System and method for improving levitation performance of a down-suspended high-temperature superconducting magnetic levitation

Abstract

The application provides a system and method for improving the suspension performance of a high-temperature superconducting magnetic levitation train, and relates to the technical field of magnetic levitation trains, comprising a track foundation, a permanent magnetic track and a low-temperature container, wherein the permanent magnetic track is fixedly arranged on the lower surface of the track foundation; the low-temperature container is arranged below the permanent magnetic track, the end of the low-temperature container away from the permanent magnetic track is fixedly connected with the magnetic levitation train, the low-temperature container and the permanent magnetic track interact through a magnetic field to realize the suspension and guidance of the magnetic levitation train, and the low-temperature container is provided with a telescopic magnetic aggregation mechanism fixedly connected with the inner bottom of the low-temperature container. The system of the application optimizes the initial magnetic flux density distribution by reasonably configuring the liquid nitrogen and superconducting bulk material in the low-temperature container and adjusting the telescopic magnetic aggregation mechanism, can enhance the internal magnetic flux density and current density in a larger range, improves the utilization efficiency of the magnetic field, and effectively improves the suspension force and the guiding force.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation train technology, and more specifically, to a system and method for improving the levitation performance of under-suspension high-temperature superconducting magnetic levitation systems. Background Technology

[0002] High-temperature superconducting magnetic levitation technology, due to its advantages such as no mechanical friction, self-stability, and low energy consumption, has been widely used in magnetic levitation transportation and logistics. Currently, magnetic levitation systems mainly adopt three suspension forms: top suspension, side suspension, and bottom suspension. Among them, top suspension, due to its large levitation force, has been successfully applied in many engineering practices; side suspension has attracted attention due to its excellent guiding performance; and bottom suspension, due to its structural design that saves ground space, is particularly suitable for applications in high-density areas. However, bottom suspension systems suffer from insufficient load-bearing capacity, which severely limits their promotion and use in practical engineering. The magnitude of the levitation force in bottom suspension mainly depends on the size of the field cooling gap and the initial magnetic flux density. Traditional field cooling methods usually enhance the levitation force by reducing the field cooling gap, but due to limitations in cooling conditions and device design, the feasibility of further reducing the field cooling gap is low.

[0003] Due to the shortcomings of existing technologies, there is an urgent need for a system and method to improve the levitation performance of under-suspension high-temperature superconducting magnetic levitation systems. Summary of the Invention

[0004] The purpose of this invention is to provide a system and preparation method for improving the levitation performance of under-suspension high-temperature superconducting magnetic levitation systems, thereby addressing the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows:

[0005] In a first aspect, this application provides a system for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, comprising: a track foundation, a permanent magnet track, and a cryogenic container. The permanent magnet track is fixedly disposed on the lower surface of the track foundation. The cryogenic container is disposed below the permanent magnet track, and the end of the cryogenic container away from the permanent magnet track is fixedly connected to the magnetic levitation train. The cryogenic container and the permanent magnet track interact through a magnetic field to achieve levitation and guidance of the magnetic levitation train. A telescopic magnetic focusing mechanism is disposed inside the cryogenic container and is fixedly connected to the bottom inner side of the cryogenic container.

[0006] Furthermore, the cryogenic container also includes a shell and a superconducting block. The shell is filled with liquid nitrogen, and the superconducting block is fixedly disposed on the end face of the shell near the permanent magnet track. The telescopic magnetizing mechanism approaches or moves away from the superconducting block by adjusting its telescopic stroke.

[0007] Furthermore, the telescopic magnetic focusing mechanism includes a telescopic drive device and a silicon steel sheet. The outer shell of the telescopic drive device is fixedly disposed at the bottom of the housing. The telescopic rod of the telescopic drive device is fixedly connected to the silicon steel sheet. The silicon steel sheet and the superconducting block are arranged parallel to each other and are both arranged in the horizontal direction.

[0008] Furthermore, the superconducting bulk material is projected vertically onto the silicon steel sheet to form a first projection area. The area of ​​the first projection area is less than or equal to the area of ​​the silicon steel sheet, and the first projection area is completely within the outline of the silicon steel sheet.

[0009] Furthermore, when the telescopic drive device is in its maximum telescopic stroke state, the gap between the silicon steel sheet and the superconducting block material is 5mm.

[0010] Furthermore, the permanent magnet track is composed of NdFeB magnets arranged in a Halbach array.

