Transient process analysis method, device and equipment of grounding grid and storage medium

Abstract

The invention provides a grounding grid transient process analysis method, device and equipment and a storage medium, and the method comprises the steps: obtaining the parameter information of soil, a main grounding grid and a secondary equipotential grounding grid, and constructing a grounding grid transient process analysis model containing a non-ideal earth. According to the method, the maximum frequency of the transient current is determined, the minimum wavelength is calculated, the main grounding grid and the secondary equipotential grounding grid are divided into a plurality of sections with the length not exceeding one sixth of the minimum wavelength, and the analysis accuracy is ensured. Then, model parameters are set based on the segmentation and parameter information, transient current of a preset observation point is obtained, and the transient current is subjected to fast Fourier decomposition and converted into a frequency domain waveform; a representative frequency point is selected for excitation, transient response characteristics in a frequency domain are obtained, time domain transient waveforms of observation points are obtained through inverse Fourier decomposition calculation, and finally transient process characteristics of the grounding grid are determined. According to the method, through refined modeling and segmented processing, the accuracy of transient process analysis of the grounding grid is improved.

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 higher and higher. As an important part of the power system, the performance of the grounding grid directly affects the operational reliability of the system and the safety of personnel and equipment. Especially in transient processes such as lightning, the grounding grid needs to withstand huge transient current and voltage shocks, so it is particularly important to analyze and evaluate the transient process of the grounding grid.

[0003] Traditionally, the analysis of grounding grids mainly focuses on steady-state characteristics, such as grounding resistance, grounding potential, etc. However, during transient processes, due to the rapid changes in current and voltage, the performance of the grounding grid will be affected by more factors, such as soil nonlinearity, grounding grid geometry, current frequency and waveform, etc. Therefore, traditional steady-state analysis methods can no longer meet the needs of accurately evaluating the transient characteristics of grounding grids. Summary of the invention

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

[0005] The present application provides a method for analyzing a transient process of a grounding grid, including:

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

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

[0008] Determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency;

[0009] Divide 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;

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

[0012] Performing fast Fourier decomposition on the transient current time domain waveform of 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 to excite 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 an observation point;

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

[0016] Optionally, the obtaining of parameter information of the soil, the main 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 the secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

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

[0020] Determine the needs 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 in a transient process based on the grounding grid transient process analysis model includes:

[0026] Set the 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 point;

[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 a copper busbar.

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

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

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

[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 segments 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, for obtaining a transient current at a preset observation point in a transient process according to the transient process analysis model of the grounding grid;

[0038] A conversion module, performing fast Fourier decomposition on the transient current time domain waveform of 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 for 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, the obtaining of parameter information of the soil, the main 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 the 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 needs 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 of a preset observation point in the transient process based on the transient process analysis model of the grounding grid, including:

[0052] Set the 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 point;

[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 a copper busbar.

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

[0058] Memory;

[0059] The processor is used to retrieve the computer executable program of the above-mentioned grounding grid transient process analysis method from the memory, and execute: 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 multiple segments, and the maximum length of the segment is ≤ one sixth of the minimum wavelength; calculating the transient current according to the model parameters of the grounding grid transient process analysis model; The model parameters are set for each segment of the transient process analysis model of the grounding grid; the transient current at 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 to be converted into a waveform in the frequency domain; a representative frequency point is selected from 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.

[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 the transient process of a grounding grid, including: 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 of the grounding grid. The model parameters are set for each segment of the process analysis model; the transient current at 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 from 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 acquiring 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 It is a schematic diagram of the main grounding grid and secondary equipoint grounding grid model in this application. DETAILED DESCRIPTION

[0065] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that various forms of implementing the present disclosure should not be limited by the embodiments set forth herein. On the contrary, the embodiments are provided to more thoroughly understand 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 method for analyzing a transient process of a grounding grid, 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 physical parameters such as resistivity and dielectric constant.

