Method for reducing the diameter of a high temperature superconducting corc cable
By establishing a mapping relationship between strain and critical current density and using a multi-objective optimization algorithm, the diameter reduction parameters of high-temperature superconducting CORC cables were optimized, solving the problem of process parameters relying on experience and achieving high reliability and consistency in cable manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-08
- Publication Date
- 2026-06-05
AI Technical Summary
The setting of process parameters for the reduction of diameter of high-temperature superconducting CORC cables relies on experience and lacks systematic guidance, resulting in a narrow process window, large performance dispersion, and affecting manufacturing reliability.
By establishing a mapping relationship between cable strain and critical current density, a multi-objective optimization algorithm is used to optimize the combination of diameter reduction parameters, including structural, dynamic, and geometric parameters, actively control the initial contact state, and use the optimized parameters for diameter reduction forming.
It improves the manufacturing reliability and performance consistency of high-temperature superconducting CORC cables, significantly increases the critical current retention rate, reduces the performance fluctuation range within batches, and broadens the process window.
Smart Images
Figure CN122158257A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-temperature superconducting cable manufacturing technology, and specifically to a method for forming a high-temperature superconducting CORC cable with a reduced diameter. Background Technology
[0002] High-temperature superconducting CORC (superconducting conductor on round core) cables have gradually become one of the key candidate conductors for future fusion magnets and high-field magnets due to their excellent bending performance, high engineering current density, and scalability. To improve the mechanical stability and current-carrying capacity of high-temperature superconducting CORC cables, an industrial cable-sheath structure is typically adopted, and a diameter reduction process is used to ensure that the outer metal sheath tightly wraps around the central CORC sub-cable. However, in this scenario, the diameter reduction process involves a complex mechanical process involving multiple layers of heterogeneous materials, large deformation contact, and nonlinear response. This process can easily introduce irreversible strain into the superconducting tape, leading to a significant degradation of the critical current of the high-temperature superconducting CORC cable.
[0003] Currently, the setting of process parameters for the reduction of CORC cables (such as sheath size, reduction speed, and mold configuration) largely relies on operator experience or limited trial-and-error experiments, lacking systematic theoretical guidance and quantitative design tools. Furthermore, existing research mainly focuses on the analysis of local mechanical behavior and / or static testing of electromagnetic performance after reduction, without establishing a complete predictive model covering "process parameters-mechanical deformation-electromagnetic performance," especially lacking research on the control of the stochastic factor of "the initial assembly position of the cable within the sheath" (which is prevalent in actual production and has a significant impact on high-temperature superconducting CORC cables). Therefore, current high-temperature superconducting CORC cables generally suffer from a narrow process window for reduction, manifesting as significant performance dispersion in mass production, which has become a technical bottleneck restricting the manufacturing reliability of high-temperature superconducting CORC cables.
[0004] Therefore, developing a method that can accurately simulate the necking process, quantitatively assess the impact of various process parameters, and achieve proactive performance optimization is crucial for promoting the engineering application of CORC cables. Summary of the Invention
[0005] The present invention aims to solve at least some of the above-mentioned technical problems and / or solve at least some of the above-mentioned technical problems, and aims to optimize the current CORC cable reduction forming process to form a quantitatively executable reduction forming process.
[0006] In view of this, the present invention provides a method for reducing the diameter of a high-temperature superconducting CORC cable, the method comprising: S100: determining an initial combination of reduction parameters, the combination of reduction parameters including structural parameters of the high-temperature superconducting CORC cable, dynamic parameters during the reduction process, and geometric parameters of the reduction mold; S200: optimizing the combination of reduction parameters based on a pre-established mapping relationship between cable strain and critical current density; S300: performing a reduction process on the high-temperature superconducting CORC cable using the optimized combination of reduction parameters.
[0007] This configuration allows for the use of optimized diameter reduction parameter combinations to reduce the diameter of high-temperature superconducting CORC cables, thereby improving the manufacturing reliability of high-temperature superconducting CORC cables.
