A method, device, equipment and storage medium for analyzing transient process of grounding grid

Abstract

The present application provides a method, device, equipment and storage medium for analyzing the transient process of a grounding grid. The method includes obtaining parameter information of soil, a main grounding grid and a secondary equipotential grounding grid, and constructing a transient process analysis model of a grounding grid including a non-ideal earth. The method determines the maximum frequency of the transient current and calculates the minimum wavelength, thereby dividing the main grounding grid and the secondary equipotential grounding grid into multiple segments with a length not exceeding one-sixth of the minimum wavelength to ensure the accuracy of the analysis. Then, the model parameters are set based on the segmentation and parameter information, the transient current at the preset observation point is obtained, and fast Fourier decomposition is performed on it to convert it into a frequency domain waveform. Representative frequency points are selected for excitation to obtain the transient response characteristics in the frequency domain, and then the time domain transient waveform of the observation point is calculated by inverse Fourier decomposition, and finally the transient process characteristics of the grounding grid are determined. This method improves the accuracy of the transient process analysis of the grounding grid through refined modeling and segmented processing.

Description

Technical Field

[0001] The present application relates to the field of grounding grids, and in particular to a method, device, equipment and storage medium for analyzing transient processes of a grounding grid. Background Art

[0002] With the continuous development of power systems, the requirements for the safety and stability of grounding grids are becoming increasingly stringent. As a critical component of power systems, the performance of grounding grids directly impacts system reliability and the safety of personnel and equipment. Especially during transient events such as lightning, grounding grids must withstand massive transient current and voltage surges. Therefore, analyzing and evaluating grounding grid transients is particularly important.

[0003] Traditionally, grounding grid analysis has focused primarily on steady-state characteristics, such as ground resistance and ground potential. However, during transient conditions, due to the rapid changes in current and voltage, the performance of the grounding grid is affected by many more factors, such as soil nonlinearity, the grid's geometry, and the frequency and waveform of the current. Consequently, traditional steady-state analysis methods are no longer sufficient for accurately assessing the transient characteristics of grounding grids. Summary of the Invention

[0004] The purpose of this application is to overcome the above-mentioned defects in the prior art and provide a grounding grid transient process analysis method, device, equipment and storage medium.

[0005] This application provides a grounding grid transient process analysis method, including:

[0006] Obtain parameter information of soil, primary grounding grid and secondary equipotential grounding grid;

[0007] Construct a transient process analysis model for the grounding grid including non-ideal earth, primary grounding grid and secondary equipotential grounding grid;

[0008] determining a maximum frequency of the transient current, and calculating a minimum wavelength of the transient current based on the maximum frequency;

[0009] Dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of each segment is less than or equal to one sixth of the minimum wavelength;

[0010] Setting model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model;

[0011] Obtaining the transient current at a preset observation point during the transient process according to the grounding grid transient process analysis model;

[0012] Performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain;

[0013] Selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain;

[0014] Performing reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at the observation point;

[0015] The transient process characteristics of the grounding grid are determined according to the time-domain transient waveform.

[0016] Optionally, obtaining parameter information of the soil, the primary grounding grid, and the secondary equipotential grounding grid includes:

[0017] Soil parameter information: soil conductivity, relative dielectric constant, relative magnetic permeability;

[0018] Parameter information of the main grounding grid and secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

[0019] Optionally, constructing a grounding grid transient process analysis model including a non-ideal earth, a primary grounding grid, and a secondary equipotential grounding grid according to the parameter information includes:

[0020] Determine the need for transient process analysis of the grounding grid;

[0021] The physical models of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid constituting the grounding grid transient process analysis model and their relative positional relationships are determined according to the analysis requirements.

[0022] Optionally, determining the maximum frequency of the transient current and calculating the minimum wavelength of the transient current according to the maximum frequency includes:

[0023] Determine the maximum frequency of transient current according to the type of transient electromagnetic disturbance suffered by the grounding grid;

[0024] The minimum wavelength corresponding to the maximum frequency is calculated according to electromagnetic wave propagation theory.

