grounding grid |
| CN112213564A (en) * | 2020-09-25 | 2021-01-12 | 南方电网科学研究院有限责任公司 | Railway soil resistivity measurement method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN206132853U (en) * | 2016-10-08 | 2017-04-26 | 大唐广元风电开发有限公司 | Aerogenerator ground net on -line monitoring early warning device |
| CN108152595A (en) * | 2017-12-12 | 2018-06-12 | 国网宁夏电力有限公司中卫供电公司 | A kind of earth mat class power-frequency earthing impedance instrument and test method |
-
2019
- 2019-12-02 CN CN201911213225.4A patent/CN110749777A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN206132853U (en) * | 2016-10-08 | 2017-04-26 | 大唐广元风电开发有限公司 | Aerogenerator ground net on -line monitoring early warning device |
| CN108152595A (en) * | 2017-12-12 | 2018-06-12 | 国网宁夏电力有限公司中卫供电公司 | A kind of earth mat class power-frequency earthing impedance instrument and test method |
Non-Patent Citations (1)
| Title |
|---|
| 曾睿: "《石化装置接地电阻计算方法研究》", 《电力***》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111641096A (en) * | 2020-04-27 | 2020-09-08 | 国网辽宁省电力有限公司电力科学研究院 | Construction process of conductive polymer material grounding grid |
| CN111641096B (en) * | 2020-04-27 | 2021-11-09 | 国网辽宁省电力有限公司电力科学研究院 | Construction process of conductive polymer material grounding grid |
| CN112213564A (en) * | 2020-09-25 | 2021-01-12 | 南方电网科学研究院有限责任公司 | Railway soil resistivity measurement method |
| CN112213564B (en) * | 2020-09-25 | 2021-09-03 | 南方电网科学研究院有限责任公司 | Railway soil resistivity measurement method |
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