[0008] In one possible implementation of the above-mentioned method for reducing the diameter of a high-temperature superconducting CORC cable, the high-temperature superconducting CORC cable includes a sub-cable and a sheath disposed on the outside of the sub-cable. The sub-cable includes a core and a multi-layer tape spirally wound around the core. The structural parameters of the high-temperature superconducting CORC cable are determined by obtaining the structural parameters of the high-temperature superconducting CORC cable based on a pre-established mechanical model of the high-temperature superconducting CORC cable.
[0009] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, the "optimization of the combination of reduction parameters" includes: optimizing the combination of reduction parameters based on a pre-established mapping relationship between cable strain and critical current density, with multiple objectives of maximizing the overall critical current of the cable and minimizing the difference rate of interlayer critical current in the cable.
[0010] By employing a multi-objective optimization algorithm, with the goal of maximizing the overall critical current retention rate of the cable and minimizing the interlayer strain difference, the variables are optimized collaboratively.
[0011] Both the overall critical current and the interlayer critical current difference rate of the cable depend on the mapping relationship. Specifically, based on the mapping relationship, the strain distribution is converted into the critical current density of each superconducting unit, and then the overall critical current of the cable is calculated, thereby maximizing the overall critical current of the cable. Similarly, it is necessary to obtain the critical current density of each layer based on the mapping relationship, and calculate the difference in critical current density between layers, thereby minimizing the interlayer critical current difference rate.
[0012] In one possible implementation of the above-mentioned method for reducing the diameter of a high-temperature superconducting CORC cable, the structural parameters of the high-temperature superconducting CORC cable include the initial relative position between the sub-cable and the inner wall of the sheath. The step of "optimizing the combination of the reduction parameters with multiple objectives of maximizing the overall critical current of the high-temperature superconducting CORC cable and minimizing the difference rate of the interlayer critical current of the high-temperature superconducting CORC" includes: making the initial relative position between the sub-cable and the inner wall of the sheath in a non-centered initial contact state.
[0013] This design allows for the proactive guidance of the asymmetry in the diameter reduction deformation, thereby mitigating strain concentration in the cable core region to some extent.
[0014] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, the non-aligned initial contact state includes a unilateral directional contact state and a non-contact state with an eccentricity.
[0015] This configuration provides a possible form of the initial contact state that is not aligned.
[0016] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, the step of "making the initial relative position between the sub-cable and the inner wall of the sheath in an initial contact state that is not centered" includes: according to the initial contact orientation of the sub-cable in the sheath, rotating the first pair of reducing rollers of the reducing mold so that the center line of the opening of the first pair of reducing rollers matches the initial contact state.
[0017] This configuration provides a method for constructing the initial contact state that is not centered.
[0018] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, in the step of "optimizing the combination of reduction parameters based on a pre-established mapping relationship between cable strain and critical current density", the mapping relationship between cable strain and critical current density is determined as follows: the mapping relationship between cable strain and critical current density is determined according to the strain-critical current density degradation function.
[0019] The strain-critical current density degradation function reflects the relationship between strain and critical current density degradation in superconducting materials. For example, this function can be determined through experimental calibration. Based on this function, for a specific initial contact state, the full-field strain distribution data of the cable obtained through mechanical finite element simulation is converted one by one into an electromagnetic simulation model used to evaluate the electromagnetic performance of the cable, thereby determining the critical current density value or degradation ratio corresponding to each superconducting unit. Clearly, those skilled in the art can determine the method for determining the strain-critical current density degradation function and its specific expression according to actual needs.
[0020] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, the structural parameters of the high-temperature superconducting CORC cables include the structural parameters of the sheath, which include the target inner diameter and wall thickness of the sheath.
[0021] This configuration provides a possible form of the structural parameters for high-temperature superconducting CORC cables in the combination of reduced-diameter parameters.
[0022] In one possible implementation of the above-mentioned method for forming the diameter reduction of high-temperature superconducting CORC cables, the dynamic parameters in the diameter reduction forming process include the feed speed of the cable during the diameter reduction forming process; and / or the geometric parameters of the diameter reduction mold include the opening angle of the diameter reduction roller.
