Grounding grid state evaluation method and system based on three-dimensional DC resistance matrix

Abstract

The invention relates to the technical field of electric power, in particular to a grounding grid state evaluation method and system based on a three-dimensional direct-current resistance matrix, accurately reflects the conduction state of each node of a grounding grid through multi-point measurement, is suitable for fine detection of a complex grounding grid, and particularly is suitable for large-scale water conservancy and hydropower engineering. Fault points or weak links can be positioned; the matrix test comprehensively covers all nodes and paths of the grounding grid, so that no omission is ensured, and a fault or corrosion area of the grounding grid can be accurately positioned; in addition, data provided by testing are rich, deep analysis and trend prediction are facilitated, early warning can be carried out, potential hazards can be found in time, and measures can be taken. The method has the advantages of high anti-interference capability, simplicity and convenience in operation, low cost and suitability for large-scale application, can provide a stable and reliable detection result especially in an electromagnetic complex scene, and is beneficial to long-term monitoring and data analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power, and particularly relates to a method and system for evaluating the state of a grounding grid based on a three-dimensional DC resistance matrix. Background Art

[0002] The grounding grid is buried in the underground soil of a plant area or a station, and is a key device to ensure reliable production and personnel safety. The grounding grid is the common reference ground for all power equipment, lightning protection devices and line structures in the station. Once the system encounters power failures such as lightning strikes and short circuits during long-term operation, the grounding device can discharge the fault current into the ground in a very short time, thus ensuring production safety; at the same time, the potential of the ground surface in the station can also be quickly reduced, so as to reduce the step voltage and achieve the purpose of protecting personnel safety.

[0003] Relevant information shows that equipment operation accidents caused by grounding grid failures in China often result in large-scale power outages, and in severe cases, unit failures, equipment damage, etc.

[0004] The grounding metal conductor operates in the complex underground environment for a long time. Due to corrosion, the conductor will delaminate and become thinner, and in severe cases, it will even break; thus affecting the effectiveness of the grounding system. At the same time, during the construction of the grounding grid, due to factors such as civil engineering excavation and construction quality management, situations such as missing embedding and interruption of the grounding grid often occur.

[0005] Since the grounding grid is buried deep underground, it is very difficult to implement grounding grid fault diagnosis or status detection once the project construction is completed. At present, there are no engineering technical measures for the grounding grid fault diagnosis or status detection of large-scale water conservancy and hydropower projects.

[0006] Taking a hydropower station as an example, the designed value of the grounding impedance of this hydropower station is 0.424 Ω. In March 2011, the measured value of the grounding impedance was 0.521 Ω; in November 2015, the measured value of the grounding impedance was 0.553 Ω; by August 2019, the measured value of the grounding impedance was 0.681 Ω, which is 60.6% larger than the designed value of the grounding impedance of 0.424 Ω, and increased by 23.1% compared with the test value of 0.553 Ω in 2015. The grounding grid impedance value exceeds the standard and shows an increasing trend. At present, this hydropower station plans to adopt technical measures to short-circuit all possible grounding lead wires to alleviate the current situation of the increasing grounding grid resistance value, but the detailed status is unknown. Considering that the extendable grounding grid range of this hydropower station is currently limited, the situation of the entire station's grounding system operating with hidden problems will continue to exist for a long time under the condition that the status of the grounding grid cannot be accurately judged.

[0007] In view of the above background, the present invention provides a method for evaluating the status of a grounding grid based on the direct current on-resistance. By analyzing the characteristic parameters of the constructed three-dimensional matrix, the main changes of each characteristic parameter are compared in the time dimension, so as to analyze the change of the grounding grid status. The characteristic information in the time dimension is used for resistance matrix inversion, so as to deduce the connection status of the grounding grid. The system is deployed in a newly built hydropower station, which can effectively analyze the status and change trend of the grounding grid, so as to realize the status evaluation of the grounding grid. Summary of the Invention

[0008] In view of the problems existing in the above-mentioned prior art, the present invention is proposed.

