Metal tube electromagnetic field prediction method, device, equipment, storage medium and product

Abstract

The application relates to a metal pipe electromagnetic field prediction method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: obtaining an electromagnetic transient simulation instruction of a hollow metal pipe simulation model, the electromagnetic transient simulation instruction carrying simulation calculation parameters; obtaining frequency-variable internal impedance fitting parameters, the frequency-variable internal impedance fitting parameters being obtained by vector matching of frequency-variable internal impedance information, the frequency-variable internal impedance information being obtained by superimposing internal boundary impedance information and external boundary impedance information corresponding to the hollow metal pipe simulation model; performing iterative calculation of an external electromagnetic field of the metal pipe based on the simulation calculation parameters, and performing iterative calculation of an internal electromagnetic field of the metal pipe based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters; and obtaining an electromagnetic field prediction result corresponding to the hollow metal pipe simulation model when a preset iteration termination condition is reached. The method can improve the prediction accuracy.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic simulation technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for predicting the electromagnetic field of a metal tube. Background Art

[0002] Electromagnetic transient simulation can study the electromagnetic field distribution and transient response inside and outside metal pipes in situations such as lightning strikes, arc faults, and short circuits. It can accurately assess the transient voltage and current distribution in metal pipes under lightning strikes and switching operations, providing a basis for optimizing overvoltage protection and cable layout. Through simulation analysis, it is possible to predict the performance of cables in power systems under transient overvoltages or other electrical disturbances, identify the shielding effectiveness of different pipe materials, shapes, and layouts, improve shielding design to reduce the impact of electromagnetic interference on the system, optimize interference protection measures in power and communication systems, reduce project costs, minimize failure risks, and improve system operation efficiency.

[0003] Currently, simulation modeling techniques such as the finite-difference time-domain method (FDTD) are commonly used to predict the distribution of electromagnetic energy in the vicinity of a metal tube under broadband impulses. However, electromagnetic transient prediction using FDTD requires the generation of complex, high-order circuit matrices, which reduces the accuracy of electromagnetic transient predictions. Summary of the Invention

[0004] Based on this, it is necessary to provide a metal tube electromagnetic field prediction method, device, computer equipment, computer-readable storage medium and computer program product that can improve prediction accuracy in response to the above technical problems.

[0005] In a first aspect, the present application provides a method for predicting the electromagnetic field of a metal tube, comprising:

[0006] Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0007] Obtain frequency-variable internal impedance fitting parameters. The frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information. The frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0008] Iterative calculation of the external electromagnetic field of the metal tube is performed based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0009] Based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, the electromagnetic field inside the metal tube is iteratively calculated to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0010] When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0011] In a second aspect, the present application further provides a metal tube electromagnetic field prediction device, comprising:

[0012] Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0013] Obtain frequency-variable internal impedance fitting parameters. The frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information. The frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0014] Iterative calculation of the external electromagnetic field of the metal tube is performed based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0015] Based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, the electromagnetic field inside the metal tube is iteratively calculated to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0016] When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0017] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0018] Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0019] Obtain frequency-variable internal impedance fitting parameters. The frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information. The frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0020] Iterative calculation of the external electromagnetic field of the metal tube is performed based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0021] Based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, the electromagnetic field inside the metal tube is iteratively calculated to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0022] When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0023] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0024] Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0025] Obtain frequency-variable internal impedance fitting parameters. The frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information. The frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0026] Iterative calculation of the external electromagnetic field of the metal tube is performed based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0027] Based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, the electromagnetic field inside the metal tube is iteratively calculated to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0028] When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0029] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the following steps:

[0030] Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0031] Obtain frequency-variable internal impedance fitting parameters. The frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information. The frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0032] Iterative calculation of the external electromagnetic field of the metal tube is performed based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0033] Based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, the electromagnetic field inside the metal tube is iteratively calculated to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0034] When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0035] The above-mentioned metal tube electromagnetic field prediction method, device, computer equipment, computer-readable storage medium and computer program product obtain electromagnetic transient simulation instructions for the hollow metal tube simulation model, and the electromagnetic transient simulation instructions carry simulation calculation parameters; obtain frequency-variable internal impedance fitting parameters, and the frequency-variable internal impedance fitting parameters are obtained by vector matching the frequency-variable internal impedance information, and the frequency-variable internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model; based on the simulation calculation parameters, iterative calculation of the external electromagnetic field of the metal tube is performed to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model; based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, iterative calculation of the internal electromagnetic field of the metal tube is performed to obtain the internal electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model; when the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained. That is, the electromagnetic field information inside the metal tube is iteratively calculated by frequency-variable internal impedance fitting parameters, without the need to generate a complex high-order circuit matrix, thereby improving the accuracy of the calculated electromagnetic field information inside the metal tube, and further improving the accuracy of the electromagnetic field prediction results. In addition, by calculating the electromagnetic field information outside the metal tube and the electromagnetic field information inside the metal tube, the electromagnetic fields inside and outside the metal tube can be bidirectionally coupled in each calculation cycle, further improving the accuracy of the calculated results. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 1 is a flow chart of a method for predicting electromagnetic fields of a metal tube according to an embodiment;

[0038] Figure 2 A schematic diagram of setting up a hollow metal tube simulation model in an FDTD grid according to one embodiment;

[0039] Figure 3 A schematic diagram of the principle of establishing a simulation model of a hollow metal tube in one embodiment;

[0040] Figure 4 A schematic diagram of a specific process for predicting the electromagnetic field of a metal tube in a specific embodiment;

[0041] Figure 5 is a structural block diagram of a metal tube electromagnetic field prediction device in one embodiment;

[0042] Figure 6FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] Metal conduits have several important uses in power systems, particularly in power transmission and distribution, and in electrical equipment installation. Key functions include cable protection, shielding and grounding, structural support, heat dissipation, and fire protection.