[0023] This configuration provides possible forms of the dynamic parameters and geometric parameters of the diameter reduction mold in the diameter reduction forming process.
[0024] In one possible implementation of the above-mentioned method for reducing the diameter of high-temperature superconducting CORC cables, the reducing mold includes a reducing roller with a replaceable or adjustable opening angle. The step of "using an optimized combination of reducing parameters to reduce the diameter of the high-temperature superconducting CORC cable" includes: achieving an optimized combination of reducing parameters by replacing the reducing roller or adjusting the opening angle of the reducing mold; and using the optimized combination of reducing parameters to reduce the diameter of the high-temperature superconducting CORC cable.
[0025] This configuration provides a possible way to construct combinations of diameter reduction parameters. Attached Figure Description
[0026] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which: Figure 1 A schematic flowchart of a method for forming a high-temperature superconducting CORC cable with reduced diameter according to an embodiment of the present invention is shown. Figure 2The diagram shows three typical initial states of the cable within the sheath, where (a) is the centering non-contact state, (b) is the +Y direction single-sided contact state, and (c) is the eccentric non-contact state. In the diagram, the structure on the radially inner side is a high-temperature superconducting CORC cable, and the structure on the radially outer side is the sheath. Figure 3 This diagram illustrates the strain-critical current density degradation relationship curve used in the diameter reduction forming method of a high-temperature superconducting CORC cable according to an embodiment of the present invention. Figure 4 A schematic diagram illustrating the working principle of a method for forming a diameter reduction of a high-temperature superconducting CORC cable according to an embodiment of the present invention is shown. Figure 5 This diagram illustrates a comparison of the critical current retention rates of each layer of a high-temperature superconducting CORC cable before and after the diameter reduction molding method of the cable according to an embodiment of the present invention. Detailed Implementation
[0027] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.
[0028] It should be noted that in the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0029] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0030] Furthermore, to better illustrate the present invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced even without certain specific details. In some instances, the principles of CORC cables and the specific steps of their diameter reduction molding, which are well-known to those skilled in the art, are not described in detail, in order to highlight the main points of the present invention.
[0031] The following describes the diameter reduction forming method of the high-temperature superconducting CORC cable of the present invention, taking a certain type of 24-layer, 66-ribbed high-temperature superconducting CORC cable as an example.
[0032] Main reference Figure 1 In one possible implementation, the method for forming a high-temperature superconducting CORC cable with reduced diameter mainly includes the following steps: S100: Determine the initial combination of reduction parameters. This combination mainly includes the structural parameters of the high-temperature superconducting CORC cable, the dynamic parameters during the reduction molding process, and the geometric parameters of the reduction die.
[0033] In one possible implementation, based on the actual geometry of a high-temperature superconducting CORC cable, a refined three-dimensional mechanical model (such as a three-dimensional finite element model) of the high-temperature superconducting CORC cable is established, including components such as the sheath, core, and all layered superconducting and metal strips. The model should accurately reproduce, for example, the spiral winding angle of the strips, interlayer gaps, and the elastoplastic constitutive relations of the material at low temperatures.
[0034] For example, a 1:1 geometric model was created in finite element software based on the measured dimensions of the cable (average outer diameter 9.52 mm). Sixty-six strips (including YBCO superconducting strips and copper strips) were arranged according to their actual layer sequence and helix angle (alternating in opposite directions), with uniform process gaps set between the layers. Material properties (such as Young's modulus and yield strength) were based on experimental data at liquid nitrogen temperature (77 K), and the contact friction coefficient between the sheath and the strip, and between the strip and the roller, was set to 0.2.
[0035] Based on this, controllable initial cable assembly conditions are introduced. Specifically, the initial relative positional relationship between the cable and the inner wall of the sheath is preset in the mechanical model, such as defining multiple initial states. Preferably, at least the following are defined: Figure 2 The three typical initial states shown are (a) centering without contact, (b) unilateral directional contact, and (c) eccentric non-contact.