[0009] Therefore, the technical problem to be solved by the present invention is: through the supporting industrial control computer system and the deployed grounding measurement system, record the test conditions and data through the installed software system, control the signal of the measurement excitation source through the control hardware circuit, based on the stored direct current on-resistance measurement data and conduct heterogeneous analysis in the time dimension, intelligently analyze the test information, generate a standardized test report, realize the standardized management of the grounding grid test information, and based on the three-dimensional direct current on-resistance matrix, realize the comprehensive, objective and scientific evaluation of the operation status of the grounding grid.

[0010] To solve the above technical problem, the present invention provides the following technical solution, a method for evaluating the status of a grounding grid based on a three-dimensional direct current resistance matrix, including: setting measurement points, constructing a three-dimensional resistance matrix model; conducting real-time monitoring during the operation of the grounding grid, collecting measurement point data; using the collected data for anomaly analysis to evaluate the status of the grounding grid.

[0011] As a preferred scheme of a method for evaluating the status of a grounding grid based on a three-dimensional direct current resistance matrix according to the present invention, wherein: the measurement points include applying a direct current power supply at the reserved terminals of the grounding grid for measurement, including at both ends of the conductor and the corresponding nodes in the network.

[0012] As a preferred scheme of a method for evaluating the status of a grounding grid based on a three-dimensional direct current resistance matrix according to the present invention, wherein: the three-dimensional resistance matrix model includes a conductor, a well-shaped network and a mesh network.

[0013] As a preferred scheme of a method for evaluating the status of a grounding grid based on a three-dimensional direct current resistance matrix according to the present invention, wherein: the measurement point data includes current and voltage, and by measuring the corresponding current and voltage, the corresponding direct current resistance and resistance matrix are obtained.

[0014] As a preferred scheme of a method for evaluating the status of a grounding grid based on a three-dimensional direct current resistance matrix according to the present invention, wherein: the direct current resistance is obtained by applying a direct current power supply at both ends of the conductor and detecting the current and voltage, and the direct current resistance R of the conductor is obtained;

[0015] The resistance matrix includes a resistance matrix of a well-shaped network and a resistance matrix of a mesh network;

[0016] Among them, the resistance matrix of the well-shaped network is expressed as:

[0017]

[0018] Where:

[0019]

[0020] Among them, I r1 , I r2 represent the input currents of the first and second rows, which are obtained by actual measurement. I c1 , I c2 represent the input currents of the first and second columns, which are obtained by actual measurement. U 11 represents the node potential of the first row and the first column, U 12 represents the node potential of the first row and the second column, U 21 represents the node potential of the second row and the first column, U 22 represents the node potential of the second row and the second column;

[0021] Among them, the resistance matrix of the mesh network is expressed as:

[0022]

[0023] Due to the complexity of the network model, the original R ij does not represent the actual corresponding branch resistance value, and the calculation is expressed as:

[0024]

[0025] R ij = R rij × R cij

[0026] Among them, I ri represents the input current of the i-th row, I cj represents the input current of the j-th column, U ij represents the node potential of the i-th row and the j-th column according to the measured current and voltage values.

[0027] As a preferred scheme of a method for evaluating the state of a grounding grid based on a three-dimensional DC resistance matrix according to the present invention, among them: the abnormal analysis is carried out by setting an engineering warning threshold for comparative analysis.

[0028] As a preferred embodiment of the method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to the present invention, wherein: the engineering warning thresholds are correspondingly set in a single conductor, a well-shaped network, and a mesh network;

[0029] Among them, in a single conductor, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 then the status evaluation system raises the failure of the grounding grid;

[0030] In a well-shaped network, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 at this time, if then the status evaluation system raises the failure of the grounding grid;

[0031] In a mesh network, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 at this time, if then the status evaluation system raises the failure of the grounding grid.

[0032] Another object of the present invention is to provide a grounding grid status evaluation system based on a three-dimensional DC resistance matrix, which can accurately evaluate the health status of the grounding grid through real-time monitoring, data collection, and abnormal analysis, and can timely discover potential fault risks by setting engineering warning thresholds, so as to realize the scientific management and maintenance optimization of the grounding grid.