[0045] 1) Cable protection conduits. Metal conduits are commonly used to protect cables in power systems. When cables are laid in buildings, factories, or underground, they prevent damage from pressure, impact, or other external forces, particularly in power transmission and distribution systems. They protect cables from mechanical damage, chemical corrosion, and other environmental influences, making them particularly suitable for harsh environments or underground installations, ensuring long-term, stable operation of cables.

[0046] 2) Shielding and grounding. Metal conduits provide electromagnetic shielding for cables, reducing electromagnetic interference (EMI) and maintaining stable power transmission, which is particularly important for the operation of sensitive electrical equipment. Furthermore, metal conduits are often connected to a grounding system to prevent potential rises caused by faults in electrical equipment and cables, protecting personnel and equipment.

[0047] 3) Structural support. Metal conduits also serve as structural support in power systems, particularly in cable tray systems. They are used to secure cables to walls, ceilings, or underground, ensuring the stability and reliability of power transmission lines.

[0048] 4) Heat dissipation and fire prevention. The excellent thermal conductivity of metal materials also helps dissipate heat from cables. In power systems, high-load cables generate heat when transmitting large amounts of current. The use of metal conduits can help better dissipate heat from the cables, preventing overheating and extending the cable's service life. In the event of a fire, metal conduits can provide a certain degree of fire protection for cables, preventing the spread of fire and ensuring the operation of critical power systems in the event of a fire, especially in critical infrastructure such as buildings and tunnels.

[0049] Therefore, by analyzing the electromagnetic field distribution and transient response inside and outside the metal pipe simulation model through electromagnetic transient analysis, the transient voltage and current distribution of the metal pipe under conditions such as lightning strikes and switching operations can be accurately evaluated, providing a basis for optimizing overvoltage protection and cable layout.

[0050] In an exemplary embodiment, Figure 1As shown, a method for predicting the electromagnetic field of a metal tube is provided. This embodiment uses the method applied to a terminal as an example for illustration. It is understandable that the method can also be applied to a server, or to a system including a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0051] S102: Obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, where the electromagnetic transient simulation instruction carries simulation calculation parameters.

[0052] In this embodiment, the simulation calculation parameters may be key parameters for calculation using FDTD, and may include calculation area size, grid size, time step, material parameters, excitation, iteration termination conditions, and the like. Among them, the FDTD calculation area size may be determined according to the size of the hollow metal tube to be simulated. This area generally extends outward by about 50% of the space on the basis of including all the hollow metal tubes to be simulated, so as to eliminate the influence of boundary effects, stray signal refraction and reflection, and the like. The grid size may then be determined based on the topological structure of the hollow metal tube. The selection range of the time step is then determined by the minimum FDTD discrete grid size, and must satisfy the Courant-Friedrich-Levy (CFL) criterion to prevent data divergence, oscillation, non-convergence, and other problems that may occur in time domain calculations, i.e.

[0053] Formula (1)

[0054] In the formula, Δx, Δy, and Δz are the minimum grid sizes of the FDTD grid in the three orthogonal directions of X, Y, and Z, c is the propagation speed of light in the corresponding medium, and ∆t refers to the time step. Generally, the FDTD time step is selected as the maximum value in formula (1) to reduce the number of simulations and improve simulation efficiency. Then, according to the spatial position of the simulated hollow metal tube, the corresponding conductivity, dielectric constant, and magnetic permeability are set in the FDTD grid. Then, at the target position, the load is set in the form of a spatial electromagnetic field or a lumped circuit parameter element. The iteration termination condition can include the number of iterations condition and the convergence condition. The number of iterations condition means that the electromagnetic field calculation is terminated when the number of electromagnetic field updates reaches the preset number of iterations. The convergence condition means that the electromagnetic field calculation is terminated when the spatial electromagnetic field is in a steady-state distribution, or forms a periodic change and the waveform deviation between two adjacent periods meets the convergence condition.

[0055] In some embodiments, the terminal can obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, which can be a component in a power simulation system. The hollow metal tube simulation model should be set on an edge of the target orthogonal direction in the FDTD grid and coincide with the electric field vector in the target orthogonal direction. The target orthogonal direction can be set as required. For example, Figure 2 The figure shows the schematic diagram of the hollow metal tube simulation model in the FDTD grid. Figure 2 (a) is a schematic diagram of the main view. Figure 2 (b) is a schematic diagram of the top view. The inner radius of the inner wall of the metal tube is , the outer radius of the outer wall of the metal tube is Taking the lower left vertex of each parallelepiped grid as the origin, the three edges connected to the origin define the electric field vectors pointing to the three orthogonal directions of XYZ respectively. 、 and , perpendicular to the three planes connected to the origin, define the magnetic field vectors pointing to the three orthogonal directions of XYZ 、 and i, j, k are the position numbers of the electric field vector based on the FDTD grid numbering.

[0056] It is understandable that before obtaining the simulation instruction, a hollow metal tube simulation model needs to be established in advance. In some embodiments, before obtaining the electromagnetic transient simulation instruction for the hollow metal tube simulation model, the following steps are further included:

[0057] A lossless metal tube simulation model is obtained. The lossless metal tube simulation model is established when the axial electric field in the simulation calculation area is set to a target value. The outer radius of the hollow metal tube simulation model is obtained. Correction parameters are calculated based on the outer radius and the radius of the lossless metal tube simulation model to obtain correction parameters corresponding to the lossless metal tube simulation model. The material parameters of the lossless metal tube simulation model are corrected according to the correction parameters to obtain an equivalent metal tube simulation model, and the equivalent metal tube simulation model is used as the hollow metal tube simulation model.

