A high-temperature superconducting maglev system with high magnetic levitation performance

Abstract

The present invention discloses a high-temperature superconducting maglev system with high magnetic levitation performance, which includes a cold source, a superconductor arrangement and a permanent magnet track; the superconductor arrangement and the cold source are arranged above the permanent magnet track, the superconductor arrangement is composed of a plurality of superconductors, the seed point of the superconductor faces the permanent magnet track, the cold source connects the superconductor and cools the superconductor, and the permanent magnet track provides an applied external magnetic field; the superconductor is symmetrically offset along the central axis of the permanent magnet track, and the offset distance is 0-5mm. In the present invention, in a single-pole or multi-pole permanent magnet track, the superconductor is symmetrically offset along the axis of a single magnetic pole or a symmetrically distributed multi-pole axis, which can suppress the guiding instability during the system's downward pressure process. When a suitable offset distance is selected, the influence of the offset on the attenuation of the suspension force can be suppressed, so that the system has higher suspension performance while taking into account the guiding stability.

Description

Technical Field

[0001] The present invention relates to the application field of high-temperature superconducting maglev technology, and in particular to a high-temperature superconducting maglev system with high maglev performance. Background Art

[0002] The high-temperature superconducting maglev system has self-stabilizing suspension and guidance capabilities, and its translation system has a theoretical maximum operating speed of 3000km / h. Therefore, it has broad application prospects in ground ultra-high-speed transportation systems. However, the suspension bearing performance and guidance performance of the high-temperature superconducting maglev system are relatively weak. Improving its suspension and guidance performance is the key to its practical application. The existing technologies mainly include:

[0003] (1) Figure 1 As shown in FIG. 1 , when the superconductor axis 22 (C axis) is arranged perpendicular to the magnetization direction of the magnet, the system can obtain higher guidance performance. However, the suspension performance of the system will be greatly attenuated, such as Figure 3 As shown, the superconductor 21 is deviated from the magnetic pole axis 33 by a distance t for field cooling. After entering the superconducting state, the superconductor 21 moves downward at a speed v. Its suspension force curve is shown in Figure 4 As shown, the suspension force decreases sharply with the increase of the deviation distance t. When the axis of the superconductor is perpendicular to the magnetization direction of the facing magnet, the system almost loses the suspension performance.

[0004] (2) Figure 2 As shown, when the superconductor axis 22 (C axis) is set parallel to the magnetization direction of the magnet, the system can obtain higher suspension performance. However, in actual applications, due to the uneven performance of the superconductor and the non-ideal symmetrical distribution of the external magnetic field applied to the permanent magnet track, there is guidance instability during the downward pressure process, which causes the system to drift laterally, further attenuating the suspension force of the system, and in severe cases, there is a risk of derailment;

[0005] (3) By setting different cooling heights, the distribution of the system's suspension performance and guidance performance can be adjusted. Increasing the cooling height of the system will result in higher suspension performance, but its guidance performance will be weakened; decreasing the cooling height of the system will result in higher guidance performance, but its suspension performance will be weakened and the safe working height of the system will be reduced;

[0006] (4) Other technologies include: reducing the operating temperature of the system through nitrogen cooling or refrigerators, using high-performance superconducting materials and increasing the amount of superconducting materials to improve the critical current density and the ability to capture magnetic flux of the system; increasing the amount of permanent magnetic materials, residual magnetism and optimizing the configuration of permanent magnetic tracks to improve the strength of the applied external magnetic field of the permanent magnetic track. The above methods mainly improve the performance of materials, increase the amount of materials and optimize the system to achieve higher suspension and guidance performance, but at the same time, they will also bring higher dead weight and high costs. Summary of the invention

[0007] The present invention aims at the shortcomings of the high-temperature superconducting maglev system in the prior art, such as the inability to take both the guidance performance and the suspension performance into consideration at the same time, the high weight and the high cost of the system, and provides a high-temperature superconducting maglev system with high magnetic levitation performance. The high suspension performance of the high-temperature superconducting maglev system under the condition of stable guidance is achieved without increasing the weight and the cost of the system.

[0008] The technical solution adopted by the present invention is:

[0009] A high-temperature superconducting maglev system with high maglev performance comprises a cold source, a superconductor arrangement and a permanent magnet track; the superconductor arrangement and the cold source are arranged above the permanent magnet track, the superconductor arrangement consists of a plurality of superconductors, the seed crystal points of the superconductors face the permanent magnet track, the cold source is connected to the superconductors and cools the superconductors, and the permanent magnet track provides an applied external magnetic field; the superconductors are symmetrically offset along the central axis of the permanent magnet track, and the offset distance is 0 to 5 mm.

