A method and device for selecting a metal part in a superconducting magnet under a target working condition, a terminal device, and a storage medium

Abstract

The application discloses a kind of selection methods of metal piece in superconducting magnet under target working condition, device, terminal equipment and storage medium, belong to superconducting magnet electromagnetic simulation and structural optimization technical field, method includes: obtaining the geometric parameter and the conductive characteristic parameter of metal piece;For each metal piece to be evaluated, extract a surface equidistant from the upper surface and the lower surface as a two-dimensional solution domain;In two-dimensional solution domain, based on magnetic field parameters, thickness and conductive characteristic parameters, solve equation;Based on target eddy current equivalent scalar, the thickness and conductive characteristic parameters of the metal piece to be evaluated, the eddy current loss surface density is calculated;Integrate the eddy current loss surface density in two-dimensional solution domain, obtain the total eddy current loss value of the metal piece to be evaluated;The metal piece to be evaluated with the lowest total eddy current loss value is selected as the selected metal piece, therefore, by implementing the present application, the problem of low efficiency in the prior art selection method of metal piece can be solved.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic simulation and structural optimization technology for superconducting magnets, and in particular to a method, apparatus, terminal equipment, and storage medium for selecting metal components in a superconducting magnet under target operating conditions. Background Technology

[0002] Superconducting magnets, due to their ability to generate highly stable and strong magnetic fields, are widely used in fusion reactors, high-energy physics devices, magnetic resonance imaging systems, and superconducting energy storage equipment. The core functional component of a superconducting magnet is the superconducting coil, but to ensure the structural integrity, thermal stability, and long-term operational reliability of the coil, numerous thin-walled metal components are embedded within the magnet, serving functions such as mechanical support, cryogenic cooling, thermal radiation shielding, and electromagnetic compatibility protection. These metal components are typically arranged close to the superconducting coil or directly integrated into structural components such as coil housings, support rings, and end plates, and are constantly exposed to a time-varying magnetic field environment during operation. When the superconducting magnet is under dynamic operating conditions such as charging and discharging, power regulation, and emergency quench protection, the time-varying magnetic field induces eddy currents within the metal components. These eddy currents can threaten structural safety and interfere with the uniformity of the main magnetic field. Therefore, during the design phase of a superconducting magnet, it is necessary to accurately assess the eddy current characteristics of different types of metal components to guide the selection of materials for these components.

[0003] In existing technologies, the three-dimensional finite element method is mainly used to analyze the eddy currents of thin-walled metal components (referred to as metal parts) in time-varying magnetic fields in superconducting magnets. Then, the model of the metal part is selected based on the eddy current analysis results. Specifically, for multiple candidate models of metal parts, their own three-dimensional finite element models are established, the eddy current loss surface density of each model of metal part under the same working conditions is calculated, and the total eddy current loss is obtained by integrating the eddy current loss surface density. The model with the lowest total eddy current loss is selected as the final solution. However, this method requires dividing multiple layers of mesh in the thickness direction to capture the current distribution of the metal part, which leads to a significant increase in the number of meshes and the degree of freedom of solution. A single calculation can take several hours or even several days. Therefore, the selection method of metal parts in the existing technology has the problem of low efficiency. Summary of the Invention

[0004] This invention provides a method, apparatus, terminal equipment, and storage medium for selecting metal components in a superconducting magnet under target operating conditions, which can solve the problem of low efficiency in the existing metal component selection methods.

[0005] The method for selecting metal components in a superconducting magnet under target operating conditions provided by this invention includes: Obtain the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; the geometric parameters include: height coordinate data at various points on the upper surface, height coordinate data at various points on the lower surface, and the thickness of the metal part to be evaluated. For each metal part to be evaluated, based on the height coordinate data of each point on the upper surface and the height coordinate data of each point on the lower surface, a curved surface equidistant from the upper and lower surfaces is extracted as a two-dimensional solution domain. Extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target operating conditions; Within the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar. Based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters, the eddy current loss surface density of the metal part to be evaluated is calculated. The total eddy current loss value of the metal part to be evaluated is obtained by integrating the eddy current loss surface density in the two-dimensional solution domain; the metal part to be evaluated with the lowest total eddy current loss value is selected as the selected metal part.

[0006] Furthermore, the magnetic field parameters include: the angular frequency of the magnetic field change and the normal magnetic flux density; the electrical conductivity parameters include: electrical conductivity. The eddy current equivalent scalar modeling equation is: in, For the Laplace operator, Let be the eddy current equivalent scalar to be solved. The imaginary unit, The angular frequency of the magnetic field change. For electrical conductivity, denoted as , where is the normal magnetic flux density.

[0007] Furthermore, within the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar, including: Obtain information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated; Based on the material type information, the material boundaries of different materials in the two-dimensional solution domain are obtained; Based on each slit, symmetry centerline, material boundary line, and outer boundary, we determine the material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same, the outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero, the slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero, and the symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. Under the constraints of material boundary line, outer boundary, kerf, and symmetry, the preset eddy current equivalent scalar modeling equation is solved in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, to obtain the target eddy current equivalent scalar.