[0036] To simulate the sinking of the high-temperature superconducting CORC cable due to gravity during actual assembly, in this embodiment, the following is selected: Figure 2 The “+Y direction single-sided contact state” shown in (b) serves as the starting condition for optimization, namely: assuming that the bottom of the high-temperature superconducting CORC cable is in contact with the inner wall of the sheath. In this way, the initial asymmetry of the diameter reduction deformation can be simulated and actively guided.
[0037] S200: Based on the pre-established mapping relationship between cable strain and critical current density, the combination of reduction parameters is optimized.
[0038] Reference Figure 3In a specific example, the following polynomial function is used as the mapping relationship between cable strain and critical current density (integrated strain to critical current density retention ratio). Jc / Jc 0): Jc / Jc 0 = -8.236 × 10 10 ε 6 -3.182×10 9 ε 5 -2.155×10 7 ε 4 +1.344×10 5 ε 3 -2962ε 2 -7.984ε+1 In the above formula, Jc This represents the critical current density of the strip under the influence of (integrated) strain ε. Jc0 This represents the critical current density of the strip when the strain ε is 0.
[0039] It can be seen that the critical current retention rate first increases and then decreases with increasing axial strain. Specifically, regardless of whether the strain is positive or negative, the larger the absolute value of the strain, the worse the performance of the superconducting tape. Therefore, within the integrated strain range shown in the figure, the absolute value of the strain first decreases and then increases, and correspondingly, the superconducting performance (critical current retention rate) of the cable first increases and then decreases.
[0040] For example, after the mechanical simulation, the strain values at all integration points on each YBCO strip are extracted. The performance degradation ratio is calculated using this function and used as input for the subsequent electromagnetic model. Specifically, the simulation employs finite element analysis to obtain the strain distribution of each strip throughout the entire diameter reduction process. The purpose of the simulation is to obtain the strain values at all integration points of the strip during this mechanical process. By substituting these values into the aforementioned mapping relationship, the critical current retention rate is calculated. Based on this, the electromagnetic simulation model is calculated again using finite element analysis (with the critical current retention rate used as the material parameter definition input for the subsequent electromagnetic model), thereby quantifying the overall critical current of the high-temperature superconducting CORC cable under the influence of the diameter reduction mechanical process.
[0041] In this way, the full-field strain distribution data obtained from mechanical simulation calculations can be converted into the intrinsic performance parameters of each superconducting unit in the electromagnetic model through an experimentally calibrated strain-critical current density degradation function, thereby establishing a mapping bridge from mechanical strain to electromagnetic performance.
[0042] The aforementioned mapping relationship was obtained by performing uniaxial tensile tests on superconducting tapes and simultaneously conducting critical current tests to obtain critical current density data at different strain levels, followed by polynomial data fitting. Clearly, the above polynomial mapping relationship is only one example; in other implementations, different mapping relationships can be obtained based on experimental data and fitting methods for different superconducting tapes.
[0043] In one possible implementation, a parametric simulation and collaborative optimization system is constructed. For example, an integrated simulation and optimization platform is built, which abstracts the key factors affecting the diameter reduction forming results into several independently adjustable process variable modules, specifically including: (1) Sheath structure parameter module: used to define and constrain the external mechanical boundaries of the cable; (2) Drawback Dynamics Parameter Module: Used to define the dynamic conditions of the drawback forming process; (3) Reduction Die Geometry Parameters Module: Used to define the shape characteristics of the die for direct loading; (4) Cable initial state parameter module: used to define the relative spatial relationship between the cable and the sheath before the diameter reduction.
[0044] For example, the parametric simulation and optimization system takes four main categories of process variables as input: structural parameters of the sheath (inner diameter and wall thickness of the sheath), dynamic parameters during the necking process (feed speed), geometric parameters of the necking die (opening angle of the necking roller), and initial state parameters of the cable (initial contact state). Its workflow is as follows: First, multiple sets of simulated process parameter combinations are generated based on experimental design methods such as orthogonal methods; these combinations are then input into a three-dimensional refined mechanical model and a CORC cable electromagnetic model for numerical calculation and post-processing; next, the simulation results are analyzed and performance evaluated; finally, through iterative optimization, the optimal process parameter combination that maximizes cable performance is output as the process parameter combination for necking of current high-temperature superconducting CORC cables. Testing showed that cable samples manufactured using the optimized necking parameter combination exhibited significantly higher critical current retention rates than samples manufactured using traditional empirical processes, and their batch-to-batch performance fluctuation range was reduced by approximately 60%.
