A high temperature superconducting motor

Abstract

The present invention discloses a high-temperature superconducting motor, comprising a motor housing, a stator and a rotor arranged in sequence from radially outward to inward, the stator being provided with a stator winding, the rotor being provided with a superconducting magnetic block; the stator being provided with a wire hole extending along its axial direction, the wire hole being provided with a superconducting wire for electrifying the superconducting magnetic block; the motor housing being sealed, and both ends of the motor housing being provided with end covers for sealing therewith; a cooling medium for maintaining the superconducting wire and the superconducting magnetic block at a superconducting critical temperature is passed through the motor housing, and the stator and the rotor are immersed in the cooling medium. The above-mentioned high-temperature superconducting motor breaks through the restriction of dynamic electrification of superconducting wires, and improves the convenience and reliability of magnetizing the superconducting magnetic block.

Description

Technical Field

[0001] The invention relates to the technical field of superconducting motors, and in particular to a high-temperature superconducting motor. Background Art

[0002] High-temperature superconducting motors are already known in the prior art. They use the super-large current-carrying capacity of superconducting wires at critical temperatures and the super-strong magnetic flux density after magnetization of superconducting magnetic blocks to greatly reduce the size of the motor. Of course, the "high temperature" here is relative to absolute zero, and the actual temperature is still lower than the superconducting critical temperature of superconducting wires and superconducting magnetic blocks. To ensure the stable operation of superconducting wires and superconducting magnetic blocks, they need to operate continuously in a critical temperature environment. The superconducting magnetic blocks and superconducting wires are both located on the rotor. The rotor is sealed and isolated from the stator as a whole, and is cooled by a cold medium. It is necessary to energize the superconducting wires through the collector ring brushes and the external voltage for magnetization. Even in the non-magnetized state, the superconducting coils and collector ring brushes still rotate relative to each other. The rotating connection needs to be sealed relative to the cold medium. The superconducting wires wear relative to the collector ring brushes when the motor is running, which reduces the reliability of magnetization. Summary of the invention

[0003] The purpose of the present invention is to provide a high-temperature superconducting motor, which breaks through the limitation of dynamic magnetization of superconducting magnetic blocks and improves the convenience and reliability of magnetization.

[0004] To achieve the above object, the present invention provides a high temperature superconducting motor, comprising a motor housing, a stator and a rotor which are sequentially arranged from outside to inside along the radial direction, wherein the stator is provided with a stator winding, and the rotor is provided with a superconducting magnetic block;

[0005] The stator is provided with a wire hole extending along its axial direction, and a superconducting wire is arranged in the wire hole for passing electricity to magnetize the superconducting magnetic block; the motor housing is sealed, and end covers are provided at both ends of the motor housing to seal therewith; a cooling medium for maintaining the superconducting wire and the superconducting magnetic block at a superconducting critical temperature is passed through the inside of the motor housing, and the stator and the rotor are immersed in the cooling medium.

[0006] Optionally, the end cover is provided with a cooling medium inlet and a cooling medium outlet, and the cooling medium inlet and the cooling medium outlet are symmetrically arranged about the center of the end cover.

[0007] Optionally, a first thermal insulation layer is provided between the end cover and the motor housing, the first thermal insulation layer is arranged parallel to the end cover, and a second thermal insulation layer is provided between the stator and the motor housing.

[0008] Optionally, a joint between the first heat insulation layer and the second heat insulation layer is provided with stepped flanges that fit together.

[0009] Optionally, the number of groups of the wire holes is the same as the number of poles of the high-temperature superconducting motor, and the wire holes of all groups are evenly arranged along the circumferential direction of the stator.

[0010] Optionally, the rotor includes a rotor core, the superconducting magnetic blocks are arranged in contact with the outer surface of the rotor core, and all the superconducting magnetic blocks are evenly arranged along the outer surface of the rotor core.

