Decoupling type stator excitation superconducting motor

Abstract

The invention provides a decoupling type stator excitation superconducting motor. The decoupling type stator excitation superconducting motor comprises a rear end cover, a front end cover and a machine shell. At least one superconducting excitation winding is arranged in the machine shell in the axial direction. Two stator structures are respectively arranged on two axial sides of each superconducting excitation winding, and only one stator structure is arranged between any two adjacent superconducting excitation windings; a rotor structure is arranged on the inner side of each stator structure and is connected with the rotating shaft extending out of the front end cover; the stator structure comprises a stator iron core and a stator winding. The top of a stator tooth on the inner side of the stator iron core is provided with uniformly distributed flux adjusting grooves I. Each rotor structure comprises a rotor iron core and a magnetic conductive block arranged between the two rotor structures, and the outer side of the rotor iron core is provided with magnetic adjusting grooves II which are uniformly distributed.

Description

Technical Field

[0001] The invention belongs to the technical field related to superconducting motor design, and in particular relates to a decoupled stator excitation superconducting motor. Background Art

[0002] The power density of motors in the fields of ship propulsion, aerospace, etc. is increasingly required. Although the development of high-performance magnetic materials has improved the power density of traditional permanent magnet motors, their power density is still difficult to meet the needs of some special occasions. In recent years, the rapid development of high-temperature superconducting technology has led to in-depth research on high-temperature superconducting materials in the fields of motors, flywheel energy storage, magnetic levitation, etc., and superconducting motor technology has also received widespread attention. Compared with traditional permanent magnet motors, superconducting motors can improve energy utilization efficiency due to the absence of copper loss; because the resistance of superconducting materials is zero, it can carry more power per unit volume or mass, and has advantages such as greater power density.

[0003] The structure of a traditional superconducting motor is similar to that of a rotor electric excitation motor. The superconducting excitation winding is located inside the rotor and requires brushes to be connected to the power supply. In addition, dynamic sealing technology and a rotating dewar are required to ensure that the liquid nitrogen used to cool the superconducting material can be properly injected and kept at a low temperature without leakage. This superconducting motor structure is relatively complex, and because the superconducting system is located inside the rotating body, its working reliability will be affected to a certain extent. To solve the above problems, Patent 201910731064.1 discloses a dual-stator field modulation superconducting motor, which places the superconducting excitation winding and its cooling device on the inner stator to achieve static sealing of the coolant and brushless current transmission.

[0004] However, whether it is a traditional superconducting motor or a stator-excited superconducting motor, the excitation magnetic field and the armature magnetic field are coupled when they are working, resulting in an induced pulsating voltage at both ends of the excitation winding, which can easily lead to problems such as complex current stability control of the excitation winding and torque fluctuations.

[0005] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and thus provide a decoupled stator excitation superconducting motor, which can solve the shortcomings of cooling liquid and induced pulsating voltage while achieving high power density of the superconducting motor.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a decoupled stator excitation superconducting motor, comprising a rear end cover, a front end cover and a casing; At least one superconducting excitation winding is axially arranged in the casing; two stator structures are arranged on both sides of the axial direction of each superconducting excitation winding, and there is only one stator structure between any two adjacent superconducting excitation windings; a rotor structure is arranged inside each stator structure, and the rotor structure is connected to the rotating shaft extending out of the front end cover; The stator structure comprises a stator core and a stator winding, and the top of the stator teeth inside the stator core is provided with evenly distributed magnetic tuning slots I; The rotor structure comprises a rotor core and a magnetic conductive block arranged between two rotor structures. The outer side of the rotor core is provided with evenly distributed magnetic tuning slots II.

[0008] Preferably, the magnetic tuning slots II of one rotor structure correspond to the magnetic tuning teeth between the magnetic tuning slots II of another rotor structure.

[0009] Preferably, the axial length of the rotor core is the same as the axial length of the stator core, and the number of the magnetic tuning slots I and the number of the magnetic tuning slots II are different.

[0010] Preferably, the diameter of the magnetic conductive block is smaller than the diameter of the rotor core.

[0011] Preferably, the superconducting excitation winding is a ring-shaped winding, and thermal insulation dewars are provided on both inner and outer sides of the superconducting excitation winding in radial direction.

[0012] Preferably, the thermal insulation dewar is a double-layer annular structure, and the interior is hollow as a circulation channel for the coolant.