[0025] Optionally, obtaining a transient current at a preset observation point during a transient process based on the grounding grid transient process analysis model includes:

[0026] Set up an excitation source in the model to simulate the transient current generated by actual faults or operations, and observe the current response at the preset observation points;

[0027] By comparing the response values ​​of the current response at different frequency points, the transient response characteristics of the grounding grid in the frequency domain are obtained, including: frequency response curve, resonant frequency, and impedance characteristics.

[0028] Optionally, determining the transient process characteristics of the grounding grid according to the time-domain transient waveform includes:

[0029] The voltage rise and current uneven distribution of the grounding grid during the transient process are evaluated based on the peak value, duration and oscillation frequency of the time domain transient waveform.

[0030] Optionally, the main grounding grid and the secondary equipotential grounding grid are connected via a conductor, and the secondary equipotential grounding grids are connected via copper busbars.

[0031] The present application also provides a grounding grid transient process analysis device, comprising:

[0032] Acquisition module, obtains parameter information of soil, main grounding grid and secondary equipotential grounding grid;

[0033] Model module, which constructs a transient process analysis model of the grounding network including non-ideal earth, main grounding network and secondary equipotential grounding network;

[0034] a wavelength module, determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency;

[0035] A segmentation module, dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segment is ≤ one sixth of the minimum wavelength;

[0036] a parameter module, which sets model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model;

[0037] A calculation module, which obtains the transient current of a preset observation point during the transient process according to the grounding grid transient process analysis model;

[0038] a conversion module, performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain;

[0039] A characteristic module, selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain;

[0040] A waveform module performs reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at an observation point;

[0041] The result module determines the transient process characteristics of the grounding grid according to the time domain transient waveform.

[0042] Optionally, obtaining parameter information of the soil, the primary grounding grid, and the secondary equipotential grounding grid includes:

[0043] Soil parameter information: soil conductivity, relative dielectric constant, relative magnetic permeability;

[0044] Parameter information of the main grounding grid and secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

[0045] Optionally, the model module constructs a grounding grid transient process analysis model including a non-ideal earth, a main grounding grid, and a secondary equipotential grounding grid according to the parameter information, including:

[0046] Determine the need for transient process analysis of the grounding grid;

[0047] The physical models of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid constituting the grounding grid transient process analysis model and their relative positional relationships are determined according to the analysis requirements.

[0048] Optionally, the wavelength module determines the maximum frequency of the transient current, and calculates the minimum wavelength of the transient current according to the maximum frequency, including:

[0049] Determine the maximum frequency of transient current according to the type of transient electromagnetic disturbance suffered by the grounding grid;

[0050] The minimum wavelength corresponding to the maximum frequency is calculated according to electromagnetic wave propagation theory.

[0051] Optionally, the calculation module obtains the transient current at a preset observation point during the transient process based on the grounding grid transient process analysis model, including:

[0052] Set up an excitation source in the model to simulate the transient current generated by actual faults or operations, and observe the current response at the preset observation points;

[0053] By comparing the response values ​​of the current response at different frequency points, the transient response characteristics of the grounding grid in the frequency domain are obtained, including: frequency response curve, resonant frequency, and impedance characteristics.

[0054] Optionally, determining the transient process characteristics of the grounding grid according to the time-domain transient waveform includes:

[0055] The voltage rise and current uneven distribution of the grounding grid during the transient process are evaluated based on the peak value, duration and oscillation frequency of the time domain transient waveform.

[0056] Optionally, the main grounding grid and the secondary equipotential grounding grid are connected via a conductor, and the secondary equipotential grounding grids are connected via copper busbars.

[0057] The present application also provides a grounding grid transient process analysis device, comprising:

[0058] Memory;

[0059] The processor is configured to retrieve the computer executable program of the above-mentioned grounding grid transient process analysis method from the memory, and execute the following steps: obtaining parameter information of soil, main grounding grid and secondary equipotential grounding grid; constructing a grounding grid transient process analysis model including non-ideal earth, main grounding grid and secondary equipotential grounding grid; determining the maximum frequency of transient current, and calculating the minimum wavelength of transient current according to the maximum frequency; dividing the main grounding grid and secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segments is ≤ one-sixth of the minimum wavelength; and calculating the transient process analysis model according to the model parameters of the grounding grid transient process analysis model. The method comprises the following steps: setting model parameters for each segment of the transient process analysis model of the grounding grid; obtaining a transient current at a preset observation point in a transient process according to the transient process analysis model of the grounding grid; performing fast Fourier decomposition on a time domain waveform of the transient current at the observation point to convert the waveform into a waveform in the frequency domain; selecting a representative frequency point in the waveform, and using the representative frequency point as a unit for excitation to obtain a transient response characteristic of the grounding grid in the frequency domain; performing inverse Fourier decomposition calculation on the transient response characteristic of the grounding grid in the frequency domain to obtain a time domain transient waveform at the observation point; and determining the transient process characteristics of the grounding grid according to the time domain transient waveform.