[0011] Furthermore, the superconducting bulk material is made of YBa2Cu3O7 superconducting material.

[0012] Furthermore, the dimensions of the superconducting bulk material are 64×32×13 mm.

[0013] Furthermore, the outer shell of the cryogenic container is made of heat-insulating material.

[0014] Secondly, this application provides a method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, including:

[0015] Obtain a first control command, the first control command including a command to control the maglev train to perform field cooling operations;

[0016] In response to the first control command, a second control command is sent, the second control command including using external force to adjust the distance between the cryogenic container and the permanent magnet track to a preset field cooling gap position;

[0017] After detecting that the cryogenic container is in place, a third control command is sent, which includes a command to drive the telescopic magnetic focusing mechanism to push to the bottom of the superconducting block and maintain a safe gap;

[0018] After detecting that the telescopic magnetic focusing mechanism is in place, a fourth control command is sent. The fourth control command includes a command to inject liquid nitrogen into the cryogenic container so that the liquid nitrogen level covers the superconducting bulk material and keeps it in a cooled state.

[0019] After detecting that the superconducting bulk material has cooled to a superconducting state, a fifth control command is sent. The fifth control command includes a command to move the silicon steel sheet away from the superconducting bulk material via a telescopic rod, so as to solidify the pinned magnetic flux and enter a stable levitation state.

[0020] The beneficial effects of this invention are as follows:

[0021] The system of this invention optimizes the initial magnetic flux density distribution by rationally configuring liquid nitrogen and superconducting bulk materials within the cryogenic container and combining this with the adjustment of the telescopic magnetic focusing mechanism. This enhances the internal magnetic flux density and current density over a wider range, improving not only the utilization efficiency of the magnetic field but also effectively increasing the suspension and guiding forces. Furthermore, the method of this invention simplifies the operation process, making system debugging and operation more efficient through clearly defined control commands and steps.

[0022] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the system in standby mode for improving the levitation performance of the lower-suspension high-temperature superconducting magnetic levitation system.

[0025] Figure 2 A schematic diagram of the structure during field cooling operation for the system used to improve the levitation performance of the under-suspended high-temperature superconducting magnetic levitation system;

[0026] Figure 3 The results are simulations of the magnetic field of silicon-free steel sheets.

[0027] Figure 4 The simulation results show the magnetic field of silicon steel sheets.

[0028] Figure 5 Schematic diagrams showing the magnetic flux density inside the superconductor using the original method (the method without silicon steel sheets) and the method described above.

[0029] Figure 6 The diagram shows the original method (the method without silicon steel sheets) and the internal current density of the superconductor after using this method.

[0030] Figure 7 Simulation data on the effect of levitation force improvement under different gaps;

[0031] Figure 8The results of levitation force tests using this method and the original method are shown with a field cooling gap of 5 mm.

[0032] Figure 9 The results of the suspension force test using this method and the original method are shown under a field cooling gap of 15 mm.

[0033] The markings in the diagram are: 1. Track foundation; 2. Permanent magnet track; 3. Cryogenic container; 31. Telescopic magnetic focusing mechanism; 311. Telescopic drive device; 312. Silicon steel sheet; 32. Shell; 33. Superconducting bulk material. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Example 1:

[0037] like Figure 1 and Figure 2As shown, this embodiment provides a system for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system. It includes a track foundation 1, a permanent magnet track 2, and a cryogenic container 3. The track foundation 1 is the supporting structure for the permanent magnet track 2 and can be the underside of a bridge or roof, etc. The permanent magnet track 2 is fixedly installed on the lower surface of the track foundation 1, providing the necessary magnetic field to support the levitation and guidance functions of the train. The cryogenic container 3 is located below the permanent magnet track 2, and its main function is to contain the superconducting material and maintain it in a superconducting state. The end of the cryogenic container 3 furthest from the permanent magnet track 2 is fixedly connected to the magnetic levitation train. The cryogenic container 3 and the permanent magnet track 2 interact through the magnetic field to achieve the levitation and guidance of the magnetic levitation train. A telescopic magnetic focusing mechanism 31 is installed inside the cryogenic container 3 to focus and adjust the magnetic field during the field cooling process. The telescopic magnetic focusing mechanism 31 is fixedly connected to the inner bottom of the cryogenic container 3 and can adjust the distance between it and the superconducting block 33 as needed, thereby optimizing the utilization efficiency of the magnetic field.