[0072] 2. Use portable soil testing instruments on site for testing, 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] Methods for obtaining the parameter information of the main grounding grid and the secondary equipotential grounding grid: Check the design drawings to obtain detailed parameters such as materials, dimensions, and structures. Conduct on-site surveys to understand the connection methods, layout of the grounding bodies, etc.

[0076] S102. Construct a transient process analysis model of a grounding grid 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 model of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid constructed includes:

[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] Taking the performance evaluation of the grounding grid under transient conditions such as lightning strikes and fault currents as an example, it is necessary to ensure that the model can accurately reflect the electrical, thermal and mechanical characteristics of the grounding grid. Therefore, the construction idea mainly includes steps such as determining the model scope and setting model parameters.

[0083] The model range can be represented by boundary conditions. When setting boundary conditions, factors such as the physical background of the model, experimental data or actual observation results are considered. For example, in a grounding grid model, boundary conditions include the shape, size, conductor material, soil resistivity distribution, and external current source of the grounding grid.

[0084] After the construction ideas are determined, 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, and relative magnetic permeability of the non-ideal earth and the parameters of the main grounding grid and the secondary equipotential grounding grid.

[0086] Specifically, according to 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 investigation results.

[0088] According to the actual situation on site or the design drawings, determine the relative position relationship between the earth, the main grounding grid and the secondary equipotential grounding grid. This includes the horizontal distance, vertical distance and connection relationship between them. For example: 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, where the ground 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 current determines the distribution and attenuation characteristics of the current in the grounding grid. In order to accurately simulate and analyze the transient behavior of the grounding grid, it is necessary to determine the maximum frequency of the transient current. The maximum frequency is determined by factors such as lightning impulses 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 propagating in the grounding conductor is calculated based on the propagation characteristics of the electromagnetic wave. The wavelength λ is the distance that the electromagnetic wave propagates in one cycle, and the relationship between it and the speed c and frequency f of the electromagnetic wave is: λ = c / f.

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

[0094] S104, 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.

[0095] like Figure 2 As shown, the main grounding grid is an important facility in the power system to ensure the safety of equipment and personnel. It usually consists of a group of interconnected conductors that are buried underground. The secondary equipotential grounding grid is used in the secondary circuit of the power system to ensure that the potential between each point in the secondary circuit is equal. This helps prevent electrical interference and faults caused by potential differences.

[0096] In order to ensure the accuracy of the grounding grid model and the accuracy of the calculation, the grounding conductor needs to 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 in it. This is because when the length of the conductor segment is close to or less than the wavelength of the electromagnetic wave, the propagation characteristics of the electromagnetic wave in the conductor segment will change significantly, resulting in a decrease in the accuracy of the model. Therefore, limiting the conductor segment to within one sixth of the minimum wavelength λ can ensure the accuracy of the model 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 frequency characteristics of transient current.

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

[0100] S106. Obtaining transient current at a preset observation point in the transient process according to the grounding grid transient process analysis model.

[0101] The transient process analysis model of the grounding grid includes key information such as the geometric structure, material properties, soil resistivity distribution, etc. of the grounding grid, 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 the transient process analysis model of the grounding grid to simulate the propagation and distribution of transient current in the grounding grid. During the simulation process, 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 ​​of the preset observation points at each time point are extracted. These values ​​are presented in the form of tables or curves, which can intuitively reflect the changes of transient current in the grounding network 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 transform a signal from the time domain (time domain) to the frequency domain (frequency domain), thereby revealing the spectral components of the signal.

[0107] In the transient process analysis of the grounding grid, FFT helps to understand the distribution of the 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] The FFT algorithm is used to process the time domain signal I(t), and the expression is as follows:

[0111]

[0112] Wherein, I(ω) is the frequency 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 calculates the spectrum signal I(ω) corresponding to each frequency component (or angular frequency ω). The angular frequency ω is 2π times the frequency f (ω = 2πf), but in the context of FFT, angular frequency is usually processed directly because it is more directly related to the Fourier transform in complex exponential form.