[0060] The present application also provides a storage medium, comprising: a computer executable program stored therein, wherein the computer executable program is used to be called by a processor to execute the steps of the above-mentioned grounding grid transient process analysis method.

[0061] The beneficial effects of this application are:

[0062] The present application provides a method for analyzing a transient process of a grounding grid, comprising: obtaining parameter information of soil, a main grounding grid, and a secondary equipotential grounding grid; constructing a transient process analysis model of a grounding grid including a non-ideal earth, a main grounding grid, and a secondary equipotential grounding grid; determining the maximum frequency of a transient current, and calculating the minimum wavelength of the transient current according to the maximum frequency; dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segments is ≤ one-sixth of the minimum wavelength; and calculating the transient process of the grounding grid according to the model parameters of the transient process analysis model. The model parameters are set for each segment of the process analysis model; the transient current of the preset observation point in the transient process is obtained according to the transient process analysis model of the grounding grid; the time domain waveform of the transient current at the observation point is subjected to fast Fourier decomposition and converted into a waveform in the frequency domain; a representative frequency point is selected in the waveform, and the transient response characteristics of the grounding grid in the frequency domain are obtained by excitation with the representative frequency point as a unit; the transient response characteristics of the grounding grid in the frequency domain are subjected to reverse Fourier decomposition calculation to obtain the time domain transient waveform at the observation point; the transient process characteristics of the grounding grid are determined according to the time domain transient waveform. The present application constructs a transient process analysis model of the grounding grid including a non-ideal earth, a main grounding grid and a secondary equipotential grounding grid by obtaining parameter information of the soil, the main grounding grid and the secondary equipotential grounding grid. Then, the main grounding grid and the secondary equipotential grounding grid are divided into multiple segments by determining the maximum frequency of the transient current and calculating the minimum wavelength to ensure the accuracy of the analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a schematic diagram of the transient process analysis flow of the grounding grid in this application;

[0064] Figure 2 This is a schematic diagram of the main grounding grid and secondary equipoint grounding grid model in this application. DETAILED DESCRIPTION

[0065] The following describes exemplary embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that various forms of implementing the present disclosure are not limited by the embodiments set forth herein. Rather, the embodiments are provided to provide a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0066] Please refer to Figure 1 As shown, the present application provides a grounding grid transient process analysis method, comprising:

[0067] S101. Obtain parameter information of soil, primary grounding grid, and secondary equipotential grounding grid.

[0068] Obtain parameter information of soil, primary grounding grid and secondary equipotential grounding grid.

[0069] Soil parameter information includes physical properties such as soil resistivity, dielectric constant, and magnetic permeability.

[0070] The soil parameter information acquisition method includes:

[0071] 1. In the laboratory, use professional soil testing instruments to test soil samples to obtain their physical parameters such as resistivity and dielectric constant.

[0072] 2. Use portable soil testing instruments for testing on site, such as resistivity testers and dielectric constant testers.

[0073] 3. Remote sensing data of soil parameter information can be obtained through meteorological data platforms or websites such as the Geographic Remote Sensing Ecology Network.

[0074] The parameter information of the main grounding grid and the secondary equipotential grounding grid includes: the material, size, structure, resistance value, and connection method of the grounding grid.

[0075] Method for obtaining the parameters of the main grounding grid and the secondary equipotential grounding grid: Consult the design drawings to obtain detailed parameters such as materials, dimensions, and structure. Conduct on-site surveys to understand the connection method and layout of the grounding bodies.

[0076] S102. Construct a grounding grid transient process analysis model including a non-ideal earth, a main grounding grid, and a secondary equipotential grounding grid.

