Distance determination method, distance determination apparatus, and computer device

Abstract

The application relates to a distance determination method, a distance determination device and a computer device. The method comprises the following steps: acquiring a remote backflow value and an on-site backflow value of a short-circuit current of a grounding network under a grounding fault condition; determining a target current shunt coefficient according to the remote backflow value and the on-site backflow value, and determining an initial potential actual value of the grounding network according to the target current shunt coefficient; acquiring a potential allowable value of the grounding network, and comparing the initial potential actual value with the potential allowable value to obtain a comparison result, wherein the comparison result is used to determine the distance between adjacent grounding conductors in the grounding network, so as to adjust the initial potential actual value of the grounding network according to the distance between the adjacent grounding conductors, and obtain a target potential actual value meeting a preset condition. The method improves the accuracy and reliability of the determination of the grounding network parameters, and can be applied to the accurate determination of the grounding network parameters under various conditions.

Description

Technical Field

[0001] This application relates to the field of power plant engineering technology, and in particular to a spacing determination method, a spacing determination device, and a computer device. Background Technology

[0002] A grounding grid, also known as a grounding grid system, is a mesh structure consisting of multiple metal grounding electrodes buried at a certain depth underground, and conductors connecting the metal grounding electrodes. Grounding grids are primarily used for safety protection in power systems. To ensure the stability of the grounding grid, its parameters need to be determined.

[0003] Currently, the determination of grounding grid parameters for power plants mainly includes the selection of grounding conductors, calculation of grounding resistance, and verification of potential in the grounding grid. Among these, the selection of grounding conductors requires that the cross-section of the grounding conductors meet the conditions for ensuring the safe entry of short-circuit current into the ground, and the actual potential value in the grounding grid needs to be within the allowable range of potential safety.

[0004] However, the above method for determining grounding grid parameters does not consider adjusting the actual potential of the grounding grid. There is no feedback step after the grounding grid parameters are determined, which makes it impossible to optimize the grounding grid parameters and is not conducive to determining the grounding grid parameters under optimal conditions. Summary of the Invention

[0005] Therefore, it is necessary to provide a spacing determination method, spacing determination device, and computer equipment with high accuracy and reliability to address the above-mentioned technical problems.

[0006] Firstly, this application provides a method for determining spacing. The method includes:

[0007] Obtain the far return current and local return current values ​​in the short-circuit current of the grounding grid under grounding fault conditions;

[0008] The target current shunting coefficient is determined based on the remote return current value and the local return current value, and the actual value of the initial potential of the grounding grid is determined based on the target current shunting coefficient.

[0009] Obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain the comparison result. This comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the target actual potential value that meets the preset conditions.

[0010] In one embodiment, determining the target current shunt coefficient based on the remote return current value and the local return current value includes:

[0011] Obtain the target current value ratio between the remote return current value and the local return current value;

[0012] Obtain the target grounding resistance value of the grounding grid connection object, and find the target current shunting coefficient in the preset mapping relationship based on the ratio of the target grounding resistance value to the target current value. The mapping relationship includes the mapping relationship between the current value ratio, the grounding resistance value and the current shunting coefficient.

[0013] In one embodiment, determining the actual value of the initial potential of the grounding grid based on the target current shunting coefficient includes:

[0014] Obtain the rated ground fault short-circuit current value of the grounding grid, and obtain the target maximum ground current value of the grounding grid based on the rated ground fault short-circuit current value and the target current shunt coefficient;

[0015] The actual value of the initial potential is determined based on the target maximum ground current value.

[0016] In one embodiment, determining the actual value of the initial potential based on the target maximum ground current value includes:

[0017] Input the target maximum ground current value into the preset potential calculation formula to obtain the initial actual potential value. The potential calculation formula includes the functional relationship between the maximum ground current value of the grounding grid, the length of the grounding conductor, the grounding grid setting coefficient, and the resistivity of the surface soil.

[0018] In one embodiment, the method further includes:

[0019] Based on the comparison results, a spacing adjustment prompt is output. The spacing adjustment prompt is used to suggest adjusting the spacing between adjacent grounding conductors.