[0114] The result of FFT is a complex array, each element of which 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, a waveform in the frequency domain is obtained, which describes the strength 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] In the process of analyzing the grounding grid, understanding its transient response characteristics at different frequencies is crucial to ensure the safety and stability of the system. This process includes selecting representative frequency points in the spectrum signal of the excitation and calculating the voltage and current responses caused by the unit excitation at these frequency points at the observation point.

[0119] In the excited spectrum signal, a series of representative frequency points are selected for subsequent analysis. These frequency points include main frequency components, key harmonic frequencies, etc. When selecting frequency points, it should be ensured that they can fully reflect the frequency domain response characteristics of the grounding grid.

[0120] Build a mathematical model of the grounding grid. The model should include elements in the space range such as the grounding grid conductor above or below the ground, underground soil, ground, and air. In the model, set the excitation as a voltage source or a current source. According to actual needs, multiple excitation sources can also be set 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 wave excitation signal with unit amplitude is applied at the frequency point.

[0122] Calculate the voltage and current response at the observation point caused by unit excitation at each selected frequency point. These response values ​​are obtained by numerically solving the electromagnetic field equations. Record the voltage and current response values ​​at each frequency point and perform subsequent analysis. 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, such as frequency response curve, resonant frequency, impedance characteristics, etc., 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 an observation point.

[0124] In electromagnetic field and circuit analysis, the conversion between frequency domain and time domain is the key to understanding the dynamic behavior of the system. When calculating the system in the frequency domain, such as obtaining the spectrum signals of voltage and current, it is often necessary to convert these results back to the time domain to observe and analyze the time domain transient waveform of the system. The following is a detailed description of this process.

[0125] In the frequency domain analysis, a series of voltage and current spectrum signals corresponding to different angular frequencies ω are obtained. These signals describe the response characteristics of the system at different frequencies. For voltage, there is an unmodulated voltage spectrum signal Vo(ω); for current, there is an excitation current spectrum signal I(ω) and an unmodulated current spectrum signal Io(ω) that may 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, the time-domain voltage V(t) and current I(t) signals at the observation point are obtained. 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: Evaluate the response speed of the grounding grid to the excitation signal by examining parameters such as waveform rise time and fall time. Faster response speed usually means better energy dissipation capability and lower potential rise.

[0133] Oscillation characteristics: Analyze the oscillation phenomena in the waveform, such as damped oscillation, resonance, etc., 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] An acquisition module obtains parameter information of soil, main grounding grid and secondary equipotential grounding grid;

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

[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 segments 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, for obtaining a transient current at a preset observation point in a transient process according to the transient process analysis model of the grounding grid;

[0141] A conversion module, performing fast Fourier decomposition on the transient current time domain waveform of 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 for 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, including:

[0146] Memory;

[0147] The processor is used to retrieve the computer executable program of the above-mentioned grounding grid transient process analysis method from the memory, and execute: 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 multiple segments, and the maximum length of the segment is ≤ one sixth of the minimum wavelength; calculating the transient current according to the model parameters of the grounding grid transient process analysis model; The model parameters are set for each segment of the transient process analysis model of the grounding grid; the transient current at 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 to be converted into a waveform in the frequency domain; a representative frequency point is selected from 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.

[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 as above by the embodiments, it is not intended to limit the protection scope 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 protection scope of the present invention.

Claims

1. A method for analyzing transient process of grounding grid, characterized in that: include: Obtain parameter information of soil, main grounding grid and secondary equipotential grounding grid; Based on the parameter information of non-ideal earth, main grounding grid and secondary equipotential grounding grid, a transient process analysis model of grounding grid is constructed; Determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency; Divide 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; 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; Acquiring the transient current at a preset observation point during the transient process according to the transient process analysis model of the grounding grid; Performing fast Fourier decomposition on the transient current time domain waveform of 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 to excite 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; The transient process characteristics of the grounding grid are determined according to the time domain transient waveform.