[0010] Furthermore, when a suitable offset distance is selected, the change of the guide force can be suppressed and the attenuation of the suspension force can be ignored. An offset distance of 0 mm to 3 mm can effectively suppress the attenuation of the system suspension force caused by the offset.

[0011] Furthermore, in a single-pole permanent magnet track, the superconductors are arranged alternately and symmetrically on both sides of the single pole along the direction of track operation; when the effect of the offset distance on the attenuation of the suspension force is not considered, a larger symmetrical offset distance can be set to give the system higher guidance stability under external interference.

[0012] Furthermore, in an odd number of multi-pole permanent magnet tracks, at least one pair of superconductors are arranged symmetrically inwardly biased, symmetrically outwardly biased, or a combination of symmetrical inward and outward biased along the magnetic pole axis symmetrically distributed along the center of the track in the transverse direction, and the remaining superconductors on both sides of the center of other tracks are arranged opposite the magnetic poles to the central superconductor.

[0013] Furthermore, in an even number of multi-pole permanent magnet tracks, at least one pair of superconductors are arranged symmetrically inwardly biased, symmetrically outwardly biased, or in a combination of symmetrical inward and outward biased along the magnetic pole axis symmetrically distributed along the track center in the transverse direction, and the remaining superconductors on both sides of the center of other tracks are arranged facing the magnetic poles.

[0014] Furthermore, in the dual-track system, at least one pair of superconductors are arranged symmetrically inwardly or outwardly or in combination along the magnetic pole axis symmetrically distributed along the center of the dual track in the lateral direction, and the remaining superconductors are arranged facing the magnetic poles.

[0015] Furthermore, the cold source is provided by a normal-pressure liquid nitrogen or low-pressure solid nitrogen cryogenic container and a refrigerator, and the superconductor is directly or indirectly cooled by liquid nitrogen, solid nitrogen, and a cold head.

[0016] Furthermore, the superconductor is arranged as a single combination structure of a block, a film, a tape stack, a tape (wire) coil or any combination structure of two or more of ReBaCuO (Re is a rare earth element) or other superconducting materials.

[0017] Furthermore, the permanent magnetic track is a single magnet combination structure of a permanent magnet, an electromagnet, a superconducting wire (strip) coil magnet, or a combination structure of any two or more. When the permanent magnetic track is assembled using permanent magnet units, its transverse structure is arranged in a horizontal top-to-top arrangement of magnetic poles or a Halbach array.

[0018] The present invention adopts the above technical solution, and in a single-pole or multi-pole permanent magnetic track, the superconductor is arranged symmetrically along the axis of the single magnetic pole or the axis of the symmetrically distributed multi-pole, which can suppress the instability of the guidance during the system's downward pressure. When a suitable offset distance is selected, the influence of the offset on the attenuation of the suspension force can be suppressed, so that the system has the highest suspension performance while taking into account stability. Compared with the prior art, the beneficial effect of the present invention is: it overcomes the deficiency of the prior art that the suspension performance and the guidance performance cannot be taken into account at the same time, so that the system has higher suspension performance while taking into account the guidance stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments;

[0020] Figure 1 Schematic diagram of setting the superconductor C axis perpendicular to the magnetization direction;

[0021] Figure 2 Schematic diagram of setting the superconductor C axis parallel to the magnetization direction;

[0022] Figure 3 Schematic diagram of superconductor bias;

[0023] Figure 4 Suspension force curves of superconductors at different bias distances;

[0024] Figure 5 Schematic diagram of the downward pressure force on a superconductor without bias;

[0025] Figure 6 Schematic diagram of the downward pressure on a superconductor when it is biased to the right;

[0026] Figure 7 Schematic diagram of the downward pressure on a superconductor when it is biased to the left;

[0027] Figure 8 Downward pressure guiding force curve of superconductor under symmetrical bias;

[0028] Fig. 9Schematic diagram of the alternating symmetrical bias arrangement of single-pole circular superconductors;

[0029] Fig.10 Schematic diagram of the alternating symmetrical bias arrangement of single-pole square superconductors;

[0030] Fig.11 Schematic diagram of vertical field distribution of three-pole permanent magnet track;

[0031] Fig.12 Schematic diagram of the internal bias structure of a three-pole superconductor;

[0032] Fig.13 Schematic diagram of the external bias structure of a three-pole superconductor;

[0033] Fig.14 Schematic diagram of the internal bias structure of a dual-pole superconductor;

[0034] Fig.15 Schematic diagram of the external bias structure of a dual-pole superconductor;

[0035] Fig.16 Schematic diagram of the internal bias structure of a double-track superconductor.