[0020] Specifically, when the actual initial potential value is greater than the allowable potential value, the spacing adjustment prompt is used to indicate a reduction in the spacing between adjacent grounding conductors; when the actual initial potential value is less than or equal to the allowable potential value, the spacing adjustment prompt is used to indicate an increase in the spacing between adjacent grounding conductors.

[0021] In one embodiment, the method further includes:

[0022] If the number of grounding conductors exceeds a preset threshold, a surface structure adjustment prompt will be output. This prompt is used to suggest adjusting the resistivity of the surface soil connected to the grounding grid.

[0023] Secondly, this application also provides a spacing determining device. The device includes:

[0024] The acquisition module is used to acquire the far return current value and the local return current value in the short circuit current of the grounding grid under grounding fault conditions;

[0025] The processing module is used to determine the target current shunting coefficient based on the remote return current value and the local return current value, and to determine the actual value of the initial potential of the grounding grid based on the target current shunting coefficient.

[0026] The determination module is used to obtain the allowable potential value of the grounding grid and compare the initial actual potential value with the allowable potential value to obtain the comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors and obtain the target actual potential value that meets the preset conditions.

[0027] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0028] Obtain the far return current and local return current values ​​in the short-circuit current of the grounding grid under grounding fault conditions;

[0029] The target current shunting coefficient is determined based on the remote return current value and the local return current value, and the actual value of the initial potential of the grounding grid is determined based on the target current shunting coefficient.

[0030] Obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain the comparison result. This comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the target actual potential value that meets the preset conditions.

[0031] Fourthly, this application also provides a computer-readable storage medium. This computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0032] Obtain the far return current and local return current values ​​in the short-circuit current of the grounding grid under grounding fault conditions;

[0033] The target current shunting coefficient is determined based on the remote return current value and the local return current value, and the actual value of the initial potential of the grounding grid is determined based on the target current shunting coefficient.

[0034] Obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain the comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the target actual potential value that meets the preset conditions.

[0035] Fifthly, this application also provides a computer program product. This computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0036] Obtain the far return current and local return current values ​​in the short-circuit current of the grounding grid under grounding fault conditions;

[0037] The target current shunting coefficient is determined based on the remote return current value and the local return current value, and the actual value of the initial potential of the grounding grid is determined based on the target current shunting coefficient.

[0038] Obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain the comparison result. This comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the target actual potential value that meets the preset conditions.

[0039] The aforementioned spacing determination method, spacing determination device, and computer equipment acquire the far-field return current value and the local-field return current value in the short-circuit current of the grounding grid under grounding fault conditions; determine the target current shunt coefficient based on the far-field return current value and the local-field return current value, and determine the actual initial potential value of the grounding grid based on the target current shunt coefficient; simultaneously, they also acquire the allowable potential value of the grounding grid, and compare the actual initial potential value with the allowable potential value to obtain a comparison result. This comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the actual initial potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the actual target potential value. This application, through the analysis and processing of grounding grid data under grounding fault conditions, determines the current shunt coefficient based on the far-field return current value and the local-field return current value in the grounding fault data, and then calculates the actual potential value of the grounding grid through the current shunt coefficient. This solves the problem that traditional methods can only obtain the current shunt coefficient through empirical values ​​when determining grounding grid parameters, and improves the accuracy and reliability of grounding grid parameter determination. Furthermore, this application judges the actual potential value obtained and adjusts the actual potential value of the grounding grid by adjusting the spacing between adjacent grounding conductors in the grounding grid, so as to obtain the target actual potential value that meets the preset conditions, thereby improving the efficiency of grounding grid parameter determination and being applicable to the accurate determination of grounding grid parameters under various conditions. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating the spacing determination method in one embodiment;

[0041] Figure 2 This is a schematic diagram illustrating the steps for determining the current shunt coefficient in one embodiment;

[0042] Figure 3 This is a flowchart illustrating the spacing determination method in another embodiment;

[0043] Figure 4 This is a structural block diagram of the spacing determination device in one embodiment;

[0044] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0046] A grounding grid, also known as a grounding grid system, is a device primarily used for safety protection in power systems. To ensure the stability of the grounding grid, its parameters need to be determined during the design phase. This ensures that the grounding grid can safely deliver short-circuit currents to the ground and provides crucial protection for personal safety during operation. Determining the grounding grid parameters includes selecting the grounding grid conductors, calculating the grounding resistance, and verifying the contact potential and step potential within the grounding grid.