[0077] Characteristics of the non-ideal Earth described in this application include finite conductivity, finite permittivity, and physical and chemical properties that may vary across regions and depths.

[0078] like Figure 2 As shown, the physical models of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid are constructed, including:

[0079] Determine the need for transient process analysis of the grounding grid.

[0080] For example, to evaluate the performance of a grounding grid under transient conditions such as lightning strikes and fault currents, the model needs to include key parameters such as the structure of the grounding grid, conductor material, and soil resistivity.

[0081] Determine the physical structure of the main grounding grid and the secondary equipotential grounding grid, including: the shape, size, conductor material, connection method, etc. of the grounding grid.

[0082] For example, evaluating the performance of a grounding grid under transient conditions such as lightning strikes and fault currents requires ensuring that the model accurately reflects the electrical, thermal, and mechanical characteristics of the grounding grid. Therefore, the construction strategy primarily involves determining the model scope and setting model parameters.

[0083] The model's scope can be expressed using boundary conditions. When setting boundary conditions, factors such as the model's physical context, experimental data, or actual observations are considered. For example, in a grounding grid model, boundary conditions include the grid's shape, dimensions, conductor material, soil resistivity distribution, and external current sources.

[0084] After determining the construction idea, a physical model of the earth is established based on soil parameter information.

[0085] A model is constructed based on the soil conductivity, relative dielectric constant, relative magnetic permeability of the non-ideal earth and the parameters of the main grounding grid and the secondary equipotential grounding grid.

[0086] Specifically, based on the design drawings of the main grounding grid or the results of on-site investigation, a physical model of the main grounding grid is established, including the material properties, size, shape, etc. of the grounding conductor.

[0087] Similar to the main grounding grid, a physical model of the secondary equipotential grounding grid is established based on design drawings or on-site survey results.

[0088] Based on actual site conditions or design drawings, determine the relative positions of the earth, the primary grounding grid, and the secondary equipotential grounding grid. This includes the horizontal and vertical distances between them, as well as their interconnectedness. For example, the primary grounding grid and the secondary equipotential grounding grid are connected by conductors, and the secondary equipotential grounding grids are connected by copper busbars. The primary grounding grid model is constructed below ground level, while the secondary equipotential grounding grid model is constructed above ground level, where ground level refers to the interface between air and soil.

[0089] S103: Determine the maximum frequency of the transient current, and calculate the minimum wavelength of the transient current according to the maximum frequency.

[0090] The frequency of transient currents determines the distribution and attenuation characteristics of currents in the grounding grid. To accurately simulate and analyze the transient behavior of the grounding grid, it is necessary to determine the maximum frequency of transient currents. This maximum frequency is determined by factors such as lightning strikes and switching overvoltages in the system.

[0091] By measuring or estimating the waveform and spectrum of these overvoltages, a reasonable maximum frequency value can be determined.

[0092] After determining the maximum frequency of the transient current, the minimum wavelength λ that propagates in the grounding conductor is calculated based on the propagation characteristics of electromagnetic waves. The wavelength λ is the distance the electromagnetic wave travels in one cycle, and the relationship between it, the velocity c, and the frequency f of the electromagnetic wave is: λ = c / f.

[0093] Furthermore, the velocity c of electromagnetic waves in grounded conductors is affected by the conductor material, cross-sectional dimensions, and surrounding medium. Therefore, when calculating wavelength, it is necessary to consider these factors and use a formula or model to estimate the velocity of electromagnetic waves in grounded conductors.

[0094] S104 , dividing the main grounding grid and the secondary equipotential grounding grid into multiple segments, wherein the maximum length of the segment is ≤ one sixth of the minimum wavelength.

[0095] like Figure 2 As shown in Figure 1, the primary grounding grid is a critical facility in power systems, ensuring the safety of equipment and personnel. It typically consists of a set of interconnected conductors buried underground. A secondary equipotential grounding grid is used in the secondary circuit of a power system to ensure equal potential between all points in the circuit. This helps prevent electrical interference and faults caused by potential differences.

