Lightning protection method and system for power grid in complex terrain area

Abstract

The invention discloses a lightning protection method and system for a power grid in a complex terrain region, and relates to the technical field of power grid lightning protection, and the method comprises the steps: carrying out the DEM simplification and highlighting of an elevation digital model of a to-be-detected region based on a power grid, and building a lightning protection analysis simulation model through simulation software; obtaining a plurality of lightning protection gap setting arrays to be screened; obtaining power grid breakdown hidden danger data and lightning protection data; establishing a lightning protection gap evaluation model; and constructing a lightning protection gap change display model by using each to-be-screened lightning protection gap setting array and the corresponding lightning protection gap evaluation model, performing curved surface analysis on the lightning protection gap change display model to obtain a screened lightning protection gap setting array, and applying the screened lightning protection gap setting array to power grid lightning protection in a complex terrain area. The problems that the lightning protection effect and equipment safety are difficult to balance due to the fact that setting of the lightning protection gap is not clear, the impact damage risk of lightning to power grid equipment is increased, or grounding faults and interphase short circuits are caused due to improper setting of the gap are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection for power grids, and more specifically, to a lightning protection method and system for power grids in complex terrain areas. Background Art

[0002] Complex terrain areas usually have the characteristics of complex and changeable terrain, high mountains and deep valleys, large changes in surface elevation and complex surface structure. These characteristics bring great challenges to the lightning protection work of the power grid.

[0003] In complex terrain areas, due to the complexity of terrain, climate and other factors, lightning activities are frequent and strong, so power grid lightning protection is particularly important. The main goal of power grid lightning protection is to reduce the damage of lightning to power grid equipment and ensure the safe and stable operation of the power grid.

[0004] In terms of lightning protection measures for power grids, multiple factors need to be considered comprehensively. On the one hand, blocking lightning protection measures can be adopted, such as installing lightning rods or lightning arresters near power grid equipment to lead lightning current into the ground, thereby preventing lightning current from directly hitting power grid equipment. The installation location and height of these lightning protection facilities need to be carefully designed to ensure that they can effectively intercept lightning and guide it safely into the ground.

[0005] On the other hand, it is also possible to adopt diversion-type lightning protection measures, such as setting up lightning conductors to guide lightning current to the ground and reduce voltage shocks on power grid equipment. The setting up of lightning conductors also needs to take into account factors such as terrain and climate to ensure that they can function effectively.

[0006] Power frequency arc induction arc extinguishing type lightning protection measures are an advanced transmission line lightning protection technology, which uses the energy generated by power frequency arcs to induce and extinguish lightning arcs, thereby protecting transmission lines from damage. This measure uses specific devices or methods to quickly guide the arc to extinguish when a power frequency arc is generated due to lightning impact, reduce the failure rate caused by lightning strikes, and improve the reliability and stability of transmission lines.

[0007] Lightning arc induced arc extinguishing type lightning protection measures use specific devices to quickly cut off the circuit when the lightning current passes through, so that the lightning arc is extinguished in a very short time. This measure uses key technologies such as multi-breakpoint arc extinguishing lightning protection devices and self-energy arc extinguishing devices to use the energy generated by lightning to develop the energy required for arc extinguishing, thereby protecting the transmission line from lightning damage. This lightning protection measure has high reliability and stability and is suitable for high-voltage transmission lines.

[0008] The above disclosed technical solutions have at least the following technical problems: The importance of lightning protection gap in lightning protection of power grids in complex terrain areas cannot be ignored. As a safety barrier between the power grid and lightning, it can effectively control the lightning discharge process, reduce the direct impact of lightning on power grid equipment, and protect the safe and stable operation of the power grid. If the lightning protection gap is too large, it may cause the lightning to be unable to discharge fully, increasing the risk of lightning impact damage to power grid equipment; If the lightning protection gap is too small, the gap may be broken down prematurely due to special conditions in complex terrain (such as sudden terrain changes, changes in soil resistivity, etc.), causing grounding faults or phase-to-phase short circuits, posing a threat to the safe operation of the power grid. The existing technology is not clear about the setting of lightning protection gaps, which makes it difficult to balance the lightning protection effect and equipment safety, increases the risk of lightning impact and damage to power grid equipment, or causes ground faults and phase-to-phase short circuits due to improper gap settings.

[0009] In view of the above problems, the present invention proposes a solution. Summary of the invention

[0010] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a lightning protection method and system for power grids in complex terrain areas. By analyzing different lightning protection gaps under complex terrain, it solves the problem that the setting of lightning protection gaps is not clear, which makes it difficult to balance the lightning protection effect and equipment safety, increases the risk of lightning impact and damage to power grid equipment, or causes ground faults and phase-to-phase short circuits due to improper gap settings.

[0011] To achieve the above object, the present invention provides the following technical solutions: A lightning protection method for power grids in complex terrain areas comprises the following steps: performing DEM simplification and highlighting processing on the elevation digital model of the area to be tested based on the power grid, and establishing a lightning protection analysis simulation model through simulation software; obtaining an initial lightning protection gap setting array based on historical data, performing several random perturbations on the initial lightning protection gap setting array, and obtaining several lightning protection gap setting arrays to be screened, wherein the lightning protection gap setting arrays include a gap width and a gap height; setting the lightning protection gaps of the lightning protection gap setting arrays to be screened in the lightning protection analysis simulation model, and obtaining power grid breakdown hidden danger data and lightning protection data; establishing a lightning protection gap evaluation model based on a long-term and short-term neural network according to the power grid breakdown hidden danger data and the lightning protection data; constructing a lightning protection gap change display model with each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model, and performing surface analysis on the lightning protection gap change display model to obtain the screened lightning protection gap setting array, and applying the screened lightning protection gap setting array to power grid lightning protection in complex terrain areas.