[0047] In one embodiment, such as Figure 1 As shown, a method for determining spacing is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and further to a system including both a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0048] Step 102: Obtain the remote return current value and the local return current value in the short-circuit current of the grounding grid under grounding fault conditions.

[0049] In the context of grounding faults, short-circuit current refers to the current generated at the grounding point when a grounding fault occurs in a power system. A grounding fault occurs when a fault in equipment or conductors in a power system causes an electrical connection with the ground. The remote return current value, also known as the remote short-circuit current value, refers to the fault current flowing back to the power source from a location far from the power source. In this remote return current, the fault current passes through a series of transmission lines and transformers before returning to the power source. The local return current value, also known as the near-field return current value or local return current value, refers to the fault current flowing back to the power source from a location close to the power source through a short-distance loop in the system. In this local return current, the fault current does not need to travel through long transmission lines but instead flows back to the power source through nearby equipment, conductors, or cables. In the grounding grid of this embodiment, the remote return current value can be the current value of the overhead line's lightning rod, and the local return current value can be the current value of the neutral point of a transformer connected to the grounding grid, such as within a power plant.

[0050] For example, the short-circuit current in the event of a ground fault can be calculated from the zero-sequence impedance diagram in the engineering data. For a constantly updated power grid system, the corresponding system impedance value can be found in a preset mapping table.

[0051] Step 104: Determine the target current shunting coefficient based on the remote return current value and the local return current value, and determine the actual value of the initial potential of the grounding grid based on the target current shunting coefficient.

[0052] The current shunting factor is a parameter used to describe the current shunting phenomenon in a power system, indicating the degree to which current is distributed proportionally among branch circuits. The calculation method of the current shunting factor depends on the specific circuit or system topology and parameters. The current shunting factor can be used to analyze issues such as power distribution, voltage drop, current protection, and other impacts in a circuit.

[0053] In this embodiment, the potentials include contact potential and step potential. Contact potential is the potential difference between a conductor and a person when the person comes into contact with a voltage-carrying conductor. In a power system, when a ground fault or equipment failure causes the equipment casing to become energized, a contact potential will be generated if a person comes into contact with the energized casing. This contact potential can cause current to flow through the person, posing a risk of electric shock. Step potential is the potential difference between a person's two feet. When a voltage gradient exists on the ground due to current flowing through it, such as when there are grounding electrodes with different potentials on the ground, a step potential will be generated between the person's two feet. Step potential is caused by current flowing through the ground. When current flows through different locations and creates different potential differences, a person will feel these potential differences when walking across these locations. When the contact potential or step potential exceeds the safety limit, a person may feel an electric shock and face a risk of electric shock. Therefore, appropriate measures need to be taken to reduce contact potential and step potential when designing the grounding grid of a power plant. Unless otherwise specified, the electric potential mentioned below refers to both the contact potential and the step potential. For example, the actual value of the initial potential includes the actual value of the initial contact potential and the actual value of the initial step potential.

[0054] In the initial design phase of grounding grids, since the designed grounding grids have no practical application, it is impossible to accurately obtain the actual potential value of the grounding grid during operation. Simulation verification is complex, and for large grounding grids, adjusting the simulation model and repeatedly calculating requires a significant amount of time, resulting in low efficiency. This embodiment obtains the target current shunt coefficient through remote and local return currents, and then determines the initial actual potential value of the grounding grid using the target current shunt coefficient, thereby improving the efficiency and accuracy of grounding grid parameter determination.

[0055] For example, the actual values ​​of the contact potential and the step potential are related to parameters such as the current magnitude and grounding resistance of the grounding grid. In this embodiment, the current shunting coefficient is first obtained, and then the actual values ​​of the initial potentials, including the actual values ​​of the initial contact potential and the initial step potential, are obtained through analysis and processing of the current shunting coefficient.

[0056] Step 106: Obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain the comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain the target actual potential value that meets the preset conditions.