[0011] Optionally, the rotor includes a rotor core, the superconducting magnetic blocks are embedded inside the rotor core, and all the superconducting magnetic blocks are evenly arranged along the inner circumference of the rotor core.

[0012] Compared with the above background technology, the high-temperature superconducting motor provided by the present invention is provided with a wire hole along the axial direction of the stator, and the superconducting wire is arranged in the stator, thereby avoiding the rotation of the superconducting wire for magnetization, reducing the wear of the superconducting wire relative to the collector ring brush, and improving the reliability of the magnetization of the superconducting magnetic block arranged in the rotor. In order to maintain the superconducting critical temperature of the superconducting wire and the superconducting magnetic block, the motor housing is a sealed housing, and a space for accommodating a cooling medium is formed by cooperating with the end cover, and the cooling medium is introduced into the motor housing, and the stator and the rotor are not in the cooling medium in the housing. Since the superconducting wire is arranged in the stator, the rotation of the superconducting wire is avoided. The wear caused by the motor operation in the non-magnetization state is avoided, the reliability of magnetization is improved, and magnetization can be performed when the motor is in operation. In addition to the motor bearing chamber, the high-temperature superconducting motor adopts a static sealing structure (relative to the sealing in the rotating state), which can meet the sealing requirements of the high-temperature superconducting motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0014] Figure 1 An axial cross-sectional view of a high temperature superconducting motor provided by an embodiment of the present invention;

[0015] Figure 2 A radial cross-sectional view of a high temperature superconducting motor provided by an embodiment of the present invention;

[0016] Figure 3 A schematic diagram of a stator provided by an embodiment of the present invention;

[0017] Figure 4 A schematic diagram of a stator provided in another embodiment of the present invention;

[0018] Figure 5 A schematic diagram of a rotor provided by an embodiment of the present invention;

[0019] Figure 6 A schematic diagram of a rotor provided in accordance with another embodiment of the present invention.

[0020] in:

[0021] 1-motor housing, 2-stator, 21-stator core, 22-stator winding, 23-stator slot, 3-rotor, 31-rotor core, 32-superconducting magnetic block, 4-conductor hole, 41-superconducting wire, 5-cooling medium inlet, 6-cooling medium outlet, 7-first thermal insulation layer, 8-second thermal insulation layer, 9-end cover. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Please refer to Figures 1 to 6 , Figure 1 An axial cross-sectional view of a high temperature superconducting motor provided by an embodiment of the present invention, Figure 2 A radial cross-sectional view of a high temperature superconducting motor provided by an embodiment of the present invention, Figure 3 A schematic diagram of a stator provided in one embodiment of the present invention, Figure 4 A schematic diagram of a stator provided in another embodiment of the present invention, Figure 5 A schematic diagram of a rotor provided by an embodiment of the present invention, Figure 6 A schematic diagram of a rotor provided in accordance with another embodiment of the present invention.

[0025] The high-temperature superconducting motor provided by the present invention comprises a motor housing 1, a stator 2 and a rotor 3. The relative positions of the motor housing 1, the stator 2 and the rotor 3 are the same as those of conventional motors, that is, they are arranged in sequence from the outside to the inside along the radial direction of the motor. The difference is that the rotor 3 is provided with a superconducting magnetic block 32 to replace the conventional rotor winding or permanent magnet, and the stator 2 is provided with a wire hole 4 extending along its axial direction, and a superconducting wire 41 is arranged in the wire hole 4. In order to maintain the superconducting wire 41 and the superconducting magnetic block 32 at a critical temperature, the motor housing 1 adopts a sealed housing, and cooperates with the end cover 9 to form a sealed space. By passing a cooling medium into the motor housing 1, the stator 2 and the rotor 3 are immersed in the cooling medium, and the superconducting wire 41 and the superconducting magnetic block 32 are cooled to maintain the temperature of both below the superconducting critical temperature. The superconducting wire 41 and the superconducting magnetic block 32 are arranged in the rotor 3, which needs to overcome the rotation power supply of the superconducting wire 41 to avoid the wear of the superconducting wire 41 relative to the collector ring brush when the motor is running in a non-magnetized state, thereby improving the reliability of magnetization.