[0058] In this embodiment, a hollow metal tube simulation model can be constructed through cross-scale modeling. In which, the terminal obtains a lossless metal tube simulation model, and when the axial electric field in the simulation calculation area is set to a target value, a lossless metal tube simulation model can be constructed in the simulation calculation area, wherein the target value can be set to 0. Then, the ratio of the outer radius of the hollow metal tube simulation model to the grid size is calculated, and the ratio of the radius of the lossless metal tube simulation model to the grid size is calculated, and then the correction parameters are calculated based on the ratio to obtain the correction parameters corresponding to the lossless metal tube simulation model. At this time, the correction parameters can be used to correct the material parameters of the corresponding position in the FDTD calculation area, that is, the dielectric constant and magnetic permeability can be corrected, thereby obtaining a hollow metal tube simulation model.

[0059] For example, Figure 3As shown in the figure, it is a schematic diagram of the principle of establishing the hollow metal tube simulation model. When the axial electric field vector of FDTD is assigned to 0, a lossless metal tube simulation model with a radius of r0 can be constructed in the FDTD calculation area. The lossless metal tube simulation model is as follows: Figure 3 (c) and Figure 3 (d) where r0 is called the intrinsic radius of the FDTD grid. By analyzing the electric field distribution near the metal tube model multiple times, it can be seen that the relationship between the intrinsic radius (r0) and the radial grid size (Δs) is: Then, the outer radius r can be obtained by modifying and constructing the non-destructive metal tube simulation model. c The lossy hollow metal tube simulation model is as follows. Figure 3 (a) and Figure 3 (b) In this case, the dielectric constant and magnetic permeability between the conductor surface and the virtual circular surface with a radius of Δs (shown as a dotted line in the figure) in the lossless metal tube simulation model can be corrected using the correction factor m, so that the mutual capacitance and mutual inductance between the conductor surface and the virtual circular surface after correction are equal to the mutual capacitance and mutual inductance values ​​in the lossy hollow metal tube simulation model. In this case, the hollow metal tube simulation model can be constructed without FDTD mesh discretization. The correction factor m can be calculated using the following formula (2):

[0060] Formula (2)

[0061] The correction coefficient m can be calculated by the radial FDTD grid size around the lossless metal tube simulation model and the outer radius of the hollow metal tube simulation model. The outer radius of the hollow metal tube simulation model is selected in the range of .

[0062] At this time, the material parameters attached to the electric field vector and magnetic field vector around the lossless metal tube simulation model are corrected by the correction coefficient m to obtain an equivalent metal tube model, which is the hollow metal tube simulation model. Among them, the dielectric constant corresponding to the four orthogonal electric field vectors perpendicular to the axial direction of the metal tube model can be multiplied by the correction coefficient to obtain the corrected dielectric constant ε', as shown in Figure 3 (c) and replace the original dielectric constant at the corresponding position.

[0063] Formula (3)

[0064] Then, the permeability corresponding to the four orthogonal magnetic field vectors surrounding the axial direction of the metal tube model is divided by the correction coefficient to obtain the corrected permeability μ', as shown in the following example: Figure 3 (d) and replace the original magnetic permeability at the corresponding position.

[0065] Formula (4)

[0066] Among them, a hollow metal tube simulation model is obtained through cross-scale modeling. That is, under a discrete strategy in which the grid size is much larger than the radial size and skin depth of the conductor, the frequency-varying impedance per unit length of the metal tube is calculated by using the Bessel function and the appropriate matching method. There is no need to set an extremely fine grid discretization, thereby reducing the number of simulation steps for the same physical time, and thus significantly reducing the overall simulation time, improving the stability and efficiency of the simulation analysis, and realizing efficient and high-precision solution of the electromagnetic transient process of the metal tube power system under broadband impact.

[0067] S104 , obtaining frequency-dependent internal impedance fitting parameters. The frequency-dependent internal impedance fitting parameters are obtained by performing vector matching on frequency-dependent internal impedance information. The frequency-dependent internal impedance information is obtained by superimposing inner boundary impedance information and outer boundary impedance information corresponding to the hollow metal tube simulation model.

[0068] In this embodiment, the terminal can obtain material parameters and radius information of a hollow metal tube simulation model. Based on the material parameters, radius information, and Bessel function information, the terminal calculates the inner and outer boundary impedances to obtain inner and outer boundary impedance information. The inner and outer boundary impedance information are superimposed to obtain frequency-dependent internal impedance information. The frequency-dependent internal impedance information is then fitted in the complex frequency domain using vector matching to obtain frequency-dependent impedance fitting parameters.

[0069] The inner boundary impedance information can be obtained by using the magnetic permeability, dielectric constant, and conductivity in the material parameters and the inner radius and outer radius in the radius information, and performing inner boundary impedance calculation using the first-kind modified Bessel function and the second-kind modified Bessel function in the Bessel function information. The inner boundary impedance information can be obtained by using the magnetic permeability, dielectric constant, and conductivity in the material parameters and the inner radius and outer radius in the radius information, and performing outer boundary impedance calculation using the first-kind modified Bessel function and the second-kind modified Bessel function in the Bessel function information.

[0070] For example, under broadband impulse, the current frequency range usually covers DC to several megahertz, and due to the existence of skin effect, the current distribution in the conductor is different at different frequencies. When the frequency is low, the current distribution tends to be uniform, and when the frequency is high, the current distribution is concentrated at the inner and outer boundaries of the cross section. At this time, the frequency-dependent internal impedance information per unit length of the hollow metal tube simulation model is By the inner boundary impedance and the outer boundary impedance The superposition can be obtained by using the function shown in the following formula (5).

[0071] Formula (5)

[0072] in, is a plural identifier, is the angular frequency, 、 are the modified Bessel functions of the first kind of order 0 and 1, 、 are the modified Bessel functions of the second kind of order 0 and 1, , , , , and σ are the magnetic permeability, dielectric constant, and conductivity of the hollow metal tube simulation model, respectively.