[0057] The allowable potential values ​​include allowable contact potential and allowable step potential. The potential comparison here involves comparing the allowable contact potential with the initial actual contact potential, and comparing the allowable step potential with the initial actual step potential, resulting in a comparison between the initial actual potential and the allowable potential values. This comparison result can be used to determine the spacing between adjacent grounding conductors in the grounding grid, ultimately obtaining the target actual potential value as the actual potential value that meets preset conditions within the allowable potential range. The preset conditions could be minimizing the total number of grounding conductors or minimizing the implementation cost of the grounding grid after determining the grounding grid parameters.

[0058] This application analyzes and processes grounding fault data in the grounding grid, determines the current shunt coefficient based on the remote and local return current values ​​in the grounding fault data, and then calculates the actual potential value of the grounding grid using the current shunt coefficient. This solves the problem that traditional methods can only obtain the current shunt coefficient based on empirical values ​​when determining grounding grid parameters, thus improving the accuracy and reliability of grounding grid parameter determination. Furthermore, this application judges the obtained actual potential value and adjusts the spacing between adjacent grounding conductors in the grounding grid to adjust the actual potential value of the grounding grid, thereby obtaining a target actual potential value that meets preset conditions. This improves the efficiency of grounding grid parameter determination and is applicable to the accurate determination of grounding grid parameters under various conditions.

[0059] In one embodiment, such as Figure 2 As shown, determining the target current shunting coefficient based on the remote return current value and the local return current value includes the following steps:

[0060] Step 202: Obtain the target current value ratio between the remote return current value and the local return current value.

[0061] The ratio between the remote return current value and the ground return current value corresponds to different current shunting coefficients. Therefore, it is necessary to first determine the ratio between the remote return current value and the ground return current value. Generally speaking, the target current value ratio between the remote return current value and the ground return current value can be 100% to 0%, 75% to 25%, 50% to 50%, or 25% to 75%.

[0062] Step 204: Obtain the target grounding resistance value of the grounding grid connection object, and find the target current shunting coefficient in the preset mapping relationship based on the ratio of the target grounding resistance value to the target current value. The mapping relationship includes the mapping relationship between the current value ratio, the grounding resistance value and the current shunting coefficient.

[0063] Based on the obtained target current value ratio, a target mapping table is determined to identify the current shunting coefficient. The corresponding current shunting coefficient in the target mapping table is then determined as the target current shunting coefficient based on the grounding resistance value. For example, when the target current value ratio between the remote return current value and the ground return current value is 75% to 25%, and the grounding resistance of a double-circuit power plant is 0.2 ohms, the current shunting coefficient is 0.6.

[0064] It should be noted that the mapping relationship in this embodiment can be obtained from empirical charts in industry-standard design standards or from empirical data. Furthermore, it should be noted that the grounding grid in this embodiment should be designed with horizontal conductors arranged as evenly as possible to improve the accuracy and reliability of the grounding grid parameter calculations.

[0065] In one embodiment, determining the actual value of the initial potential of the grounding grid based on the target current shunting coefficient includes: obtaining the rated ground fault short-circuit current value of the grounding grid, and obtaining the target maximum ground current value of the grounding grid based on the rated ground fault short-circuit current value and the target current shunting coefficient; and determining the actual value of the initial potential based on the target maximum ground current value.

[0066] The calculation of the actual potential value is related to the maximum ground current value, and the current shunting coefficient needs to be obtained first when determining the maximum ground current value. For example, the target current shunting coefficient is multiplied by the rated ground fault short-circuit current value to obtain the target maximum ground current value, and then the initial actual potential value can be obtained from the target maximum ground current value.

[0067] In this embodiment, the target current shunting coefficient obtained through the remote return current value and the local return current value is more accurate than the empirical shunting reference value obtained through traditional methods. The actual potential value calculated based on the target current shunting coefficient obtained in this embodiment is more accurate and has higher reliability.

[0068] In one embodiment, determining the actual value of the initial potential based on the target maximum ground current value includes: inputting the target maximum ground current value into a preset potential calculation formula to obtain the actual value of the initial potential. The potential calculation formula includes a functional relationship between the maximum ground current value of the grounding grid, the length of the grounding conductor, the grounding grid setting coefficient, and the resistivity of the surface soil.