[0012] In a preferred embodiment, the elevation digital model of the area to be measured is simplified and highlighted based on the DEM of the power grid, and a lightning protection analysis simulation model is established through simulation software, specifically: DEM data of the area to be measured is obtained, and the DEM data is preprocessed; according to the layout and characteristics of the power grid, the DEM data is dimensionally reduced and resampled of the terrain height information to highlight the terrain characteristics of the power grid, wherein the terrain characteristics of the power grid include the terrain characteristics around the key positions of the power grid, and the key positions of the power grid include substations and transmission lines; based on the power system simulation software, a lightning protection analysis simulation model is established according to the simplified and highlighted DEM data and the power grid layout information.

[0013] In a preferred embodiment, the initial lightning protection gap setting array is randomly disturbed several times to obtain several lightning protection gap setting arrays to be screened, specifically: according to historical data, the variation range of gap width and gap height is obtained; according to computing resources and time constraints, the number of random disturbances is set; the gap width and gap height are adjusted according to the number of random disturbances, and the gap width and gap height obtained after each disturbance are recorded to obtain several lightning protection gap setting arrays to be screened.

[0014] In a preferred embodiment, the power grid breakdown hazard data includes a line lightning resistance influence coefficient and a power grid operation tripping stability coefficient; the specific method for obtaining the line lightning resistance influence coefficient is as follows: mark each lightning protection device node in the lightning monitoring system, obtain the line connection relationship number between each marked point, obtain the lightning strike ratio and lightning strike detection frequency of each lightning protection device node, and the preset line lightning resistance level and line length between adjacent marked points; according to the line connection relationship number, obtain the lightning strike ratio and lightning strike detection frequency of each lightning protection device node, and the preset line lightning resistance level and line length between adjacent marked points to calculate the lightning impact fluctuation value, and calculate the line lightning resistance influence coefficient based on the line lightning resistance influence coefficient according to the lightning impact fluctuation value.

[0015] In a preferred embodiment, the specific method for obtaining the power grid operation tripping stability coefficient is as follows: The specific method for obtaining the power grid operation tripping stability coefficient is as follows: obtain the waveform of the timestamp of the power grid operation parameters and the tripping event changing with time; perform spectrum analysis on the power grid operation parameter signal waveform and the timestamp waveform of the tripping event within a preset time window, respectively, to identify and extract the main features of the basic state and the tripping event; convert the main features of the basic state and the tripping event back to the time domain signal based on Fourier transform; and calculate the floating value of the harmonic according to the relative change between the time domain signal and the basic state and the main features of the tripping event; perform data analysis on the floating value of the harmonic to calculate the power grid operation tripping stability coefficient.

[0016] In a preferred embodiment, the lightning protection data includes a lightning protection leakage fluctuation coefficient; the specific method for obtaining the lightning protection leakage fluctuation coefficient is as follows: obtain the leakage current change rate of the power grid during lightning protection under each lightning protection gap; calculate the leakage current change rate standard deviation and the leakage current change rate average value of the leakage current change rate at different times within a preset time; calculate the leakage current change rate abnormality coefficient based on the leakage current change rate standard deviation and the leakage current change rate average value; calculate the lightning protection leakage fluctuation coefficient based on the leakage current change rate abnormality coefficient based on the preset lightning protection leakage fluctuation coefficient calculation formula.

[0017] In a preferred embodiment, each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model are used to construct a lightning protection gap change display model, specifically: the output of the lightning protection gap evaluation model and the corresponding lightning protection gap setting array to be screened are mapped to a three-dimensional rectangular coordinate system, and a lightning protection gap change display model is constructed, specifically: the gap width of the lightning protection gap setting array to be screened is used as the X-axis of the three-dimensional rectangular coordinate system; the gap height of the lightning protection gap setting array to be screened is used as the Y-axis of the three-dimensional rectangular coordinate system; the lightning protection gap evaluation coefficient is used as the Z-axis of the three-dimensional rectangular coordinate system; each group of lightning protection gap setting arrays to be screened and its corresponding lightning protection gap evaluation coefficient are mapped to the three-dimensional rectangular coordinate system, and each lightning protection gap setting array to be screened corresponds to a rectangular coordinate point; according to the mapped rectangular coordinate points, a number of rectangular coordinate points are associated using the difference method to obtain a surface, and a lightning protection gap change display model is constructed.

[0018] In a preferred embodiment, the lightning protection gap change display model is subjected to surface analysis to obtain a screened lightning protection gap setting array, and applied to power grid lightning protection in complex terrain areas, specifically: obtaining several maximum values ​​of the surface of the lightning protection gap change display model; taking the lightning protection gap setting array to be screened corresponding to the maximum value whose slope is closest to zero among all maximum values ​​as the screened lightning protection gap setting array, and applying it to power grid lightning protection in complex terrain areas.

