Linear motor based on superconducting cable excitation

Abstract

The application belongs to the field of superconducting technology and is a linear motor based on superconducting cable excitation, comprising a mover and a stator, an air gap between the mover and the stator, the mover capable of linear motion along the stator; the mover comprising a mover core and an armature winding, the mover core being slotted, and the armature winding being embedded in the slots of the mover core; the stator comprising a stator core and a superconducting excitation cable, the superconducting excitation cable being arranged side by side inside the stator core, the superconducting excitation cable being divided into a positive cable and a negative cable, the current directions in the two cables being opposite. After current is passed through the superconducting excitation current, a magnetic field is induced in the stator core, the magnetic field being uniformly distributed along the magnetic circuit of the stator core, and N-pole and S-pole magnetic poles being formed in the stator core in a staggered distribution. When alternating three-phase current is passed through the mover armature, a linear motion magnetic field can be generated in the air gap, the magnetic field generating a force with the stator magnetic poles, driving the mover to linearly move along the stator, thereby completing electromechanical energy conversion.

Description

Technical Field

[0001] This invention belongs to the field of applied superconducting technology, specifically, it is a linear motor based on superconducting cable excitation. Background Technology

[0002] With the development of rail transit and technologies such as maglev and electromagnetic propulsion in my country, the industry has a strong demand for high-thrust, high-efficiency linear propulsion motors. Applying resistance-free, high-current superconducting materials to the field of linear motors can significantly improve the power density and peak thrust of linear motors while reducing motor losses, and has important application prospects.

[0003] However, due to the high cost of superconducting materials and the limitations imposed by factors such as temperature, magnetic field, and stress on their application, superconducting linear motors have extremely complex structures. The design of the excitation coils and cryogenic systems within these motors is challenging, resulting in low reliability and high cost. Currently proposed superconducting linear motors mainly include linear motors based on superconducting bulk materials, superconducting linear synchronous motors, superconducting linear synchronous motors, and transverse flux superconducting motors. Summary of the Invention

[0004] This invention discloses a superconducting linear motor based on superconducting cable excitation, which effectively solves the design problems of excitation coil and its cryogenic system in superconducting linear motors. The structure is simple and reliable, reducing the difficulty and cost of motor design and manufacturing. By integrating the linear motor with superconducting DC transmission technology, the cost of future rail transit and DC transmission can be further reduced.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] A linear motor based on superconducting DC cable excitation includes a linear motor mover and a linear motor stator, which are arranged in parallel with an air gap between them. The linear motor mover can perform bidirectional linear motion along the linear motor stator.

[0007] Furthermore, the mover of the linear motor consists of a mover core and an armature winding. The mover core has slots on the stator side of the linear motor, and the armature winding is a three-phase winding, evenly arranged in the slots of the mover core. When three-phase alternating current is passed through the armature winding, a linearly moving magnetic field can be generated in the air gap.

[0008] Furthermore, the linear motor stator consists of a stator core and two parallel superconducting DC cables. The superconducting DC cables include a positive transmission cable and a negative transmission cable, which are arranged side-by-side along the direction of the stator core. The superconducting DC cables include a current-carrying superconductor and a Dewar breaker filled with a cryogenic cooling medium. The Dewar breaker serves to insulate against heat and shield the alternating magnetic field. The stator core is made of a high-permeability material and can be divided into three parts according to function: a back plate, a U-shaped core, and a C-shaped core. The U-shaped and C-shaped cores are arranged alternately with gaps in between. The back plate is located below the U-shaped and C-shaped cores and has two parallel slots on its upper surface for housing the superconducting excitation cables. After current is passed through the superconducting cables, the back plate acts as a magnetic conductor, and the magnetic field forms the N-pole magnetic field and the S-pole magnetic field in the U-shaped and C-shaped cores, respectively, thus constituting the N and S poles of the motor excitation system. The configuration of the N and S poles depends on the direction of the current in the superconducting excitation cable.

[0009] Furthermore, when a direct current in opposite direction is passed through the superconducting linear cable, a magnetic field is induced in the stator core, and N and S magnetic poles are formed in the C-shaped and T-shaped cores. The N and S magnetic poles are arranged alternately and interact with the magnetic field of linear motion formed by the mover armature in the air gap, thereby driving the mover of the linear motor to make linear motion and realizing electromechanical energy conversion.

[0010] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0011] (1) The excitation system of the linear motor has a simple and reliable structure and good economy, making it very suitable for long-distance, large-capacity linear motor drive applications.

[0012] (2) The cryogenic cooling system of superconducting DC cable was comprehensively utilized, which solved the design problems of complex structures such as cryogenic system of superconducting linear motor;

[0013] (3) In the future, superconducting DC power transmission projects and linear motor driven rail transit can achieve functional reuse, which can greatly save land for power and transportation construction and primary investment. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a linear motor structure for superconducting cable excitation provided in an embodiment of the present invention.