[0008] Furthermore, before calculating the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and its conductivity parameters, the following steps are also included: Obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

[0009] Furthermore, based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and current eddy current loss surface density of the metal part to be evaluated are obtained, including: Perform gradient calculation on the current eddy current equivalent scalar to obtain the eddy current potential gradient vector; perform vector cross product of the eddy current potential gradient vector and the preset normal vector to obtain the eddy current density per unit thickness. The amplitude of the eddy current density per unit thickness is converted based on the thickness to obtain the current density of the eddy current surface. The eddy current surface current density is multiplied by itself to obtain the square of the eddy current surface current modulus. Then, based on the square of the eddy current surface current modulus, conductivity, and thickness, the current eddy current loss surface density of the metal part to be evaluated is obtained.

[0010] Another embodiment of the present invention provides a selection device for metal components in a superconducting magnet under target operating conditions, comprising: a data acquisition module, a two-dimensional solution domain determination module, a magnetic field parameter determination module, a target eddy current equivalent scalar determination module, an eddy current loss surface density determination module, and a selection module; The data acquisition module is used to acquire the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; among which, the geometric parameters include: height coordinate data at various points on the upper surface, height coordinate data at various points on the lower surface, and the thickness of the metal part to be evaluated. The two-dimensional solution domain determination module is used to extract a curved surface equidistant from the upper and lower surfaces as the two-dimensional solution domain for each metal part to be evaluated, based on the height coordinate data of each location on the upper surface and the height coordinate data of each location on the lower surface. The magnetic field parameter determination module is used to extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target working conditions. The target eddy current equivalent scalar determination module is used to solve the preset eddy current equivalent scalar modeling equation in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, so as to obtain the target eddy current equivalent scalar. The eddy current loss surface density determination module is used to calculate the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters. The selected module is used to integrate the eddy current loss surface density in the two-dimensional solution domain to obtain the total eddy current loss value of the metal part to be evaluated; the metal part to be evaluated with the lowest total eddy current loss value is selected as the selected metal part.

[0011] Furthermore, the target eddy current equivalent scalar determination module includes: a first data acquisition sub-unit, a material boundary line determination sub-unit, a constraint condition determination sub-unit, and a solution sub-unit; The first data acquisition subunit is used to acquire information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated. Each material boundary line determination sub-element is used to obtain the material boundary lines of different materials in the two-dimensional solution domain based on the material type information; The constraint condition determination sub-element is used to determine the following constraints based on each slit, symmetry centerline, material boundary line, and outer boundary: material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same; outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero; slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero; and symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. The solver sub-element is used to solve the preset eddy current equivalent scalar modeling equation in a two-dimensional solution domain under material boundary constraints, outer boundary constraints, kerf constraints, and symmetry constraints, based on magnetic field parameters, the thickness of the metal part to be evaluated, and electrical conductivity parameters, to obtain the target eddy current equivalent scalar.

[0012] Furthermore, it also includes: a correction module; The correction module is used to obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions, as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

[0013] Another embodiment of the present invention provides a terminal device, including: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps of the selection method for metal components in a superconducting magnet under target operating conditions provided by the present invention.

[0014] Another embodiment of the present invention also provides a computer-readable storage medium item, including: a stored computer program, which, when the computer program is running, controls the device where the computer-readable storage medium is located to perform the steps of the selection method for metal parts in a superconducting magnet under target operating conditions provided by the present invention.

[0015] The following benefits can be obtained by implementing the present invention: This invention provides a method, apparatus, terminal device, and storage medium for selecting metal components in superconducting magnets under target operating conditions. Compared to existing technologies, this method no longer establishes individual three-dimensional finite element models for each metal component to be evaluated, thereby calculating the eddy current loss surface density of each type of metal component under the same operating conditions. Instead, it addresses the structural characteristics of superconducting magnet metal components, which are thin-walled structures with thickness dimensions much smaller than their planar extension dimensions. Based on the principle that the electromagnetic field distribution along the thickness direction of the metal component is uniform and the eddy current parameters show no significant gradient change, this invention abandons the layered solution along the thickness direction and innovatively introduces an eddy current equivalent scalar to equivalently simulate the overall eddy current field distribution characteristics of the metal component under a time-varying magnetic field. Then, combining the magnetic field variation angular frequency, metal component conductivity, normal magnetic flux density, and thickness under the target operating conditions, an eddy current equivalent scalar modeling equation is constructed, and solving the equation yields... The target eddy current equivalent scalar can be obtained, and then the eddy current loss surface density can be obtained based on the target eddy current equivalent scalar. Finally, the total eddy current loss value can be obtained by integrating the eddy current loss surface density, thus completing the selection. Since this invention uses a two-dimensional modeling method to replace the traditional three-dimensional solid modeling, the equations are constructed and solved only in the two-dimensional solution domain plane corresponding to the metal part. Unlike the three-dimensional finite element model, it does not require multi-layer meshing in the thickness direction of the metal part, construction of a large-scale three-dimensional mesh model, and multi-degree-of-freedom iterative solution. This greatly reduces the number of meshes and the degrees of freedom of solution, and simplifies the modeling process and calculation logic. Therefore, it can efficiently calculate the eddy current loss surface density of each type of metal part under the same working conditions. Then, the total eddy current loss can be obtained by integrating the eddy current loss surface density in the solution domain. Finally, the model with the smallest total eddy current loss is selected. Therefore, this invention improves the selection efficiency of metal parts in superconducting magnets. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a method for selecting metal components in a superconducting magnet under target operating conditions, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of eddy currents in a metal part provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of an equivalent lumped circuit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a selection device for metal components in a superconducting magnet under target operating conditions, provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0024] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0025] See Figure 1 To address the problem of low efficiency in existing metal component selection methods, an embodiment of the present invention provides a method for selecting metal components in a superconducting magnet under target operating conditions, comprising: S101: Obtain the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; wherein, the geometric parameters include: height coordinate data at various points on the upper surface, height coordinate data at various points on the lower surface, and thickness. Specifically, the height coordinate data of each point on the upper surface refers to the set of three-dimensional spatial height coordinates corresponding to all discrete spatial points on the upper surface of the thin metal part, which is used to characterize the geometric contour of the upper surface of the metal part in space. The height coordinate data of each point on the lower surface refers to the set of three-dimensional spatial height coordinates corresponding to all discrete spatial points on the lower surface of the metal sheet, which is used to characterize the geometric contour of the lower surface of the metal part in space. The thickness of the metal part to be evaluated refers to the perpendicular distance between the upper and lower surface points of the metal part along the normal of the thin plate at the same plane projection position. For metal parts with variable thickness, different plane projection positions correspond to different thickness values. Therefore, the thickness is a set of spatial distribution data that varies with the plane position. The local thickness corresponding to each position will be substituted into the eddy current equivalent scalar modeling equation of the corresponding position to participate in the solution.