[0038] Preferably, the cryogenic container 3 further includes a shell 32 and a superconducting block 33. The shell 32 is filled with liquid nitrogen to ensure that the superconducting block 33 maintains its superconducting state during cooling. The superconducting block 33 is fixedly mounted on the shell 32 near the end face of the permanent magnet track 2, enabling it to effectively interact with the magnetic field between the permanent magnet track 2, thereby achieving levitation and guidance functions. The telescopic magnetic focusing mechanism 31 moves closer to or further away from the superconducting block 33 by adjusting its telescopic stroke. This design not only improves the magnetic flux focusing ability but also allows for adjustment of the superconductor's operating state according to actual needs, thereby effectively enhancing the levitation performance and guidance capability of the under-suspended high-temperature superconducting magnetic levitation system.

[0039] Preferably, the telescopic magnetic focusing mechanism 31 includes a telescopic drive device 311 and a silicon steel sheet 312. The outer shell of the telescopic drive device 311 is fixedly disposed at the bottom of the housing 32. The telescopic rod of the telescopic drive device 311 is fixedly connected to the silicon steel sheet 312. The silicon steel sheet 312 and the superconducting block material 33 are arranged parallel to each other and are both arranged in a horizontal direction. With this preferred structure, the telescopic magnetic focusing mechanism 31 can better adapt to different working conditions, improve the overall system's levitation performance and efficiency, and thus solve the problem of insufficient load-bearing capacity faced by the under-suspension high-temperature superconducting magnetic levitation system in practical applications.

[0040] Preferably, the superconducting bulk material 33 is projected vertically onto the silicon steel sheet 312 to form a first projection region. The area of ​​the first projection region is less than or equal to the area of ​​the silicon steel sheet 312, and the first projection region is completely within the outline of the silicon steel sheet 312. This design ensures that almost all of the accumulated magnetic flux energy passes through the superconductor.

[0041] Preferably, when the telescopic drive device 311 is in its maximum telescopic stroke state, the gap between the silicon steel sheet 312 and the superconducting block material 33 is 5mm. Firstly, superconductors are brittle materials and should not be subjected to collisions or mechanical contact. Therefore, a safety clearance margin is required, such as... Figure 7 As shown, Figure 7 Simulation data on the levitation force enhancement effect under different gaps reveals that the levitation force enhancement effect is not significant when the gap is less than 5 mm. Therefore, a 5 mm gap can be selected to fully enhance the levitation force while ensuring safety. Furthermore, the thickness of the silicon steel sheet 312 is related to the magnetic field strength of the permanent magnet track 2; a stronger magnetic field requires a thicker sheet. Silicon steel also exhibits a saturated magnetic field of approximately 1.8 T. Simulation results show that the magnetic field integral on the upper surface of the permanent magnet track 2 on the silicon steel is 0.0085 Wb / m. According to the saturated magnetic flux formula, 0.0085 / 1.8 = 0.0047 m. Therefore, a 5 mm thickness is sufficient to conduct the entire magnetic field, providing a significant effect; further increasing the thickness will have little effect.

[0042] Preferably, the permanent magnet track 2 is composed of NdFeB magnets arranged in a Halbach array. The Halbach array design significantly enhances the magnetic field strength and uniformity of the track, making it suitable for efficient magnetic levitation operation.

[0043] Preferably, the superconducting bulk material 33 is made of YBa2Cu3O7 superconducting material. Its main function is to achieve self-stabilized levitation through the interaction of the pinning effect with the magnetic field of the permanent magnet track 2.

[0044] Preferably, the superconducting bulk material 33 has dimensions of 64×32×13 mm. Furthermore, the combination of the three seed structure designs of the bulk material can improve the flux pinning strength and significantly improve the vertical levitation force and lateral guiding force.

[0045] Preferably, the outer shell of the cryogenic container 3 is made of heat-insulating material, which can effectively reduce liquid nitrogen evaporation and environmental heat intrusion, and ensure that the superconducting bulk material 33 is maintained in a superconducting state for a long time.

[0046] Example 2

[0047] Corresponding to the above system embodiment for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, this embodiment provides a method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, including steps S100 to S500:

[0048] Step S100: Obtain a first control command, the first control command including a command to control the maglev train to perform field cooling operation;

[0049] As is understandable, field cooling refers to the process of cooling superconducting materials to achieve a superconducting state, thereby enabling magnetic levitation. This command is fundamental to the entire operation, ensuring that subsequent steps are performed in the predetermined order and according to requirements.

