A device and method for testing the corrosion rate of an electric grounding grid

Abstract

The present application relates to the technical field of power grounding corrosion detection, and particularly relates to a device and method for testing the corrosion rate of a power grounding grid. The bypass lead is drawn from the same grounding circuit as the power grounding grid, and is connected to the reference test body and the buried test body in turn. The buried test body is buried in the soil in the same environment as the power grounding grid, and is connected to the voltage monitoring device. The reference test body is set in a normal temperature environment, and is connected to the voltage monitoring device. The voltage monitoring device is connected to the host computer. The host computer is used to obtain the voltage value monitored by the voltage monitoring device and store it as voltage data according to a fixed time sequence. The present application obtains the resistance change of the buried test body within a preset time, and calculates the corrosion rate of the buried test body, i.e. the corrosion rate of the power grounding grid, thereby successfully converting the corrosion rate into resistance change and solving the problem of inaccurate detection results of the corrosion state of the grounding grid in the prior art.

Description

Technical Field

[0001] This invention relates to the field of power grounding corrosion detection technology, and in particular to a testing device and method for the corrosion rate of power grounding grids. Background Technology

[0002] A grounding grid is a general term for a mesh structure composed of multiple metal grounding electrodes buried at a certain depth underground and conductors connecting these grounding electrodes. In the daily operation of power facilities such as substations, the grounding grid plays a role in preventing equipment leakage, lightning strikes, and diverting the current generated during equipment operation. It is an important facility to ensure the safe operation of substations.

[0003] Corrosion of grounding grids occurs because the soil in which the grounding grid is buried is composed of countless soil particles and has a certain degree of porosity. In these pores, the mixture of air, salt, and moisture gives the soil electrolyte properties. The entire underground metal grounding grid and the soil form countless galvanic cell connections, causing anodic polarization at the point where the current flows out of the grounding grid. The anode part undergoes an electrochemical reaction with the electrolyte, and the grounding grid is corroded. The degree of grounding corrosion varies depending on the composition and texture of the soil and the magnitude of the current flowing through the grounding grid.

[0004] To predict the corrosion status of grounding grids and prevent them from prematurely exiting service, staff have been trying various methods to test their corrosion condition. Currently, the main methods for measuring the corrosion rate of power grounding metals in soil include electrochemical methods, thickness measurement methods, and weight loss methods. These methods calculate the corrosion rate of grounding metals by analyzing the electrochemical parameters or the thickness and weight loss of the material after it has been buried in the soil for a period of time. However, these methods have significant limitations and cannot fully consider the influence of grounding current and soil environment on the corrosion rate, resulting in inaccurate detection results for the corrosion status of grounding grids. Summary of the Invention

[0005] This invention provides a testing device and method for the corrosion rate of power grounding grids, which solves the problem of inaccurate detection results of grounding grid corrosion status in existing technologies.

[0006] The first aspect of this invention provides a testing device for the corrosion rate of a power grounding grid, characterized in that it comprises: a buried specimen, a reference specimen, a bypass lead, a voltage monitoring device, and a host computer, wherein:

[0007] The bypass lead is drawn from the same grounding line as the power grounding grid and connected to the reference specimen and the buried specimen in sequence, so as to provide the reference specimen and the buried specimen with the same level of grounding current as the power grounding grid;

[0008] The buried specimen is placed in soil with the same environment as the power grounding grid and connected to the voltage monitoring device to simulate the same corrosion conditions as the power grounding grid.

[0009] The reference specimen is placed in a room temperature environment and connected to the voltage monitoring device to compare the resistance change with that of the buried specimen.

[0010] The voltage monitoring device is connected to the host computer and is used to monitor the voltage values ​​of the buried specimen and the reference specimen in real time and upload them to the host computer.

[0011] The host computer is used to acquire the voltage values ​​monitored by the voltage monitoring device and store them as voltage data according to a fixed time sequence.

[0012] Specifically, the reference specimen is wrapped with a sealing material to isolate it from the air and prevent the complex chemical components in the air from corroding it.

[0013] Specifically, the buried test specimen is identical in material and shape to the power grounding grid, and their sizes are proportional.

[0014] Specifically, the buried specimen is a cuboid, and during the burial process, only one of the outer surfaces of the buried specimen is in contact with the soil, while the remaining outer surfaces are covered with a sealing coating to remove the influence of irrelevant variables on the test.

[0015] Specifically, the buried specimen is buried in the soil at the same depth as the power grounding grid and in a close proximity to it, in order to simulate the soil environment where the power grounding grid is located.