[0019] The technical effects and advantages of the lightning protection method and system for power grids in complex terrain areas of the present invention are as follows: 1. The present invention establishes a lightning protection analysis simulation model by simplifying and highlighting the DEM of the power grid, obtains the lightning protection gap setting array to be screened by combining the random disturbance of historical data, and sets it in the simulation model to obtain the power grid breakdown hidden danger data and lightning protection data (including the line lightning resistance influence coefficient, the power grid operation tripping stability coefficient and the lightning protection leakage fluctuation coefficient). This method can clarify the basis for setting the lightning protection gap, balance the lightning protection effect and equipment safety, reduce the risk of lightning impact damage to power grid equipment, and reduce the occurrence of ground faults and interphase short circuits. At the same time, by deeply analyzing these coefficients, scientific guidance can be provided for the design and optimization of power grid lightning protection, and the lightning protection capability and safety stability of the power grid can be improved.

[0020] 2. The present invention can comprehensively consider the line lightning protection impact coefficient, the power grid operation tripping stability coefficient and the lightning protection leakage fluctuation data through the lightning protection gap assessment model established based on the long-term and short-term neural network, and generate an accurate lightning protection gap assessment coefficient. Furthermore, the lightning protection gap setting array to be screened is combined with the lightning protection gap assessment model to construct a lightning protection gap change display model, and the optimal lightning protection gap setting array is screened out through surface analysis. This method not only improves the accuracy and efficiency of lightning protection gap assessment, but also can be applied to power grid lightning protection in complex terrain areas, effectively improving the safety and stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic structural diagram of a lightning protection method for power grids in complex terrain areas.

[0022] Figure 2 The present invention is a schematic structural diagram of a lightning protection system for a power grid in a complex terrain area. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Embodiment 1, Figure 1 The present invention provides a lightning protection method for power grids in complex terrain areas, comprising the following steps: S1, the elevation digital model of the area to be tested is simplified and highlighted based on the DEM of the power grid, and a lightning protection analysis simulation model is established through simulation software.

[0025] The elevation digital model of the area to be measured is simplified and highlighted based on the DEM of the power grid, and a lightning protection analysis simulation model is established through simulation software, specifically: Obtain DEM data of the area to be measured and preprocess the DEM data; According to the layout and characteristics of the power grid, the DEM data is subjected to dimensionality reduction and resampling of terrain height information to highlight the terrain characteristics of the power grid, wherein the terrain characteristics of the power grid include the terrain characteristics around the key positions of the power grid, and the key positions of the power grid include the substation and the transmission line. Based on the power system simulation software, a lightning protection analysis simulation model is established according to the simplified and highlighted DEM data and power grid layout information.

[0026] It should be noted that DEM data is a digital model that describes the height information of the earth's surface terrain. It is usually stored in the form of a grid, and each grid point has a corresponding height value. DEM data is widely used in geographic information systems (GIS), terrain analysis, environmental simulation and other fields.

[0027] Preprocessing is the process of cleaning, organizing, converting, etc. the raw data. In DEM data processing, preprocessing may include removing noise (such as abnormal height values), filling missing data (such as using interpolation methods), smoothing data, etc., to improve the accuracy and usability of the data.

[0028] Dimensionality reduction is the process of reducing the dimensions of data while maintaining the main features of the data. In DEM data processing, dimensionality reduction may involve simplifying terrain height information to reduce the amount of calculation and improve analysis efficiency. For example, dimensionality reduction can be achieved by reducing the number of grid points or merging adjacent grid points.

[0029] Resampling is the process of changing the sampling rate or resolution of data. In DEM data processing, resampling may involve resampling terrain height information to suit different analysis requirements. For example, high-resolution DEM data can be downsampled to low-resolution data to reduce the amount of data and increase processing speed.

[0030] Key locations in the power grid refer to locations with important significance or potential risks in the power grid. In lightning protection analysis, these locations usually include substations (power conversion and distribution centers in the power grid) and along transmission lines (main channels for power transmission). The terrain characteristics of these locations have an important impact on the lightning protection effect; Terrain features refer to the topographical shape and features of the earth's surface, including mountains, hills, plains, rivers, etc. In lightning protection analysis, terrain features have an important impact on the propagation of lightning shock waves and the response of power grid equipment. Therefore, when establishing a lightning protection analysis simulation model, it is necessary to highlight the terrain features around the key locations of the power grid.

[0031] Power system simulation software is a software tool used to simulate and analyze the operating status of power systems. It can establish mathematical models and perform simulation calculations based on the structure, parameters and operating conditions of the power system. In lightning protection analysis, power system simulation software can be used to establish lightning protection analysis simulation models, simulate the potential impact of lightning on the power grid, and evaluate the effectiveness of lightning protection measures.

[0032] S2, based on historical data, obtain an initial lightning protection gap setting array, perform several random perturbations on the initial lightning protection gap setting array, and obtain several lightning protection gap setting arrays to be screened, wherein the lightning protection gap setting array includes a gap width and a gap height.

[0033] In this implementation, the initial lightning protection gap setting array is randomly disturbed several times to obtain several lightning protection gap setting arrays to be screened, specifically: According to historical data, obtain the variation range of gap width and gap height; According to the computing resources and time constraints, set the number of random perturbations; The gap width and gap height are adjusted according to the number of random disturbances, and the gap width and gap height obtained after each disturbance are recorded to obtain a plurality of lightning protection gap setting arrays to be screened.