[0050] Step S200: In response to the first control command, send a second control command, the second control command including using external force to adjust the distance between the cryogenic container and the permanent magnet track to a preset field cooling gap position;

[0051] The external force specifically refers to clamps or mechanical fixing devices to ensure that the gap remains constant during the field cooling process. The field cooling gap is typically 5mm or 15mm.

[0052] Step S300: After detecting that the cryogenic container is in place, a third control command is sent. The third control command includes a command to drive the telescopic magnetic focusing mechanism to push to the bottom of the superconducting block and maintain a safe gap.

[0053] Step S400: After detecting that the telescopic magnetic focusing mechanism is in place, a fourth control command is sent. The fourth control command includes a command to inject liquid nitrogen into the cryogenic container so that the liquid nitrogen level covers the superconducting bulk material and keeps it in a cooled state.

[0054] It needs to be explained that,

[0055] Specifically, silicon steel sheets are a material with very high magnetic permeability, far exceeding that of air. According to the principle of minimum magnetic circuit, the magnetic field of a permanent magnet track will pass through the nearby silicon steel sheet and return, allowing more of the magnetic field to pass completely through the superconductor located between the permanent magnet track and the silicon steel sheet, thus trapping more magnetic flux. Electromagnetic simulation can be used to model the effect of silicon steel sheets on magnetic field concentration and levitation force enhancement. The physical equations involved in the electromagnetic simulation include:

[0056] ;

[0057] in, Indicates magnetic flux density; Indicates the permeability of free space; This indicates the relative permeability of silicon steel; Indicates magnetic field strength; The remanence of the magnet is indicated; in this embodiment, it is a typical N50 magnet, which has a remanence of 1.4T.

[0058] Maxwell's equations:

[0059] ;

[0060] ;

[0061] in, Represents the Laplace operator; Indicates electric field strength; Indicates time.

[0062] Superconductor constitutive equation:

[0063] ;

[0064] in, Indicates the critical electric field strength; Indicates current density; Indicates the critical current density; It represents the power exponent.

[0065] Lorentz force equation:

[0066] ;

[0067] in, Represents the volume space of a superconductor; This represents the volume of a small element.

[0068] Magnetic field simulation results are as follows Figure 3 and Figure 4 As shown. Figure 3 The simulation results for the magnetic field without silicon steel sheets show that the dispersion of the magnetic field above the track, without silicon steel sheets, leads to a decrease in magnetic field utilization efficiency. This dispersed magnetic field cannot be effectively concentrated on the superconducting bulk material, resulting in the magnetic flux density and current density inside the superconductor not reaching their optimal state, thus affecting the levitation performance and guiding capability of the suspended high-temperature superconducting magnetic levitation system.

[0069] Figure 4 Simulation results using silicon steel sheets show that the magnetic field, originally dispersed above the track, is effectively concentrated, primarily in the region between the silicon steel sheet and the track, i.e., the location of the superconductor. This phenomenon indicates that the introduction of silicon steel sheets significantly enhances the focusing ability of the magnetic field, thereby increasing the magnetic flux density inside the superconductor.

[0070] Figure 5 The diagram shows the magnetic flux density inside the superconductor after applying the original method (the method without silicon steel sheets) and the method described above. Figure 6 The diagram shows the internal current density of the superconductor using the original method (without silicon steel sheets) and the method described above. The comparison reveals that the range and intensity of the magnetic field trapped inside the superconductor are significantly increased after using this method. This indicates that the superconductor can more effectively trap and utilize magnetic fields under the influence of an externally applied magnetic field.

[0071] Simultaneously, the area over which the superconductor generates superconducting current is also expanded, directly increasing the intensity of the superconducting current. According to the Lorentz force principle, an increase in magnetic field strength and current intensity will lead to a significant enhancement of the levitation force. Therefore, using this method, the superconductor not only increases its internal magnetic flux density and current density but also further enhances its overall levitation force.

[0072] In summary, this invention significantly improves the levitation performance of a suspended high-temperature superconducting magnetic levitation system by optimizing the magnetic field and current distribution inside the superconductor.

[0073] Step S500: After detecting that the superconducting bulk material has cooled to a superconducting state, a fifth control command is sent. The fifth control command includes a command to move the silicon steel sheet away from the superconducting bulk material via a telescopic rod, so as to solidify the pinned magnetic flux and enter a stable levitation state.