[0045] Among them, the multi-objective optimization algorithm can be any algorithm suitable for problems with mixed continuous and discrete variables, such as the Non-Dominated Sorting Genetic Algorithm (NSGA-II) or the Multi-Objective Particle Swarm Optimization Algorithm (MOPSO). In one specific implementation, the Non-Dominated Sorting Genetic Algorithm (NSGA-II) with an elitist strategy is used for optimization. Specifically, continuous variables such as the inner diameter of the sheath and the opening angle of the tapering roller, and discrete variables such as the feed speed and wall thickness are encoded as chromosomes. The difference rate between the overall critical current and the interlayer critical current obtained from simulation calculations is used as the fitness function. The population is iteratively evolved through operations such as selection, crossover, and mutation, and finally the optimal combination of tapering parameters is selected from the Pareto optimal solution set.
[0046] In the parameterized optimization system for the high-temperature superconducting CORC cable of this embodiment, the following range is set for the combination of diameter reduction parameters: (1) Structural parameters of the sheath: The target inner diameter of the sheath is limited to vary between 9.1 mm and 9.5 mm, and the wall thickness of the sheath can be selected as 0.9 mm or 1.0 mm.
[0047] (2) Dynamic parameters of the diameter reduction process: The feed rate can be selected as 5, 10 or 15 mm / s.
[0048] (3) Geometric parameters of the diameter reduction mold: The opening angle of the diameter reduction roller is set to vary between 130° and 160°.
[0049] (4) Initial state of high temperature superconducting CORC cable: In this example, it is fixed as +Y direction single-sided contact.
[0050] In one specific embodiment, an orthogonal experimental design method was used to arrange the simulation combinations, resulting in a total of 18 fully coupled simulations. The simulation results show that when the target inner diameter of the sheath is limited to 9.5 mm, the combination of diameter reduction parameters—a thin-walled sheath with an inner diameter of 0.9 mm, a feed speed of 15 mm / s, and an opening angle of 140° for the diameter reduction roller—can enable the high-temperature superconducting CORC cable to achieve the best overall performance.
[0051] S300 uses an optimized combination of diameter reduction parameters to perform diameter reduction forming on high-temperature superconducting CORC cables.
[0052] For example, if you need to develop such Figure 5The illustrated diameter reduction forming equipment, capable of executing optimized strategies, processes a high-temperature superconducting CORC cable 1, primarily consisting of a sub-cable and a sheath covering the sub-cable. The equipment, capable of performing diameter reduction forming on the high-temperature superconducting CORC cable, includes a diameter reduction mold 2 with multiple adjustable diameter reduction rollers. Furthermore, the equipment includes an online detection and adjustment device for cable orientation and a control unit capable of closed-loop control of process parameter combinations. For example, by replacing the diameter reduction rollers or adjusting the opening angle of the diameter reduction mold, the opening angle of the diameter reduction rollers can be determined to be 140°. The control unit can then automatically adjust the orientation of the diameter reduction mold and process parameters according to the determined optimized strategy. Clearly, the specific structural form of the equipment can be flexibly selected according to actual needs.
