A homopolar asymmetric magnetic circuit permanent magnet memory motor

Abstract

The present invention discloses a permanent magnet memory motor with a same-pole asymmetric magnetic circuit, which relates to the technical field of permanent magnet memory motors. The present invention comprises: a stator, on which an armature winding is mounted; a hybrid permanent magnet rotor, which is rotatably connected to the inner side of the stator; the hybrid permanent magnet rotor comprises a rotor core, on which a plurality of magnetic pole assemblies are mounted, and the plurality of magnetic pole assemblies are evenly arranged in the circumferential direction; the magnetic pole assemblies comprise a first hybrid permanent magnet unit arranged in different magnetic circuits and a second hybrid permanent magnet unit in a series magnetic circuit; the first hybrid permanent magnet unit and the second hybrid permanent magnet unit form an angle that opens outward, and the first hybrid permanent magnet unit and the second hybrid permanent magnet unit are alternately arranged on the outer side of the rotor core. By combining the advantages of series-parallel magnetic circuits, the present invention further broadens the motor's magnetic adjustment range while simplifying the rotor structure, and at the same time ensures the stability of the permanent magnet operating point during load operation.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet memory motors, in particular to a same-pole asymmetric magnetic circuit type permanent magnet memory motor. Background Art

[0002] Variable Flux Memory Machine (VFMM) is attracting more and more attention from scholars and industry. This type of motor can change the magnetization state of low coercive force (LCF) permanent magnet materials by applying instantaneous charging and demagnetizing current pulses to the stator winding, thereby flexibly adjusting the air gap magnetic field. The magnetic flux density level of the LCF permanent magnet can be determined according to the amplitude of the applied pulse current, and has the characteristic of "memory". By flexibly adjusting the air gap magnetic field, the constant power operating range of the motor is expanded, thereby improving its efficiency under light load or high speed operation without basically increasing the electric excitation loss. In order to further improve the torque capacity of the motor, most of the current research on VFMM at home and abroad is focused on hybrid permanent magnet structures.

[0003] According to the magnetic circuit relationship, hybrid permanent magnet VFMM can be divided into parallel magnetic circuit type and series magnetic circuit type. The former has a wider magnetic adjustment range, but under load, LCF is easily affected by cross-coupling demagnetization, thereby reducing the static and dynamic performance of the motor; while the latter has high torque density and stable operating point of low coercive force permanent magnet, but the magnetic adjustment range is limited. Therefore, we propose a permanent magnet memory motor with a same-pole asymmetric magnetic circuit. Summary of the Invention

[0004] The purpose of the present invention is to provide a permanent magnet memory motor with a same-pole asymmetric magnetic circuit, which can solve the serious problem of cross-coupling demagnetization of low-coercive force permanent magnets by high-coercive force permanent magnets and improve the working point stability of low-coercive force permanent magnets.

[0005] To achieve the above object, the present invention provides the following technical solution: a homopolar asymmetric magnetic circuit permanent magnet memory motor, comprising:

[0006] Stator, on which the armature winding is mounted:

[0007] a hybrid permanent magnet rotor rotatably connected to an inner side of the stator, the hybrid permanent magnet rotor comprising a rotor core, a plurality of magnetic pole assemblies mounted on the rotor core, and the plurality of magnetic pole assemblies being uniformly arranged circumferentially;

[0008] The magnetic pole assembly includes a first hybrid permanent magnet unit arranged in different magnetic circuits and a second hybrid permanent magnet unit in a series magnetic circuit. The first hybrid permanent magnet unit and the second hybrid permanent magnet unit form an angle opening outward, and the first hybrid permanent magnet unit and the second hybrid permanent magnet unit are alternately arranged on the outside of the rotor core.

[0009] Furthermore, the first hybrid permanent magnet unit includes a first permanent magnet and a second permanent magnet, and both the first permanent magnet and the second permanent magnet are mounted on the side wall of the rotor core.

[0010] Furthermore, a parallel magnetic circuit is formed between the first permanent magnet and the second permanent magnet.