[0069] The initial potential value includes the initial contact potential value and the initial step potential value. The potential calculation formula for the initial contact potential value or the initial step potential value is determined based on the maximum ground current value of the grounding grid, the length of the grounding conductor, the grounding grid setting coefficient, and the resistivity of the surface soil. The target maximum ground current value is input into the preset potential calculation formula to obtain the initial contact potential value or the initial step potential value.

[0070] For example, the formula for calculating the contact potential Em can be expressed as:

[0071]

[0072] Where ρ represents the resistivity of the surface soil, and I G K represents the maximum ground current value. m K represents the coefficient in the grounding grid setting factor used to characterize the conductor burial method. i L represents the irregularity coefficient in the grounding grid setting factor, used to characterize the inconsistent current flow in different parts of the grounding grid. m Indicates the length of the grounding conductor.

[0073] Step potential E s The formula for calculating electric potential can be expressed as:

[0074]

[0075] Among them, I G K represents the maximum ground current value. s L represents the coefficient used to characterize the conductor burial method in the grounding grid setting coefficient. s Indicates the length of the grounding conductor.

[0076] It should be noted that when calculating the actual value of the initial contact potential or the actual value of the initial step potential using formulas (1) and (2), the grounding grid must be a regular grounding grid, that is, the grounding grid of the grounding grid is evenly set.

[0077] It should be noted that this embodiment only provides an example of one calculation method for the actual value of the initial contact potential or the actual value of the initial step potential. This application does not limit the calculation method for the actual value of the initial contact potential or the actual value of the initial step potential. Those skilled in the art can use other calculation formulas to determine the actual value of the initial contact potential or the actual value of the initial step potential through the maximum ground current value, and are not limited to the method provided in the above embodiment, as long as it can achieve the goal of determining the actual value of the initial contact potential or the actual value of the initial step potential through the maximum ground current value.

[0078] In one embodiment, the method further includes: outputting a spacing adjustment prompt based on a comparison result, the spacing adjustment prompt being used to prompt adjustment of the spacing between adjacent grounding conductors; wherein, when the actual value of the initial potential is greater than the allowable potential value, the spacing adjustment prompt is used to prompt a reduction in the spacing between adjacent grounding conductors; when the actual value of the initial potential is less than or equal to the allowable potential value, the spacing adjustment prompt is used to prompt an increase in the spacing between adjacent grounding conductors.

[0079] In calculating the contact potential and step potential of the grounding grid, the spacing between adjacent grounding conductors is a crucial parameter. Firstly, uniformly distributing the grounding conductors facilitates the calculation of the actual contact potential and step potential values. Therefore, when determining the grounding grid parameters, adjacent grounding conductors must be evenly distributed.

[0080] For example, the calculated actual values ​​of contact potential and step potential are compared with the allowable values ​​of contact potential and step potential during the grounding grid design. If the calculated actual initial potential value is less than or equal to the allowable potential value, it indicates that the actual initial potential value meets the design requirements of the grounding grid. A spacing adjustment prompt can be output to encourage increasing the spacing between adjacent grounding conductors, reducing the number of grounding conductors, and lowering the installation cost of the grounding grid. If the calculated actual initial potential value is greater than the allowable potential value, it indicates that the actual initial potential value does not meet the design requirements of the grounding grid. A spacing adjustment prompt can be output to reduce the spacing between adjacent grounding conductors, increasing the number of grounding conductors to lower the actual potential value and bring it within the allowable potential range. It should be noted that when the actual initial potential value is less than or equal to the allowable potential value, it indicates that the current grounding grid parameter design meets the safety requirements of the grounding grid design, but there is still room for optimization, meaning there is still a margin for optimization. In this case, the number of grounding conductors can be reduced by increasing the spacing between adjacent grounding conductors, thereby lowering the installation cost of the grounding grid.

[0081] In one implementation approach, an appropriate spacing between adjacent grounding conductors can be selected based on the size and layout of the power plant buildings. For example, an initial spacing between adjacent grounding conductors can be set based on experience, such as 10 meters for the transformer area and 40 meters for the auxiliary plant area. Then, the spacing between adjacent grounding conductors can be verified and adjusted based on calculations.