[0073] The terminal can then fit the frequency-varying internal impedance information using the vector matching method, converting it into a set of rational functions, which are then substituted into the time-domain simulation calculation in the form of convolution. This frequency-varying internal impedance information is used to characterize the impedance parameter characteristic curve that varies with frequency. That is, by fitting the frequency characteristic curve of the internal impedance per unit length of the metal tube in the complex frequency domain using the vector matching method, the function shown in the following formula (6) can be obtained.

[0074] Formula (6)

[0075] Here, s represents the complex frequency domain, d refers to the DC component, h refers to the inductive component, cm refers to the residue, am refers to the pole, and N refers to the vector matching order. When fitting, as many frequency points as possible can be uniformly selected within each frequency order of magnitude of the original characteristic frequency curve to improve the accuracy of the curve fit. The fitting coefficients in the function can then be used to obtain the frequency-dependent internal impedance fitting parameters, which can include the DC component, inductive component, residue, pole, and vector matching order, among others.

[0076] S106 , performing iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

[0077] In this embodiment, the simulation calculation parameters can be parameters used when performing simulation calculations, and can be pre-set parameters, for example, they can be key parameters for set FDTD calculations. The external electromagnetic field information of the metal tube can include the external electric field information of the metal tube and the external magnetic field information of the metal tube. The external electric field information of the metal tube includes three electric field vectors in orthogonal directions, and the external magnetic field information of the metal tube can include three magnetic field vectors in orthogonal directions. The terminal can then obtain the electric field vector value at the previous moment and the four magnetic field vectors surrounding the electric field vector, and then use the equivalent conductivity and corrected dielectric constant in the simulation calculation parameters as well as the electric field vector value at the previous moment and the four magnetic field vectors surrounding the electric field vector to calculate the external electric field of the metal tube to obtain the external electric field information of the metal tube. The external electric field information of the metal tube, the material parameters in the simulation calculation parameters, and the external magnetic field information of the metal tube at the previous iteration can then be used to calculate the external magnetic field of the metal tube to obtain the external magnetic field information of the metal tube.

[0078] S108 , performing iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-dependent internal impedance fitting parameters, to obtain electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model.

[0079] In this embodiment, the electromagnetic field information inside the metal tube may include electric field information and magnetic field information inside the metal tube. The terminal can use the DC component, inductive component, residue, and poles in the frequency-dependent internal impedance fitting parameters, as well as the time step in the simulation calculation parameters, to update the axial electric field at the hollow metal tube simulation model using the time-domain convolution form of an inverse Laplace transform to obtain the electric field information inside the metal tube. The terminal can then use the electric field information inside the metal tube, the simulation calculation parameters, and the magnetic field information from the previous iteration to calculate the magnetic field information to obtain the magnetic field information inside the metal tube.

[0080] S110, when a preset iteration termination condition is reached, an electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

[0081] In this embodiment, the terminal iteratively calculates the electromagnetic field information corresponding to the calculation region, i.e., the hollow metal tube simulation model. Each iterative calculation is equivalent to updating the electromagnetic field quantities in the calculation region in time and estimating them to the next time, thereby achieving a step-by-step solution of the electromagnetic field quantities in time. When the preset iterative termination condition is calculated, the electromagnetic field information corresponding to the hollow metal tube simulation model obtained from each iterative calculation is output, thereby obtaining the electromagnetic field prediction result corresponding to the hollow metal tube simulation model.

[0082] The above-mentioned metal tube electromagnetic field prediction method iteratively calculates the electromagnetic field information inside the metal tube through frequency-dependent internal impedance fitting parameters, without the need to generate a complex high-order circuit matrix, thereby improving the accuracy of the calculated electromagnetic field information inside the metal tube, and further improving the accuracy of the electromagnetic field prediction results. In addition, by calculating the external electromagnetic field information and the internal electromagnetic field information of the metal tube, the internal and external electromagnetic fields of the metal tube can be bidirectionally coupled in each calculation cycle, further improving the accuracy of the obtained calculation results.

[0083] In some embodiments, S S102, performing iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model includes:

[0084] Obtain the electric field information corresponding to the previous moment and the magnetic field information surrounding the electric field information, perform electric field calculation using the preset current moment electric field information calculation formula through the electric field information, magnetic field information and simulation calculation parameters, and obtain the external electric field information of the metal tube corresponding to the hollow metal tube simulation model; perform magnetic field calculation using the preset current moment magnetic field information calculation formula through the magnetic field information, the external electric field information of the metal tube and simulation calculation parameters, and obtain the external magnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

[0085] In this embodiment, the electric field information and the magnetic field information surrounding the electric field information at the start of the simulation can be obtained based on the excitation source. Then, the obtained electric field information and the magnetic field information surrounding the electric field information, as well as the simulation calculation parameters, are used to perform an iterative calculation of the electric field information by presetting the electric field information calculation formula at the current moment. The preset electric field information calculation formula at the current moment can be an FDTD electric field equation. The iterative process involves the electric field vector values ​​in three orthogonal directions of the previous time step and the four magnetic field vectors surrounding the electric field vector. The specific update equation is as follows:

[0086] Formula (7a)

[0087] Formula (7b)

[0088] Formula (7c)

[0089] in, 、 、 are the electric field vectors in three orthogonal directions, i, j, k are the position numbers of the electric field vector based on the FDTD grid numbering, n represents the number of time steps, σ, Represent the equivalent conductivity and modified dielectric constant in the corresponding space, respectively, and ∆t refers to the time step. That is, the electric field vector in the orthogonal direction x is calculated using formula (7a), the electric field vector in the orthogonal direction y is calculated using formula (7b), and the electric field vector in the orthogonal direction z is calculated using formula (7a). The magnetic field information, the external electric field information of the metal tube, and the simulation calculation parameters can then be used to calculate the magnetic field using the preset current-time magnetic field information calculation formula to obtain the external magnetic field information of the hollow metal tube corresponding to the hollow metal tube simulation model. The preset current-time magnetic field information calculation formula can also be used to calculate the magnetic field using the FDTD magnetic field vector update equation. That is, the FDTD algorithm is used outside the metal tube to calculate the distribution characteristics of the electromagnetic field under spatial transient impact through spatial discretization and electromagnetic field iteration. The electromagnetic field outside the metal tube can be solved based on a large-scale discrete grid, thereby reducing memory usage, increasing the time step, and improving computational efficiency.