[0011] Furthermore, the second hybrid permanent magnet unit includes a third permanent magnet and a fourth permanent magnet, and the third permanent magnet and the fourth permanent magnet are both mounted on the side wall of the rotor core.

[0012] Furthermore, a series magnetic circuit is formed between the third permanent magnet and the fourth permanent magnet.

[0013] Furthermore, the first permanent magnet and the fourth permanent magnet are neodymium iron boron permanent magnets, and the second permanent magnet and the third permanent magnet are aluminum nickel cobalt permanent magnets.

[0014] Furthermore, the number of the first hybrid permanent magnet units and the second hybrid permanent magnet units is equal, and the first hybrid permanent magnet units and the second hybrid permanent magnet units constitute the N pole and the S pole of the magnetic pole assembly respectively.

[0015] Furthermore, in the same magnetic pole assembly, the first permanent magnet and the second permanent magnet are both magnetized along the tangential direction, and the third permanent magnet and the fourth permanent magnet are both magnetized along the tangential direction.

[0016] Furthermore, when the magnetization directions of the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are all the same, the motor is in a forward magnetization state; otherwise, the motor is in a reverse magnetization state.

[0017] Furthermore, the stator includes a stator yoke, stator teeth are provided between the stator yoke and the hybrid permanent magnet rotor, and stator slots are formed between two adjacent stator teeth.

[0018] The present invention has at least the following beneficial effects:

[0019] 1. In the present invention, the first permanent magnet and the second permanent magnet form a parallel magnetic circuit, and the third permanent magnet and the fourth permanent magnet form a series magnetic circuit. The symmetrical design of the permanent magnets with different coercive forces in each hybrid permanent magnet unit forms a magnetic concentration effect, which helps to improve the working point stability of the low-coercive force permanent magnet and enhance the magnetic stabilization effect.

[0020] 2. The rotor of the present invention adopts a mixed magnetic pole structure, and the unified magnetic pole adopts different permanent magnet arrangements to form an asymmetric magnetic circuit structure under the same pole. While simplifying the rotor structure, it can improve the space utilization of the rotor to a certain extent.

[0021] 3. The same-pole asymmetric magnetic circuit structure can increase the freedom of design of the motor's permanent magnet rotor and effectively reduce the amount of permanent magnets used.

[0022] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the cross-sectional structure of a motor according to an embodiment of the present invention;

[0024] Figure 2 1 is a magnetic field line distribution diagram of the motor in the magnetization state according to an embodiment of the present invention;

[0025] Figure 3 3 is a diagram showing the distribution of magnetic lines of force of the motor in the demagnetized state according to an embodiment of the present invention.

[0026] Reference numerals

[0027] 1. Stator; 11. Stator yoke; 12. Stator teeth; 13. Stator slots; 2. Armature winding; 3. Hybrid permanent magnet rotor; 31. Rotor core; 32. First permanent magnet; 33. Second permanent magnet; 34. Third permanent magnet; 35. Fourth permanent magnet. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0029] See also Figure 1 The present invention provides a technical solution: a homopolar asymmetric magnetic circuit type permanent magnet memory motor, comprising:

[0030] Stator 1, on which armature winding 2 is installed:

[0031] A hybrid permanent magnet rotor 3 is rotatably connected to the inner side of the stator 1. The hybrid permanent magnet rotor 3 includes a rotor core 31. A plurality of magnetic pole assemblies are mounted on the rotor core 31, and the plurality of magnetic pole assemblies are evenly arranged in the circumferential direction.

[0032] The magnetic pole assembly includes a first hybrid permanent magnet unit arranged in different magnetic circuits and a second hybrid permanent magnet unit in a series magnetic circuit. An angle opening outward is formed between the first hybrid permanent magnet unit and the second hybrid permanent magnet unit, and the first hybrid permanent magnet unit and the second hybrid permanent magnet unit are alternately arranged on the outside of the rotor core 31.