[0026] The high temperature superconducting motor provided by the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments.

[0027] In the specific implementation provided by the present invention, the configuration of the high temperature superconducting motor can refer to Figure 1 and Figure 2 The wire holes 4 for installing the superconducting wire 41 are arranged on the stator yoke of the stator 2, and penetrate from the stator yoke along the axial direction of the stator 2 to the other end of the stator 2. The wire holes 4 are usually evenly arranged along the circumferential direction of the stator yoke, so that when the superconducting wire 41 is energized, a symmetrical and relatively uniform super-strong magnetic field is formed in the rotor 3, and the superconducting magnetic blocks 32 arranged in the rotor 3 are evenly magnetized. Generally speaking, the number of wire holes 4 is equal to the number of poles of the high-temperature superconducting motor, that is, twice the number of pole pairs.

[0028] Multiple groups of wire holes 4 are evenly arranged along the circumferential direction of the stator 2. When the number of pole pairs of the high-temperature superconducting motor is 2, there are four groups of wire holes 4, and the four groups of wire holes 4 are arranged at 90° intervals. There are four superconducting magnetic blocks 32 correspondingly, and two pairs of magnetic poles are formed after magnetization. A group of wire holes 4 can usually include two adjacently arranged wire holes 4. Since the superconducting wire 41 and the superconducting magnetic block 32 of the superconducting motor provided by the present invention are respectively arranged in the stator 2 and the rotor 3, the distance between the superconducting magnetic block 32 and the superconducting wire 41 is increased, and the induced magnetic field intensity generated by the superconducting wire 41 magnetizing the superconducting magnetic block 32 is stronger. The instantaneous current and current change rate of the superconducting wire 41 are larger than those of the traditional magnetization method. The magnetization current usually reaches hundreds of amperes to thousands of amperes. The magnetization time, that is, the duration of the magnetization current, is between a few milliseconds and hundreds of milliseconds. The magnitude of the current and the duration depend on the model and power of the high-temperature superconducting motor.

[0029] The increase of current in the superconducting wire 41 increases the requirement for insulation. In order to meet the insulation of the superconducting wire 41 relative to the stator 2, in addition to the insulation setting of the superconducting wire 41 itself, an insulating layer is usually added in the wire hole 4. The insulating layer can be an insulating paint brushed on the inner wall of the wire hole 4, or it can be a plastic or resin insulating sleeve embedded in the wire hole 4. When the second insulating setting is adopted, the diameter of the wire hole 4 is twice the thickness of the insulating sleeve than that of the first insulating setting.

[0030] In order to maintain the superconducting critical temperature of the superconducting wire 41 and the superconducting magnet block 32, the motor housing 1 adopts a cylindrical sealed housing; end covers 9 are provided at both ends of the motor housing 1, and the end covers 9 cooperate with the motor housing 1 to form a sealed space for accommodating the cooling medium. By introducing the cooling medium into the motor housing 1, the superconducting wire 41 in the stator 2 and the superconducting magnet block 32 in the rotor 3 are maintained below the superconducting critical temperature, and the superconducting state of the two is maintained. The cooling medium can be liquid nitrogen or liquid helium, and the temperature (lower than) of the cooling medium depends on the material of the superconducting wire 41 and the superconducting magnet block 32, and different materials correspond to different superconducting critical temperatures.

[0031] In order to maintain the temperature of the cooling medium, the cooling medium actually circulates in the motor housing 1, and a cooling medium inlet 5 and a cooling medium outlet 6 need to be set. Low-temperature cooling medium is injected into the motor housing 1 through the cooling medium inlet 5, and the circulating and heated cooling medium is discharged from the cooling medium outlet 6.