[0090] In some embodiments, S108, performing iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-dependent internal impedance fitting parameters to obtain electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model includes:

[0091] Obtain the total current at the previous moment and the total current at the current moment corresponding to the axial electric field at the hollow metal tube simulation model; weight the total current at the previous moment and the total current at the current moment based on the frequency-variable internal impedance fitting parameters and the time step in the simulation calculation parameters to obtain the weighted current at the previous moment and the weighted current at the current moment; perform time domain convolution calculation based on the frequency-variable internal impedance fitting parameters and the time step in the simulation calculation parameters to obtain the total current at the historical moments; add the historical weighted current, the current weighted current and the historical total current to obtain the electric field information inside the metal tube corresponding to the hollow metal tube simulation model; obtain the magnetic field information at the previous moment, and perform magnetic field calculation using the preset current moment magnetic field information calculation formula based on the magnetic field information at the previous moment, the electric field information inside the metal tube and the simulation calculation parameters to obtain the magnetic field information inside the metal tube corresponding to the hollow metal tube simulation model.

[0092] In this embodiment, the first-order rational function of the frequency characteristic curve fitted by the vector matching method, namely, formula (6), can be converted into a time domain convolution form by inverse Laplace transformation. That is, the axial FDTD electric field vector coincident with the hollow metal tube simulation model is The update equation of can be replaced by formula (7) as follows:

[0093] Formula (8)

[0094] in, The calculated electric field information inside the metal tube at the current moment. I represents the current. Indicates the total current at the current moment. Indicates the total current at the previous moment. ,Should The weighting coefficient used to characterize the total current at the current moment is obtained by calculating the sum of the ratio of the DC component d in the frequency-variable internal impedance fitting parameters to the inductive component h in the frequency-variable internal impedance fitting parameters and the time step ∆t. ,Should It refers to the weighting coefficient used to characterize the total current at the previous moment, which is obtained by calculating the negative of the ratio of the inductive component h and the time step ∆t in the frequency-variable internal impedance fitting parameter. Refers to the time step. To ensure the stability of the simulation, the time step can be appropriately reduced when combined with the time domain convolution calculation. Usually, the time step can be reduced to between 0.8 and 0.9 times. is a convolution term, which is used to calculate the total current at the historical moment by convolution using the current at the current moment, the series and residue in the frequency-variable internal impedance fitting parameters, and the time step, that is, .

[0095] Then, the magnetic field information at the previous moment, the electric field information inside the metal tube, and the simulation calculation parameters can be used to calculate the magnetic field using the preset current moment magnetic field information calculation formula to obtain the magnetic field information inside the metal tube corresponding to the hollow metal tube simulation model. Among them, the classic FDTD magnetic field vector update equation can be used to calculate the magnetic field vector of the entire area, that is, the external magnetic field information of the metal tube can be calculated, and the magnetic field information inside the metal tube can also be calculated. The specific equation is as follows:

[0096] Formula (9a)

[0097] Formula (9b)

[0098] Formula (9c)

[0099] in, Refers to the corrected magnetic permeability, It is the guiding magnetic coefficient, which is generally set to 0. The magnetic permeability corresponding to the four orthogonal magnetic field vectors surrounding the axial direction of the metal tube model has been replaced by the corrected magnetic permeability μ'. Represents the magnetic field vector at time n+1 / 2 pointing in the direction perpendicular to x. Represents the magnetic field vector at time n+1 / 2 pointing in the y-orthogonal direction. Represents the magnetic field vector at time n+1 / 2 pointing in the direction orthogonal to z. Represents the magnetic field vector at time n+1 / 2 before pointing in the direction perpendicular to x. Represents the magnetic field vector at the moment n+1 / 2 before pointing in the orthogonal y direction. Represents the magnetic field vector at time n+1 / 2 before the moment pointing in the direction orthogonal to z.

[0100] In the above embodiment, the internal electric field information of the hollow metal tube corresponding to the hollow metal tube simulation model is obtained by summing the historical weighted current, the current weighted current, and the historical total current. In other words, through the inverse Laplace transform, the internal impedance characteristics that take into account broadband effects are embedded in the FDTD electromagnetic field vector calculation, thereby improving the accuracy of the calculated electromagnetic field information.

[0101] It is understandable that after calculating the magnetic field vectors of the entire calculation area, the total current of the metal tube axial electric field calculation at the next moment can be calculated. That is, in some embodiments, the metal tube electromagnetic field prediction method further includes the steps of:

[0102] The magnetic field information inside the metal tube corresponding to the current moment is obtained, and the total current at the next moment is calculated based on the magnetic field information inside the metal tube and the grid size in the simulation calculation parameters to obtain the total current at the next moment corresponding to the hollow metal tube simulation model.