[0096] To ensure the accuracy of the grounding grid model and calculations, the grounding conductors must be segmented. The basic principle of segmentation is to ensure that the length of each conductor segment does not exceed one-sixth of the minimum wavelength λ of the electromagnetic wave within it. This is because when the length of a conductor segment approaches or is less than the wavelength of the electromagnetic wave, the propagation characteristics of the electromagnetic wave within the conductor segment change significantly, resulting in a decrease in model accuracy. Therefore, limiting the conductor segment length to within one-sixth of the minimum wavelength λ ensures model accuracy in transient analysis.

[0097] S105 : Setting model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model.

[0098] Set accurate model parameters for each segment of the grounding grid, including: grounding grid layout, conductor material, conductor cross-section, conductor length, soil resistivity distribution, and transient current frequency characteristics.

[0099] Specifically, the model parameters for each segment are automatically set based on the physical model constructed above. Using the physical model constructed above and the collected parameter information, model parameters are automatically set for each segment of the grounding grid. For each segment, electrical parameters such as resistance and inductance are calculated based on its conductor material, cross-section, and length. The grounding resistance of each segment is calculated based on the soil resistivity distribution map.

[0100] S106. Obtaining transient currents at preset observation points during the transient process according to the grounding grid transient process analysis model.

[0101] The grounding grid transient process analysis model includes key information such as the grounding grid's geometric structure, material properties, soil resistivity distribution, etc., and has been appropriately segmented and parameterized according to actual needs.

[0102] Select specific observation points on the grounding grid. These observation points can be nodes of the grounding grid, midpoints of conductor segments, or other critical locations.

[0103] Use simulation software to run a grounding grid transient analysis model to simulate the propagation and distribution of transient currents in the grounding grid. During the simulation, the transient current value at each time point is calculated based on the preset model and parameters.

[0104] In the simulation results, the transient current values ​​at each time point at the preset observation points are extracted. These values ​​are presented in the form of tables or curves, which can intuitively reflect the changes in transient current in the grounding grid over time.

[0105] S107 , performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain.

[0106] Fast Fourier Transform (FFT) is an efficient algorithm that can convert signals from the time domain (time domain) to the frequency domain (frequency domain), thereby revealing the spectral components of the signal.

[0107] In grounding grid transient process analysis, FFT helps understand the distribution of excitation current or transient current at different frequencies, which is very useful for evaluating the frequency response characteristics of the grounding system, identifying harmonic components, and performing fault diagnosis.

[0108] This application focuses on the time domain waveform I(t) of the transient current, which may be obtained through actual measurement or calculated through a simulation model.

[0109] Make sure the time domain signal I(t) is discrete, that is, it is a series of values ​​sampled at specific points in time. If the signal is continuous, it needs to be sampled first.

[0110] Use the FFT algorithm to process the time domain signal I(t), and the expression is as follows:

[0111]

[0112] Where I(ω) is the spectrum signal of the excitation current; I(t) is the time domain signal of the excitation current; ω is the angular frequency; and t is the time.

[0113] The FFT algorithm computes the spectrum signal I(ω) corresponding to each frequency component (or angular frequency ω). Angular frequency ω is 2π times the frequency f (ω = 2πf), but in the context of the FFT, angular frequencies are usually dealt with directly because they are more directly related to the Fourier transform in complex exponential form.

[0114] The result of the FFT is a complex array, where each element corresponds to the spectrum signal I(ω) at a specific angular frequency ω. The real part of this complex array represents the cosine component at that frequency, and the imaginary part represents the sine component.

[0115] By calculating the amplitude (i.e., the modulus of the complex number) and phase (i.e., the argument of the complex number) of each frequency component, the waveform in the frequency domain is obtained, which describes the intensity of the signal at different frequencies.

[0116] Analyze frequency domain waveforms to identify major frequency components and harmonics.

[0117] S108 , selecting a representative frequency point in the waveform, and using the representative frequency point as a unit for excitation to obtain a transient response characteristic of the grounding grid in the frequency domain.

[0118] When analyzing a grounding grid, understanding its transient response characteristics at different frequencies is crucial to ensuring system safety and stability. This process involves selecting representative frequencies from the excitation spectrum and calculating the voltage and current responses at observation points induced by unit excitation at these frequencies.

[0119] From the excitation spectrum, select a series of representative frequency points for subsequent analysis. These frequency points include the main frequency components and key harmonic frequencies. When selecting frequency points, ensure that they fully reflect the frequency domain response characteristics of the grounding grid.