[0032] The cooling medium inlet 5 and the cooling medium outlet 6 can be arranged on the side wall of the motor housing 1, or on the end cover 9; they can be arranged on the same end cover 9, or on two end covers 9 at both ends of the motor housing 1. Figure 1 In the embodiment shown, the cooling medium inlet 5 and the cooling medium outlet 6 are arranged on the same end cover 9 and are symmetrically arranged about the center of the end cover 9. A rotating seal structure is provided at the place where the motor shaft passes through the end cover 9, and a circular groove is provided on the inner end surface of the end cover 9 where the motor shaft passes through, and the rotating seal structure is arranged in the circular groove. The rotating seal structure can be arranged with reference to the existing superconducting motor.

[0033] In order to maintain the temperature of the cooling medium, in addition to circulating the cooling medium through the cooling medium inlet 5 and the cooling medium outlet 6, since the temperature of the cooling medium is much lower than the ambient temperature, the heat absorption of the cooling medium from the external environment must also be considered. Therefore, a heat insulation layer is specially provided to slow down the heat absorption of the cooling medium. The heat insulation layer specifically includes a disc-shaped first heat insulation layer 7 provided between the end cover 9 and the motor housing 1 and parallel to the end cover 9, and a sleeve-shaped second heat insulation layer 8 sleeved between the stator and the motor housing 1. The connection between the first heat insulation layer 7 and the second heat insulation layer 8 is provided with a mutually matching stepped flange, which can be either single-step or multi-step, as long as the sealing of the connection is ensured. The sealing of the connection can also be achieved by using a toothed structure that engages with each other. At this time, the cooling medium is actually in the first heat insulation layer 7 and the second heat insulation layer 8.

[0034] Furthermore, a heat-insulating layer may be coated on the outer surface of the motor housing 1. The heat-insulating layer and the heat-insulating layer are made of conventional heat-insulating materials, which will not be elaborated here.

[0035] In one embodiment, the structure of the stator 2 is as follows: Figure 3 As shown, the stator core 21 includes a stator core 21, the inner wall of the stator core 21 is provided with teeth uniformly arranged along its circumference, and stator slots 23 are formed between adjacent teeth for winding stator windings 22. The yoke of the stator 2 is provided with a wire hole 4 for passing a superconducting wire 41. In another embodiment, the stator 2 can be used as follows Figure 4 In the air stator core 21 shown, the inner wall of the stator core 21 is not provided with stator slots 23, and the stator winding 22 is fixed along the circumferential direction of the inner wall of the stator 2 by spacers arranged at intervals.

[0036] The present invention also provides two kinds of Figure 5 and Figure 6 In the rotor structure shown, a high temperature superconducting motor with a pole pair number of 2 is taken as an example. The superconducting magnetic blocks 32 are respectively arranged on the outer wall of the rotor core 31 or embedded in the inner circumference of the rotor core 31, and the superconducting magnetic blocks 32 are magnetized to serve as rotor windings. Regardless of the arrangement direction of the superconducting magnetic blocks 32, the superconducting magnetic blocks 32 need to be evenly arranged along the circumference of the rotor core 31. Of course, when the superconducting magnetic blocks 32 are arranged in different ways, the diameter of the corresponding rotor core 31 also varies.

[0037] When magnetizing the above-mentioned high-temperature superconducting motor, it is necessary to first connect the external magnetizing circuit to the superconducting wire 41. This can be done by setting up multiple groups of magnetizing circuits to connect all groups of superconducting wires 41 at the same time, or by using one group of magnetizing circuits to connect different groups of superconducting wires 41 in sequence, so as to magnetize the superconducting magnetic blocks 32 in the rotor 3 step by step.

[0038] After the magnetizing circuit is connected to the superconducting wire 41, it is necessary to inject cooling medium into the cooling channel and between the stator 2 and the rotor 3 through the medium injection port. The magnetizing current is then passed after detecting that the temperature inside the superconducting wire 41 and the rotor 3 reaches below the corresponding superconducting critical temperature.