[0103] In this embodiment, the total current used for the calculation of the axial electric field of the metal tube in the next cycle can be estimated by using the loop integral of the magnetic field vector at time n+1 / 2 in the FDTD calculation area. That is, the axial current of each section of the metal tube can be updated. For the simulation model of the hollow metal tube with the axis x and the mth section, the total current flowing through the cross section of the metal tube is The calculation equation is as follows:

[0104] Formula (10)

[0105] Where m represents the position number corresponding to the FDTD grid after the metal tube is segmented along the axial direction. That is, the total current at the next moment is calculated by formula (10), and then the electric field and magnetic field vectors in the calculation area can be repeatedly solved iteratively according to formulas (7), (8), (9) and (10). Each iterative calculation is equivalent to updating the electromagnetic field quantity in the calculation area in time and estimating it to the next time step Δt, thereby realizing the step-by-step iterative calculation of the electromagnetic field quantity in time. When the iterative calculation meets the preset iterative termination condition, the electromagnetic field calculation is terminated and the calculation result is output. The calculation result can include the electric field vector and magnetic field vector obtained by each iterative calculation. That is, by calculating the total current at the next moment corresponding to the hollow metal tube simulation model, the step-by-step iterative calculation of the electromagnetic field quantity in time can be realized, ensuring the normal progress of the iterative calculation, thereby improving the accuracy of the obtained electromagnetic field prediction results.

[0106] In a specific embodiment, Figure 4As shown, a schematic diagram of the specific process of electromagnetic field prediction of a metal tube is provided, that is, the implementation process of the hollow metal tube simulation model considering broadband loss is specifically:

[0107] 1) Obtain the key parameters of the FDTD calculation. This means obtaining the specific values ​​of the pre-set key parameters of the FDTD calculation, such as the calculation area size, grid size, time step, material parameters, excitation source, and iteration termination conditions.

[0108] 2) Calculate the correction coefficient for the metal tube model in the FDTD grid. This is done by constructing a lossless metal tube model. Then, through iterative analysis of the electric field distribution near the metal tube model, the relationship between the intrinsic radius (r0) and the radial grid size (Δs) is determined. The correction coefficient is then calculated using the correction coefficient calculation formula (2) based on the outer radius of the hollow metal tube and the radial FDTD grid size around the metal tube model.

[0109] 3) Correct the material parameters at the corresponding locations in the FDTD calculation area to construct an equivalent metal tube model. This means using the calculated correction coefficients to correct the material parameters attached to the electric and magnetic field vectors around the metal tube model to obtain the equivalent metal tube model.

[0110] 4) Calculate the frequency-dependent internal impedance per unit length of the metal tube. This internal impedance per unit length can be calculated by superimposing the inner and outer boundary impedances. For example, the frequency-dependent internal impedance can be calculated using formula (5). The frequency-dependent internal impedance is then converted to a rational function using the vector matching method, resulting in the function shown in formula (6).

[0111] 5) Update the FDTD electric field. After receiving the simulation command, you can perform simulation iterations. At this time, first update the FDTD electric field. That is, you can use formula (7), including formulas (7a), (7b), and (7c), to calculate the electric field vectors in the three orthogonal directions of x, y, and z.

[0112] 6) Update the axial electric field at the hollow metal tube simulation model. When calculating the axial electric field at the metal tube model, formula (8) can be used to perform an updated iterative calculation of the axial electric field at the hollow metal tube simulation model.

[0113] 7) Update the FDTD magnetic field. That is, when the electric field simulation is completed, the magnetic field vectors of the entire simulation area can be calculated. Formula (9), including formulas (9a), (9b), and (9c), can be used to calculate the magnetic field vectors pointing in the three orthogonal directions of x, y, and z.

[0114] 8) Update the axial current of each section of the hollow metal tube simulation model. That is, when the magnetic field simulation calculation is completed, the total current used in the next iterative calculation can be calculated. This total current is used to calculate the axial electric field at the hollow metal tube simulation model in the next cycle. The axial current of each section of the hollow metal tube simulation model can be calculated using formula (10).

[0115] 9) Determine whether the calculation iterations meet the preset iteration termination conditions. This involves determining whether the preset iteration termination conditions have been met. For example, this can be determining whether the number of iterations has reached the termination limit or whether the iteration convergence condition has been met. If the preset iteration termination conditions have not been met, the calculation can be returned to step 5) to continue iterating until the preset iteration termination conditions are met. At this point, the electromagnetic field calculation is terminated and the calculation results are output.

[0116] Specifically, the FDTD calculation domain is divided into two parts: the interior of the hollow metal tube simulation model and the exterior of the hollow metal tube simulation model. The exterior of the hollow metal tube simulation model uses a traditional FDTD algorithm, using spatial discretization and electromagnetic field iteration to calculate the electromagnetic field distribution characteristics under spatial transient impacts. The interior of the hollow metal tube simulation model is then modeled across scales, eliminating the need for extremely fine mesh discretization. By modifying the material parameters surrounding the lossless metal tube simulation model, an equivalent metal tube model can be constructed. The frequency-dependent internal impedance per unit length of the metal tube is then calculated using Bessel functions, allowing for a macroscopic analysis of the current waveform and frequency-dependent losses within the metal tube under broadband impacts. The appropriate matching method is then used to fit the frequency-dependent internal impedance to a rational function. Through an inverse Laplace transform, the broadband-effect internal impedance characteristics are embedded in the FDTD electromagnetic field vector calculation. This allows the electromagnetic field within the hollow metal tube simulation model to influence the electromagnetic field outside the hollow metal tube simulation model through the internal impedance, and the electromagnetic field outside the hollow metal tube simulation model influences the electromagnetic field within the hollow metal tube simulation model through the spatial magnetic field loop integral in the vicinity of the conductor. Then, the electromagnetic fields inside and outside the hollow metal tube simulation model are bidirectionally coupled in each calculation cycle to ensure the accuracy of the calculation results.

[0117] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0118] Based on the same inventive concept, embodiments of the present application also provide a metal tube electromagnetic field prediction device for implementing the aforementioned metal tube electromagnetic field prediction method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the metal tube electromagnetic field prediction device provided below can be found in the above-mentioned limitations of the metal tube electromagnetic field prediction method and will not be further elaborated here.