[0120] Build a mathematical model of the grounding grid. This model should include all spatial elements, including the grounding grid conductors (above and below ground), the soil, the ground, and the air. In the model, set the excitation as a voltage source or a current source. Depending on your needs, you can also configure multiple excitation sources to work together to simulate a more complex electromagnetic environment.

[0121] For each selected frequency point, a unit excitation is defined, that is, a sinusoidal excitation signal with unit amplitude is applied at the frequency point.

[0122] Calculate the voltage and current responses at each observation point due to a unit excitation at each selected frequency. These responses are obtained by numerically solving the electromagnetic field equations. Record the voltage and current responses at each frequency for subsequent analysis. By comparing the current response values ​​at different frequencies, the transient response characteristics of the grounding grid in the frequency domain, such as the frequency response curve, resonant frequency, and impedance characteristics, are obtained.

[0123] S109 , performing inverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at the observation point.

[0124] In electromagnetic field and circuit analysis, conversion between the frequency domain and the time domain is crucial for understanding a system's dynamic behavior. After performing calculations on a system in the frequency domain, such as obtaining voltage and current spectrum signals, it is often necessary to convert these results back to the time domain to observe and analyze the system's transient waveforms. The following describes this process in detail.

[0125] Frequency-domain analysis yields a series of voltage and current spectrum signals corresponding to different angular frequencies ω. These signals describe the system's response characteristics at different frequencies. For voltage, there's the unmodulated voltage spectrum signal, Vo(ω); for current, there's the excitation current spectrum signal, I(ω), and the unmodulated current spectrum signal, Io(ω), which can be calculated from it.

[0126] In order to convert the frequency domain signal back to the time domain, the inverse Fourier decomposition (inverse Fourier transform) is used. The formula for the inverse Fourier transform is as follows:

[0127]

[0128] Among them, V(t) is the time domain signal of voltage; I(t) is the time domain signal of current; Vo(ω) is the unmodulated voltage spectrum signal; Io(ω) is the unmodulated current spectrum signal; I(ω) is the spectrum signal of excitation current; t is time; ω is angular frequency.

[0129] By performing an inverse Fourier transform, we obtain the time-domain voltage V(t) and current I(t) signals at the observation point. These signals describe the dynamic behavior of the system over time, including any transient or transient effects.

[0130] S110 determines the transient process characteristics of the grounding grid according to the time domain transient waveform.

[0131] Voltage and current relationship: Analyze the relationship between the voltage and current waveforms at the observation point, such as phase difference, amplitude ratio, etc., to understand the impedance characteristics and current distribution of the grounding grid.

[0132] Transient response speed: This function evaluates the grounding grid's response speed to an excitation signal by examining parameters such as waveform rise and fall times. A faster response speed generally means better energy dissipation and lower potential rise.

[0133] Oscillation characteristics: Analyze the oscillation phenomena in the waveform, such as damped oscillation and resonance, to understand the dynamic stability and potential resonant frequency of the grounding grid.

[0134] The present application also provides a grounding grid transient process analysis device, comprising:

[0135] Acquisition module, obtains parameter information of soil, main grounding grid and secondary equipotential grounding grid;

[0136] Model module, which constructs a transient process analysis model of the grounding network including non-ideal earth, main grounding network and secondary equipotential grounding network;

[0137] a wavelength module, determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency;

[0138] A segmentation module, dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segment is ≤ one sixth of the minimum wavelength;

[0139] a parameter module, which sets model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model;

[0140] A calculation module, which obtains the transient current of a preset observation point during the transient process according to the grounding grid transient process analysis model;

[0141] a conversion module, performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain;

[0142] A characteristic module, selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain;

[0143] A waveform module performs reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at an observation point;

[0144] The result module determines the transient process characteristics of the grounding grid according to the time domain transient waveform.