[0034] It should be noted that the variation range refers to the interval within which the gap width and gap height may fluctuate within a reasonable or acceptable range. This range is usually determined based on historical data, industry standards, engineering experience or theoretical calculations. The variation range should be large enough to cover the possible best lightning protection gap setting, but not too large to avoid introducing unrealistic or dangerous settings; Computational resources refer to the computer hardware, software, and computing power required to perform random perturbations and subsequent lightning protection analysis. This includes CPU, memory, storage, computing speed, and algorithm efficiency. The limitation of computing resources will affect the number of random perturbations and the accuracy of lightning protection analysis.

[0035] Time constraints refer to the time required to perform the entire lightning clearance optimization process. This includes the time for the random perturbation, lightning protection analysis, result evaluation and decision making phases. Time constraints may be determined by project requirements, resource availability or external factors such as weather conditions.

[0036] The random perturbation technique is a method for generating multiple possible solutions. In this embodiment, the random perturbation technique is used to adjust the gap width and gap height of the initial lightning protection gap setting array. By introducing randomness, a wider range of lightning protection gap setting spaces can be explored, making it possible to find a more optimal setting.

[0037] S3, setting the lightning protection gap of the lightning protection gap setting array to be screened in the lightning protection analysis simulation model, and obtaining power grid breakdown potential risk data and lightning protection data.

[0038] In this embodiment, the grid breakdown potential risk data includes the line lightning resistance influence coefficient and the grid operation tripping stability coefficient, and the lightning protection data includes the lightning protection leakage fluctuation coefficient; The line lightning impact coefficient is used to measure the ability of the line insulator to withstand the maximum lightning current amplitude without lightning when the line is struck by lightning under a specific lightning protection gap setting. This coefficient reflects the lightning resistance level of the line, that is, the line's ability to withstand lightning impulses. The method for obtaining the line lightning impact coefficient usually involves conducting lightning impulse tests on the line, recording the flashover conditions of the line insulators under different lightning protection gap settings, and deriving the coefficient through statistical analysis and calculation. In practical applications, the line lightning impact coefficient can provide an important reference for the lightning protection design and optimization of the power grid, helping engineers choose reasonable lightning protection gap settings, thereby improving the safety and stability of the power grid.

[0039] Analyzing the lightning protection coefficient of the line has the following advantages in solving the problem that the setting of the lightning protection gap is not clear, which makes it difficult to balance the lightning protection effect and equipment safety, increases the risk of lightning impact damage to power grid equipment, or causes grounding faults and phase-to-phase short circuits due to improper gap setting: Clarify the basis for setting the lightning protection gap. The line lightning protection impact coefficient is an important indicator for measuring the lightning protection performance of the line. It reflects the ability of the line to maintain normal operation under the action of lightning strikes. By deeply analyzing the line lightning protection impact coefficient, the reasonable setting range of the lightning protection gap can be determined more accurately. This helps to avoid the risk of the lightning protection gap being set too small, causing the lightning impulse current to directly pass through the equipment, causing equipment damage or tripping, and the gap being set too large, increasing the length and range of the lightning wave propagation line in the power grid.

[0040] To balance the lightning protection effect and equipment safety, a reasonable lightning protection gap setting needs to find a balance between the lightning protection effect and equipment safety. The line lightning protection influence coefficient provides a scientific basis for this balance point. By comparing the line lightning protection influence coefficient under different lightning protection gap settings, a lightning protection gap setting value that can effectively prevent lightning strikes and ensure equipment safety can be selected.

[0041] Reduce the risk of lightning impact damage to power grid equipment. The analysis of line lightning impact coefficient helps to identify the weak links of power grid equipment under the action of lightning. By optimizing the lightning protection gap setting, the protection of these weak links can be strengthened, thereby reducing the risk of lightning impact damage to power grid equipment. In addition, the line lightning impact coefficient can also be used to evaluate the effectiveness of lightning protection measures and provide guidance for improving lightning protection design.

[0042] Reduce the occurrence of ground faults and interphase short circuits. Unreasonable lightning protection gap settings may lead to ground faults and interphase short circuits. Through in-depth analysis of the line lightning protection impact coefficient, improper lightning protection gap settings can be discovered and corrected in a timely manner, thereby effectively reducing the occurrence of such faults. This helps to improve the stability and reliability of the power grid and ensure the normal operation of the power system.

[0043] In summary, the line lightning protection influence coefficient has the advantages of clarifying the basis for setting the lightning protection gap, balancing the lightning protection effect and equipment safety, reducing the risk of lightning impact damage to power grid equipment, and reducing the occurrence of grounding faults and phase-to-phase short circuits in solving the problem of unclear lightning protection gap setting. Therefore, in the design and optimization of power grid lightning protection, full attention should be paid to the analysis and application of the line lightning protection influence coefficient.

[0044] In this embodiment, the specific method for obtaining the line lightning resistance influence coefficient is as follows: Mark each lightning protection device node in the lightning monitoring system, obtain the line connection relationship number between the two marked points, obtain the lightning strike ratio and lightning strike detection frequency of each lightning protection device node, and the preset line lightning resistance level and line length between adjacent marked points; According to the line connection relationship number, the proportion of lightning strikes and lightning strike detection frequency of each lightning protection device node are obtained, and the preset line lightning resistance level and line length between adjacent marking points are used to calculate the lightning strike impact fluctuation value.