[0082] In this embodiment, by dynamically adjusting the spacing between adjacent grounding conductors and comparing the calculated actual potential value with the allowable potential value, the total number of grounding conductors in the grounding grid is determined. This allows for the most economical grounding grid setup scheme within the allowable potential range, thereby improving the accuracy and reliability of grounding grid parameter determination.

[0083] In one embodiment, the method further includes: if the number of grounding conductors is greater than a preset number threshold, outputting a surface structure adjustment prompt, the surface structure adjustment prompt being used to prompt adjustment of the resistivity of the surface soil connected to the grounding grid.

[0084] Topsoil resistivity refers to the degree to which the soil impedes the flow of electric current; it is a physical quantity used to represent the soil's conductivity. Topsoil resistivity typically ranges from a few units to hundreds or thousands of units, measured in ohm-meters (Ω·m). First, topsoil resistivity is affected by factors such as soil composition, moisture content, temperature, and salt concentration. For example, higher moisture content in topsoil generally results in lower resistivity, while dry soil, lacking moisture, tends to have higher resistivity. Second, topsoil resistivity varies depending on soil type. For instance, sandy soils typically have higher resistivity, while soils with higher organic matter content tend to have lower resistivity. Furthermore, specific environmental conditions, such as saline-alkali areas or soils containing large amounts of minerals, can also lead to significant variations in resistivity.

[0085] It is important to note that the resistivity of topsoil is an approximation and may fluctuate in reality. To accurately assess soil resistivity, experimental measurements or reference to relevant soil resistivity data tables are recommended.

[0086] When the calculated actual potential value cannot meet the allowable potential value requirement, and the number of grounding conductors is greater than the preset threshold, and adjusting the grounding grid parameters requires a lot of grounding conductors, this embodiment can also output a surface structure adjustment prompt. By prompting to adjust the surface structure, the resistivity of the surface soil connected to the grounding grid can be adjusted, increasing the allowable potential value, making it easier for the actual potential value to meet the allowable potential value, and finally obtaining the arrangement scheme with the lowest consumption under the condition of meeting the allowable potential value.

[0087] In one embodiment, such as Figure 3 As shown, a method for determining grounding grid parameters is provided, including the following steps:

[0088] Step 302: Collect the engineering parameters of the grounding grid.

[0089] Among them, the engineering parameters include those required when determining the grounding grid parameters, such as the resistivity of the surface soil, the short-circuit fault current value, and the short-circuit duration.

[0090] Step 304: Determine the cross-sectional area of ​​the grounding grid conductor, the allowable value of the contact potential, and the allowable value of the step potential.

[0091] For example, the cross-sectional area A of the grounding grid conductor mm2 The expression is:

[0092]

[0093] Where I represents the maximum short-circuit fault current, TCAP represents the thermal constant per unit volume, and t c α represents the short-circuit duration. r ρ represents the temperature coefficient of resistivity at a reference temperature. r K0 represents the resistivity of the grounding conductor at the reference temperature, and T represents the thermal conductivity of the grounding conductor. m T represents the maximum permissible temperature. a Indicates ambient temperature.

[0094] The above formula calculates the minimum cross-section of the down conductor at the short-circuit fault point, but the actual grounding grid is mesh-like. Depending on the severity of the grounding fault, the grounding grid can split current in at least two directions horizontally. Therefore, the current flowing through the horizontal grounding conductor should be 50% of the short-circuit fault current. In this embodiment, 75% of the down conductor cross-section is used as the horizontal grounding conductor cross-section value.

[0095] Permissible contact potential E for a body weight of 50kg touch50 The expression is:

[0096]

[0097] Among them, C s This represents the surface derating factor, which can be understood as a correction factor. Without a protective layer, C... s =1,ρ s The resistivity of the topsoil, t s This indicates the duration of current carrying. Studies have shown that 99.5% of people weighing close to 50kg can withstand an impact energy S. B It is approximately 0.0135, therefore, Approximately 0.116, This indicates the current intensity that the device can withstand.

[0098] Allowable step potential E for a weight of 50kg step50 The expression is:

[0099]

[0100] Step 306: Determine the grounding resistance of the grounding grid based on the initial parameters of the grounding grid.

