Linear motor using superconducting cable excitation

Abstract

The present invention belongs to the field of superconducting application technology, and provides a linear motor excited by a superconducting cable. The motor includes a rotor and a stator, an air gap is provided between the rotor and the stator, and the rotor moves linearly along the stator. The rotor includes a mover core and an armature winding, a groove is provided in the mover core, and the armature winding is fitted into the groove in the mover core. The stator includes a stator core and a superconducting excitation cable, the superconducting excitation cable is arranged in parallel inside the stator core, the superconducting excitation cable includes a positive cable and a negative cable, and currents flow in opposite directions in the two cables. When current is supplied to the superconducting cable, a magnetic field is generated in the stator core, and the magnetic field is uniformly distributed along the magnetic circuit of the stator core, forming magnetic poles in which N poles and S poles are arranged alternately in the stator core. When three-phase AC current is supplied to the armature winding, a magnetic field is generated that causes linear motion within the air gap. This magnetic field and the stator poles generate a force that drives the rotor in linear motion along the stator, thereby achieving electromechanical energy conversion.

Description

Technical Field

[0001] The present invention belongs to the technical field of superconducting application technology, and particularly relates to a linear motor excited by a superconducting cable.

Background Art

[0002] With the development of technologies such as railway transportation, magnetic levitation, and electromagnetic propulsion in our country, the industry's demand for high-thrust and high-efficiency linear motors is increasing. Applying a non-resistive high-current superconducting material to the field of linear motors can significantly improve the output density and maximum thrust of the linear motor, and reduce motor losses, making it promising as an important application.

[0003] However, superconducting materials are expensive, and their applications are limited by factors such as temperature, magnetic field, and stress. Also, the structure of superconducting linear motors is very complex, and the design of the excitation coils inside the superconductors and their cryogenic systems is complicated. Therefore, the application of linear motors is difficult, and there are problems of low reliability and high cost. Conventionally, as superconducting linear motors, mainly linear motors using superconducting blocks, superconducting linear synchronous motors, and transverse flux type superconducting motors have been proposed.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to solve the design problems of the excitation coils and cryogenic systems in superconducting linear motors, provide a superconducting linear motor excited by a superconducting cable that has a simple structure, high reliability, significantly reduces the motor design difficulty and cost, and can further reduce the future railway transportation and DC power transmission costs by combining the linear motor and the superconducting DC power transmission technology.

Means for Solving the Problems

[0005] The present invention proposes the following technical solutions.

[0006] The present invention provides a linear motor using superconducting DC cable excitation, which comprises a linear motor rotor and a linear motor stator, the rotor and stator being arranged in parallel and with an air gap between them. The linear motor rotor can perform linear motion in both directions along the linear motor stator.

[0007] Preferably, the linear motor rotor consists of a movable core and an armature winding. The movable core has a groove on the linear motor stator side, and the armature winding is a three-phase winding, evenly distributed in the groove of the movable core. When three-phase AC power is supplied to the armature winding, a magnetic field for linear motion can be generated in the air gap.

[0008] Preferably, the linear motor stator consists of a stator core and two parallel superconducting DC cables. The superconducting DC cables include a positive electrode transmission cable and a negative electrode transmission cable, which are arranged parallel to each other along the direction of the core. The superconducting DC cables include a current-carrying superconductor and a dewar, the dewar being filled with a low-temperature cooling medium. The dewar serves as a thermal insulator and a shield against the alternating magnetic field. The stator core is made of a high-permeability material and is divided into three parts according to function: a backplate, a T-shaped core, and a C-shaped core. The T-shaped and C-shaped cores are arranged alternately with a gap in between, and the backplate is located below the T-shaped and C-shaped cores and has two grooves arranged parallel to each other on its upper surface, the grooves are Superconducting DC cable Used to fix the superconducting cable, when current is supplied to the superconducting cable, the backplate acts as a magnetic conductor, and the magnetic field forms a north pole and a south pole on the T-shaped and C-shaped iron cores, respectively, forming the north and south poles of the motor excitation system. The configuration of the north and south poles is Superconducting DC cable It is determined by the direction of the current flowing through it.

[0009] Preferably, when a DC current in the reverse direction is passed through the superconducting linear cable, a magnetic field is generated in the stator core, forming north and south magnetic poles in the C-shaped and T-shaped cores, with the north and south magnetic poles arranged alternately. The armature winding 11 of the movable part interacts with the linear motion magnetic field formed in the air gap, pressing the linear motor rotor into linear motion and realizing electromechanical energy conversion. [Effects of the Invention]

[0010] Compared to the prior art, the present invention has the following advantageous effects.

[0011] (1) The linear motor excitation system has a simple structure and is highly reliable and economical. It can also be applied to long-distance, high-capacity linear motor drive applications.

[0012] (2) The comprehensive use of a low-temperature cooling system for superconducting DC cables can solve the design problems of complex structures such as the low-temperature systems for superconducting linear motors.