[0045] The calculation method of the lightning impact fluctuation value is as follows:

[0046] In the formula, is the fluctuation value of lightning impact, is the percentage of lightning strikes on the node, is the lightning detection frequency, is the node number, is the total number of nodes, It is the preset line lightning resistance level between two marking points. is the line length between two nodes; Label the line connection relationship between the node and the marked point, is the total number of links between nodes and markers; Calculate the line lightning resistance coefficient. The specific calculation method is as follows:

[0047] In the formula, is the line lightning resistance coefficient, is the fluctuation value of lightning impact at time x, is the preset standard lightning impact fluctuation value, and g is the range of detection time.

[0048] The power grid operation tripping stability coefficient is used to quantitatively evaluate the tripping time window caused by lightning strikes under different lightning protection gap settings. It comprehensively considers the line length, the number of thunderstorm days, and the number of trips caused by lightning strikes. By analyzing the number of lightning trips under standard thunderstorm days, the lightning resistance performance of the line and the safety and stability of the power grid are obtained. This coefficient not only reflects the line's ability to resist lightning strikes, but also affects the overall reliability and stability of the power grid. It is an indispensable and important reference in the design and optimization of power grid lightning protection.

[0049] Analyzing the tripping stability coefficient of power grid operation has the following advantages in solving the problem that the setting of lightning protection gap is not clear, which makes it difficult to balance lightning protection effect and equipment safety, increases the risk of lightning impact damage to power grid equipment, or causes grounding faults and phase-to-phase short circuits due to improper gap setting: Clarify the rationality of the lightning protection gap setting. The power grid operation tripping stability coefficient is an important indicator to measure the line lightning tripping rate, which reflects the stability and reliability of the power grid under the action of lightning strikes. By deeply analyzing the power grid operation tripping stability coefficient, the reasonable setting range of the lightning protection gap can be determined more accurately. This helps to avoid various problems caused by improper lightning protection gap setting, such as equipment damage, tripping, grounding fault and phase short circuit.

[0050] To balance the lightning protection effect and equipment safety, a reasonable lightning protection gap setting needs to find a balance between the lightning protection effect and equipment safety. The power grid operation tripping stability coefficient provides a scientific basis for this balance point. By comparing the power grid operation tripping stability coefficient under different lightning protection gap settings, a lightning protection gap setting value that can effectively prevent lightning strikes and ensure equipment safety can be selected. This helps reduce the risk of lightning impact damage to power grid equipment while ensuring the normal operation of the equipment.

[0051] Reduce the lightning trip rate and improve the stability of the power grid. The power grid operation trip stability coefficient is closely related to the lightning trip rate. By optimizing the lightning protection gap setting, the lightning trip rate can be reduced, thereby improving the stability and reliability of the power grid. This helps to reduce power outages caused by lightning strikes and ensure the normal operation of the power system and the power demand of users.

[0052] Reduce the occurrence of ground faults and phase-to-phase short circuits. Unreasonable lightning protection gap settings may lead to ground faults and phase-to-phase short circuits. The power grid operation tripping stability coefficient can be used as one of the important indicators for evaluating the rationality of lightning protection gap settings. By deeply analyzing the power grid operation tripping stability coefficient, improper lightning protection gap settings can be discovered and corrected in a timely manner, thereby effectively reducing the occurrence of ground faults and phase-to-phase short circuits. This helps to improve the safety and reliability of the power grid.

[0053] The grid operation tripping stability coefficient can also provide guidance for grid lightning protection design and optimization. By analyzing the relationship between the grid operation tripping stability coefficient and the lightning protection gap setting, the optimal lightning protection gap setting value can be found, and corresponding preventive measures can be taken to reduce the risk of grid breakdown and lightning protection leakage. This helps to improve the lightning protection capability of the power grid and ensure the safe operation of the power system.

[0054] In this embodiment, the specific method for obtaining the power grid operation tripping stability coefficient is as follows: The specific method for obtaining the power grid operation tripping stability coefficient is as follows: Obtain waveforms of grid operation parameters and timestamps of tripping events changing over time; Perform spectrum analysis on the grid operation parameter signal waveform and the timestamp waveform of the tripping event within the preset time window to identify and extract the main features of the basic state and the tripping event; The main features of the basic state and the tripping event are converted back to the time domain signal based on Fourier transform; and the floating value of the harmonic is calculated according to the relative change amount between the time domain signal and the main features of the basic state and the tripping event; The floating values ​​of harmonics are analyzed and the power grid operation tripping stability coefficient is calculated.

[0055] Among them, the specific calculation formula of the power grid operation tripping stability coefficient is as follows:

[0056] In the formula, is the tripping stability coefficient of the power grid operation, is the number of main features of basic status and tripping events, is the signal quantity of the power grid operation parameter, z is the signal quantity of the power grid operation parameter, j is the label of the main characteristics of the basic state and tripping event, is the inverse Fourier transform, is the waveform of the power grid operation parameters, Assign waveforms to trip events, is the average value of the power grid operation parameters, Assign a mean value to the trip events.