[0036] Names of the numbers in the accompanying drawings: 1-cold source, 2-superconductor arrangement, 21-superconductor, 22-superconductor axis, 23-superconductor seed point, 3-permanent magnetic track, 31-horizontally magnetized magnet, 32-vertically magnetized magnet, 33-magnetic pole axis, t-superconductor bias distance, Gap-suspension gap, F l - Suspension force, F g -Guiding force, B ⊥ -Vertical field. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0038] like Figures 9 to 16 As shown in one, the present invention discloses a high-temperature superconducting maglev system with high magnetic levitation performance, which includes a cold source, a superconductor arrangement and a permanent magnet track; the superconductor arrangement and the cold source are arranged above the permanent magnet track, the superconductor arrangement is composed of a plurality of superconductors, the seed point of the superconductor faces the permanent magnet track, the cold source is connected to the superconductor and cools the superconductor, and the permanent magnet track provides an applied external magnetic field; the superconductors are symmetrically offset along the central axis of the permanent magnet track, and the offset distance is 0 to 5 mm.

[0039] Example 1: Fig. 9 , Fig.10As shown, in a single-pole permanent magnet track, circular or square superconductors 21 are arranged alternately and symmetrically at an external offset distance t on both sides of a single pole along the track running direction. By selecting a suitable offset distance t, the high-temperature superconducting magnetic levitation system based on a single-pole permanent magnet track can have a higher suspension force density.

[0040] Furthermore, when the influence of the offset distance t on the attenuation of the suspension force is not considered, a larger symmetrical offset distance t can be set, so that the system can have higher guiding stability under external interference.

[0041] Example 2: Fig.11 , Fig.12 The three-pole permanent magnet track and its high-temperature superconducting maglev system shown in the figure have the superconductors 21 arranged symmetrically inwardly along the magnetic pole axes 33 symmetrically distributed on both sides of the track center in the lateral direction. The central superconductor is arranged opposite to the magnetic pole. By selecting a suitable offset distance t, the high-temperature superconducting maglev system based on the three-pole permanent magnet track can have a higher suspension force density under the condition of stable guidance.

[0042] Furthermore, if Fig.13 As shown, the superconductors 21 are arranged symmetrically along the magnetic pole axes 33 symmetrically distributed on both sides of the track center, and the central superconductor is arranged directly opposite the magnetic poles. By selecting a suitable offset distance t, the high-temperature superconducting magnetic levitation system based on the three-pole permanent magnet track can have a higher suspension force density under the condition of stable guidance.

[0043] Furthermore, in an odd number of multi-pole permanent magnet tracks, at least one pair of superconductors are arranged symmetrically inwardly biased, symmetrically outwardly biased, or a combination of internal and external symmetrical biases along the magnetic pole axes symmetrically distributed on both sides of the track center in the horizontal direction, and the remaining superconductors on both sides of the center of other tracks are arranged opposite the magnetic poles to the central superconductor. This can enable a high-temperature superconducting magnetic levitation system based on an odd number of multi-pole permanent magnet tracks to have a higher suspension force density under the condition of stable guidance.

[0044] Example 3: Fig.14 The double-pole permanent magnet track high-temperature superconducting maglev system shown in the figure arranges the superconductors 21 symmetrically inwardly offset along the magnetic pole axes 33 symmetrically distributed on both sides of the track center in the lateral direction. By selecting a suitable offset distance t, the high-temperature superconducting maglev system based on the double-pole permanent magnet track can have a higher suspension force density under the condition of stable guidance.