[0033] It should be noted that the first hybrid permanent magnet unit includes a first permanent magnet 32 ​​and a second permanent magnet 33, and the first permanent magnet 32 ​​and the second permanent magnet 33 are both installed on the side wall of the rotor core 31, and a parallel magnetic circuit is formed between the first permanent magnet 32 ​​and the second permanent magnet 33; the second hybrid permanent magnet unit includes a third permanent magnet 34 and a fourth permanent magnet 35, and the third permanent magnet 34 and the fourth permanent magnet 35 are both installed on the side wall of the rotor core 31, and a series magnetic circuit is formed between the third permanent magnet 34 and the fourth permanent magnet 35.

[0034] Furthermore, the first permanent magnet 32 ​​and the fourth permanent magnet 35 are neodymium iron boron permanent magnets, the second permanent magnet 33 and the third permanent magnet 34 are aluminum nickel cobalt permanent magnets, the first permanent magnet 32 ​​and the second permanent magnet 33 are both magnetized tangentially in the same direction; the third permanent magnet 34 and the fourth permanent magnet 35 are both magnetized tangentially in the same direction.

[0035] The number of the first hybrid permanent magnet units and the second hybrid permanent magnet units is equal, and an outward-opening angle is formed between the first hybrid permanent magnet units and the second hybrid permanent magnet units. According to the technical solution of the present application, the angle is an obtuse angle, and the first hybrid permanent magnet units and the second hybrid permanent magnet units respectively constitute the N pole and S pole of the magnetic pole assembly. The permanent magnets with different coercive forces under the same magnetic pole form a magnetic concentration effect, which helps to improve the working point stability of the low-coercive force permanent magnet and enhance the magnetic stabilization effect.

[0036] The number of magnetic pole assemblies is an even number, and the number of the first permanent magnet 32, the second permanent magnet 33, the third permanent magnet 34, and the fourth permanent magnet 35 is the same as the number of magnetic pole assemblies. For the embodiment provided in this application, the number of the first permanent magnet 32, the second permanent magnet 33, the third permanent magnet 34, and the fourth permanent magnet 35 is eight. When the magnetization directions of the first permanent magnet 32, the second permanent magnet 33, the third permanent magnet 34, and the fourth permanent magnet 35 are the same, the motor is in a forward magnetization state; otherwise, the motor is in a reverse magnetization state.

[0037] In addition, the stator 1 includes a stator yoke 11, and stator teeth 12 are arranged between the stator yoke 11 and the hybrid permanent magnet rotor 3. A stator slot 13 is formed between two adjacent stator teeth 12. The armature winding 2 is wound on the stator teeth 12. The stator slot 13 is used to place the armature winding 2. An air gap is left between the stator 1 and the hybrid permanent magnet rotor 3.

[0038] The operating principle of the homopolar asymmetric magnetic circuit permanent magnet memory motor disclosed in the present invention is as follows:

[0039] In the magnetization state, the motor magnetic lines of force are distributed as follows Figure 2As shown; the first hybrid permanent magnet unit and the second hybrid permanent magnet unit constitute the north pole (N pole) and south pole (S pole) of the motor; the second permanent magnet 33 is magnetized along the magnetic flux direction of the first permanent magnet 32, and the third permanent magnet 34 is magnetized along the magnetic flux direction of the fourth permanent magnet 35. At this time, the second permanent magnet 33 and the third permanent magnet 34 are in a magnetization state. After the magnetic flux of the two is superimposed, it passes through the air gap and first reaches the stator tooth 12, then passes through the stator yoke 11 and passes through the adjacent symmetrically distributed first hybrid permanent magnet unit and the second hybrid permanent magnet unit, and finally returns to the south pole (S pole) of the first permanent magnet 32.

[0040] In the weak magnetic state, the motor magnetic field lines are distributed as follows Figure 3 As shown; the second permanent magnet 33 is magnetized in the opposite direction of the magnetic flux of the first permanent magnet 32, and the third permanent magnet 34 is magnetized in the opposite direction of the magnetic flux of the fourth permanent magnet 35. At this time, the second permanent magnet 33 and the third permanent magnet 34 are in a weak magnetic state, and part of the permanent magnetic flux of the first permanent magnet 32 ​​starting from the north pole is short-circuited, and the magnetic flux passes through the second permanent magnet 33 and directly returns to the south pole of the first permanent magnet 32. The remaining magnetic flux passes through the air gap and first reaches the stator tooth 12, and then passes through the stator yoke 11 and passes through the adjacent symmetrically distributed first hybrid permanent magnet unit and the second hybrid permanent magnet unit, and finally returns to the south pole (S pole) of the first permanent magnet 32.