[0016] Specifically, several testing devices for the corrosion rate of the power grounding grid are set up and surrounded by the power grounding grid at equal intervals.

[0017] Furthermore, it also includes: relays;

[0018] The relay is connected to the grounding line and the bypass lead respectively, and is used to control the on / off of the introduced grounding current, thereby controlling the test duration.

[0019] In another aspect, the present invention provides a method for testing the corrosion rate of a power grounding grid. The device for testing the corrosion rate of a power grounding grid provided by the present invention includes the following steps:

[0020] S1: Obtain the resistance and voltage data of the reference specimen and the voltage data of the embedded specimen at the test start time and after the preset test time, respectively;

[0021] S2: Calculate the resistance of the embedded specimen at the start of the test by using the resistance data of the reference specimen and the voltage data of the embedded specimen and the reference specimen at the start of the test.

[0022] S3: Calculate the resistance of the buried specimen after the preset test time by using the voltage and resistance of the reference specimen after the preset test time and the voltage of the buried specimen;

[0023] Among them, the voltage of the reference specimen after the preset test time is the same as the voltage of the reference specimen at the start of the test;

[0024] S4: Assuming the corrosion length of the buried specimen remains constant, the change in cross-sectional area is obtained by measuring the change in resistance of the buried specimen after the test start time and the preset test time.

[0025] S5: The corrosion rate of the buried specimen is determined by the change in the cross-sectional area of ​​the buried specimen. The corrosion rate of the buried specimen is the corrosion rate of the power grounding grid.

[0026] Specifically, the buried specimen is a cuboid, and during the burial process, only one of the outer surfaces of the buried specimen comes into contact with the soil, while the remaining outer surfaces are covered with a sealing coating to ensure the uniqueness of the variable.

[0027] Specifically, several testing devices for the corrosion rate of the power grounding grid are set up and surrounded by the power grounding grid at equal intervals. The corrosion rate of the power grounding grid is the average value of the corrosion rate of each testing device.

[0028] The beneficial effects of this invention are that the embodiments of this invention provide a testing device for the corrosion rate of a power grounding grid. This testing device includes: a buried specimen, a reference specimen, a bypass lead, a voltage monitoring device, and a host computer, wherein:

[0029] The voltage monitoring device is connected to the buried specimen and the reference specimen respectively. The voltage monitoring device is used to acquire the voltage data of the buried specimen and the reference specimen and send it to the host computer. The host computer is connected to the voltage monitoring device and is used to calculate the corrosion rate of the buried specimen based on the acquired voltage data, the resistance of the reference specimen and the preset test time.

[0030] The bypass lead is drawn from the same grounding line as the power grounding grid and connected to the buried test specimen and the reference test specimen respectively, for providing grounding current to the reference test specimen and the buried test specimen;

[0031] The buried specimen was placed in soil in the same environment as the power grounding grid.

[0032] The power grounding grid corrosion rate testing device provided by this invention can introduce grounding current through a bypass lead and provide the same soil environment as the power grounding grid, so that the corrosion rate of the power grounding grid is converted into the corrosion rate of the buried specimen provided by this invention. A reference specimen is then used to provide a standard specimen for the buried specimen before corrosion, and a voltage monitoring device is used to monitor the voltage value of the corroded specimen and the voltage value of the reference specimen, providing a basis for operators to calculate the corrosion rate based on voltage changes. The device calculates the resistance change of the buried specimen within a preset test time, effectively isolating the influence of temperature drift and other factors on the resistance value during the test. Based on the resistance change of the buried specimen within the preset time, the corrosion rate of the buried specimen, i.e., the corrosion rate of the power grounding grid, is calculated. This effectively simulates the various types of corrosion that the power grounding grid suffers in the soil environment, which are difficult to calculate, and successfully converts the corrosion rate into a resistance change, solving the problem of inaccurate detection results of the grounding grid corrosion state in existing technologies. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the structure of a test device for the corrosion rate of a power grounding grid;

[0035] Figure 2 A flowchart of the test method for corrosion rate of power grounding grid; Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The first aspect of this invention provides a testing device for the corrosion rate of a power grounding grid, comprising: a buried specimen, a reference specimen, a bypass lead, a voltage monitoring device, and a host computer, wherein:

[0038] The voltage monitoring device is connected to the buried specimen and the reference specimen respectively. The voltage monitoring device is used to acquire the voltage data of the buried specimen and the reference specimen and send it to the host computer. The host computer is connected to the voltage monitoring device and is used to calculate the corrosion rate of the buried specimen based on the acquired voltage data, the resistance of the reference specimen and the preset test time.