[0101] Grounding resistance R g The expression is:

[0102]

[0103] Where ρ represents the resistivity of the surface soil, and L T A represents the length of the horizontal grounding conductor, A represents the area of ​​the grounding grid, and h represents the burial depth of the grounding grid.

[0104] It should be noted that this embodiment only provides an example of a calculation method for the cross-sectional area of ​​the grounding grid conductor, the grounding resistance, the allowable value of the contact potential, and the allowable value of the step potential. This application does not limit the calculation method for the cross-sectional area of ​​the grounding grid conductor, the grounding resistance, the allowable value of the contact potential, and the allowable value of the step potential. Those skilled in the art can use other calculation formulas to obtain the cross-sectional area of ​​the grounding grid conductor, the grounding resistance, the allowable value of the contact potential, and the allowable value of the step potential, and are not limited to the method provided in the above embodiment.

[0105] Step 308: Obtain the far return current value and local return current value in the short circuit current of the grounding grid under grounding fault conditions, determine the target current shunting coefficient, and then obtain the actual value of the initial potential.

[0106] The target current shunting coefficient is obtained by looking up a table using the ratio of the far return current to the local return current in the short-circuit current under ground fault conditions. The target current shunting coefficient is multiplied by the rated ground fault short-circuit current value to obtain the target maximum ground current value. Based on the aforementioned formulas (1) and (2), the actual initial potential value is obtained according to the target maximum ground current value, including the actual initial contact potential value and the actual initial step potential value.

[0107] Step 310: Compare the actual value of the initial potential with the allowable potential value.

[0108] If the actual value of the initial potential is less than or equal to the allowable potential value, proceed to step 3102; if the actual value of the initial potential is greater than the allowable potential value, proceed to step 3104.

[0109] Step 3102: Output a spacing adjustment prompt. The spacing adjustment prompt is used to suggest increasing the spacing between adjacent grounding conductors.

[0110] Step 3104: Output a spacing adjustment prompt. The spacing adjustment prompt is used to suggest reducing the spacing between adjacent grounding conductors.

[0111] In one implementation, if the actual value of the initial potential is greater than the allowable potential value and the number of grounding conductors is greater than a preset threshold, a surface structure adjustment prompt is output. This surface structure adjustment prompt is used to prompt the adjustment of the resistivity of the surface soil connected to the grounding grid.

[0112] Step 312: Obtain the actual value of the target potential that is within the allowable potential range and meets the preset conditions.

[0113] When the actual value of the target potential of the grounding grid is within the allowable potential range and meets the preset conditions, the grounding grid parameters corresponding to the actual value of the target potential are determined as target parameters.

[0114] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0115] Based on the same inventive concept, this application also provides a spacing determination device for implementing the spacing determination method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more spacing determination device embodiments provided below can be found in the limitations of the spacing determination method described above, and will not be repeated here.

[0116] In one embodiment, such as Figure 4 As shown, a spacing determination device is provided, including: an acquisition module 402, a processing module 404, and a determination module 406, wherein:

[0117] The acquisition module 402 is used to acquire the far return current value and the local return current value in the short circuit current of the grounding grid under grounding fault conditions;

[0118] Processing module 404 is used to determine the target current shunting coefficient based on the remote return current value and the local return current value, and to determine the actual value of the initial potential of the grounding grid based on the target current shunting coefficient.

[0119] The determination module 406 is used to obtain the allowable potential value of the grounding grid and compare the initial actual potential value with the allowable potential value to obtain a comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors and obtain the target actual potential value that meets the preset conditions.

[0120] In one embodiment, the processing module 404 is further configured to: obtain the target current value ratio between the remote return current value and the local return current value; obtain the target grounding resistance value of the grounding grid connection object, and find the target current shunting coefficient in a preset mapping relationship based on the target grounding resistance value and the target current value ratio, wherein the mapping relationship includes the mapping relationship between the current value ratio, the grounding resistance value and the current shunting coefficient.

[0121] In one embodiment, the processing module 404 is further configured to: obtain the rated ground fault short-circuit current value of the grounding grid, and obtain the target maximum ground current value of the grounding grid based on the rated ground fault short-circuit current value and the target current shunting coefficient; and determine the actual value of the initial potential based on the target maximum ground current value.