[0045] Furthermore, if Fig.15 As shown, the superconductor 21 is arranged symmetrically along the magnetic pole axes 33 symmetrically distributed on both sides of the track center, and a suitable offset distance t is selected, so that the high-temperature superconducting magnetic levitation system based on the dual-pole permanent magnet track can have a higher suspension force density under the condition of stable guidance;

[0046] Furthermore, in an even number of multi-pole permanent magnet tracks, at least one pair of superconductors are arranged symmetrically inwardly biased, symmetrically outwardly biased, or a combination of symmetrically biased and symmetrically biased along the magnetic pole axes symmetrically distributed on both sides of the track center in the horizontal direction, and the remaining superconductors on both sides of the center of other tracks are arranged facing the magnetic poles. This can enable a high-temperature superconducting magnetic levitation system based on an even number of multi-pole permanent magnet tracks to have a higher suspension force density under the condition of stable guidance.

[0047] Example 4: Fig.16 The monopole permanent magnet dual-track high-temperature superconducting maglev system shown in the figure arranges the superconductors 21 symmetrically inwardly offset along the magnetic pole axes 33 symmetrically distributed on both sides of the center of the dual tracks in the lateral direction. By selecting a suitable offset distance t, the high-temperature superconducting maglev system based on the dual tracks can have a higher suspension force density under the condition of stable guidance.

[0048] Furthermore, in the multi-pole permanent magnet dual-track system, at least one pair of superconductors is arranged symmetrically inwardly biased or symmetrically outwardly biased or a combination of internal and external symmetrical biases along the magnetic pole axes symmetrically distributed on both sides of the center of the dual track in the lateral direction, and the other remaining superconductors are arranged directly opposite the magnetic poles. This can enable the high-temperature superconducting magnetic levitation system based on the multi-pole permanent magnet dual track to have a higher suspension force density under the condition of stable guidance.

[0049] The specific working principle of the present invention is described in detail below:

[0050] As shown in formulas (1), (2), and (3), the basic principle formula of the high-temperature superconducting magnetic levitation system is: By external magnetic field The nonlinearity is usually described by the power exponential model and the KIM model.

[0051]

[0052]

[0053]

[0054] Furthermore, by calculating the induced current With external magnetic field The vector product of can be used to solve the electromagnetic force between the high-temperature superconducting material and the permanent magnet track. Its z-axis (normal) component generates a suspension force F l , the x-axis (lateral) component generates the guiding force F g , the y-axis (running direction) component generates magnetic resistance. Assuming that the permanent magnet track is infinitely long along the y-axis and the external magnetic field is uniformly distributed along the y-axis, the magnetic resistance is zero. The system suspension force F can be obtained through equations (1) and (3): lWith the guiding force F g for:

[0055] F l = -μ∫∫∫ V (J y H x )dV (4)

[0056] F g =μ∫∫∫ V (J y H z )dV (5)

[0057] Among them, J y for:

[0058]

[0059] like Figure 5 As shown, when the superconductor axis 22 coincides with the magnetic pole axis 33, assuming that the superconductor 21 has uniform performance and is perpendicular to the field B ⊥ The superconductor moves downward at a speed v, and the induced current J with equal magnitude and opposite direction and perpendicular to the paper surface will be generated in the area on both sides of the superconductor axis 22. y According to equations (4), (5), and (6), the superconductor 21 is subjected to an upward suspension force F l , guiding force F g However, in practical applications, the performance of superconductor 21 is not uniform, and the vertical field B ⊥ It is not an ideal symmetrical distribution. At the same time, it is impossible to strictly make the superconductor axis 22 and the magnetic pole axis 33 completely coincide with each other, resulting in the guiding force F g It is not zero, so that the superconductor 21 has a tendency to deviate from the magnetic pole axis 33, which is the inherent lateral drift phenomenon of the high-temperature superconducting magnetic levitation system.

[0060] In order to study the guiding force F g In order to explore the changing characteristics of the system during the pressure-down process and to explore the stable system configuration, the following experiments were designed: Figure 6 , Figure 7 As shown in the figure, the superconductor is deviated from the magnetic pole axis by the same distance t to the right and left respectively for field cooling. After entering the superconducting state, the superconductor is moved downward at a speed v, and the curve of the guiding force changing with the suspension gap Gap is measured. The results are shown in Figure 8As shown in the figure, when the superconductor deviates from the magnetic pole to the right, it is subject to a rightward guiding force during the downward pressure process, and its magnitude increases as the suspension gap decreases; when the superconductor deviates from the magnetic pole to the left, it is subject to a leftward guiding force during the downward pressure process, and its magnitude increases as the suspension gap decreases. The above results show that the superconductor deviates from the magnetic pole axis and is field-cooled. When the system is pressed down, it will generate a guiding force in the same direction as the deviation direction, driving the superconductor to deviate from the magnetic pole axis, and the guiding forces under symmetrical bias are opposite in direction and similar in magnitude. Therefore, in the single-pole and multi-pole permanent magnet track high-temperature superconducting maglev systems, symmetrically biasing the superconductors can generate guiding forces of opposite directions and similar magnitudes, achieving the purpose of mutually weakening and inhibiting the changes in the guiding forces, thereby making the system have higher guiding stability.