[0053] The optimized diameter reduction parameter combination (inner diameter of the sheath is 9.3 mm, wall thickness of the sheath is 0.9 mm, feed speed is 10 mm / s, opening angle of the diameter reduction rollers is 140°, alignment of the first diameter reduction rollers + initial contact in the Y direction) is input to the equipment's control unit. Before actual diameter reduction, the actual orientation of the cable within the sheath can be detected by a visual sensor or other detection components. The control unit can then drive a rotating mechanism to adjust the first pair of diameter reduction rollers of the diameter reduction mold to a position aligned with the contact side of the cable (adjusting the center line of the opening of the first pair of diameter reduction rollers to a position aligned with the vertical direction to alleviate strain concentration in the inner strip material using controllable asymmetric deformation), and then perform the diameter reduction operation. Comparison shows that the load-displacement curve monitored by the online force sensor matches the simulation prediction curve well, indicating that the present invention can achieve accurate process reproduction.
[0054] For example, mechanical-electromagnetic coupling simulation software platform and process optimization decision support software can be used to execute steps S100 to S200, and adjustable diameter reduction equipment and online monitoring hardware can be used to execute S300.
[0055] To verify the effect of the diameter reduction parameter combination determined based on this invention, a set of comparative simulations were conducted. One set used conventional centering diameter reduction, while the other set used the mechanical energy based on the diameter reduction parameter combination determined by this invention. The results show that after using the diameter reduction parameter combination determined by this invention to perform diameter reduction forming on the high-temperature superconducting CORC cable to be processed, the average strain of the inner layer (layers 1-8) of the cable tape decreased by about 15%, and the overall predicted critical current increased from 2465A to 2580A. Figure 5 The difference in critical current retention rates of each layer of high-temperature superconducting CORC cables manufactured using the conventional process (before optimization) and the optimized process of the present invention (after optimization) is shown. It can be seen that the cable sample manufactured using the above-mentioned optimized combination of diameter reduction parameters has a significantly higher critical current retention rate than the sample manufactured using the conventional empirical process, and its batch performance fluctuation range is reduced by about 60%.
[0056] It can be seen that, in the preferred embodiment of the present invention, by actively controlling the initial contact state of the cable and coordinating with multiple process parameters, the diameter reduction forming method of the conductor-wound round core cable in the sheath diameter reduction assembly process of the high-temperature superconducting CORC cable is optimized. Based on this, it is expected to improve the electromagnetic performance and consistency of the high-temperature superconducting CORC cable. Specifically: (1) An active control mechanism for initial contact was proposed for the first time. Based on this, the assembly deviation that is difficult to avoid in the traditional molding process can be transformed into a favorable factor that can be used to improve performance. By guiding the deformation mode, the strain damage of the inner superconducting tape can be significantly reduced. As shown in the experiment, the retention rate of the critical current of the cable under the same diameter reduction can be increased by more than 10% on average.
[0057] (2) By introducing a clear influence law of parameter coupling, the collaborative quantitative optimization of multiple process parameters was realized, breaking the traditional mode of relying on single parameter trial and error, broadening the process window of the diameter reduction process of high temperature superconducting CORC cable, and greatly improving the performance consistency of high temperature superconducting CORC cable in mass production.
[0058] (3) Based on the established complete chain of “modeling-optimization-control”, the digital and intelligent design of the diameter reduction process of high temperature superconducting CORC cable has been realized. In this way, a feasible complete solution from digital simulation to physical manufacturing can be provided, which can significantly reduce the number of trial productions and costs of experimental samples, and will significantly shorten the R&D cycle.
[0059] (4) In addition, the present invention has the obvious advantage of strong versatility. For example, the core methodology can be applied to high-temperature superconducting CORC cables with different number of layers and structural forms, and can also be extended to the development of diameter reduction molding processes for other multilayer composite conductors.
[0060] Clearly, the combination of reduction parameters for the reduction process of the CORC cable of the above specifications is an exemplary description. This invention is also applicable to determining the combination of reduction parameters for other types of CORC cables with different ply numbers (e.g., 16 or 32 layers) and different core diameters. Specifically, it is necessary to update the geometric model / material parameters of the corresponding CORC cable specifications. Based on this, by rerunning the optimization system, the optimized combination of reduction parameters for the corresponding CORC cable specifications can be obtained.
[0061] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effects of the present invention, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously or in other orders, and some steps can be added, replaced or omitted.