[0057] It should be noted that the main features of the basic state and tripping events are identified and extracted by performing spectral analysis on the grid operation parameter signal waveform and the timestamp waveform of the tripping event to obtain the harmonic composition, and performing harmonic component analysis to obtain the basic waveform component as the main feature of the basic state and tripping events.

[0058] The lightning protection leakage fluctuation coefficient is based on the leakage current data between the lightning protection device and the protected equipment or line under different lightning protection gap settings. By considering the leakage current value and its changing trend, the grounding resistance value and its change, and combining factors such as environmental humidity and temperature, it quantitatively analyzes the lightning protection leakage situation and its development trend, and then evaluates the impact of different lightning protection gap settings on the lightning protection effect of the power grid.

[0059] Analyzing the lightning protection leakage fluctuation coefficient has the following advantages in solving the problem that the setting of the lightning protection gap is not clear, which makes it difficult to balance the lightning protection effect and equipment safety, increases the risk of lightning impact damage to power grid equipment, or causes grounding faults and phase-to-phase short circuits due to improper gap setting: The lightning protection leakage fluctuation coefficient can accurately reflect the leakage performance of the lightning protection device under different gaps. This feature allows us to accurately evaluate the rationality of the lightning protection gap by measuring and analyzing this coefficient. In practical applications, we can determine the optimal setting value of the lightning protection gap based on the size of the lightning protection leakage fluctuation coefficient, thereby ensuring that the lightning protection device can respond quickly and effectively discharge lightning current under lightning impulse.

[0060] Secondly, the lightning protection leakage fluctuation coefficient helps to balance the lightning protection effect and equipment safety. Too large a lightning protection gap may lead to poor lightning protection effect, while too small a gap may increase the safety risk of the equipment. By measuring the lightning protection leakage fluctuation coefficient, we can find the best lightning protection gap setting value, which can ensure both the lightning protection effect and the safe operation of the equipment.

[0061] In addition, the lightning protection leakage fluctuation coefficient can also provide guidance for the optimization design and improvement of lightning protection gaps. By analyzing the variation of this coefficient under different conditions, we can understand the performance characteristics and defects of lightning protection devices, and thus propose targeted optimization designs and improvement measures. This helps to improve the overall performance of lightning protection devices and better protect power grid equipment from lightning damage.

[0062] In summary, the lightning protection leakage fluctuation coefficient has the advantages of high accuracy, good balance effect and strong guidance when screening lightning protection gaps. These advantages make the lightning protection leakage fluctuation coefficient an indispensable and important reference for screening lightning protection gaps. In this embodiment, the specific method for obtaining the lightning protection leakage fluctuation coefficient is as follows: Obtain the leakage current change rate of the power grid during lightning protection under each lightning protection gap; Calculate the leakage current change rate standard deviation and the leakage current change rate average value of the leakage current change rate at different times within a preset time; Calculate the leakage current change rate abnormality coefficient according to the leakage current change rate standard deviation and the leakage current change rate average value; The abnormal coefficient of the leakage current change rate is used to calculate the lightning protection leakage fluctuation coefficient based on the preset lightning protection leakage fluctuation coefficient calculation formula.

[0063] The specific calculation formula of the leakage current change rate abnormal coefficient is as follows:

[0064] The specific calculation formula of the lightning protection leakage fluctuation coefficient is as follows:

[0065] In the formula, is the leakage current change rate abnormality coefficient, is the leakage current change rate, is the total number of leakage current change rates collected within a preset time, and j is the time label; It is the lightning protection leakage fluctuation coefficient.

[0066] This example establishes a lightning protection analysis simulation model based on the simplification and protrusion processing of the DEM of the power grid, obtains the lightning protection gap setting array to be screened by combining the random disturbance of historical data, and sets it in the simulation model to obtain the power grid breakdown potential data and lightning protection data (including the line lightning resistance influence coefficient, the power grid operation tripping stability coefficient and the lightning protection leakage fluctuation coefficient). This method can clarify the basis for setting the lightning protection gap, balance the lightning protection effect and equipment safety, reduce the risk of lightning impact damage to power grid equipment, and reduce the occurrence of grounding faults and phase-to-phase short circuits. At the same time, through in-depth analysis of these coefficients, scientific guidance can be provided for the design and optimization of power grid lightning protection, and the lightning protection capability and safety and stability of the power grid can be improved.

[0067] Embodiment 2, S4, establishes a lightning protection gap assessment model based on a long-term and short-term neural network according to the power grid breakdown potential risk data and lightning protection data.

[0068] In this embodiment, a lightning protection gap assessment model is established based on the long-term and short-term neural network according to the power grid breakdown potential risk data and lightning protection data, specifically: The obtained line lightning resistance influence coefficient, power grid operation tripping stability coefficient and lightning protection leakage fluctuation data are used to construct a lightning protection gap assessment model to generate a lightning protection gap assessment coefficient; The specific calculation formula of the lightning protection gap assessment coefficient is as follows:

[0069] In the formula, is the lightning protection gap assessment coefficient, is the preset proportional coefficient of the line lightning resistance coefficient, It is the preset proportional coefficient of the power grid operation tripping stability coefficient. It is the preset proportional coefficient of the lightning protection leakage fluctuation data. is the line lightning resistance coefficient, is the tripping stability coefficient of the power grid operation, To protect against lightning leakage fluctuations.