[0039] The bypass lead is drawn from the same grounding line as the power grounding grid and connected to the buried test specimen and the reference test specimen respectively;

[0040] The test specimens were buried in soil in the same environment as the power grounding grid.

[0041] It is understandable that by calculating the resistance of the buried specimen using the reference resistance of the reference specimen measured in advance and the voltage of the reference specimen and the buried specimen collected by the voltage monitoring device, the influence of drift factors such as temperature and humidity on the resistance value during measurement can be eliminated.

[0042] In a specific embodiment of the present invention, based on the foregoing embodiments, the reference specimen is wrapped with a sealing material to isolate the reference specimen from the air and prevent the complex chemical components in the air from corroding the reference specimen.

[0043] In a specific embodiment of the present invention, based on the foregoing embodiments, the buried test specimen is made of the same material and shape as the power grounding grid, and is proportional in size.

[0044] In one specific embodiment, the reference specimen is a resistor-adjustable body. By adjusting the reference specimen according to the current change of the power grounding grid, the current in the buried specimen is made consistent with the current in the power grounding grid.

[0045] In a more specific embodiment of the present invention, based on the foregoing embodiments, the buried specimen is a cuboid, and during the burial process, only one of the outer surfaces of the buried specimen is in contact with the soil, while the remaining outer surfaces are covered with a sealing coating to remove the influence of irrelevant variables on the test and make the test results more intuitive.

[0046] In a more specific embodiment of the present invention, based on the foregoing embodiments, the buried specimen is buried in the soil at the same depth as the power grounding grid and at the same burial depth and at a distance between a first preset distance and a second preset distance;

[0047] The first preset distance is 5 to 10 meters, which is used to prevent the current flowing into the ground from the power grounding grid from affecting the buried entity, and also to keep the soil environment the same.

[0048] It is understood that the preset distance given in this embodiment is only one case. In tests with different soil environments and grounding grids of different areas and grounding current intensities, the preset distance can be changed without limitation.

[0049] In a specific embodiment of the present invention, based on the foregoing embodiments, the buried test subjects include multiple ones, all of which are connected to the voltage monitoring device and the host computer, and the multiple buried test subjects are equally spaced around the power grounding grid.

[0050] It is understandable that, given the vast coverage area of ​​the power grounding grid and the slight differences in soil environment, including humidity and temperature, at each location, an unlimited number of power grounding grid corrosion rate testing devices can be set up to reduce testing errors caused by these differences.

[0051] In a specific embodiment of the present invention, based on the foregoing embodiments, a testing device for the corrosion rate of a power grounding grid further includes: a relay;

[0052] The relays are connected to the grounding line and the bypass lead respectively to control the on / off of the introduced grounding current, thereby controlling the test duration.

[0053] In a specific embodiment of the present invention, based on the foregoing embodiments, a testing device for the corrosion rate of a power grounding grid further includes: a display;

[0054] The monitor is connected to the host computer and is used to display the corrosion rate data calculated by the host computer to the staff.

[0055] In one specific embodiment of the present invention, the preset testing time is greater than one month to ensure the accuracy of the test.

[0056] In a more specific embodiment of the invention, the bypass lead is drawn from the same grounding line as the power grounding grid and connected in series with the buried test specimen and the reference test specimen, respectively.

[0057] This invention also provides an embodiment of a method for testing the corrosion rate of a power grounding grid, applied to a testing device for the corrosion rate of a power grounding grid provided by this invention, specifically including the following steps:

[0058] S1: Obtain the reference resistance, reference voltage, first embedding voltage of the embedded specimen at the start of the test, and second embedding voltage after the preset test time;

[0059] S2: The first buried resistance R2 of the buried specimen at the start of the test is calculated using the reference resistance, reference voltage, and first buried voltage of the buried specimen. The formula is as follows:

[0060]

[0061] In the formula: R1 is the reference voltage, U1 is the reference voltage, and U2 is the first buried voltage;

[0062] S3: Calculate the second embedded resistance of the specimen after the preset test time using the reference resistance, reference voltage, and second embedded voltage after ΔT time. The formula is as follows:

[0063]

[0064] In the formula: Second buried voltage;

[0065] S4: Assuming the corrosion length of the buried specimen remains constant, the change in resistance of the buried specimen after time ΔT is converted into the change in length using the following formula:

[0066]

[0067] S5: The corrosion rate γ of the buried specimen is determined by the change in the length of the buried specimen. The corrosion rate of the buried specimen is the corrosion rate of the power grounding grid.