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

3. A method for analyzing transient process of grounding grid according to claim 1, characterized in that: The transient process analysis model of the grounding grid is constructed based on the parameter information of the non-ideal earth, the main grounding grid and the secondary equipotential grounding grid, including: Determine the needs 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 method for analyzing transient process of grounding grid according to claim 1, characterized in that: Determining a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency, comprises: Determine the maximum frequency of transient current according to the type of transient electromagnetic disturbance suffered by the grounding grid; The minimum wavelength corresponding to the maximum frequency is calculated according to an electromagnetic wave propagation algorithm.

5. A method for analyzing transient process of grounding grid according to claim 1, characterized in that: Obtaining the transient current of a preset observation point in the transient process according to the transient process analysis model of the grounding grid 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 of 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.

6. A method for analyzing transient process of grounding grid 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.

7. A method for analyzing transient process of grounding grid according to claim 1, characterized in that: The main grounding grid and the secondary equipotential grounding grid are connected via a conductor, and the secondary equipotential grounding grids are connected via a copper busbar.

8. A grounding grid transient process analysis device, characterized in that: include: An acquisition module obtains parameter information of soil, main grounding grid and secondary equipotential grounding grid; Model module, constructing a transient process analysis model of the grounding grid including non-ideal earth, main grounding grid and secondary equipotential grounding grid; 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; 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 segments 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, for obtaining a transient current at a preset observation point in a transient process according to the transient process analysis model of the grounding grid; A conversion module, performing fast Fourier decomposition on the transient current time domain waveform of 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 to excite and 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; The result module determines the transient process characteristics of the grounding grid according to the time domain transient waveform.

9. A grounding grid transient process analysis device according to claim 8, characterized in that: The obtaining of parameter information of soil, main grounding grid and secondary equipotential grounding grid includes: Soil parameter information: soil conductivity, relative dielectric constant, relative magnetic permeability; Parameter information of the main grounding grid and the secondary equipotential grounding grid: grounding conductor material properties and equivalent radius.

10. A grounding grid transient process analysis device according to claim 8, characterized in that: The model module constructs a transient process analysis model of a grounding network including a non-ideal earth, a main grounding network and a secondary equipotential grounding network according to the parameter information, including: Determine the needs 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.

11. A grounding grid transient process analysis device according to claim 8, characterized in that: 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: Determine the maximum frequency of transient current according to the type of transient electromagnetic disturbance suffered by the grounding grid; The minimum wavelength corresponding to the maximum frequency is calculated according to electromagnetic wave propagation theory.

12. A grounding grid transient process analysis device according to claim 8, characterized in that: The calculation module obtains the transient current of a preset observation point in the transient process based on the transient process analysis model of the grounding grid, including: Set the 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 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.

13. A grounding grid transient process analysis device according to claim 8, 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.

14. A grounding grid transient process analysis device according to claim 8, characterized in that: The main grounding grid and the secondary equipotential grounding grid are connected via a conductor, and the secondary equipotential grounding grids are connected via a copper busbar.

15. A grounding grid transient process analysis device, characterized in that: include: Memory; A processor, used 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 7, and execute: 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 a maximum frequency of a transient current, and calculating a minimum wavelength of the transient current according to the maximum frequency; Divide 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; 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; acquiring transient currents at preset observation points in the transient process according to the grounding grid transient process analysis model; Performing fast Fourier decomposition on the transient current time domain waveform of 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 to excite to obtain a transient response characteristic of the grounding grid in the frequency domain; The transient response characteristics of the grounding grid in the frequency domain are subjected to inverse Fourier decomposition calculation to obtain a time-domain transient waveform at an observation point; and the transient process characteristics of the grounding grid are determined based on the time-domain transient waveform.

16. 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 as described in any one of claims 1 to 7.

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