[0070] S5, constructing a lightning protection gap change display model with each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model, and performing surface analysis on the lightning protection gap change display model to obtain the screened lightning protection gap setting array, and applying it to power grid lightning protection in complex terrain areas.

[0071] In this embodiment, each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model are used to construct a lightning protection gap change display model, specifically: The output of the lightning protection gap evaluation model and the corresponding lightning protection gap setting array to be screened are mapped to a three-dimensional rectangular coordinate system, and a lightning protection gap change display model is constructed, specifically: The gap width of the lightning protection gap setting array to be screened is used as the X-axis of the three-dimensional rectangular coordinate system; The gap height of the array of lightning protection gaps to be screened is set as the Y axis of the three-dimensional rectangular coordinate system; The lightning protection gap assessment coefficient is taken as the Z axis of the three-dimensional rectangular coordinate system; Mapping each set of lightning protection gap setting arrays to be screened and their corresponding lightning protection gap assessment coefficients to a three-dimensional rectangular coordinate system, wherein each lightning protection gap setting array to be screened corresponds to a rectangular coordinate point; According to the mapped rectangular coordinate points, several rectangular coordinate points are associated using the difference method to obtain a surface and construct a lightning protection gap change display model.

[0072] In this embodiment, a surface analysis is performed on the lightning protection gap change display model to obtain a screened lightning protection gap setting array, which is applied to power grid lightning protection in complex terrain areas, specifically: Obtain several maximum values ​​of the surface of the lightning protection gap change display model; The lightning protection gap setting array to be screened corresponding to the maximum value whose slope of all maximum values ​​is closest to zero is used as the screened lightning protection gap setting array and applied to power grid lightning protection in complex terrain areas.

[0073] This embodiment uses a lightning protection gap assessment model established based on a long-term and short-term neural network to comprehensively consider the line lightning resistance influence coefficient, the power grid operation tripping stability coefficient, and the lightning protection leakage fluctuation data to generate an accurate lightning protection gap assessment coefficient. Furthermore, the lightning protection gap setting array to be screened is combined with the lightning protection gap assessment model to construct a lightning protection gap change display model, and the optimal lightning protection gap setting array is screened out through surface analysis. This method not only improves the accuracy and efficiency of lightning protection gap assessment, but also can be applied to power grid lightning protection in complex terrain areas, effectively improving the safety and stability of the power grid.

[0074] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0075] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0076] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0077] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0078] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0079] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lightning protection method for power grids in complex terrain areas, characterized in that: The steps include: The elevation digital model of the area to be tested is simplified and highlighted based on the DEM of the power grid, and a lightning protection analysis simulation model is established through simulation software; Based on historical data, an initial lightning protection gap setting array is obtained, and the initial lightning protection gap setting array is randomly disturbed several times to obtain several lightning protection gap setting arrays to be screened, wherein the lightning protection gap setting array includes a gap width and a gap height; Set the lightning protection gap of the lightning protection gap setting array to be screened in the lightning protection analysis simulation model, and obtain power grid breakdown potential risk data and lightning protection data; According to the grid breakdown potential data and lightning protection data, a lightning protection gap assessment model is established based on long-term and short-term neural networks; A lightning protection gap change display model is constructed by combining each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model. A surface analysis is performed on the lightning protection gap change display model to obtain the screened lightning protection gap setting array, which is then applied to power grid lightning protection in complex terrain areas.

2. A lightning protection method for power grids in complex terrain areas according to claim 1, characterized in that: The elevation digital model of the area to be measured is simplified and highlighted based on the DEM of the power grid, and a lightning protection analysis simulation model is established through simulation software, specifically: Obtain DEM data of the area to be measured and preprocess the DEM data; According to the layout and characteristics of the power grid, the DEM data is subjected to dimensionality reduction and resampling of terrain height information to highlight the terrain characteristics of the power grid, wherein the terrain characteristics of the power grid include the terrain characteristics around the key positions of the power grid, and the key positions of the power grid include the substation and the transmission line. Based on the power system simulation software, a lightning protection analysis simulation model is established according to the simplified and highlighted DEM data and power grid layout information.

3. A lightning protection method for power grids in complex terrain areas according to claim 2, characterized in that: The initial lightning protection gap setting array is randomly disturbed several times to obtain several lightning protection gap setting arrays to be screened, specifically: According to historical data, obtain the variation range of gap width and gap height; According to the computing resources and time constraints, set the number of random perturbations; The gap width and gap height are adjusted according to the number of random disturbances, and the gap width and gap height obtained after each disturbance are recorded to obtain a plurality of lightning protection gap setting arrays to be screened.

4. A lightning protection method for power grids in complex terrain areas according to claim 3, characterized in that: The grid breakdown hidden danger data includes the line lightning resistance influence coefficient and the grid operation tripping stability coefficient; the specific method for obtaining the line lightning resistance influence coefficient is as follows: Mark each lightning protection device node in the lightning monitoring system, obtain the line connection relationship number between the two marked points, obtain the lightning strike ratio and lightning strike detection frequency of each lightning protection device node, and the preset line lightning resistance level and line length between adjacent marked points; According to the line connection relationship number, the proportion of lightning strikes and the lightning strike detection frequency of each lightning protection device node are obtained, and the lightning impact fluctuation value is calculated based on the preset line lightning resistance level and line length between adjacent marking points. The line lightning resistance influence coefficient is calculated based on the lightning impact fluctuation value based on the line lightning resistance influence coefficient.

