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

Abstract

The invention 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: acquiring an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters; frequency-varying internal impedance fitting parameters are obtained, the frequency-varying internal impedance fitting parameters are obtained by carrying out vector matching on frequency-varying internal impedance information, and the frequency-varying internal impedance information is obtained by superposing internal boundary impedance information and external boundary impedance information corresponding to the hollow metal tube simulation model; and performing metal tube external electromagnetic field iterative calculation based on the simulation calculation parameters, performing metal tube internal electromagnetic field iterative calculation based on the simulation calculation parameters and the frequency-variable internal impedance fitting parameters, and when a preset iteration termination condition is reached, obtaining an electromagnetic field prediction result corresponding to the hollow metal tube simulation model. By adopting the method, the prediction accuracy can be improved.

Description

Technical Field

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

[0002] Electromagnetic transient simulation can study the electromagnetic field distribution and transient response inside and outside the metal pipe under lightning strikes, arc faults, short circuits, etc., accurately evaluate the transient voltage and current distribution of metal pipes under lightning strikes, switch operations, etc., and provide 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, find out the shielding effects 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, reduce failure risks, and improve system operation efficiency.

[0003] At present, the distribution of electromagnetic energy in the vicinity of the metal tube under broadband impact is usually predicted by simulation modeling techniques such as the finite time-difference method (FDTD). However, electromagnetic transient prediction using the finite time-difference method requires the generation of a complex high-order circuit matrix, which reduces the accuracy of electromagnetic transient prediction. 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 the prediction accuracy in response to the above technical problems.

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

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

[0007] Obtain frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information, where 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-dependent 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 also provides a metal tube electromagnetic field prediction device, comprising:

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

[0013] Obtain frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information, where 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-dependent 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, including 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] Obtaining an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0019] Obtain frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information, where 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-dependent 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] Obtaining an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein the electromagnetic transient simulation instruction carries simulation calculation parameters;

[0025] Obtain frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information, where 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-dependent 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, including a computer program, which implements the following steps when executed by a processor:

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

[0031] Obtain frequency-variable internal impedance fitting parameters, where the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on the frequency-variable internal impedance information, where 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-dependent 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, 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, and there is no need to generate a complex high-order circuit matrix, thereby improving the accuracy of the calculated electromagnetic field information inside the metal tube, and then 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 drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. 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 creative work.

[0037] FIG1 is a schematic diagram of a flow chart of a method for predicting electromagnetic fields of a metal tube in one embodiment;

[0038] FIG2 is a schematic diagram of setting a hollow metal tube simulation model in an FDTD grid in one embodiment;

[0039] FIG3 is a schematic diagram showing the principle of establishing a simulation model of a hollow metal tube in one embodiment;

[0040] FIG4 is a schematic diagram of a specific process of electromagnetic field prediction of a metal tube in a specific embodiment;

[0041] FIG5 is a structural block diagram of a device for predicting electromagnetic fields of a metal tube in one embodiment;

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

[0043] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

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

[0045] 1) Cable protection pipes. Metal pipes are often used to protect cables in power systems. When laying cables in buildings, factories or underground, metal pipes can prevent cables from being damaged by pressure, impact or other external forces, especially in power transmission and distribution systems. They can protect cables from mechanical damage, chemical corrosion or other external environmental influences, and are particularly suitable for harsh environments or underground installations to ensure long-term stable operation of cables.

[0046] 2) Shielding and grounding. Metal pipes can provide electromagnetic shielding for cables, reduce electromagnetic interference (EMI), and maintain the stability of power transmission, which is particularly important for the operation of some sensitive power equipment. In addition, metal pipes are usually connected to the grounding system to prevent the potential increase caused by faults in electrical equipment and cables, protecting the safety of personnel and equipment.

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

[0048] 4) Heat dissipation and fire prevention. The good thermal conductivity of metal materials can also help cables dissipate heat. In power systems, high-load cables generate heat when transmitting large amounts of current. The use of metal pipes can help cables dissipate heat better, prevent overheating, and extend the service life of cables. Metal pipes can provide certain fire protection for cables in the event of a fire, preventing the spread of fire, while ensuring the operation of important power systems in the event of a fire, especially in important 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 lightning strikes, switch operations, etc. can be accurately evaluated, providing a basis for optimizing overvoltage protection and cable layout.