[0119] In an exemplary embodiment, Figure 5 As shown, a metal tube electromagnetic field prediction device is provided, comprising: an instruction acquisition module 502, a parameter acquisition module 504, an external calculation module 506, an internal calculation module 508 and a prediction module 510, wherein:

[0120] An instruction acquisition module 502 is used to acquire an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0121] Parameter acquisition module 504, used to obtain frequency-dependent internal impedance fitting parameters, the frequency-dependent internal impedance fitting parameters are obtained by performing vector matching on the frequency-dependent internal impedance information, and the frequency-dependent internal impedance information is obtained by superimposing the inner boundary impedance information and the outer boundary impedance information corresponding to the hollow metal tube simulation model;

[0122] The external calculation module 506 is used to perform iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model;

[0123] The internal calculation module 508 is used to perform iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-dependent internal impedance fitting parameters to obtain the electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model;

[0124] The prediction module 510 is used to obtain the electromagnetic field prediction result corresponding to the hollow metal tube simulation model when a preset iteration termination condition is reached.

[0125] In one embodiment, the parameter acquisition module 504 is also used to obtain material parameters and radius information of the hollow metal tube simulation model; calculate the inner boundary impedance and the outer boundary impedance based on the material parameters, radius information and Bessel function information to obtain the inner boundary impedance information and the outer boundary impedance information; superimpose the inner boundary impedance information and the boundary impedance information to obtain frequency-variable internal impedance information; and fit the frequency-variable internal impedance information in the complex frequency domain through vector matching to obtain frequency-variable impedance fitting parameters.

[0126] In one embodiment, the parameter acquisition module 504 is also used to use the magnetic permeability, dielectric constant and conductivity in the material parameters and the inner radius and outer radius in the radius information, and perform inner boundary impedance calculation through the first-type modified Bessel function and the second-type modified Bessel function in the Bessel function information to obtain inner boundary impedance information; use the magnetic permeability, dielectric constant and conductivity in the material parameters and the inner radius and outer radius in the radius information, and perform outer boundary impedance calculation through the first-type modified Bessel function and the second-type modified Bessel function in the Bessel function information to obtain inner boundary impedance information.

[0127] In one embodiment, the external calculation module 506 is also used to obtain the electric field information corresponding to the previous moment and the magnetic field information surrounding the electric field information, and perform electric field calculation using the preset current moment electric field information calculation formula through the electric field information, magnetic field information and simulation calculation parameters to obtain the external electric field information of the metal tube corresponding to the hollow metal tube simulation model; and perform magnetic field calculation using the preset current moment magnetic field information calculation formula through the magnetic field information, the external electric field information of the metal tube and simulation calculation parameters to obtain the external magnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

[0128] In one embodiment, the internal calculation module 508 is also used to obtain the total current at the previous moment and the total current at the current moment corresponding to the axial electric field at the hollow metal tube simulation model; weight the total current at the previous moment and the total current at the current moment based on the frequency-variable internal impedance fitting parameters and the time step in the simulation calculation parameters to obtain the weighted current at the previous moment and the weighted current at the current moment; perform time domain convolution calculation based on the frequency-variable internal impedance fitting parameters and the time step in the simulation calculation parameters to obtain the total current at the historical moments; add the historical weighted current, the current weighted current and the historical total current to obtain the electric field information inside the metal tube corresponding to the hollow metal tube simulation model; obtain the magnetic field information at the previous moment, and perform magnetic field calculation using the preset current moment magnetic field information calculation formula based on the magnetic field information at the previous moment, the electric field information inside the metal tube and the simulation calculation parameters to obtain the magnetic field information inside the metal tube corresponding to the hollow metal tube simulation model.

[0129] In one embodiment, the metal tube electromagnetic field prediction device further includes:

[0130] The current calculation module is used to obtain the internal magnetic field information of the metal tube corresponding to the current moment, and calculate the total current at the next moment based on the internal magnetic field information of the metal tube and the grid size in the simulation calculation parameters to obtain the total current at the next moment corresponding to the hollow metal tube simulation model.

[0131] In one embodiment, the metal tube electromagnetic field prediction device further includes:

[0132] The model establishment module is used to obtain a lossless metal tube simulation model, which is established when the axial electric field in the simulation calculation area is set to a target value; obtain the outer radius of the hollow metal tube simulation model, calculate the correction parameters based on the outer radius and the radius of the lossless metal tube simulation model, and obtain the correction parameters corresponding to the lossless metal tube simulation model; correct the material parameters of the lossless metal tube simulation model according to the correction parameters to obtain an equivalent metal tube simulation model, and use the equivalent metal tube simulation model as the hollow metal tube simulation model.

[0133] Each module in the aforementioned metal tube electromagnetic field prediction device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0134] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 6 As shown. The computer device includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via wired or wireless means, and the wireless means can be implemented via Wi-Fi, a mobile cellular network, near-field communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for predicting the electromagnetic field of a metal tube. The display unit of the computer device is used to form a visually visible image, and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

[0135] Those skilled in the art will understand that Figure 6The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0136] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0137] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0138] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0139] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0140] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0141] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for predicting the electromagnetic field of a metal tube, characterized in that: The method comprises: Obtaining an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters; Obtaining frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on frequency-variable internal impedance information, where the frequency-variable internal impedance information is obtained by superimposing inner boundary impedance information and outer boundary impedance information corresponding to a hollow metal tube simulation model, including: obtaining material parameters and radius information of the hollow metal tube simulation model; calculating inner boundary impedance and outer boundary impedance based on the material parameters, the radius information, and Bessel function information when the current distribution is concentrated at the inner and outer boundaries of the cross section to obtain the inner boundary impedance information and the outer boundary impedance information; superimposing the inner boundary impedance information and the outer boundary impedance information to obtain the frequency-variable internal impedance information; fitting the frequency-variable internal impedance information in a complex frequency domain by vector matching to obtain the frequency-variable internal impedance fitting parameters, wherein a first-order first-kind modified Bessel function and a first-order second-kind modified Bessel function are used to calculate the inner boundary impedance information, and a zero-order and first-order first-kind modified Bessel function and a zero-order and first-order second-kind modified Bessel function are used to calculate the outer boundary impedance information; Performing iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model; Performing iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters to obtain electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model; When the preset iteration termination condition is reached, the electromagnetic field prediction result corresponding to the hollow metal tube simulation model is obtained.