[0026] S102: For each metal part to be evaluated, based on the height coordinate data of each location on the upper surface and the height coordinate data of each location on the lower surface, a curved surface equidistant from the upper and lower surfaces is extracted as a two-dimensional solution domain. Specifically, based on the three-dimensional height coordinates of discrete points on the upper and lower surfaces of the metal part, the midpoint of the spatial line segment between the two points on each set of identical planar projection positions is determined. The midpoints corresponding to all projection positions are then fitted to form a surface equidistant from both the upper and lower surfaces; this surface is the mid-surface of the metal part. This invention selects this mid-surface as the two-dimensional solution domain, reducing the original three-dimensional eddy current problem of thin plates to a solution on this two-dimensional surface. For metal parts with uniform thickness, this mid-surface is a regular plane; for irregularly shaped thin plates with varying thickness, this mid-surface is a surface that changes with the shape of the component.

[0027] It should be noted that the reason why this invention can use two-dimensional modeling instead of traditional three-dimensional solid modeling without affecting the solution of the total eddy current loss value is based on three core assumptions: 1) Quasi-static assumption: The superconducting magnet operates in a steady state or low-frequency dynamic condition, and the eddy currents in the metal parts are excited by a low-frequency quasi-static electromagnetic field. The displacement current can be ignored in the solution process, and the quasi-static electromagnetic field theory is applicable; 2) Thin-part assumption: The metal components in the superconducting magnet that perform cooling and mechanical support functions are mostly disc-shaped structures. The thickness d of the metal parts is much smaller than the skin depth of the alternating magnetic field in the metal material, satisfying: (1) in, It's about thickness. It is the angular frequency of the magnetic field change, which characterizes how fast the alternating magnetic field changes with time, and is determined by the target operating conditions of the superconducting magnet; The electrical conductivity of metallic materials It is the magnetic permeability of metallic materials. This represents the skin depth of the alternating magnetic field in a conductive metal. 3) Planar current assumption: Based on the thin-layer geometry of the metal component, the induced eddy currents inside the component mainly flow tangentially along the plane, with the normal component of the eddy current being negligible. Simultaneously, the eddy currents are uniformly distributed along the thickness direction. Under the condition that all three assumptions hold true, there is no need to discretize the mesh along the thickness direction of the metal component. The three-dimensional thin-plate eddy current problem can be equivalently transformed into a two-dimensional solution domain constructed from a mid-surface equidistant from the upper and lower surfaces. Numerical calculations are performed using eddy current equivalent scalar modeling equations, significantly reducing the computational scale while ensuring the reliability of the total eddy current loss solution.

[0028] S103: Extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target working condition; In one possible implementation, the magnetic field parameters include: the magnetic field variation angular frequency and the normal magnetic flux density.

[0029] Specifically, a complete three-dimensional electromagnetic geometric model of the superconducting magnet is first constructed. Then, external conditions such as the coil current loading law and boundary electromagnetic conditions corresponding to the target working condition are input to solve the electromagnetic field and obtain the complex amplitude distribution of the global time-harmonic electromagnetic field.

[0030] Two types of key parameters were obtained from this: The first type is the magnetic field change angular frequency. This parameter is directly determined by the rate of change of the magnetic field of the currently selected target working condition (charge and discharge, quench loss, and other dynamic processes). It is a globally unified time domain parameter that characterizes how fast the alternating magnetic field oscillates with time. The second type is the normal magnetic flux density, which is a spatially distributed field quantity. It needs to be located in the two-dimensional solution domain (mid-surface of the metal part) constructed by S102. At each spatial point on the mid-surface, the complex amplitude of the magnetic flux density perpendicular to the curved surface of the mid-surface is extracted.

[0031] S104: In the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar. Furthermore, the magnetic field parameters include: the angular frequency of the magnetic field change and the normal magnetic flux density; the electrical conductivity parameters include: electrical conductivity. The eddy current equivalent scalar modeling equation is: (2) in, For the Laplace operator, Let be the eddy current equivalent scalar to be solved. The imaginary unit, The angular frequency of the magnetic field change. For electrical conductivity, denoted as , where is the normal magnetic flux density.