[0050] In an exemplary embodiment, as shown in FIG1 , a method for predicting electromagnetic fields of a metal tube is provided. This embodiment is illustrated by applying the method to a terminal. 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 the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0051] S102, obtaining an electromagnetic transient simulation instruction for a hollow metal tube simulation model, wherein 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, that is,

[0053] Formula (1)

[0054] In the formula, Δx, Δy, 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. In general, the FDTD time step selects the maximum value in formula (1) to reduce the number of simulations and improve the 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 concentrated circuit parameter element. The iteration termination condition can include the iteration number condition and the convergence condition. The iteration number condition means that when the number of electromagnetic field updates reaches the preset iteration number, the electromagnetic field calculation is terminated. The convergence condition means that when the spatial electromagnetic field is in a steady-state distribution, or a periodic change is formed and the waveform deviation between two adjacent periods meets the convergence condition, the electromagnetic field calculation is terminated.

[0055] In some embodiments, the terminal can obtain an electromagnetic transient simulation instruction for a hollow metal tube simulation model, and the hollow metal tube simulation model can be a component in an electric power simulation system. Among them, the hollow metal tube simulation model should be set on the 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 according to requirements. Exemplarily, as shown in Figure 2, it is a schematic diagram of setting a hollow metal tube simulation model in an FDTD grid, and Figure 2 (a) is a schematic diagram of the main view, and Figure 2 (b) is a schematic diagram of the top view. Among them, 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 also 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 by cross-scale modeling. Among them, the terminal obtains the lossless metal tube simulation model, and the lossless metal tube simulation model can be constructed in the simulation calculation area by setting the axial electric field in the simulation calculation area to the target value, 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 parameter calculation is performed according to the ratio to obtain the correction parameter corresponding to the lossless metal tube simulation model. At this time, the material parameters of the corresponding position of the FDTD calculation area can be corrected using the correction parameters, that is, the dielectric constant and magnetic permeability can be corrected, thereby obtaining the hollow metal tube simulation model.

[0059] For example, as shown in FIG3 , it is a schematic diagram of the principle of establishing a hollow metal tube simulation model, where, when the axial electric field vector of FDTD is assigned a value of 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 shown in FIG3 (c) and FIG3 (d), where r0 is called the intrinsic radius of the FDTD grid. Through multiple solutions and analyses of the electric field distribution near the metal tube model, 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. The lossy hollow metal tube simulation model is shown in Figure 3 (a) and Figure 3 (b). Among them, the dielectric constant and magnetic permeability between the conductor surface and the virtual circular surface with a radius of Δs in the lossless metal tube simulation model can be corrected by the correction coefficient 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 in the lossy hollow metal tube simulation model. At this time, the hollow metal tube simulation model can be constructed without FDTD mesh discretization. The correction coefficient m can be calculated by 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 a 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 magnetic 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 magnetic permeability μ', as shown in Figure 3 (d), and replace the original magnetic permeability at the corresponding position.

[0065] Formula (4)

[0066] Among them, a simulation model of a hollow metal tube 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-dependent impedance per unit length of the metal tube is calculated by 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 achieving 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, where the frequency-dependent internal impedance fitting parameters are obtained by performing vector matching on frequency-dependent internal impedance information, where 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 the material parameters and radius information of the hollow metal tube simulation model. Based on the material parameters, radius information and Bessel function information, the inner boundary impedance and the outer boundary impedance are calculated to obtain the inner boundary impedance information and the outer boundary impedance information. The inner boundary impedance information and the boundary impedance information are superimposed to obtain the frequency-dependent internal impedance information. The frequency-dependent internal impedance information is fitted in the complex frequency domain through vector matching to obtain the 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 calculating the inner boundary impedance through the first modified Bessel function and the second 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 calculating the outer boundary impedance through the first modified Bessel function and the second modified Bessel function in the Bessel function information.