[0015] Figure 2 This is a magnetic circuit distribution diagram provided in an embodiment of the present invention.

[0016] Figure 3 This is a simulation diagram of the magnetic field of a linear motor provided in an embodiment of the present invention.

[0017] In the diagram: 1-Linear motor mover, 2-Linear motor stator, 11-Armature winding, 12-Motor core, 21-Negative superconducting DC cable, 22-Positive superconducting DC cable, 23-Stator core, 221-Dewar, 222-Current-carrying superconductor. Detailed Implementation

[0018] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the invention and do not limit the scope of protection of the invention.

[0019] like Figure 1 As shown, a linear motor based on superconducting cable excitation includes a linear motor mover 1 and a linear motor stator 2.

[0020] In this embodiment, the linear motor mover 1 and the linear motor stator 2 are arranged in parallel, with an air gap between them. The linear motor mover 1 can perform bidirectional linear motion along the linear motor stator 2. The linear motor mover 1 consists of a mover core 12 and an armature winding 11. The mover core 12 has slots on the linear motor stator 2 side, and the armature winding 11 is a three-phase winding, evenly arranged in the slots of the mover core 12. When three-phase alternating current is applied to the armature winding 11, a linearly moving magnetic field can be generated in the air gap.

[0021] The stator 2 of the linear motor consists of a stator core 23 and two superconducting DC cables arranged side-by-side. The superconducting DC cables include a positive pole transmission cable 22 and a negative pole transmission cable 21, which are arranged side-by-side along the direction of the stator core 23. The superconducting DC cables include a current-carrying superconductor 222, a Dewar 221, and a cryogenic cooling medium filling the Dewar. The Dewar 221 serves to insulate against heat and shield the alternating magnetic field. The stator core 23 is made of a high-permeability material and can be divided into three parts according to its function: a back plate, a U-shaped core, and a C-shaped core. The back plate serves to fix the superconducting excitation cable and guide the magnetic field. The U-shaped core and C-shaped core form the magnetic circuits of the N-pole magnetic field and the S-pole magnetic field, respectively, thus constituting the N-pole and S-pole of the motor. The formation of the N-pole and S-pole depends on the direction of the current in the superconducting excitation cable. The distribution of magnetic lines of force and the formation of the N-pole and S-pole magnetic poles of the linear motor are as follows: Figure 2 As shown. Figure 3 The distribution of the formed magnetic field was demonstrated through three-dimensional magnetic field simulation.

[0022] When a direct current in opposite direction is passed through a superconducting linear cable, a magnetic field is induced in the stator core, and N and S poles are formed in the C-shaped and T-shaped cores. The N and S poles are arranged alternately and interact with the linear magnetic field formed by the armature winding 11 in the air gap, which drives the linear motor to move in a linear motion, thus realizing the electromechanical energy conversion.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A linear motor based on superconducting cable excitation, characterized by, The system includes a linear motor mover and a linear motor stator, which are arranged in parallel with an air gap between them. The linear motor mover consists of a mover core and an armature winding. The mover core has a slot on the side of the linear motor stator, and the armature winding is embedded in the slot. The linear motor stator includes a stator core and a superconducting excitation cable. The stator core is divided into three parts: a back plate, a T-shaped core, and a C-shaped core. The superconducting excitation cable is divided into a positive cable and a negative cable. The current flowing through the two cables is direct current and in opposite directions. The positive and negative superconducting cables are arranged in parallel and pass through the interior of the stator core.

2. The superconducting cable excited linear motor of claim 1, wherein, The linear motor mover consists of a mover core and an armature winding. The armature winding is a three-phase winding, which is evenly arranged in the slots of the mover core. Three-phase alternating current is passed through the armature winding to generate a magnetic field for linear motion.

3. The superconducting cable excited linear motor of claim 2, wherein, The superconducting excitation cable includes a current-carrying superconductor and a Dewar. The Dewar is filled with a cryogenic medium to cool the superconductor, and a shielding material is arranged on its surface to provide insulation and shield against alternating magnetic fields.

4. The superconducting cable excited linear motor of claim 3, wherein, The stator core is made of a high-permeability magnetic material and consists of three parts: a back plate, a shaped core, and a C-shaped core. The shaped and C-shaped cores are arranged alternately with gaps in between. The back plate is located below the shaped and C-shaped cores and has two parallel slots on its upper surface for mounting the superconducting excitation cable. When current is passed through the superconducting cable, the back plate acts as a magnetic conductor, and the magnetic field forms the N-pole magnetic field and the S-pole magnetic field in the shaped and C-shaped cores, respectively, thus constituting the N-pole and S-pole of the motor excitation system.

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