[0033] To solve the above technical problems, the present invention provides the following technical solutions: A grounding grid status evaluation system based on a three-dimensional DC resistance matrix, comprising: a model construction module, a monitoring and collection module, and an abnormal evaluation module;

[0034] The model construction module sets measurement points and constructs a three-dimensional resistance matrix model;

[0035] The monitoring and collection module performs real-time monitoring during the operation of the grounding grid and collects measurement point data;

[0036] The abnormal evaluation module uses the collected data for abnormal analysis and evaluates the status of the grounding grid.

[0037] A computer device includes a memory and a processor, the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix as described above are implemented.

[0038] A computer-readable storage medium stores a computer program thereon, and is characterized in that when the computer program is executed by a processor, the steps of the method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix as described above are implemented.

[0039] Advantages of the present invention: Refined detection: Through multi-point measurement, the three-dimensional DC conductivity matrix can accurately reflect the conduction state between each node of the grounding grid, providing a more refined detection result. It is applicable to the refined detection of complex grounding grids, can locate specific fault points or weak links, and is especially suitable for large-scale water conservancy and hydropower projects.

[0040] Comprehensive coverage: Matrix testing can cover all nodes and paths of the grounding grid to ensure no omission in detection. For the grounding grid in water conservancy and hydropower projects, which is much larger than that in power transmission and transformation projects, after comprehensive detection, it ensures that each part is effectively evaluated.

[0041] Accurate fault location: Through matrix analysis, the fault points or corrosion areas in the grounding grid can be accurately located; theoretically, the granularity of detection points and the accuracy of fault detection are positively correlated.

[0042] Abundant data: Matrix testing provides a large amount of data, facilitating in-depth analysis and trend prediction. It is applicable to scenarios that require long-term monitoring and data analysis, such as smart grids, Internet of Things, etc.

[0043] Early warning: Through regular matrix testing, potential hidden dangers can be discovered in time and measures can be taken in advance.

[0044] Strong anti-interference ability: DC signals are less affected by external electromagnetic interference, and the test results are more stable and reliable. It is applicable to scenarios with complex electromagnetic environments.

[0045] Simple operation: Matrix testing equipment is relatively simple and easy to operate, suitable for on-site applications. It can be used in scenarios that require rapid detection and evaluation, such as emergency repairs, regular inspections, etc.

[0046] Low cost: Compared with other detection methods, the DC conductivity matrix test has a lower cost and is suitable for large-scale applications.

[0047] Data analysis: The data provided by matrix testing can be used to establish models for trend analysis and prediction. Description of the drawings

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0049] Figure 1 It is a flowchart of a grounding grid status evaluation method based on a three-dimensional DC resistance matrix provided by an embodiment of the present invention.

[0050] Figure 2The grounding grid mesh model diagram of a grounding grid status evaluation method provided by an embodiment of the present invention based on a three-dimensional DC resistance matrix.

[0051] Figure 3 The simplified model diagram of a conductor of a grounding grid status evaluation method provided by an embodiment of the present invention based on a three-dimensional DC resistance matrix.

[0052] Figure 4 The well-shaped conductor model diagram of a grounding grid status evaluation method provided by an embodiment of the present invention based on a three-dimensional DC resistance matrix.

[0053] Figure 5 The equivalent resistance model diagram of the grounding grid mesh model of a grounding grid status evaluation method provided by an embodiment of the present invention based on a three-dimensional DC resistance matrix. Detailed implementation manners

[0054] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention with reference to the accompanying drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0055] Embodiment 1, referring to Figures 1 - 5 , which is an embodiment of the present invention. This embodiment provides a grounding grid status evaluation method based on a three-dimensional DC resistance matrix, including:

[0056] S1: Set measurement points and construct a three-dimensional resistance matrix model.

[0057] It should be noted that as shown in S1 in Figure 1 , the measurement points include applying a DC power supply at the reserved terminals of the grounding grid for measurement, including at both ends of the conductor and the corresponding nodes in the network; the three-dimensional resistance matrix model includes a single conductor, a well-shaped network, and a mesh network.