[0032] Furthermore, within the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar, including: Obtain information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated; Based on the material type information, the material boundaries of different materials in the two-dimensional solution domain are obtained; Based on each slit, symmetry centerline, material boundary line, and outer boundary, we determine the material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same, the outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero, the slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero, and the symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. Under the constraints of material boundary line, outer boundary, kerf, and symmetry, the preset eddy current equivalent scalar modeling equation is solved in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, to obtain the target eddy current equivalent scalar.

[0033] It should be noted that the eddy current equivalent scalar modeling equation (2) is a modeling formula provided by this invention, and is not a conventional eddy current field solution expression in this field. The principle on which equation (2) is based is as follows: Based on the thin-film assumption and the planar current assumption, the induced eddy currents inside the thin metal sheet flow only within the plane of the sheet, the normal component of the eddy current is negligible, and the eddy currents are uniformly distributed along the thickness direction. On this basis, a dimensionless quantity is introduced. An auxiliary scalar U, with the dimension of magnetic field strength, is used as a descriptor of eddy current curl. The induced eddy current density within the thin plate is modeled using the following formula: (3) in, This represents the vector of induced eddy current density within the metal component. Represents the preset unit normal vector. The auxiliary scalar (eddy current equivalent scalar) introduced in this invention. For Hamiltonian differential operators, The gradient of the eddy current equivalent scalar. It is the curl operator.

[0034] Based on the above eddy current density expression (3), and combined with Faraday's law of electromagnetic induction in three-dimensional space, the dimension reduction relationship is derived mathematically as follows (4): (4) in, Represents the preset unit normal vector. For Hamiltonian differential operators, The vector of the induced electric field intensity within the metal part; Let be the curl of the induced electric field. Let t be the magnetic flux density vector, and t represent time. This represents the component of the magnetic flux density in the normal direction of the two-dimensional solution domain (normal magnetic flux density). This represents the dot product projection of a vector along the normal to the plate surface; Furthermore, the induced electric field and eddy current density in a metallic conductor satisfy the Ohmic property relationship: (5) in, The vector of the induced electric field intensity within the metal part; This represents the vector of induced eddy current density within the metal component. The resistivity of the metallic material; Furthermore, the surface density of eddy current loss in the thin plate can be expressed by equation (6): (6) in, The surface density of eddy current loss. It is the dot product of the electric field and the eddy current density, representing the eddy current loss per unit volume; Indicates thickness.

[0035] in, (7) in, It is electrical conductivity. It refers to the resistivity of the metallic material; By combining the above series of relations (3)-(7), the two-dimensional Poisson eddy current equivalent scalar modeling equation (2) with the auxiliary scalar U (i.e. the target eddy current equivalent scalar) as the solution quantity is finally obtained.

[0036] Preferably, the material type information refers to the material type identifier of the metal part to be evaluated, such as oxygen-free copper or aluminum alloy. The corresponding conductivity can be determined by the material type. Each cut refers to the gap structure opened in the metal part to avoid structural interference, release thermal stress, or adapt to the assembly requirements of the magnet, corresponding to the gap contour edge line in the two-dimensional solution domain. The symmetry center line refers to the central symmetry axis that satisfies the symmetry characteristics of the geometric structure of the metal part and the magnetic field distribution. The outer boundary refers to the outermost geometric contour boundary of the two-dimensional solution domain of the metal part to be evaluated, which is the limit boundary of the effective conductive area of ​​the thin plate.

[0037] Preferably, based on material type information, the material boundaries of different materials in the two-dimensional solution domain are obtained, including: projecting the three-dimensional geometry of the metal part to be evaluated onto the two-dimensional solution domain composed of mid-surfaces; distinguishing the conductive regions corresponding to different materials within the solution domain based on the material type information corresponding to each projection position; the boundary contour lines formed by the adjacency of different material regions are the material boundaries. The material boundaries are used to subsequently apply corresponding continuity constraints to ensure the continuity of the eddy current equivalent scalar on both sides of the boundary lines.

[0038] Preferably, the material boundary constraint condition is as follows: (8) in, , It is the vector of induced eddy current density in the different material regions on both sides of the boundary line. It is the unit tangential vector of the material boundary line; It is the eddy current equivalent scalar in the region on one side of the boundary line; It is the eddy current equivalent scalar in the region on the other side of the boundary line; , These are the directional derivatives of the scalars along the tangential direction of the boundary line. The principle behind this constraint is that at the interface between different materials, the normal component of the eddy current density is continuous, satisfying... Combining eddy current density and eddy current equivalent scalar The vector relationship can be derived as follows: Combining the requirements of the boundary conditions, it is finally obtained that the eddy current equivalent scalar U is continuous on the boundary, that is... .

[0039] Preferably, the kerf constraint condition is as follows: (9) in, The induced eddy current density vector, It is the unit normal vector of the cut edge itself (perpendicular to the cut direction in the two-dimensional plane of the mid-surface). It is the unit tangent vector of the cut edge (along the direction of the cut extension). This is a preset unit normal vector. The principle behind this constraint is that the slit is a physically insulated break region, and no current can pass through the normal vector of the slit. direction); Preferably, the outer boundary constraint condition is as follows: (10) in, This represents the equivalent scalar of eddy current. The principle of constructing this constraint is: establish a cross section at any two points on the outer boundary, and the total current flux of the cross section is always zero. Therefore, the Dirichlet condition is established according to the curl condition as shown in equation (10).

[0040] Preferably, the symmetric constraint condition is as follows: (11) in, The induced eddy current density vector, It is the unit tangent vector of the cut edge (along the direction of the cut extension). The gradient of the eddy current equivalent scalar. Represents the preset unit normal vector. It is the unit tangential vector of the material boundary line; the principle of this constraint is: the structure and the excitation magnetic field are mirror symmetrical along the center line of symmetry, and there are no eddies crossing their own normal at the center line.