[0070] For example, under broadband impact, the current frequency range usually covers DC to several megahertz, and due to the 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] Then the terminal can fit the frequency-varying internal impedance information through the vector matching method, convert it into a set of rational functions, and then substitute it into the time domain simulation calculation in the form of convolution. The frequency-varying internal impedance information is used to characterize the impedance parameter characteristic curve that changes 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 through the vector matching method, the function shown in the following formula (6) can be obtained.

[0074] Formula (6)

[0075] Among them, 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. Then, when fitting, as many frequency points as possible can be uniformly selected in each frequency order of magnitude of the original characteristic frequency curve to improve the accuracy of curve fitting. Then, the frequency-dependent internal impedance fitting parameters can be obtained according to the fitting coefficients in the function. The frequency-dependent internal impedance fitting parameters may include the DC component, the inductive component, the residue, the pole, the vector matching order, and so on.

[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, can be set key parameters for 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, and 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. Then the terminal can 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 the corrected dielectric constant in the simulation calculation parameters and 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, and obtain the external electric field information of the metal tube. Then, 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 last iteration can 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, and obtaining 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 the electric field information inside the metal tube and the magnetic field information inside the metal tube. The terminal may use the DC component, the inductive component, the residue and the pole in the frequency-dependent internal impedance fitting parameters and the time step in the simulation calculation parameters to update the axial electric field at the hollow metal tube simulation model through the time domain convolution form of the inverse Laplace transform to obtain the electric field information inside the metal tube. Then, the magnetic field information may be calculated using the electric field information inside the metal tube, the simulation calculation parameters and the magnetic field information of the previous iteration 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 area, that is, the hollow metal tube simulation model. Each iterative calculation is equivalent to updating the electromagnetic field quantity in the calculation area in time and estimating it to the next time, thereby realizing a step-by-step solution of the electromagnetic field quantity in time. When the preset iteration termination condition is calculated, the electromagnetic field information corresponding to the hollow metal tube simulation model obtained by 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-variable internal impedance fitting parameters, and does not 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 electromagnetic fields inside and outside the metal tube can be bidirectionally coupled in each calculation cycle, further improving the accuracy of the calculated 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] The electric field information corresponding to the previous moment and the magnetic field information surrounding the electric field information are obtained, and the electric field calculation is performed using the preset electric field information calculation formula at the current moment 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; the magnetic field calculation is performed using the preset magnetic field information calculation formula at the current moment 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.

[0085] In this embodiment, the electric field information at the start of the simulation and the magnetic field information surrounding the electric field information can be obtained according to the excitation source, and then the electric field information can be updated and iterated by using the obtained electric field information and the magnetic field information surrounding the electric field information and the simulation calculation parameters through the preset electric field information calculation formula at the current moment. The preset electric field information calculation formula at the current moment can be the FDTD electric field equation. Among them, 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 vectors based on the FDTD grid numbering, n represents the number of time steps, σ, Respectively represent the equivalent conductivity and the modified dielectric constant in the corresponding space, and ∆t refers to the time step. That is, the electric field vector in the orthogonal direction x is calculated by formula (7a), the electric field vector in the orthogonal direction y is calculated by formula (7b), and the electric field vector in the orthogonal direction z is calculated by formula (7a). Then, the magnetic field information, the external electric field information of the metal tube and the simulation calculation parameters can be used to calculate the magnetic field using the preset current magnetic field information calculation formula to obtain the external magnetic field information of the metal tube corresponding to the hollow metal tube simulation model. The preset current 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, and the electromagnetic field quantity distribution characteristics under spatial transient impact are calculated through spatial discretization and electromagnetic field quantity iteration. The external electromagnetic field of the metal tube can be solved based on a large-size discrete grid, thereby reducing memory usage, increasing the time step, and improving calculation 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] 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 are obtained; the total current at the previous moment and the total current at the current moment are weighted 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; time domain convolution calculation is performed 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; the historical weighted current, the current weighted current and the historical total current are added 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 the magnetic field calculation is performed 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, that is, formula (6), can be transformed 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, It indicates the calculated electric field information inside the metal tube at the current moment. I indicates 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 parameters. 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 moment, the series and residue in the frequency-dependent 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 refers to the guiding magnetic coefficient, which is generally set to 0. Among them, 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 orthogonal to x. Represents the magnetic field vector at time n+1 / 2 pointing in the orthogonal direction to y. Represents the magnetic field vector at time n+1 / 2 pointing in the z-orthogonal direction. Represents the magnetic field vector at time n+1 / 2 before pointing in the direction orthogonal to x. Represents the magnetic field vector at the moment n+1 / 2 before pointing in the orthogonal direction to y. Represents the magnetic field vector at time n+1 / 2 before pointing in the direction orthogonal to z.