[0058] Furthermore, as shown in Figure 3 , when there is only one conductor, measurement points are arranged at both ends of the conductor for detection; as shown in Figure 4 , when a well-shaped network is formed by 4 conductors, the 4 nodes are the measurement points, corresponding to the current and voltage values of each row and column; as shown in Figure 5 , when an n×m conductor forms a mesh network, each node is the measurement point, also corresponding to the current and voltage values of each row and column.

[0059] S2: During the operation of the grounding grid, perform real-time monitoring and collect measurement point data.

[0060] It should be noted that, as Figure 1 shown in S2, the measurement point data includes current and voltage. By measuring the corresponding current and voltage, the corresponding DC resistance and resistance matrix are obtained.

[0061] Furthermore, the grounding grid of a hydropower station is essentially composed of conductors buried deep underground, in building structures or in water. The main materials of the conductors are steel or copper; the conductors are interconnected with each other, as Figure 2 shown (the grounding grid is generally buried in the depth range of 0.8 m below the ground surface or in concrete, and is mainly formed by horizontally laid conductors connected to each other to form a grid shape; usually, metal materials such as flat steel, round steel, and copper conductors are used. These conductors are arranged vertically and horizontally at a certain spacing at a certain depth below the ground to form a shape similar to a grid; the size and density of the grid are determined according to specific grounding requirements and site conditions. Generally speaking, the grid spacing may vary from several meters to more than ten meters) of a mesh grounding network; at the edge of the grounding grid, grounding reserved terminals are configured; by applying a DC power supply at the grounding reserved terminals and measuring the current and voltage conditions, the current state of the grounding grid can be analyzed.

[0062] Even further, as Figure 3 shown (a single conductor is generally used in transmission line projects as a grounding conductor for radial extension, and usually metal materials such as flat steel, round steel, and copper conductors are used), when there is only one conductor, by applying a DC power supply at both ends of the conductor and detecting the current and voltage, the DC resistance R of the conductor can be obtained; as Figure 4 shown (a well-shaped grounding grid is generally used in transmission line projects as a grounding conductor for radial extension, and usually metal materials such as flat steel, round steel, and copper conductors are used), when four conductors form a well-shaped network, by inputting a DC power supply and measuring the corresponding current and voltage values, the voltage values of the four nodes and the input current values of the rows and columns can be obtained. By measuring the corresponding current and voltage, the corresponding resistance matrix is obtained, expressed as:

[0063]

[0064] Where:

[0065]

[0066] Where, I r1 , I r2 represent the input currents of the first and second rows, which are obtained by actual measurement. I c1 , I c2 represent the input currents of the first and second columns, which are obtained by actual measurement. U 11 represents the node potential of the first row and the first column. U 12 represents the node potential of the first row and the second column. U 21 represents the node potential of the second row and the first column.22 Denotes the node potential at the second row and the second column. The above voltage values are all measured parameters. According to the measured I r1 , I r2 , I c1 , I c2 , R 11 , R 12 , R 21 , R 22 can be calculated;

[0067] As Figure 5 shown (the mesh model is used for power transmission and transformation projects and water conservancy and hydropower projects), when n×m conductors form a mesh network, by passing a DC power supply for a certain time and detecting the corresponding current and voltage, the voltage values of the corresponding nodes and the input current values of the rows and columns can be obtained. By measuring the corresponding current and voltage, the corresponding resistance matrix is obtained, which is expressed as:

[0068]

[0069] Due to the complexity of the network model, the original R ij does not represent the actual resistance value of the corresponding branch. Its specific calculation is expressed as:

[0070]

[0071] Among them, I ri represents the input current of the i-th row, I cj represents the input current of the j-th column, and U ij represents the node potential at the i-th row and the j-th column. According to the measured current and voltage values, R rij , R cij can be calculated, and further R ij can be calculated.

[0072] S3: Use the collected data for anomaly analysis to evaluate the status of the grounding grid.