[0041] S105: Based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters, the eddy current loss surface density of the metal part to be evaluated is calculated. Furthermore, before calculating the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and its conductivity parameters, the following steps are also included: Obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

[0042] Furthermore, based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and current eddy current loss surface density of the metal part to be evaluated are obtained, including: Gradient calculation is performed on the current eddy current equivalent scalar to obtain the eddy current potential gradient vector; the eddy current potential gradient vector is then cross-multiplied with the preset normal vector to obtain the eddy current density per unit thickness. The amplitude of the eddy current density per unit thickness is converted based on the thickness to obtain the current density of the eddy current surface. The eddy current surface current density is multiplied by itself to obtain the square of the eddy current surface current modulus. Then, based on the square of the eddy current surface current modulus, conductivity, and thickness, the current eddy current loss surface density of the metal part to be evaluated is obtained.

[0043] Preferably, for metal parts with low conductivity such as 316L, the eddy current induced magnetic field is much smaller than the back field (superconducting magnet magnetic field), and the inductive effect of the eddy current field on the magnet's self-field can be ignored. Therefore, for metal parts with low conductivity such as 316L, it is not necessary to correct the eddy current equivalent scalar. However, for heat-conducting metal parts with high conductivity such as oxygen-free copper, the eddy current induced magnetic field is larger and will have a certain mutual inductance coupling with the superconducting magnet magnetic field. Therefore, for heat-conducting metal parts with high conductivity such as oxygen-free copper, it is necessary to correct the eddy current equivalent scalar. That is, it is necessary to repeatedly perform the scalar correction operation to correct the target eddy current equivalent scalar and obtain the corrected target eddy current equivalent scalar.

[0044] Specifically, the current eddy current loss surface density is integrated within the two-dimensional solution domain to obtain the current eddy current loss value of the metal part to be evaluated. This includes: traversing all discrete mesh elements within the two-dimensional solution domain to obtain the eddy current loss surface density corresponding to each mesh element; using the mesh element area as the integration weight, performing area integration on the eddy current loss surface density over the entire two-dimensional solution domain; the integration result is the current eddy current loss value of the metal part to be evaluated.

[0045] It should be noted that the principle of using the current eddy current density as a current source to obtain the current equivalent current source is as follows: based on the thin-film assumption and the planar current assumption, the induced eddy current inside the metal sheet (metal part) is uniformly distributed along the thickness direction. The volume eddy current effect in the thin sheet can be equivalent to the surface current effect distributed on the two-dimensional solution domain (the surface of the metal part). The eddy current density is used to characterize the overall eddy current effect of the thin sheet. The eddy current density distributed on the two-dimensional solution domain is mapped to the equivalent surface current source applied to the corresponding geometric position of the three-dimensional electromagnetic model. In this way, the additional induced magnetic field generated by the eddy current in the three-dimensional space of the metal part is reproduced, thereby realizing the electromagnetic coupling information transmission between the two-dimensional reduced solution domain and the three-dimensional superconducting magnet model.

[0046] Preferably, based on the current equivalent current source and the current three-dimensional electromagnetic model, an updated three-dimensional electromagnetic model is obtained, including: mapping and superimposing the current equivalent current source onto the geometric region corresponding to the metal part to be evaluated in the current three-dimensional electromagnetic model; keeping the original excitation conditions such as the superconducting magnet coil current unchanged, solving the global three-dimensional electromagnetic field after superimposing the equivalent current source, obtaining the total magnetic field distribution including the original magnetic field of the magnet and the additional induced magnetic field of the eddy current of the metal part, and forming the updated three-dimensional electromagnetic model.

[0047] Preferably, the normal magnetic flux density of the updated three-dimensional electromagnetic model is extracted to obtain the corrected normal magnetic flux density, including: First, in the updated three-dimensional electromagnetic model, the two-dimensional mid-surface solution region corresponding to the metal part to be evaluated is accurately matched and located; second, the total magnetic flux density vector after superimposed eddy current reverse action at each discrete position of the mid-surface is read. This total magnetic flux density vector simultaneously includes the original excitation magnetic field component of the superconducting magnet and the induced magnetic field component excited by the eddy current equivalent current source of the metal part; finally, the total magnetic flux density vector at each position is uniformly projected onto the unit normal direction of the plate surface in the two-dimensional solution domain, the tangential magnetic field component is filtered out, and only the normal magnetic field component perpendicular to the mid-surface of the thin plate is retained, finally obtaining the corrected normal magnetic flux density distributed throughout the entire region.

[0048] Preferably, the preset deviation threshold value can be: .

[0049] Preferably, the process of "performing gradient calculation on the current eddy current equivalent scalar to obtain the eddy current potential gradient vector; performing a vector cross product between the eddy current potential gradient vector and a preset normal vector to obtain the eddy current density per unit thickness; and performing amplitude conversion on the eddy current density per unit thickness based on the thickness to obtain the current eddy current surface current density" can be characterized by the following formula: (12) in, It is the current eddy current density. It's about thickness. It is a surface gradient operator in the two-dimensional solution domain. It is a preset unit normal vector. For eddy current equivalent scalars It is the vector cross product operator.