[0145] The present application also provides a grounding grid transient process analysis device, comprising:

[0146] Memory;

[0147] The processor is configured to retrieve the computer executable program of the above-mentioned grounding grid transient process analysis method from the memory, and execute the following steps: obtaining parameter information of soil, main grounding grid and secondary equipotential grounding grid; constructing a grounding grid transient process analysis model including non-ideal earth, main grounding grid and secondary equipotential grounding grid; determining the maximum frequency of transient current, and calculating the minimum wavelength of transient current according to the maximum frequency; dividing the main grounding grid and secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segments is ≤ one-sixth of the minimum wavelength; and calculating the transient process analysis model according to the model parameters of the grounding grid transient process analysis model. The method comprises the following steps: setting model parameters for each segment of the transient process analysis model of the grounding grid; obtaining a transient current at a preset observation point in a transient process according to the transient process analysis model of the grounding grid; performing fast Fourier decomposition on a time domain waveform of the transient current at the observation point to convert the waveform into a waveform in the frequency domain; selecting a representative frequency point in the waveform, and using the representative frequency point as a unit for excitation to obtain a transient response characteristic of the grounding grid in the frequency domain; performing inverse Fourier decomposition calculation on the transient response characteristic of the grounding grid in the frequency domain to obtain a time domain transient waveform at the observation point; and determining the transient process characteristics of the grounding grid according to the time domain transient waveform.

[0148] The present application also provides a storage medium, comprising: a computer executable program stored therein, wherein the computer executable program is used to be called by a processor to execute the steps of the above-mentioned grounding grid transient process analysis method.

[0149] Although the present invention is disclosed above with reference to the embodiments, it is not intended to limit the scope of protection of the present invention. Any changes and modifications made by any technician familiar with the technology without departing from the concept and scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for analyzing transient processes of a grounding grid, characterized in that: include: Obtain parameter information of soil, primary grounding grid and secondary equipotential grounding grid; A grounding grid transient process analysis model is constructed based on the parameter information of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid; Determining the maximum frequency of the transient current and calculating the minimum wavelength of the transient current based on the maximum frequency, including: determining the maximum frequency of the transient current based on the type of transient electromagnetic disturbance suffered by the grounding grid; and calculating the minimum wavelength corresponding to the maximum frequency based on an electromagnetic wave propagation algorithm; Dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of each segment is less than or equal to one sixth of the minimum wavelength; Setting model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model; Obtaining the transient current at a preset observation point during the transient process according to the grounding grid transient process analysis model; Performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain; Selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain; Performing reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform of the observation point; determining transient process characteristics of the grounding grid according to the time-domain transient waveform; Among them, the main grounding grid and the secondary equipotential grounding grid are connected by conductors, and the secondary equipotential grounding grids are connected by copper bars; the main grounding grid model is built below the ground, and the secondary equipotential grounding grid model is built above the ground, and the ground refers to the interface between air and soil.

2. A grounding grid transient process analysis method according to claim 1, characterized in that: The obtaining of parameter information of the soil, the primary grounding grid, and the secondary equipotential grounding grid includes: Soil parameter information: soil electrical conductivity, relative permittivity and relative magnetic permeability; Parameter information of the main grounding grid and secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

3. A grounding grid transient process analysis method according to claim 1, characterized in that: A grounding grid transient process analysis model is constructed based on the parameter information of the non-ideal earth, the primary grounding grid, and the secondary equipotential grounding grid, including: Determine the need for transient process analysis of the grounding grid; The physical models of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid constituting the grounding grid transient process analysis model and their relative positional relationships are determined according to the analysis requirements.

4. A grounding grid transient process analysis method according to claim 1, characterized in that: Obtaining a transient current at a preset observation point during a transient process according to the grounding grid transient process analysis model includes: Setting an excitation source in the grounding grid transient process analysis model to simulate the transient current generated by an actual fault or operation, and observing the current response at a preset observation point; By comparing the response values ​​of the current response at different frequency points, the transient response characteristics of the grounding grid in the frequency domain are obtained, including: frequency response curve, resonant frequency and impedance characteristics.

5. A grounding grid transient process analysis method according to claim 1, characterized in that: Determining the transient process characteristics of the grounding grid according to the time domain transient waveform includes: The voltage rise and current uneven distribution of the grounding grid during the transient process are evaluated based on the peak value, duration and oscillation frequency of the time domain transient waveform.