[0122] In one embodiment, the processing module 404 is further configured to: input the target maximum ground current value into a preset potential calculation formula to obtain the initial potential actual value, wherein the potential calculation formula includes the functional relationship between the maximum ground current value of the grounding grid, the length of the grounding conductor, the grounding grid setting coefficient, and the resistivity of the surface soil.

[0123] In one embodiment, the device is further configured to: output a spacing adjustment prompt based on a comparison result, the spacing adjustment prompt being used to prompt adjustment of the spacing between adjacent grounding conductors; wherein, when the actual value of the initial potential is greater than the allowable potential value, the spacing adjustment prompt is used to prompt reduction of the spacing between adjacent grounding conductors; when the actual value of the initial potential is less than or equal to the allowable potential value, the spacing adjustment prompt is used to prompt increase of the spacing between adjacent grounding conductors.

[0124] In one embodiment, the device is further configured to: if the number of grounding conductors exceeds a preset number threshold, output a surface structure adjustment prompt, the surface structure adjustment prompt being used to prompt adjustment of the resistivity of the surface soil connected to the grounding grid.

[0125] Each module in the aforementioned spacing determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0126] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a spacing determination method. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0127] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0128] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0129] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0130] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0131] It should be noted that the information involved in this application (including but not limited to equipment information), grounding grid parameter data, and power plant data (including but not limited to data used for analysis and processing, stored data, and displayed data) are all information and data authorized by the user or fully authorized by all parties.

[0132] Those skilled in the art will understand that all or part of the processes in the above-described embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method of distance determination, characterized by, The method includes: Obtain the far return current and local return current values ​​in the short-circuit current of the grounding grid under grounding fault conditions; Obtain the target current value ratio between the remote return current value and the local return current value; Obtain the target grounding resistance value of the grounding grid connection object, and find the target current shunting coefficient in a preset mapping relationship based on the ratio of the target grounding resistance value to the target current value. The mapping relationship includes the mapping relationship between the current value ratio, the grounding resistance value and the current shunting coefficient. Obtain the rated ground fault short-circuit current value of the grounding grid, and obtain the target maximum ground current value of the grounding grid based on the rated ground fault short-circuit current value and the target current shunt coefficient; The target maximum ground current value is input into a preset potential calculation formula to obtain the initial actual potential value. The potential calculation formula includes the functional relationship between the maximum ground current value of the grounding grid, the length of the grounding conductor, the grounding grid setting coefficient, and the resistivity of the surface soil. The allowable potential value of the grounding grid is obtained, and the initial actual potential value is compared with the allowable potential value to obtain a comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between adjacent grounding conductors, and obtain a target actual potential value that meets the preset conditions.

2. The method of claim 1, wherein, The method further includes: Based on the comparison result, a spacing adjustment prompt is output, which is used to prompt adjustment of the spacing between adjacent grounding conductors; Wherein, if the actual value of the initial potential is greater than the allowable potential value, the spacing adjustment prompt is used to prompt a reduction in the spacing between the adjacent grounding conductors; if the actual value of the initial potential is less than or equal to the allowable potential value, the spacing adjustment prompt is used to prompt an increase in the spacing between the adjacent grounding conductors.

3. The method of claim 2, wherein, The method further includes: If the number of grounding conductors exceeds a preset threshold, a surface structure adjustment prompt will be output. The surface structure adjustment prompt is used to suggest adjusting the resistivity of the surface soil connected to the grounding grid.

4. A distance determination apparatus characterized by comprising: For implementing the spacing determination method as described in claim 1, the apparatus includes: The acquisition module is used to acquire the far return current value and the local return current value in the short circuit current of the grounding grid under grounding fault conditions; The processing module is used to determine the target current shunting coefficient based on the remote return current value and the local return current value, and to determine the actual value of the initial potential of the grounding grid based on the target current shunting coefficient. A determining module is used to obtain the allowable potential value of the grounding grid, and compare the initial actual potential value with the allowable potential value to obtain a comparison result. The comparison result is used to determine the spacing between adjacent grounding conductors in the grounding grid, so as to adjust the initial actual potential value of the grounding grid according to the spacing between the adjacent grounding conductors to obtain the target actual potential value. 5.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-4 when the computer program is executed by the processor. When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

7. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

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