[0013] Preferably, a cooling / electrical interface is provided on the casing, and the cooling / electrical interface is connected to the flow channel of the thermal insulation dewar and the superconducting excitation winding.

[0014] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, (1) The excitation magnetic field and the armature magnetic field are decoupled, the induced pulsating voltage at the end of the superconducting excitation coil is small and easy to control, thus reducing torque fluctuations; (2) Compared with other superconducting motors that require one set of superconducting coils for one magnetic pole, the present invention only requires one set of superconducting coils. The required superconducting excitation coils are much smaller than those of other superconducting motors, and the ring structure is adopted, which is simple in structure and easy to install. (3) The thermal insulation dewar is fixed inside the casing and does not require manual sealing. The cooling structure is simple, with high reliability and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view of the present invention; Figure 2 It is an external overall schematic diagram of the present invention; Figure 3It is a structural schematic diagram of the heat preservation dewar of the present invention; Figure 4 It is a schematic diagram of the position of the stator structure of the present invention; Figure 5 It is a structural schematic diagram of the stator structure of the present invention; Figure 6 is a schematic structural diagram of the rotor structure of the present invention; Figure 7 It is a schematic diagram of the magnetic circuit of the present invention; In the figure: 1. rear end cover; 2. front end cover; 3. casing; 4. stator core; 41. magnetic adjustment slot I; 5. stator winding; 6. insulation dewar; 7. superconducting excitation winding; 8. cooling / electrical interface; 9. rotor core; 91. magnetic adjustment slot II; 10. magnetic conductive block; 11. rotating shaft. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0017] Example 1 This embodiment provides a decoupled stator excitation superconducting motor, such as Figure 1 As shown, it includes a rear end cover 1, a front end cover 2 and a housing 3. In one embodiment, the housing is made of a magnetic conductive material, and the end cover is made of a non-magnetic conductive material.

[0018] like Figure 2 As shown, a hole is opened on the side of the housing 3, and the cooling / electrical interface 8 is placed in the hole. The housing 3 is provided with a rotating shaft 11, which extends out of the front cover 2 and is slidably connected with the rear cover 1 and the front cover 2 through bearings.

[0019] At least one superconducting excitation winding 7 is axially arranged in the housing 3, and there is only one stator structure between any two adjacent superconducting excitation windings. Preferably, this embodiment is described by taking one superconducting excitation winding as an example.

[0020] The superconducting excitation winding is a ring-shaped winding, and the superconducting excitation winding 7 is provided with a thermal insulation dewar 6 on both inner and outer sides in the radial direction.

[0021] like Figure 3 As shown, the thermal insulation dewar 6 is a double-layer annular structure, and the inner hollow serves as a circulation channel for the coolant; the superconducting excitation winding 7 is formed by annular winding of superconducting wire, and is annular as a whole; the coolant of the thermal insulation dewar 6 and the two ends of the superconducting excitation winding 7 are connected by a cooling / electrical interface 8 to realize the transmission of coolant and electric energy. Since the thermal insulation dewar in this embodiment is fixed in the casing, manual sealing is not required, and the cooling structure is simple, the reliability is high, and the service life is long.

[0022] Two stator structures are disposed on both axial sides of each superconducting excitation winding 7, and there is only one stator structure between any two adjacent superconducting excitation windings 7. Figure 4 As shown, the superconducting excitation winding and the stator winding 5 are spatially isolated by the double stator structure to weaken the direct coupling between the armature reaction magnetic field and the superconducting coil. It can be understood that the insulation dewar 6 is also located between the two stator cores 4.

[0023] The stator structure includes a stator core 4 and a stator winding 5. Figure 5 As shown, the stator core 4 is annular as a whole, and has stator teeth for fixing the stator winding 5. Furthermore, evenly distributed magnetic tuning slots I41 are opened at the top of the stator teeth inside the stator core 4, so that the air gap magnetic field generates harmonics, and the harmonics generate torque; the magnetic tuning teeth I are between any two magnetic tuning slots I41.

[0024] A rotor structure is disposed inside each stator structure, and the rotor structure is connected to the rotating shaft 11. Specifically, Figure 6 As shown, the rotor structure includes a rotor core 9 and a magnetic conductive block 10 arranged between the two rotor structures. The outer side of the rotor core 9 is provided with uniformly distributed magnetic tuning slots II91.