6. A grounding grid transient process analysis device, characterized in that: include: Acquisition module, obtains parameter information of soil, main grounding grid and secondary equipotential grounding grid; Model module, which constructs a transient process analysis model of the grounding network including non-ideal earth, main grounding network and secondary equipotential grounding network; a wavelength module, determining the maximum frequency of the transient current and calculating the minimum wavelength of the transient current based on the maximum frequency, including: determining the maximum frequency of the transient current based on the type of transient electromagnetic disturbance suffered by the grounding grid; and calculating the minimum wavelength corresponding to the maximum frequency based on an electromagnetic wave propagation algorithm; A segmentation module, dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of the segment is ≤ one sixth of the minimum wavelength; a parameter module, which sets model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model; A calculation module, which obtains the transient current of a preset observation point during the transient process according to the grounding grid transient process analysis model; a conversion module, performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain; A characteristic module, selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain; A waveform module performs reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at an observation point; A result module, which determines the transient process characteristics of the grounding grid according to the time domain transient waveform; Among them, the main grounding grid and the secondary equipotential grounding grid are connected by conductors, and the secondary equipotential grounding grids are connected by copper bars; the main grounding grid model is built below the ground, and the secondary equipotential grounding grid model is built above the ground, and the ground refers to the interface between air and soil.

7. The grounding grid transient process analysis device according to claim 6, characterized in that: The obtaining of parameter information of the soil, the primary grounding grid, and the secondary equipotential grounding grid includes: Soil parameter information: soil electrical conductivity, relative permittivity and relative magnetic permeability; Parameter information of the main grounding grid and secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

8. The grounding grid transient process analysis device according to claim 6, characterized in that: The model module constructs a grounding grid transient process analysis model including a non-ideal earth, a main grounding grid, and a secondary equipotential grounding grid according to the parameter information, including: Determine the need for transient process analysis of the grounding grid; The physical models of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid constituting the grounding grid transient process analysis model and their relative positional relationships are determined according to the analysis requirements.

9. The grounding grid transient process analysis device according to claim 6, characterized in that: The calculation module obtains the transient current of a preset observation point in the transient process based on the grounding grid transient process analysis model, including: Set up an excitation source in the model to simulate the transient current generated by actual faults or operations, and observe the current response at the preset observation points; By comparing the response values ​​of the current response at different frequency points, the transient response characteristics of the grounding grid in the frequency domain are obtained, including: frequency response curve, resonant frequency and impedance characteristics.

10. The grounding grid transient process analysis device according to claim 6, characterized in that: Determining the transient process characteristics of the grounding grid according to the time domain transient waveform includes: The voltage rise and current uneven distribution of the grounding grid during the transient process are evaluated based on the peak value, duration and oscillation frequency of the time domain transient waveform.

11. A grounding grid transient process analysis device, characterized in that: include: Memory; A processor, configured to retrieve from the memory a computer executable program of a method for analyzing a transient process of a grounding grid according to any one of claims 1 to 5, and execute the following steps: obtaining parameter information of soil, a primary grounding grid, and a secondary equipotential grounding grid; constructing a transient process analysis model of a grounding grid including a non-ideal earth, a primary grounding grid, and a secondary equipotential grounding grid; determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current based on the maximum frequency; Dividing the main grounding grid and the secondary equipotential grounding grid into a plurality of segments, wherein the maximum length of each segment is less than or equal to one sixth of the minimum wavelength; Setting model parameters for each of the segments of the grounding grid transient process analysis model according to the model parameters of the grounding grid transient process analysis model; obtaining transient currents at preset observation points during a transient process according to the grounding grid transient process analysis model; Performing fast Fourier decomposition on the time-domain waveform of the transient current at the observation point to convert it into a waveform in the frequency domain; Selecting a representative frequency point in the waveform, and using the representative frequency point as a unit of excitation to obtain a transient response characteristic of the grounding grid in the frequency domain; Performing reverse Fourier decomposition calculation on the transient response characteristics of the grounding grid in the frequency domain to obtain a time domain transient waveform at the observation point; and determining the transient process characteristics of the grounding grid based on the time domain transient waveform.

12. A storage medium, characterized in that: include: A computer executable program is stored, and the computer executable program is used to be called by a processor to execute the steps of a grounding grid transient process analysis method according to any one of claims 1 to 5.

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