[0074] Furthermore, in some other embodiments, step S500 further includes testing the levitation system, specifically:

[0075] Remove the external forces previously used to fix the height of the cryogenic container (such as loosening the clamps or releasing the mechanical fixation), allowing the system to enter a free-floating state. At this point, the superconducting bulk material achieves self-stabilized levitation under the magnetic field of the permanent magnet track. Adjust the height of the cryogenic container to change the working gap between the superconducting bulk material and the permanent magnet track. Use a high-precision force sensor to measure the vertical levitation force and lateral guiding force of the system, and record the relevant performance data. By adjusting different working gaps, analyze the variation law of the system's levitation force.

[0076] A comparative test was conducted using this method and the original method (the method without silicon steel sheets) to test the levitation force of the two methods. Figure 8 As shown, when the field cooling gap FCG = 5 mm, the levitation force of this method is increased by approximately 32%; Figure 9 As shown, when FCG=15 mm, the suspension force of this method is increased by about 25%.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, comprising a system for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system, characterized in that, The system for improving the levitation performance of the suspended high-temperature superconducting magnetic levitation system includes: Track foundation (1); A permanent magnet track (2), which is fixedly mounted on the lower surface of the track base (1); and A cryogenic container (3) is located below the permanent magnet track (2). The end of the cryogenic container (3) away from the permanent magnet track (2) is fixedly connected to the magnetic levitation train. The cryogenic container (3) and the permanent magnet track (2) interact through magnetic fields to achieve levitation and guidance of the magnetic levitation train. A telescopic magnetic focusing mechanism (31) is provided inside the cryogenic container (3) and is fixedly connected to the bottom of the inner side of the cryogenic container (3). The cryogenic container (3) further includes a shell (32) and a superconducting block (33). The shell (32) is filled with liquid nitrogen. The superconducting block (33) is fixedly installed on the shell (32) near the end face of the permanent magnet track (2). The telescopic magnetic focusing mechanism (31) approaches or moves away from the superconducting block (33) by adjusting the telescopic stroke. The telescopic magnetic focusing mechanism (31) includes a telescopic drive device (311) and a silicon steel sheet (312). The outer shell of the telescopic drive device (311) is fixedly installed at the bottom of the housing (32). The telescopic rod of the telescopic drive device (311) is fixedly connected to the silicon steel sheet (312). The silicon steel sheet (312) and the superconducting block material (33) are arranged parallel to each other and are both arranged in the horizontal direction. The superconducting bulk material (33) is projected vertically onto the silicon steel sheet (312) to form a first projection area. The area of ​​the first projection area is less than or equal to the area of ​​the silicon steel sheet (312), and the first projection area is completely within the outline of the silicon steel sheet (312). When the telescopic drive device (311) is in the maximum telescopic stroke state, the gap between the silicon steel sheet (312) and the superconducting block material (33) is 5mm. The method for improving the levitation performance of the suspended high-temperature superconducting magnetic levitation system includes: Obtain a first control command, the first control command including a command to control the maglev train to perform field cooling operations; In response to the first control command, a second control command is sent, the second control command including using external force to adjust the distance between the cryogenic container (3) and the permanent magnet track (2) to a preset field cooling gap position; After detecting that the cryogenic container (3) is in place, a third control command is sent, which includes a command to drive the telescopic magnetic focusing mechanism (31) to push to the bottom of the superconducting block (33) and maintain a safe gap; After detecting that the telescopic magnetic focusing mechanism (31) is in place, a fourth control command is sent, which includes a command to inject liquid nitrogen into the cryogenic container (3) so that the liquid nitrogen level covers the superconducting block (33) and keeps it in a cooled state; After detecting that the superconducting bulk material (33) has cooled to a superconducting state, a fifth control command is sent. The fifth control command includes a command to move the silicon steel sheet (312) away from the superconducting bulk material (33) by means of a telescopic rod, so as to solidify the pinned magnetic flux and enter a stable levitation state.

2. The method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system according to claim 1, characterized in that: The permanent magnet track (2) is composed of NdFeB magnets arranged in a Halbach array.

3. The method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system according to claim 1, characterized in that: The superconducting bulk material (33) is made of YBa2Cu3O7 superconducting material.

4. The method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system according to claim 3, characterized in that: The dimensions of the superconducting bulk material (33) are 64×32×13 mm.

5. The method for improving the levitation performance of a suspended high-temperature superconducting magnetic levitation system according to claim 1, characterized in that: The outer shell of the cryogenic container (3) is made of heat-insulating material.

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