[0039] Secondly, it is necessary to set a suitable magnetizing current and magnetizing time, that is, the duration of the magnetizing current. According to the power of the high-temperature superconducting motor, the magnetic field strength to be achieved by the superconducting magnetic block 32, and the distance between the superconducting magnetic block 32 and the superconducting wire 41, the strength of the induced magnetic field to be generated by the superconducting wire 41 is found or calculated, and then the suitable magnetizing current and magnetizing time are set according to the strength of the induced magnetic field.

[0040] Finally, the superconducting wire 41 can be powered on and off according to the preset magnetizing current and magnetizing time. In addition, the magnetizing circuit can be directly connected to the three phases of the stator winding 22, and the magnetizing current is passed through the stator winding 22 to generate an induced magnetic field to magnetize the superconducting magnetic block 32 arranged in the rotor 3. When the magnetizing current (DC) is directly passed through the stator winding 22, the magnetizing current of phase A is I, and the magnetizing current of phases B and C is -I / 2. The negative sign indicates that the magnetizing currents of phases B and C are in opposite directions to that of phase A. It is just that the magnetizing current when magnetizing through the three-phase magnetizing current of the stator winding 22 is smaller than the magnetizing current passing only through the superconducting wire 41 to maintain the insulation between the phases.

[0041] The above is a detailed introduction to the high temperature superconducting motor provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A high-temperature superconducting motor, comprising a motor housing (1), a stator (2) and a rotor (3) arranged in sequence from the outside to the inside along the radial direction, wherein the stator (2) is provided with a stator winding (22), and the rotor (3) is provided with a superconducting magnetic block (32); characterized in that: The stator (2) is provided with a wire hole (4) extending along its axial direction, and a superconducting wire (41) is provided in the wire hole (4) for passing electricity to magnetize the superconducting magnetic block (32); the motor housing (1) is sealed, and end covers (9) are provided at both ends of the motor housing (1) to seal therewith; a cooling medium for maintaining the superconducting wire (41) and the superconducting magnetic block (32) at a superconducting critical temperature is passed through the motor housing (1), and the stator (2) and the rotor (3) are immersed in the cooling medium; The stator (2) comprises a stator core (21), and the stator winding (22) is fixed along the circumferential direction of the inner wall of the stator (2) by spacers arranged at intervals. The wire hole (4) is located at the stator yoke of the stator (2), and an insulating layer is also provided in the wire hole (4); A first heat insulation layer (7) is provided between the end cover (9) and the motor housing (1), the first heat insulation layer (7) being arranged in parallel with the end cover (9), and a second heat insulation layer (8) is provided between the stator (2) and the motor housing (1); The connection between the first heat insulation layer (7) and the second heat insulation layer (8) is provided with stepped flanges which match each other.

2. The high temperature superconducting motor according to claim 1, characterized in that: The end cover (9) is provided with a cooling medium inlet (5) and a cooling medium outlet (6), and the cooling medium inlet (5) and the cooling medium outlet (6) are symmetrically arranged with respect to the center of the end cover (9).

3. The high temperature superconducting motor according to any one of claims 1 to 2, characterized in that: The number of groups of the wire holes (4) is the same as the number of poles of the high-temperature superconducting motor, and all groups of the wire holes (4) are evenly arranged along the circumference of the stator (2).

4. The high temperature superconducting motor according to claim 3, characterized in that: The rotor (3) comprises a rotor core (31), the superconducting magnetic blocks (32) are arranged in contact with the outer surface of the rotor core (31), and all the superconducting magnetic blocks (32) are evenly arranged along the outer surface of the rotor core (31).

5. The high temperature superconducting motor according to claim 3, characterized in that: The rotor (3) comprises a rotor core (31), the superconducting magnetic blocks (32) are embedded inside the rotor core (31), and all the superconducting magnetic blocks (32) are evenly arranged along the inner circumference of the rotor core (31).

Images