[0041] At the same time, a three-phase alternating current with the same rotational speed as the hybrid permanent magnet rotor 3 is fed into the motor armature winding 2, and the rotating magnetic fields formed by the stator and rotor interact with each other, thereby realizing electromechanical energy conversion.

[0042] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0043] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on", "installed on", "fixed on" or "set on" another element, it can be directly on the other element or there can be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be a central element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0045] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Claims

1. A permanent magnet memory motor with a homopolar asymmetric magnetic circuit, comprising: A stator (1), wherein an armature winding (2) is mounted on the stator (1): A hybrid permanent magnet rotor (3), the hybrid permanent magnet rotor (3) being rotatably connected to the inner side of the stator (1), the hybrid permanent magnet rotor (3) comprising a rotor core (31), a plurality of magnetic pole assemblies being mounted on the rotor core (31), and the plurality of magnetic pole assemblies being uniformly arranged in the circumferential direction; The magnetic pole assembly comprises a first hybrid permanent magnet unit arranged in a parallel magnetic circuit and a second hybrid permanent magnet unit arranged in a series magnetic circuit, wherein an angle opening outward is formed between the first hybrid permanent magnet unit and the second hybrid permanent magnet unit, and the first hybrid permanent magnet unit and the second hybrid permanent magnet unit are alternately arranged on the outside of the rotor core (31); The first hybrid permanent magnet unit comprises a first permanent magnet (32) and a second permanent magnet (33), wherein a parallel magnetic circuit is formed between the first permanent magnet (32) and the second permanent magnet (33); The second hybrid permanent magnet unit includes a third permanent magnet (34) and a fourth permanent magnet (35), and a series magnetic circuit is formed between the third permanent magnet (34) and the fourth permanent magnet (35); The number of the first hybrid permanent magnet units is equal to that of the second hybrid permanent magnet units, and the first hybrid permanent magnet units and the second hybrid permanent magnet units respectively constitute the N pole and S pole of the same magnetic pole assembly; In the same magnetic pole assembly, the first permanent magnet (32) and the second permanent magnet (33) are both magnetized along the tangential direction, and the third permanent magnet (34) and the fourth permanent magnet (35) are both magnetized along the tangential direction.

2. The same-pole asymmetric magnetic circuit permanent magnet memory motor according to claim 1, characterized in that: The first permanent magnet (32) and the second permanent magnet (33) are both mounted on the side wall of the rotor core (31).

3. The same-pole asymmetric magnetic circuit permanent magnet memory motor according to claim 2, characterized in that: The third permanent magnet (34) and the fourth permanent magnet (35) are both mounted on the side wall of the rotor core (31).

4. The same-pole asymmetric magnetic circuit permanent magnet memory motor according to claim 3, characterized in that: The first permanent magnet (32) and the fourth permanent magnet (35) are neodymium iron boron permanent magnets, and the second permanent magnet (33) and the third permanent magnet (34) are aluminum nickel cobalt permanent magnets.

5. The same-pole asymmetric magnetic circuit permanent magnet memory motor according to claim 4, characterized in that: When the magnetization directions of the first permanent magnet (32), the second permanent magnet (33), the third permanent magnet (34) and the fourth permanent magnet (35) are all the same, the motor is in a forward magnetization state; otherwise, the motor is in a reverse magnetization state.

6. The homopolar asymmetric magnetic circuit permanent magnet memory motor according to claim 5, characterized in that: The stator (1) comprises a stator yoke (11), stator teeth (12) are arranged between the stator yoke (11) and the hybrid permanent magnet rotor (3), and stator slots (13) are formed between two adjacent stator teeth (12).

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