[0050] Preferably, "multiplying the eddy current density by itself to obtain the square of the eddy current modulus, and then obtaining the current eddy current loss surface density of the metal part to be evaluated based on the square of the eddy current modulus, conductivity, and thickness" can be characterized by the following formula: (13) in, This represents the current eddy current loss surface density. It is the current eddy current density. For electrical conductivity, It refers to thickness.

[0051] Preferably, please refer to Figure 2 , Figure 2 This is a schematic diagram of eddy currents in a metal part according to an embodiment of the present invention, as shown below. Figure 2 As shown, the metal plate has longitudinal slits, transverse slit 1, and transverse slit 2. The continuous metal plate is cut by the slits, and the eddy currents that could originally circulate over a large area are forcibly divided into three independent closed loops: eddy current loop 1, eddy current loop 2, and eddy current loop 3 (orange dashed lines). The slits are insulating barriers, and current cannot pass through the slits. Therefore, the currents in the three loops are independent of each other and almost do not communicate.

[0052] Please see Figure 3 , Figure 3 This is a schematic diagram of an equivalent lumped circuit provided in an embodiment of the present invention, in which a single eddy current loop is equivalent to a rectangular closed resistor loop. Wherein, It is the equivalent resistance of the longitudinal metal path of the corresponding loop (the conductive area along the longitudinal cut). This corresponds to the equivalent resistance of the horizontal metal path in the upper and lower loops. The entire loop is a closed circuit formed by connecting the resistors end to end, corresponding to the lumped resistance in formula (14). In addition to resistance, a complete circuit also contains self-inductance. External magnetic field through mutual inductance Applying an induced electromotive force to the loop constitutes the physical basis of equation (14).

[0053] The following combination Figure 2 , 3 Explain the physical principle of equation (14): Current is passed through the D-type superconducting coil. When the current changes, an alternating magnetic field is generated. This alternating magnetic field passes through the outer metal plate and, through electromagnetic induction, attempts to form a large-scale closed eddy current on the metal plate. Therefore, it is usually necessary to artificially create longitudinal and transverse slits to break a large plate into multiple unconnected eddy current loops. Each loop enclosed by an orange dashed line is an independent conductive closed loop, equivalent to a lumped circuit of resistance and self-inductance. There is mutual inductance between the superconducting coil and the loop. The change in coil current induces an electromotive force (EMF) within the loop; this EMF drives the generation of equivalent eddy currents within the loop. Part of the electromotive force is used to overcome the loop self-inductance, and the other part generates heat across the equivalent resistance, corresponding to the equation: (14) in, The mutual inductance between the superconducting magnet and the eddy current loop of the metallic component. The self-inductance of the eddy current loop in the metal component. For superconducting magnet coils to carry current; The lumped equivalent eddy current corresponding to the eddy current loop. This is the lumped resistance of the eddy current path.

[0054] Based on formula (14), in one possible implementation, the eddy current loss surface density of the metal part to be evaluated can also be obtained by the following method: For metal parts with slits, the originally continuous eddy current path on the metal part is divided and blocked by the slits, forming multiple closed eddy current loops with clear boundaries and approximately independent of each other. Each independent eddy current loop satisfies formula (14). Using the eddy current field dimensionality reduction calculation method mentioned above, sample data under multiple working conditions are obtained to complete the identification and fitting of lumped circuit model parameters; determine , , After setting the parameters, input the superconducting magnet operating current. The rate of change of current with time is obtained and substituted into formula (14) to obtain the lumped equivalent eddy current of each loop; the eddy current loss of a single eddy current loop is calculated based on the lumped resistance and lumped equivalent eddy current of the loop; all eddy current loops are traversed and the eddy current losses of each loop are summed and the result is the total eddy current loss of the metal part to be evaluated.

[0055] S105: Based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters, the eddy current loss surface density of the metal part to be evaluated is calculated. Specifically, the conductivity parameter is the electrical conductivity of the metal part.

[0056] Based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and its conductivity parameters, the eddy current loss surface density of the metal part to be evaluated is calculated, including by the following formula: (15) in, It is the current eddy current density. It's about thickness. It is a surface gradient operator in the two-dimensional solution domain. It is a preset unit normal vector. The target eddy current equivalent scalar. It is the vector cross product operator.

[0057] (16) in, This represents the surface density of eddy current losses. It is the current eddy current density. For electrical conductivity, It refers to thickness.

[0058] S106: Integrate the eddy current loss surface density in the two-dimensional solution domain to obtain the total eddy current loss value of the metal part to be evaluated; select the metal part to be evaluated with the lowest total eddy current loss value as the selected metal part.

[0059] Eddy current loss surface density characterizes the Joule heat power generated per unit area at various locations of a metal component. By integrating across the entire two-dimensional solution domain, the total heat generation power generated by the entire metal component under evaluation can be obtained, i.e., the total eddy current loss value. Simulation calculations were performed on various metal components under evaluation with different slit layouts and structural forms. The total eddy current loss values ​​corresponding to each group of schemes were compared, and the structural scheme with the lowest total eddy current loss was selected as the final selected metal component.