[0025] In one embodiment, the diameter of the magnetic conductive block 10 is smaller than the diameter of the rotor core 9 .

[0026] During specific implementation, the magnetic tuning slots II91 of one rotor structure may also correspond to the magnetic tuning teeth between the magnetic tuning slots II91 of another rotor structure.

[0027] It should be noted that the number of the magnetic tuning slots II91 of the rotor core 9 is different from the number of the magnetic tuning slots I41 of the stator core 4 .

[0028] The working principle of the decoupled stator excitation superconducting motor is as follows: like Figure 7 As shown, the magnetic field generated after the superconducting excitation winding 7 is energized passes through the housing 3—stator core 4—air gap—rotor core 9—magnetic block 10—rotor core 9—air gap—stator core 4—housing 3 to form a magnetic circuit.

[0029] The magnetic field generated by the superconducting excitation winding 7 is modulated by the magnetic tuning slots II91 of the stator core 4 and the rotor core 9, and then interacts with the magnetic field generated by the stator winding 5 to generate a rotation torque. Since the side magnetic field generated by the stator winding 5 is radial, it is completely decoupled from the superconducting excitation winding 7, thereby avoiding the generation of induced pulsating voltage by the superconducting excitation winding 7 and reducing the control difficulty of the superconducting motor.

[0030] It should be noted that this embodiment is described based on the basic structure of the present technology, that is, both the stator side and the rotor side are three-layer structures, respectively, with a layer of superconducting excitation structure sandwiched between the stator cores 4 on both sides and a magnetic block sandwiched between two layers of rotor cores 9. The number of superconducting excitation coils required is small, and a ring structure is adopted, which is simple in structure and easy to install.

[0031] In practice, the output power of the motor can be increased by adding a layer of superconducting excitation structure, a layer of stator core 4, a layer of magnetic conductive block 10, and a layer of rotor core 9 in the axial direction to form a five-layer structure.

[0032] It is understandable that the decoupled stator excitation superconducting motor can also be increased to a seven-layer, nine-layer or other structure in the axial direction to improve the output power of the motor.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A decoupled stator excitation superconducting motor, characterized in that: It includes a rear cover, a front cover and a casing; At least one superconducting excitation winding is axially arranged in the casing; two stator structures are arranged on both sides of the axial direction of each superconducting excitation winding, and there is only one stator structure between any two adjacent superconducting excitation windings; a rotor structure is arranged inside each stator structure, and the rotor structure is connected to the rotating shaft extending out of the front end cover; The stator structure comprises a stator core and a stator winding, and the top of the stator teeth inside the stator core is provided with evenly distributed magnetic tuning slots I; The rotor structure comprises a rotor core and a magnetic conductive block arranged between two rotor structures. The outer side of the rotor core is provided with evenly distributed magnetic tuning slots II.

2. The decoupled stator excitation superconducting motor according to claim 1, characterized in that: The magnetic tuning slots II of one rotor structure correspond to the magnetic tuning teeth between the magnetic tuning slots II of the other rotor structure.

3. A decoupled stator excitation superconducting motor according to claim 2, characterized in that: The axial length of the rotor core is the same as the axial length of the stator core, and the number of the magnetic tuning slots I and the number of the magnetic tuning slots II are different.

4. The decoupled stator excitation superconducting motor according to claim 3, characterized in that: The diameter of the magnetic conductive block is smaller than the diameter of the rotor core.

5. The decoupled stator excitation superconducting motor according to claim 1, characterized in that: The superconducting excitation winding is a ring-shaped winding, and thermal insulation dewars are arranged on both inner and outer sides of the superconducting excitation winding in radial direction.

6. The decoupled stator excitation superconducting motor according to claim 3, characterized in that: The heat preservation dewar is a double-layer annular structure, and the inner hollow portion serves as a circulation channel for the coolant.

7. The decoupled stator excitation superconducting motor according to claim 3, characterized in that: The casing is provided with a cooling / electrical interface, and the cooling / electrical interface is connected to the flow channel of the thermal insulation dewar and the superconducting excitation winding.

8. The decoupled stator excitation superconducting motor according to claim 3, characterized in that: The casing material is a magnetic conductive material, and the end cover is a non-magnetic conductive material.

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