[0062] It should be noted that although the control method of the cooking device constructed in the above specific manner has been described as an example, those skilled in the art will understand that the present invention is not limited thereto. In fact, users can flexibly adjust the parameters and other elements in the relevant steps according to the actual application scenario and other circumstances. For example, those skilled in the art can flexibly choose the method for determining the mapping relationship between cable strain and critical current density according to actual needs.
[0063] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.
Claims
1. A method for forming a high-temperature superconducting CORC cable with reduced diameter, characterized in that, The method includes: S100: Determine the initial combination of diameter reduction parameters, which includes the structural parameters of the high-temperature superconducting CORC cable, the dynamic parameters during the diameter reduction forming process, and the geometric parameters of the diameter reduction mold; S200. Based on the pre-established mapping relationship between cable strain and critical current density, optimize the combination of the reduction parameters; S300 uses an optimized combination of diameter reduction parameters to perform diameter reduction forming on high-temperature superconducting CORC cables.
2. The method according to claim 1, characterized in that, The high-temperature superconducting CORC cable includes a sub-cable and a sheath disposed on the outside of the sub-cable. The sub-cable includes a core and a multi-layer tape spirally wound around the core. The structural parameters of the high-temperature superconducting CORC cable are determined as follows: Based on a pre-established mechanical model of a high-temperature superconducting CORC cable, the structural parameters of the high-temperature superconducting CORC cable are obtained.
3. The method according to claim 2, characterized in that, The "optimization of the diameter reduction parameter combination" includes: Based on a pre-established mapping relationship between cable strain and critical current density, the combination of the cable diameter reduction parameters is optimized with multiple objectives, namely maximizing the overall critical current of the cable and minimizing the difference in critical current between the layers.
4. The diameter reduction forming method according to claim 3, characterized in that, The structural parameters of the high-temperature superconducting CORC cable include the initial relative position between the sub-cable and the inner wall of the sheath. The step of "optimizing the combination of the necking parameters with multiple objectives of maximizing the overall critical current of the high-temperature superconducting CORC cable and minimizing the difference rate of the interlayer critical current of the high-temperature superconducting CORC cable" includes: This ensures that the initial relative position between the sub-cable and the inner wall of the sheath is in a non-aligned initial contact state.
5. The diameter reduction forming method according to claim 4, characterized in that, The non-centered initial contact state includes a unilateral directional contact state and a non-contact state with an eccentric distance.
6. The method according to claim 4 or 5, characterized in that, The phrase "to make the initial relative position between the sub-cable and the inner wall of the sheath in a non-aligned initial contact state" includes: Based on the initial contact position of the sub-cable within the sheath, the first pair of diameter reduction rollers of the diameter reduction mold are rotated so that the center line of the opening of the first pair of diameter reduction rollers matches the initial contact state.
7. The method according to claim 1, characterized in that, In the step of "optimizing the combination of cable diameter reduction parameters based on a pre-established mapping relationship between cable strain and critical current density", the mapping relationship between cable strain and critical current density is determined as follows: The mapping relationship between the strain and the critical current density of the cable is determined based on the strain-critical current density degradation function.
8. The CORC cable diameter reduction forming method according to claim 2, characterized in that, The structural parameters of the high-temperature superconducting CORC cable include the structural parameters of the sheath, which include the target inner diameter and wall thickness of the sheath.
9. The CORC cable diameter reduction forming method according to claim 1, characterized in that, The dynamic parameters in the diameter reduction forming process include the cable feed speed during the diameter reduction forming process; and / or The geometric parameters of the diameter reduction die include the opening angle of the diameter reduction roller.
10. The CORC cable diameter reduction forming method according to claim 9, characterized in that, The diameter reduction die includes diameter reduction rollers with replaceable or adjustable opening angles. The aforementioned "using an optimized combination of reduction parameters to perform reduction molding on high-temperature superconducting CORC cables" includes: The optimized combination of diameter reduction parameters can be achieved by replacing the diameter reduction rollers or adjusting the opening angle of the diameter reduction mold. The high-temperature superconducting CORC cable was shaped by using an optimized combination of diameter reduction parameters.