[0060] like Figure 4 As shown, based on the above method embodiments, corresponding apparatus embodiments are provided; An embodiment of the present invention provides a selection device for metal components in a superconducting magnet under target working conditions, comprising: a data acquisition module 201, a two-dimensional solution domain determination module 202, a magnetic field parameter determination module 203, a target eddy current equivalent scalar determination module 204, an eddy current loss surface density determination module 205, and a selection module 206. The data acquisition module 201 is used to acquire the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; wherein, the geometric parameters include: height coordinate data at various points on the upper surface, height coordinate data at various points on the lower surface, and thickness. The two-dimensional solution domain determination module 202 is used to extract a curved surface equidistant from the upper and lower surfaces as a two-dimensional solution domain for each metal part to be evaluated, based on the height coordinate data of each location on the upper surface and the height coordinate data of each location on the lower surface. The magnetic field parameter determination module 203 is used to extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target working condition; The target eddy current equivalent scalar determination module 204 is used to solve the preset eddy current equivalent scalar modeling equation in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, so as to obtain the target eddy current equivalent scalar. The eddy current loss surface density determination module 205 is used to calculate the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters. Select module 206 to integrate the eddy current loss surface density in the two-dimensional solution domain to obtain the total eddy current loss value of the metal part to be evaluated; select the metal part to be evaluated with the lowest total eddy current loss value as the selected metal part.

[0061] The target eddy current equivalent scalar determination module 204 includes: a first data acquisition sub-unit, a material boundary line determination sub-unit, a constraint condition determination sub-unit, and a solution sub-unit; The first data acquisition subunit is used to acquire information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated. Each material boundary line determination sub-element is used to obtain the material boundary lines of different materials in the two-dimensional solution domain based on the material type information; The constraint condition determination sub-element is used to determine the following constraints based on each slit, symmetry centerline, material boundary line, and outer boundary: material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same; outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero; slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero; and symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. The solver sub-element is used to solve the preset eddy current equivalent scalar modeling equation in a two-dimensional solution domain under material boundary constraints, outer boundary constraints, kerf constraints, and symmetry constraints, based on magnetic field parameters, the thickness of the metal part to be evaluated, and electrical conductivity parameters, to obtain the target eddy current equivalent scalar.

[0062] The selection of metal components in superconducting magnets under target operating conditions also includes: correction modules; The correction module is used to obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions, as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

[0063] It is understood that the above-described device embodiments correspond to the method embodiments of the present invention, and can realize the selection method of metal parts in superconducting magnets under target working conditions provided by any of the above-described method embodiments of the present invention.

[0064] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0065] Based on the above-described method for selecting metal components in a superconducting magnet under target operating conditions, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the method for selecting metal components in a superconducting magnet under target operating conditions according to any embodiment of the present invention.

[0066] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0067] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0068] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0069] Based on the above-described method embodiments, another embodiment of the present invention provides a computer-readable storage medium, including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the selection method for metal components in a superconducting magnet under target operating conditions as described in any of the above-described method embodiments of the present invention.

[0070] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0071] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for selecting metal components in a superconducting magnet under target operating conditions, characterized in that, include: Obtain the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; the geometric parameters include: height coordinate data at various points on the upper surface, height coordinate data at various points on the lower surface, and the thickness of the metal part to be evaluated. For each metal part to be evaluated, based on the height coordinate data of each point on the upper surface and the height coordinate data of each point on the lower surface, a curved surface equidistant from the upper and lower surfaces is extracted as a two-dimensional solution domain. Extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target operating conditions; Within the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar. Based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters, the eddy current loss surface density of the metal part to be evaluated is calculated. The total eddy current loss value of the metal part to be evaluated is obtained by integrating the eddy current loss surface density in the two-dimensional solution domain; the metal part to be evaluated with the lowest total eddy current loss value is selected as the selected metal part.

2. The method for selecting metal components in a superconducting magnet under target operating conditions as described in claim 1, characterized in that, The magnetic field parameters include: the angular frequency of the magnetic field change and the normal magnetic flux density; the electrical conductivity parameters include: electrical conductivity. The eddy current equivalent scalar modeling equation is: in, For the Laplace operator, Let be the eddy current equivalent scalar to be solved. The imaginary unit, The angular frequency of the magnetic field change. For electrical conductivity, denoted as , where is the normal magnetic flux density.

3. The method for selecting metal components in a superconducting magnet under target operating conditions as described in claim 2, characterized in that, Within the two-dimensional solution domain, based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, the preset eddy current equivalent scalar modeling equation is solved to obtain the target eddy current equivalent scalar, including: Obtain information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated; Based on the material type information, the material boundaries of different materials in the two-dimensional solution domain are obtained; Based on each slit, symmetry centerline, material boundary line, and outer boundary, we determine the material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same, the outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero, the slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero, and the symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. Under the constraints of material boundary line, outer boundary, kerf, and symmetry, the preset eddy current equivalent scalar modeling equation is solved in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, to obtain the target eddy current equivalent scalar.

4. The method for selecting metal components in a superconducting magnet under target operating conditions as described in claim 3, characterized in that, Before calculating the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and its conductivity parameters, the following steps are also included: Obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

5. The method for selecting metal components in a superconducting magnet under target operating conditions as described in claim 4, characterized in that, Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and current eddy current loss surface density of the metal part to be evaluated are obtained, including: Gradient calculation is performed on the current eddy current equivalent scalar to obtain the eddy current potential gradient vector; the eddy current potential gradient vector is then cross-multiplied with the preset normal vector to obtain the eddy current density per unit thickness. The amplitude of the eddy current density per unit thickness is converted based on the thickness to obtain the current density of the eddy current surface. The eddy current surface current density is multiplied by itself to obtain the square of the eddy current surface current modulus. Then, based on the square of the eddy current surface current modulus, conductivity, and thickness, the current eddy current loss surface density of the metal part to be evaluated is obtained.