[0013] (3) In the future, it can be applied to superconducting DC power transmission projects and railway transportation using linear motor drives, which can significantly reduce construction land and initial investment for power and transportation. [Brief explanation of the drawing]

[0014] [Figure 1] This is a conceptual diagram of the structure of a linear motor using superconducting cable excitation provided by an embodiment of the present invention. [Figure 2] This figure shows the magnetic field line distribution provided by an embodiment of the present invention. [Figure 3] This is a simulation result of the magnetic field of a linear motor provided by an embodiment of the present invention. [Explanation of symbols]

[0015] 1: Linear motor rotor; 2: Linear motor stator; 11: Armature winding; 12: Movement core; 21: Negative superconducting DC cable; 22: Positive superconducting DC cable; 23: Stator core; 221: Dewar; 222: Conductive superconductor. [Modes for carrying out the invention]

[0016] To further the understanding of the present invention, the present invention will be described in detail below with reference to the drawings and embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0017] As shown in Figure 1, the linear motor using superconducting cable excitation according to the present invention comprises a linear motor rotor 1 and a linear motor stator 2.

[0018] In this embodiment, the linear motor rotor 1 and the linear motor stator 2 are arranged parallel to each other, with an air gap between them. The linear motor rotor 1 can perform bidirectional linear motion along the linear motor stator 2. The linear motor rotor 1 consists of a movable core 12 and an armature winding 11. The movable core 12 has a groove on the linear motor stator 2 side, and the armature winding 11 is a three-phase winding, evenly distributed within the groove of the movable core 12. When three-phase AC power is supplied to the armature winding 11, a magnetic field for linear motion can be generated within the air gap.

[0019] The linear motor stator 2 is composed of a stator core 23 and two superconducting DC cables arranged in parallel. The superconducting DC cables include a positive power transmission cable 22 and a negative power transmission cable 21. The positive power transmission cable 22 and the negative power transmission cable 21 are arranged side by side along the direction of the stator core 23. The superconducting DC cable includes a current-carrying superconductor 222, a dewar 221, and a cryogenic cooling medium filled in the dewar. The dewar 221 serves as insulation and a shield for the alternating magnetic field. The stator core 23 is made of a high-permeability material and is divided into three parts, a back plate, a T-shaped iron core, and a C-shaped iron core, according to its function. The back plate Superconducting DC cable fixes and plays a role in conducting magnetism. The T-shaped iron core and the C-shaped iron core respectively form the magnetic circuits of the N-pole magnetic field and the S-pole magnetic field, and form the N pole and S pole of the motor. The configuration of the N pole and the S pole Superconducting DC cable is determined by the direction of the current flow in

[0020] When a DC current in the reverse direction is passed through the superconducting linear cable, a magnetic field is generated in the stator core, and N-pole and S-pole magnetic poles are formed in the C-shaped iron core and the T-shaped iron core. The N-pole and S-pole magnetic poles are alternately arranged, and the armature winding 11 of the mover interacts with the linear motion magnetic field formed in the air gap to press the linear motor rotor into linear motion, and the conversion of electromechanical energy can be realized.

[0021] The basic principle, main features, and advantages of the present invention have been described above. Those skilled in the art can understand that the present invention is not limited to the above-described embodiments. In addition, the above-described embodiments and the detailed description of the invention are only examples to illustrate the principle of the present invention, and any changes and improvements can be made without departing from the technical spirit and scope of the present invention, and such changes and improvements are all included within the scope of the present invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. It comprises a linear motor rotor and a linear motor stator, The linear motor rotor and the linear motor stator are arranged in parallel, and an air gap is provided between the linear motor rotor and the linear motor stator. The linear motor rotor is composed of a movable core and an armature winding. The movable core is provided with a groove on the linear motor stator side, and the armature winding is provided so as to be fitted into the groove. The linear motor stator comprises a stator core and a superconducting DC cable. A linear motor using superconducting cable excitation, characterized in that the superconducting DC cable comprises a positive electrode cable and a negative electrode cable, and the positive electrode cable and the negative electrode cable are arranged in the direction in which the stator cores of the linear motor stator are aligned.

2. The stator core is divided into three parts: a back plate, a T-shaped core, and a C-shaped core. The currents flowing through the positive and negative electrodes are DC currents in opposite directions. The linear motor using superconducting cable excitation according to claim 1, characterized in that the positive and negative superconducting cables are arranged in parallel and pass through the inside of the stator core.

3. The linear motor using superconducting cable excitation according to claim 2, characterized in that the armature winding is a three-phase winding, evenly arranged within the groove of the movable core, and three-phase alternating current is supplied to the armature winding to generate a magnetic field for linear motion.

4. The linear motor using superconducting cable excitation according to claim 3, wherein the superconducting DC cable comprises an energized superconductor and a dewar, the dewar is filled with a low-temperature cooling medium for cooling the superconductor, and the surface is covered with a shielding material that serves as both heat insulation and shielding against alternating magnetic fields.

5. The stator core is made of a high-permeability material and is divided into three parts: a back plate, a T-shaped core, and a C-shaped core. The T-shaped core and the C-shaped core are arranged alternately with a gap between them. The back plate is located below the T-shaped core and the C-shaped core and has two parallel grooves on its upper surface. These grooves are used to fix the superconducting DC cable. When current is supplied to the superconducting cable, the back plate acts as a magnetic conductor, and the magnetic field forms an N-pole magnetic field and an S-pole magnetic field on the T-shaped core and the C-shaped core, respectively, forming the N-pole and S-pole of the motor excitation system. This is the linear motor using superconducting cable excitation according to claim 4.

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