5. A lightning protection method for power grids in complex terrain areas according to claim 4, characterized in that: The specific method for obtaining the power grid operation tripping stability coefficient is as follows: The specific method for obtaining the power grid operation tripping stability coefficient is as follows: Obtain waveforms of grid operation parameters and timestamps of tripping events changing over time; Perform spectrum analysis on the grid operation parameter signal waveform and the timestamp waveform of the tripping event within the preset time window to identify and extract the main features of the basic state and the tripping event; The main features of the basic state and the tripping event are converted back to the time domain signal based on Fourier transform; and the floating value of the harmonic is calculated according to the relative change amount between the time domain signal and the main features of the basic state and the tripping event; The floating values ​​of harmonics are analyzed and the power grid operation tripping stability coefficient is calculated.

6. A lightning protection method for power grids in complex terrain areas according to claim 5, characterized in that: The lightning protection data includes a lightning protection leakage fluctuation coefficient; the specific method for obtaining the lightning protection leakage fluctuation coefficient is as follows: Obtain the leakage current change rate of the power grid during lightning protection under each lightning protection gap; Calculate the leakage current change rate standard deviation and the leakage current change rate average value of the leakage current change rate at different times within a preset time; Calculate the leakage current change rate abnormality coefficient according to the leakage current change rate standard deviation and the leakage current change rate average value; The abnormal coefficient of the leakage current change rate is used to calculate the lightning protection leakage fluctuation coefficient based on the preset lightning protection leakage fluctuation coefficient calculation formula.

7. A lightning protection method for power grids in complex terrain areas according to claim 6, characterized in that: The lightning protection gap change display model is constructed by setting each lightning protection gap array to be screened and the corresponding lightning protection gap evaluation model, specifically: The output of the lightning protection gap evaluation model and the corresponding lightning protection gap setting array to be screened are mapped to a three-dimensional rectangular coordinate system, and a lightning protection gap change display model is constructed, specifically: The gap width of the lightning protection gap setting array to be screened is used as the X-axis of the three-dimensional rectangular coordinate system; The gap height of the array of lightning protection gaps to be screened is set as the Y axis of the three-dimensional rectangular coordinate system; The lightning protection gap assessment coefficient is taken as the Z axis of the three-dimensional rectangular coordinate system; Mapping each set of lightning protection gap setting arrays to be screened and their corresponding lightning protection gap assessment coefficients to a three-dimensional rectangular coordinate system, wherein each lightning protection gap setting array to be screened corresponds to a rectangular coordinate point; According to the mapped rectangular coordinate points, several rectangular coordinate points are associated using the difference method to obtain a surface and construct a lightning protection gap change display model.

8. A lightning protection method for power grids in complex terrain areas according to claim 7, characterized in that: The surface analysis of the lightning protection gap change display model is performed to obtain a screened lightning protection gap setting array, which is applied to power grid lightning protection in complex terrain areas, specifically: Obtain several maximum values ​​of the surface of the lightning protection gap change display model; The lightning protection gap setting array to be screened corresponding to the maximum value whose slope of all maximum values ​​is closest to zero is used as the screened lightning protection gap setting array and applied to power grid lightning protection in complex terrain areas.

9. A lightning protection method for power grids in complex terrain areas according to claim 8, characterized in that: The calculation method of the lightning impact fluctuation value is as follows: In the formula, is the fluctuation value of lightning impact, is the percentage of lightning strikes on the node, is the lightning detection frequency, is the node number, is the total number of nodes, It is the preset line lightning resistance level between two marking points. is the line length between two nodes; Label the line connection relationship between the node and the marked point, is the total number of links between nodes and markers; Calculate the line lightning resistance coefficient. The specific calculation method is as follows: In the formula, is the line lightning resistance coefficient, is the fluctuation value of the lightning impact at time x, is the preset standard lightning impact fluctuation value, and g is the range of detection time.

10. A system for implementing the lightning protection method for power grid in complex terrain area as claimed in any one of claims 1 to 9, characterized in that: It includes a simulation model building module, a lightning protection gap setting array acquisition module, a data acquisition module, a lightning protection gap evaluation module and a lightning protection gap screening module; The simulation model building module is used to simplify and highlight the elevation digital model of the area to be tested based on the DEM of the power grid, and to establish a lightning protection analysis simulation model through simulation software; A lightning protection gap setting array acquisition module is used to acquire an initial lightning protection gap setting array based on historical data, and to perform several random disturbances on the initial lightning protection gap setting array to obtain several lightning protection gap setting arrays to be screened, wherein the lightning protection gap setting array includes a gap width and a gap height; A data acquisition module is used to set the lightning protection gap of the lightning protection gap setting array to be screened and the lightning protection analysis simulation model, and obtain the power grid breakdown hidden danger data and lightning protection data; A lightning protection gap assessment module is used to establish a lightning protection gap assessment model based on long-term and short-term neural networks according to power grid breakdown potential risk data and lightning protection data; The lightning protection gap screening module is used to construct a lightning protection gap change display model based on each lightning protection gap setting array to be screened and the corresponding lightning protection gap evaluation model, and perform surface analysis on the lightning protection gap change display model to obtain the screened lightning protection gap setting array, which is applied to power grid lightning protection in complex terrain areas.

Images