6. A selection device for metal components in a superconducting magnet under target operating conditions, characterized in that, include: The module includes a data acquisition module, a two-dimensional solution domain determination module, a magnetic field parameter determination module, a target eddy current equivalent scalar determination module, an eddy current loss surface density determination module, and a selection module. The data acquisition module is used to acquire the geometric parameters and electrical conductivity parameters of each metal part to be evaluated; among which, the geometric parameters include: height coordinate data of various points on the upper surface, height coordinate data of various points on the lower surface, and the thickness of the metal part to be evaluated. The two-dimensional solution domain determination module is used to extract a curved surface equidistant from the upper and lower surfaces as the two-dimensional solution domain for each metal part to be evaluated, based on the height coordinate data of each location on the upper surface and the height coordinate data of each location on the lower surface. The magnetic field parameter determination module is used to extract the magnetic field parameters of the three-dimensional electromagnetic model corresponding to the superconducting magnet under the target working conditions. The target eddy current equivalent scalar determination module is used to solve the preset eddy current equivalent scalar modeling equation in the two-dimensional solution domain based on the magnetic field parameters, the thickness of the metal part to be evaluated, and the conductivity parameters, so as to obtain the target eddy current equivalent scalar. The eddy current loss surface density determination module is used to calculate the eddy current loss surface density of the metal part to be evaluated based on the target eddy current equivalent scalar, the thickness of the metal part to be evaluated, and the conductivity parameters. The selected module is used to integrate the eddy current loss surface density in the two-dimensional solution domain to obtain the total eddy current loss value of the metal part to be evaluated; the metal part to be evaluated with the lowest total eddy current loss value is selected as the selected metal part.

7. The selection device for metal components in a superconducting magnet under target operating conditions as described in claim 6, characterized in that, The target eddy current equivalent scalar determination module includes: a first data acquisition sub-unit, a material boundary line determination sub-unit, a constraint condition determination sub-unit, and a solution sub-unit; The first data acquisition subunit is used to acquire information on the material type, cuts, center line of symmetry, and outer boundary of the metal part to be evaluated. Each material boundary line determination sub-element is used to obtain the material boundary lines of different materials in the two-dimensional solution domain based on the material type information; The constraint condition determination sub-element is used to determine the following constraints based on each slit, symmetry centerline, material boundary line, and outer boundary: material boundary line constraint condition to characterize that the eddy current equivalent scalar at each position on the same material boundary line is the same; outer boundary constraint condition to characterize that the eddy current equivalent scalar at each position on the outer boundary is zero; slit constraint condition to characterize that the tangential gradient of the eddy current equivalent scalar along the slit direction is zero; and symmetry constraint condition to characterize that the gradient of the eddy current equivalent scalar along the tangential direction at the symmetry centerline is zero. The solver sub-element is used to solve the preset eddy current equivalent scalar modeling equation in a two-dimensional solution domain under material boundary constraints, outer boundary constraints, kerf constraints, and symmetry constraints, based on magnetic field parameters, the thickness of the metal part to be evaluated, and electrical conductivity parameters, to obtain the target eddy current equivalent scalar.

8. The selection device for metal components in a superconducting magnet under target operating conditions as described in claim 7, characterized in that, Also includes: Correction module; The correction module is used to obtain the three-dimensional electromagnetic model of the superconducting magnet under the target operating conditions, as the initial three-dimensional electromagnetic model; Based on the initial three-dimensional electromagnetic model, the scalar correction operation is repeatedly performed to correct the target eddy current equivalent scalar, and the corrected target eddy current equivalent scalar is obtained. The scalar correction operation includes: Based on the current eddy current equivalent scalar, thickness, and conductivity, the current eddy current surface current density and the current eddy current loss surface density of the metal part to be evaluated are obtained. Integrating the current eddy current loss surface density within the two-dimensional solution domain yields the current eddy current loss value of the metal part to be evaluated. Using the current eddy current density as a current source, we obtain the current equivalent current source; Based on the current equivalent current source and the current three-dimensional electromagnetic model, the updated three-dimensional electromagnetic model is obtained; wherein, the current three-dimensional electromagnetic model when the scalar correction operation is performed for the first time is the initial three-dimensional electromagnetic model; Extract the normal magnetic flux density of the updated 3D electromagnetic model to obtain the corrected normal magnetic flux density; If the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is less than a preset deviation threshold, the current eddy current equivalent scalar is used as the corrected target eddy current equivalent scalar. Specifically, the current normal magnetic flux density at the time of the first scalar correction operation is the normal magnetic flux density in the magnetic field parameters corresponding to the initial three-dimensional electromagnetic model; the current normal magnetic flux density at subsequent scalar correction operations is the corrected normal magnetic flux density at the time of the last scalar correction operation. When the deviation between the corrected normal magnetic flux density and the current normal magnetic flux density is greater than or equal to a preset deviation threshold, the eddy current equivalent scalar modeling equation is solved within the two-dimensional solution domain of the metal part to be evaluated, based on the magnetic field change angular frequency, the corrected normal magnetic flux density, the conductivity and thickness of the metal part to be evaluated, to obtain the updated eddy current equivalent scalar.

9. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements the selection method for metal components in a superconducting magnet under target operating conditions as described in any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, include: A stored computer program, wherein, when the computer program is executed, the device containing the computer-readable storage medium is controlled to perform the selection method for metal components in a superconducting magnet under target operating conditions as described in any one of claims 1-5.

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