2. The method according to claim 1, characterized in that The calculating the inner boundary impedance and the outer boundary impedance based on the material parameters, the radius information, and the Bessel function information to obtain the inner boundary impedance information and the outer boundary impedance information includes: Using the magnetic permeability, dielectric constant and conductivity in the material parameters and the inner radius and outer radius in the radius information, and using the first kind modified Bessel function and the second kind modified Bessel function in the Bessel function information to calculate the inner boundary impedance, the inner boundary impedance information is obtained; The outer boundary impedance information is obtained by using the magnetic permeability, dielectric constant and conductivity in the material parameters and the inner radius and outer radius in the radius information and calculating the outer boundary impedance through the first and second modified Bessel functions in the Bessel function information.

3. The method according to claim 1, characterized in that The iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters to obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model includes: Obtaining electric field information corresponding to a previous moment and magnetic field information surrounding the electric field information, performing electric field calculation using a preset current moment electric field information calculation formula based on the electric field information, the magnetic field information, and the simulation calculation parameters, to obtain external electric field information of the metal tube corresponding to the hollow metal tube simulation model; The magnetic field information, the external electric field information of the metal tube and the simulation calculation parameters are used to perform magnetic field calculation using a preset current moment magnetic field information calculation formula to obtain the external magnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

4. The method according to claim 1, wherein The iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters to obtain electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model includes: Obtaining the total current at the previous moment and the total current at the current moment corresponding to the axial electric field at the hollow metal tube simulation model; Based on the frequency-variable internal impedance fitting parameter and the time step in the simulation calculation parameter, the total current at the previous moment and the total current at the current moment are weighted to obtain a weighted current at the previous moment and a weighted current at the current moment; Performing a time domain convolution calculation based on the frequency-variable internal impedance fitting parameter and the time step in the simulation calculation parameter to obtain a total current at a historical moment; Adding the weighted current at the previous moment, the weighted current at the current moment, and the total current at the historical moments to obtain the electric field information inside the metal tube corresponding to the hollow metal tube simulation model; The magnetic field information at the previous moment is obtained, and based on the magnetic field information at the previous moment, the electric field information inside the metal tube and the simulation calculation parameters, a magnetic field calculation is performed using a preset current moment magnetic field information calculation formula to obtain the internal magnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

5. The method according to claim 1, wherein The method further comprises: The internal magnetic field information of the metal tube corresponding to the current moment is obtained, and the total current at the next moment is calculated based on the internal magnetic field information of the metal tube and the grid size in the simulation calculation parameters to obtain the total current at the next moment corresponding to the hollow metal tube simulation model.

6. The method according to claim 1, characterized in that Before obtaining the electromagnetic transient simulation instruction for the hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters, the method further includes: Acquiring a lossless metal tube simulation model, wherein the lossless metal tube simulation model is established when the axial electric field in the simulation calculation area is set to a target value; Obtaining an outer radius of the hollow metal tube simulation model, and calculating correction parameters based on the outer radius and the radius of the lossless metal tube simulation model to obtain correction parameters corresponding to the lossless metal tube simulation model; The material parameters of the lossless metal tube simulation model are corrected according to the correction parameters to obtain an equivalent metal tube simulation model, and the equivalent metal tube simulation model is used as the hollow metal tube simulation model.

7. A metal tube electromagnetic field prediction device, characterized in that: The device comprises: An instruction acquisition module is used to acquire an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters; a parameter acquisition module for acquiring frequency-variable internal impedance fitting parameters, the frequency-variable internal impedance fitting parameters being obtained by vector matching frequency-variable internal impedance information, the frequency-variable internal impedance information being obtained by superimposing inner boundary impedance information and outer boundary impedance information corresponding to a hollow metal tube simulation model, including: acquiring material parameters and radius information of the hollow metal tube simulation model; calculating inner boundary impedance and outer boundary impedance based on the material parameters, radius information, and Bessel function information when current distribution is concentrated at the inner and outer boundaries of the cross section to obtain the inner boundary impedance information and the outer boundary impedance information; superimposing the inner boundary impedance information and the outer boundary impedance information to obtain the frequency-variable internal impedance information; and fitting the frequency-variable internal impedance information in a complex frequency domain by vector matching to obtain the frequency-variable internal impedance fitting parameters, wherein a first-order first-kind modified Bessel function and a first-order second-kind modified Bessel function are used to calculate the inner boundary impedance information, and a zero-order and first-order first-kind modified Bessel function and a zero-order and first-order second-kind modified Bessel function are used to calculate the outer boundary impedance information; an external calculation module, configured to perform iterative calculation of the external electromagnetic field of the metal tube based on the simulation calculation parameters, and obtain the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model; An internal calculation module, configured to perform iterative calculation of the electromagnetic field inside the metal tube based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, and obtain electromagnetic field information inside the metal tube corresponding to the hollow metal tube simulation model; The prediction module is used to obtain the electromagnetic field prediction result corresponding to the hollow metal tube simulation model when a preset iteration termination condition is reached.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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