[0100] In the above embodiment, the historical weighted current, the current weighted current and the historical total current are added to obtain the internal electric field information of the metal tube corresponding to the hollow metal tube simulation model. That is, through the inverse Laplace transform, the internal impedance characteristics considering the broadband effect 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 all calculation areas, 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 magnetic field vector loop integral 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. Among them, for the simulation model of the hollow metal tube with the axial direction as 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 according to formula (7), formula (8), formula (9) and formula (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 may 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, as shown in FIG4 , a specific process diagram 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 FDTD calculation. That is, obtain the specific values ​​of the key parameters of FDTD calculation that are preset, such as the calculation area size, grid size, time step, material parameters, excitation source, and iteration termination conditions.

[0108] 2) Calculate the correction coefficient of the metal tube model in the FDTD grid. That is, by constructing a lossless metal tube model. Then, by iteratively analyzing the electric field distribution near the metal tube model, the relationship between the intrinsic radius (r0) and the radial grid size (Δs) is obtained. Then, the correction coefficient is 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 of the corresponding position in the FDTD calculation area and construct an equivalent metal tube model. That is, use the calculated correction coefficient to correct the material parameters attached to the electric field vector and magnetic field vector 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. That is, the internal impedance per unit length of the metal tube can be obtained by superimposing the inner boundary impedance and the outer boundary impedance. For example, the frequency-dependent internal impedance can be calculated using formula (5). Then, the frequency-dependent internal impedance is converted into a rational function using the vector matching method, thereby obtaining the function shown in formula (6).

[0111] 5) Update the FDTD electric field. After obtaining the simulation command, you can perform simulation iteration calculations. 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 xyz.

[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 on 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 calculation is completed, the magnetic field vector of the entire simulation calculation area can be calculated, and the magnetic field vector pointing to the three orthogonal directions of xyz can be calculated using formula (9), including formula (9a), (9b) and (9c).

[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. The total current is used to calculate the axial electric field at the hollow metal tube simulation model of 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 the calculation iteration and the preset iteration termination condition. That is, determine whether the preset iteration termination condition is reached, for example, whether the iteration termination number is reached, or whether the iteration convergence condition is reached. When the preset iteration termination condition is not reached, it can return to step 5) to continue the iterative calculation until the preset iteration termination condition is reached, terminate the electromagnetic field calculation, and output the calculation results.

[0116] That is, the FDTD calculation area is divided into two parts, including the inside of the hollow metal tube simulation model and the outside of the hollow metal tube simulation model. Among them, the traditional FDTD algorithm is used outside the hollow metal tube simulation model to calculate the electromagnetic field quantity distribution characteristics under spatial transient impact through spatial discretization and electromagnetic field quantity iteration. Then, the inside of the hollow metal tube simulation model is modeled across scales, without the need for extremely fine grid discretization, and the metal tube model can be equivalently constructed by correcting the material parameters around the lossless metal tube simulation model. Then, the Bessel function is used to calculate the frequency-variant internal impedance per unit length of the metal tube, and the current waveform and frequency-variant loss in the metal tube under broadband impact are analyzed from a macroscopic perspective. Then, the appropriate matching method is used to fit the frequency-variant internal impedance to a rational function, and the internal impedance characteristics considering the broadband effect are embedded in the FDTD electromagnetic field vector calculation through the inverse Laplace transform, so that the electromagnetic field inside the hollow metal tube simulation model can affect 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 affects the electromagnetic field inside 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 above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed 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 part of the steps or stages in other steps.

[0118] Based on the same inventive concept, the embodiment of the present application also provides a metal tube electromagnetic field prediction device for implementing the metal tube electromagnetic field prediction method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more metal tube electromagnetic field prediction device embodiments provided below can refer to the limitations of the metal tube electromagnetic field prediction method above, and will not be repeated here.