[0061] However, if Figure 4 The levitation force curve of the superconductor at different bias distances shown in the figure shows that the levitation force of the system will be reduced if the superconductor is set away from the magnetic pole axis, and it will decrease sharply with the increase of the bias distance. When the appropriate bias distance (t≤3mm) is selected, the magnitude of the levitation force is almost unaffected, thereby achieving higher levitation performance under the condition of system guidance stability.

[0062] The present invention adopts the above technical solution, and in a single-pole or multi-pole permanent magnetic track, the superconductor is arranged symmetrically along the axis of the single magnetic pole or the axis of the symmetrically distributed multi-pole, which can suppress the guidance instability during the system's downward pressure process. When a suitable offset distance is selected, the influence of the offset on the attenuation of the suspension force can be suppressed, so that the system has higher suspension performance while taking into account the guidance stability. Compared with the prior art, the beneficial effect of the present invention is: it overcomes the deficiency of the prior art that the suspension performance and the guidance performance cannot be taken into account at the same time, so that the system has higher suspension performance while taking into account the guidance stability.

[0063] Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians of the art without making creative work are within the scope of protection of the present application.

Claims

1. A high-temperature superconducting maglev system with high maglev performance, characterized in that: It includes a cold source, a superconductor arrangement and a permanent magnet track; the superconductor arrangement and the cold source are arranged above the permanent magnet track, the superconductor arrangement consists of a plurality of superconductors, the seed crystal point of the superconductor faces the permanent magnet track, the cold source connects the superconductor and cools the superconductor, and the permanent magnet track provides an applied external magnetic field; the superconductors are symmetrically offset along the central axis of the permanent magnet track, and the offset distance is 0-5mm; the permanent magnet track is a single-pole or multi-pole permanent magnet track; in the single-pole permanent magnet track, the superconductors are alternately symmetrically offset on both sides of the single pole along the running direction of the track; in the multi-pole permanent magnet track, at least one pair of superconductors are offset along the axis of the poles symmetrically distributed in the center of the track in the transverse direction, and the offset arrangement includes a symmetrical inner offset arrangement or a symmetrical outer offset arrangement or a combination arrangement of inner and outer symmetrical offsets; in an odd-numbered multi-pole permanent magnet track, the remaining superconductors on both sides of the track center and the central superconductor are arranged facing the poles; in an even-numbered multi-pole permanent magnet track, the remaining superconductors on both sides of the track center are arranged facing the poles.

2. A high temperature superconducting maglev system with high maglev performance according to claim 1, characterized in that: The offset distance is 0mm to 3mm.

3. A high temperature superconducting maglev system with high maglev performance according to claim 1, characterized in that: In a dual-track system, at least one pair of superconductors is offset in a laterally arranged manner along the magnetic pole axis symmetrically distributed along the center of the track, and the offset arrangement includes a symmetrical inner offset arrangement, a symmetrical outer offset arrangement, or a combination of inner and outer symmetrical offsets; the remaining superconductors are arranged facing the magnetic poles.

4. A high temperature superconducting maglev system with high maglev performance according to claim 1, characterized in that: The cold source is provided by a normal-pressure liquid nitrogen or low-pressure solid nitrogen cryogenic container and a refrigerator. The cold source directly or indirectly cools the superconductor through liquid nitrogen, solid nitrogen, and a cold head.

5. A high temperature superconducting maglev system with high maglev performance according to claim 1, characterized in that: The superconducting material is a single combination structure or any combination structure of two or more of a block, a stack of strips, or a coil of ReBaCuO or other superconducting materials, and Re is a rare earth element.

6. A high temperature superconducting maglev system with high maglev performance according to claim 1, characterized in that: The permanent magnet track is a single magnet structure of a permanent magnet, an electromagnet, a superconducting coil magnet, or a combination structure of any two or more thereof; when the permanent magnet track is assembled using permanent magnets, the transverse structure of the permanent magnet track is arranged according to the Halbach array.

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