[0073] It should be noted that, as shown in S3 in Figure 1 , the anomaly analysis is carried out by setting the engineering warning threshold for comparative analysis; the engineering warning threshold includes corresponding settings in a single conductor, a well-shaped network, and a mesh network.

[0074] Furthermore, in a single conductor, as Figure 3 shown, the resistance value put into operation in the first year of the project operation is marked as R 1 , and the one put into operation in the nth year is marked as R n ; the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 , the status evaluation system upgrades the grounding grid failure;

[0075] In a well-shaped network, as Figure 4 shown, the resistance value mark put into operation in the first year of the project operation, the mark put into operation in the nth year is the same as that of "a conductor". The project warning threshold is expressed as: when the conductor cross-section decreases by more than the project warning threshold R 阈值 at this time, if then the state evaluation system upgrades the grounding grid failure;

[0076] In a mesh network, as Figure 5 shown, the resistance value mark put into operation in the first year of the project operation, the mark put into operation in the nth year is the same as that of "a conductor". The project warning threshold is expressed as: when the conductor cross-section decreases by more than the project warning threshold R 阈值 at this time, if then the state evaluation system upgrades the grounding grid failure.

[0077] Furthermore, as Figure 3 shown, a certain project arranges a single radial conductor as the grounding grid. At the initial operation, the measured DC resistance of the conductor by a DC resistance meter is 0.8 Ω, that is, R 1 = 0.8 Ω; according to the project design boundary conditions, R 阈值 = 1 Ω, and this threshold is provided or determined by the project design unit; during the 1st - 19th years of operation, the measured DC resistance of the conductor is lower than 1 Ω, but there is a gradually increasing trend, which needs attention; by the 20th year, the measured R 20 = 1.05 Ω, exceeding the warning value, and the grounding grid is evaluated as failed; as Figure 4 shown, at the initial operation, by injecting current, measuring the node voltage and branch current, and through calculation, According to the project design boundary conditions, this threshold is provided or determined by the project design unit, usually obtained through numerical calculation based on the designed grounding grid model; during the 1st - 19th years of operation, the measured DC resistance of the conductor is lower than 1 Ω, but there is a gradually increasing trend, which needs attention; by the 20th year, the measured exceeds the warning value, and the grounding grid is evaluated as failed; as Figure 5 shown, the same as the well-shaped network, at the initial operation, by injecting current, measuring the node voltage and branch current, and calculating According to obtained through numerical calculation; during the 1st - 19th years of operation, the measured DC resistance of the conductor is lower than 1 Ω, showing a gradually increasing trend, which needs attention; by the 20th year, the measured exceeds the warning value, and the grounding grid is evaluated as failed;

[0078] Among them, The setting can select the measurement value in the first year as the reference and default this value as the reference value. When the corresponding R value is greater than 150% of the reference value, it is determined that the grounding grid in the corresponding area fails; among them, 150% is a specified value, not a limiting value; it can be adjusted to any value in the interval greater than 100%.

[0079] The above is a schematic solution of a grounding grid status evaluation method based on a three-dimensional DC resistance matrix in this embodiment. It should be noted that the technical solution of the system of a grounding grid status evaluation method based on a three-dimensional DC resistance matrix belongs to the same concept as the above-mentioned technical solution of a grounding grid status evaluation method based on a three-dimensional DC resistance matrix. For the details not described in detail in the technical solution of a grounding grid status evaluation system based on a three-dimensional DC resistance matrix in this embodiment, reference can be made to the description of the technical solution of the above-mentioned grounding grid status evaluation method based on a three-dimensional DC resistance matrix.

[0080] Embodiment 2 is an embodiment of the present invention, which provides a grounding grid status evaluation system based on a three-dimensional DC resistance matrix, including: a model construction module, a monitoring and acquisition module, and an anomaly evaluation module;

[0081] The model construction module sets measurement points and constructs a three-dimensional resistance matrix model;

[0082] The monitoring and acquisition module performs real-time monitoring during the operation of the grounding grid and collects measurement point data;

[0083] The anomaly evaluation module uses the collected data for anomaly analysis and evaluates the status of the grounding grid.