[0119] In an exemplary embodiment, as shown in FIG5 , 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] The parameter acquisition module 504 is used to acquire the frequency-dependent internal impedance fitting parameters, which 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 the frequency-variable internal impedance information; fit the frequency-variable internal impedance information in the complex frequency domain through vector matching to obtain the 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 of modified Bessel function and the second type of modified Bessel function in the Bessel function information to obtain the 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 of modified Bessel function and the second type of modified Bessel function in the Bessel function information to obtain the 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; 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-dependent 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-dependent internal impedance fitting parameters and the time step in the simulation calculation parameters to obtain the total current at 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 based on the magnetic field information at the previous moment, the electric field information inside the metal tube and the simulation calculation parameters 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.

[0129] In one embodiment, the electromagnetic field prediction device for a metal tube 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 electromagnetic field prediction device for a metal tube 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 correction parameters based on the outer radius and the radius of the lossless metal tube simulation model, and obtain 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 above-mentioned metal tube electromagnetic field prediction device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0134] In an exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG6. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, the memory, and the input / output interface are connected via a system bus, and the communication interface, the display unit, and the 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 an 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 the 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 an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a method for predicting the electromagnetic field of a metal tube is implemented. The display unit of the computer device is used to form a visually visible picture, which may 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 shell, or an external keyboard, touchpad or mouse.

[0135] Those skilled in the art will understand that the structure shown in FIG. 6 is merely a block diagram of a partial 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 arrangement of components.

[0136] In an exemplary embodiment, in one 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] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and 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. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0140] The technical features of the above embodiments may be combined arbitrarily. 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 only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for predicting electromagnetic fields of metal tubes, 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; Acquire frequency-variable internal impedance fitting parameters, wherein the frequency-variable internal impedance fitting parameters are obtained by performing vector matching on frequency-variable internal impedance information, wherein the frequency-variable internal impedance information is obtained by superimposing inner boundary impedance information and outer boundary impedance information corresponding to the hollow metal tube simulation model; 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; Perform an 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; 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 obtaining of frequency-dependent impedance fitting parameters comprises: Get the 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, the radius information and the Bessel function information to obtain the inner boundary impedance information and the outer boundary impedance information; Superimposing the inner boundary impedance information and the boundary impedance information to obtain the frequency-dependent internal impedance information; The frequency-variable internal impedance information is fitted in the complex frequency domain through vector matching to obtain the frequency-variable impedance fitting parameters.

3. The method according to claim 2, 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 calculating the inner boundary impedance through the first modified Bessel function and the second modified Bessel function in the Bessel function information, the inner boundary impedance information is obtained; The inner 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 modified Bessel function and the second modified Bessel function in the Bessel function information.

4. 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 the electric field information corresponding to the previous moment and the magnetic field information surrounding the electric field information, performing electric field calculation using the electric field information, the magnetic field information and the simulation calculation parameters using a preset current moment electric field information calculation formula, and obtaining the 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 magnetic field information calculation formula to obtain the external magnetic field information of the metal tube corresponding to the hollow metal tube simulation model.

5. The method according to claim 1, characterized in that The 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 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 respectively to obtain the weighted current at the previous moment and the weighted current at the current moment; Performing time domain convolution calculation based on the frequency-variable internal impedance fitting parameter and the time step in the simulation calculation parameter to obtain the total current at the historical moment; Adding 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; 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.

6. The method according to claim 1, characterized in that The method further comprises: 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.

7. 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 the simulation calculation parameters, the method further includes: Acquire 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.

8. A metal tube electromagnetic field prediction device, characterized in that: The device comprises: An instruction acquisition module, 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, used to acquire frequency-variable internal impedance fitting parameters, wherein the frequency-variable internal impedance fitting parameters are obtained by vector matching of frequency-variable internal impedance information, wherein 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; An external calculation module, used for iteratively calculating the external electromagnetic field of the metal tube based on the simulation calculation parameters, and obtaining the external electromagnetic field information of the metal tube corresponding to the hollow metal tube simulation model; An internal calculation module, used for 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; 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.

9. 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 7 are implemented.

10. 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 7 are implemented.

11. 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 7 are implemented.

Images