[0068] In a specific embodiment of the present invention, after the host computer calculates the corrosion rate of the buried specimen each time, it increases the preset test time according to the preset time interval and performs the test again until the buried specimen is damaged due to corrosion and cannot play a grounding role.

[0069] The preset time interval is set to more than one month.

[0070] The buried specimens are cuboids, with one outer surface in contact with the soil and the remaining outer surfaces covered with a sealing coating to maintain the uniqueness of the variables. Only the length of the buried specimens is calculated.

[0071] When there are several buried test specimens, the several buried test specimens are arranged at equal intervals around the power grounding grid, and the corrosion rate of the power grounding grid is the average value of the corrosion rates of each buried test specimen.

[0072] The present invention also provides a more specific embodiment, in which the buried specimen is a cuboid, and during the burial process, only one of the outer surfaces of the buried specimen is in contact with the soil, while the remaining outer surfaces are covered with a sealing coating to ensure the uniqueness of the variable.

[0073] The present invention also provides a more specific embodiment, which, based on the foregoing embodiment, sets up a plurality of power grounding grid corrosion rate testing devices, which are equally spaced around the power grounding grid to obtain the corrosion rate at different locations of the power grounding grid.

[0074] The present invention also provides a more specific embodiment, which, based on the foregoing embodiment, obtains multiple corrosion rate values ​​by increasing the preset test time at preset time intervals and performing multiple tests, and calculates the rate of change of corrosion rate based on the multiple corrosion rate values, in order to observe the change of corrosion rate corresponding to different test durations.

[0075] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in this application’s specification are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0076] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0078] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0079] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

Claims

1. An apparatus for testing the corrosion rate of an electrically grounded mesh, characterized by, The utility model relates to a kind of buried test body, reference test body, bypass lead, voltage monitoring device, host computer, wherein: The reference test body is arranged in normal temperature environment; The voltage monitoring device is connected with the buried test body and the reference test body respectively, and the voltage monitoring device is used to obtain the voltage data of the buried test body and the reference test body and send to the host computer;The host computer is connected with the voltage monitoring device, and is used to calculate the corrosion rate of buried test body according to the obtained voltage data, the resistance of reference test body and the preset test time; The bypass lead is led out from the same grounding line with the power grounding net, and is connected with the buried test body and the reference test body in series respectively, to provide grounding current to the reference test body and the buried test body; The buried test body is buried in the soil with the same environment as the power grounding net. The corrosion rate of buried test body is calculated according to the reference resistance of reference test body measured in advance and the voltage of reference test body and buried test body collected by voltage monitoring device. The reference test body is wrapped with sealing coating. The buried test body is cuboid, and one outer surface of the cuboid is in contact with soil, and the remaining outer surfaces are wrapped with sealing coating.

2. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, characterized by, The buried test body is the same in material and shape as the power grounding net.

3. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, characterized by, The buried test body is the same in depth as the power grounding net and is at a first preset distance from the power grounding net.

4. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, characterized by, The buried test body is multiple, and multiple buried test bodies are equally spaced around the power grounding net.

5. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, wherein It also includes:

6. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, wherein The display is connected with the host computer, and is used to show the corrosion rate data calculated by the host computer to staff.

7. The test apparatus for the corrosion rate of a power grounding grid according to claim 1, wherein The steps include: S1: obtaining the reference resistance, reference voltage of reference test body, first buried voltage of buried test body at the starting time of test and second buried voltage after preset test time; S2: calculating the first buried resistance of buried test body by reference resistance, reference voltage of reference test body and first buried voltage of buried test body at the starting time of test; 8. A method for testing the corrosion rate of a power grounding grid, applied to the testing device for testing the corrosion rate of a power grounding grid according to any one of claims 1-7, characterized in that, S3: calculating the second buried resistance by reference resistance, reference voltage of reference test body and second buried voltage of buried test body after preset test time; S4: obtaining the change value of length of buried test body by the relationship between the difference of first buried resistance and second buried resistance and the change of resistance length; S5: obtaining the corrosion rate of buried test body by preset test time and the change value of length of buried test body, and the corrosion rate of buried test body is the corrosion rate of power grounding net. After calculating the corrosion rate of buried test body, the preset test time is increased according to the preset time interval for retesting until the buried test body is damaged due to corrosion and cannot play the grounding role. By increasing the preset test time at the preset time interval, multiple corrosion rates are obtained after multiple tests, and the change rate of corrosion rate is calculated according to the multiple corrosion rates. ​ 9. The method of testing the corrosion rate of a power grounding grid of claim 8, wherein, ​ 10. The method of testing the corrosion rate of a power grounding grid of claim 9, wherein, ​

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