[0084] This embodiment also provides a computing device, applicable to the situation of a grounding grid status evaluation method based on a three-dimensional DC resistance matrix, including:

[0085] A memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement a grounding grid status evaluation method proposed in the above embodiment.

[0086] This embodiment also provides a storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements a grounding grid status evaluation method proposed in the above embodiment.

[0087] The storage medium proposed in this embodiment and the grounding grid status evaluation method proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0088] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0089] The logics and / or steps described otherwise herein, for example, can be considered as a defined sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0090] It should be understood that each part of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following well-known technologies in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGA), field-programmable gate arrays (FPGA), etc.

[0091] It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention, and all of them should be covered by the scope of the claims of the present invention.

Claims

1. A method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix, characterized in that: Including: Set measurement points and construct a three-dimensional resistance matrix model; During the operation of the grounding grid, conduct real-time monitoring and collect data at the measurement points; Use the collected data for anomaly analysis and evaluate the status of the grounding grid.

2. The method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to claim 1, wherein: The measurement points include applying a DC power supply at the reserved terminals of the grounding grid for measurement, including at both ends of the conductor and corresponding nodes in the network.

3. The method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to claim 2, wherein: The three-dimensional resistance matrix model includes a conductor, a well-shaped network, and a mesh network.

4. The method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to claim 3, characterized in that: The measurement point data includes current and voltage. By measuring the corresponding current and voltage, the corresponding DC resistance and resistance matrix are obtained.

5. The method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to claim 4, characterized in that: The DC resistance is obtained by applying a DC power supply at both ends of the conductor and detecting the current and voltage to obtain the DC resistance R of the conductor; The resistance matrix includes the resistance matrix of the well-shaped network and the resistance matrix of the mesh network; Among them, the resistance matrix of the well-shaped network is expressed as: Where: Among them, I r1 and I r2 represent the input currents of the first and second rows, which are obtained by actual measurement. I c1 and I c2 represent the input currents of the first and second columns, which are obtained by actual measurement. U 11 represents the node potential of the first row and the first column. U 12 represents the node potential of the first row and the second column. U 21 represents the node potential of the second row and the first column. U 22 represents the node potential of the second row and the second column; Among them, the resistance matrix of the mesh network is expressed as: Due to the complexity of the network model, the original R ij does not represent the actual corresponding branch resistance value, and the calculation is expressed as: R ij = R rij × R cij Among them, I ri represents the input current of the i-th row, and I cj represents the input current of the j-th column. U ij represents the node potential of the i-th row and the j-th column according to the measured current and voltage values.

6. The method for evaluating the grounding grid status based on a three-dimensional DC resistance matrix according to claim 5, characterized in that: The anomaly analysis is performed by setting an engineering warning threshold for comparative analysis.

7. The method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to claim 6, wherein: The engineering warning threshold is correspondingly set in a conductor, a well-shaped network, and a mesh network; Among them, in a conductor, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 then the state evaluation system upgrades the grounding grid failure; In the well-shaped network, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 If the state evaluation system then upgrades the grounding grid failure; In a mesh network, the engineering warning threshold is expressed as: when the reduction of the conductor cross-section exceeds the engineering warning threshold R 阈值 at this time, if then the status evaluation system upgrades the grounding grid failure.

8. A system for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to any one of claims 1-7, characterized in that: Including: A model construction module, a monitoring and acquisition module, and an anomaly evaluation module; The model construction module sets measurement points and constructs a three-dimensional resistance matrix model; The monitoring and acquisition module conducts real-time monitoring during the operation of the grounding grid and collects data at the measurement points; The anomaly evaluation module uses the collected data for anomaly analysis and evaluates the status of the grounding grid.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of a method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to any one of claims 1 to 7.

10. A computer-readable storage medium, having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of a method for evaluating the status of a grounding grid based on a three-dimensional DC resistance matrix according to any one of claims 1 to 7.

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