An asymmetric circumferentially arranged internal permanent magnet motor

Abstract

The present invention discloses an asymmetric circumferentially arranged internal permanent magnet motor, which relates to the technical field of motors. The present invention comprises: a stator, on which an armature winding is mounted; a permanent magnet rotor, which is rotatably connected to the inner side of the stator, and a rotating shaft is mounted at the center of the permanent magnet rotor; the permanent magnet rotor comprises a rotor core, on which a plurality of magnetic pole assemblies are mounted to reduce the magnetic field offset effect; every two magnetic pole assemblies are arranged as a group. By adopting an asymmetric structural design of permanent magnets, the present invention further expands the rotor structure design space, effectively reduces the amount of permanent magnets used, and enhances the asymmetric magnetic field offset effect, further improving the motor torque density.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to an asymmetric circumferentially arranged internal permanent magnet motor. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) utilize traditional rare earth permanent magnet materials with high magnetic energy products (such as neodymium iron boron), offering advantages such as high power / torque density and high efficiency. Consequently, they are widely used in a wide range of high-end equipment, including aerospace, ship propulsion, and electric vehicles. Interior permanent magnet motors, with their advantages of high efficiency, high torque density, and excellent weak magnetic properties, have been widely used in electric vehicles, wind power generation, and aerospace.

[0003] In traditional internal permanent magnet motors, there is a 90-degree electrical angle difference between the permanent magnet magnetic axis and the reluctance magnetic axis, which causes the corresponding current angle difference when the permanent magnet torque and reluctance torque reach their peak values ​​to be around 45 degrees electrical angle, resulting in problems such as limited torque utilization of the motor. To this end, we propose an asymmetric circumferentially arranged internal permanent magnet motor. Summary of the Invention

[0004] The object of the present invention is to provide an asymmetric circumferentially arranged internal permanent magnet motor, which can effectively improve the magnetic field offset effect and enable the motor to maintain a high torque density.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an asymmetric circumferentially arranged interior permanent magnet motor, comprising:

[0006] a stator, wherein an armature winding is mounted on the stator;

[0007] a permanent magnet rotor, the permanent magnet rotor being rotatably connected to the inner side of the stator, and a rotating shaft being installed at the center of the permanent magnet rotor;

[0008] The permanent magnet rotor includes a rotor core, on which a plurality of magnetic pole assemblies are mounted for reducing the magnetic field offset effect; every two magnetic pole assemblies are arranged in a group, and the two magnetic pole assemblies in the same group are distributed in a mirror-symmetrical manner, and the plurality of groups of magnetic pole assemblies are distributed in a circumferentially asymmetrical manner as a whole.

[0009] Furthermore, the magnetic pole assembly includes a plurality of magnetic barriers and a first permanent magnet and a second permanent magnet mounted on the rotor core.

[0010] Furthermore, the plurality of magnetic barriers are opened outward and are evenly distributed in the circumferential direction of the rotor core.

[0011] Furthermore, the first permanent magnet and the second permanent magnet are respectively arranged on both sides of the magnetic barrier, and an angle is formed between the first permanent magnet and the second permanent magnet.

[0012] Furthermore, the stator includes a stator yoke, stator teeth are provided between the stator yoke and the permanent magnet rotor, and a stator slot is formed between two adjacent stator teeth.

[0013] Furthermore, the armature winding is three-phase, and the armature winding is mounted on the stator teeth.

[0014] Furthermore, a series magnetic circuit is formed between the two first permanent magnets in the same group of magnetic pole assemblies that are mirror-symmetrical.

[0015] Furthermore, a parallel magnetic circuit is formed between two adjacent second permanent magnets in the two adjacent groups of magnetic pole assemblies.

[0016] Furthermore, an air gap is left between the radial inner side of the stator and the radial outer side of the permanent magnet rotor.

[0017] The present invention has at least the following beneficial effects:

[0018] 1. The present invention changes the original symmetrical V-shaped structure of the permanent magnet, so that the amount of permanent magnet on one side of the V-shaped permanent magnet is reduced, thereby effectively reducing the amount of permanent magnet, saving costs, and facilitating manufacturing.

[0019] 2. Under the premise of a certain amount of permanent magnets, the present invention reduces the magnetic field offset effect through the asymmetric design of the permanent magnets, so that the permanent magnet torque and reluctance torque components reach their maximum values ​​at relatively similar current angles, thereby improving the torque component utilization rate, thereby increasing the total output torque and improving the motor efficiency.

[0020] 3. The present invention uses an asymmetric design of the permanent magnet, which can reduce the amount of permanent magnets used under the premise of requiring a certain amount of output torque, thereby reducing the permanent magnet torque component and increasing the reluctance torque component.

[0021] 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

[0022] Figure 1 A cross-sectional structural diagram of a motor according to the present invention;

[0023] Figure 2 This is a no-load magnetic field line distribution diagram of the motor of the present invention.

[0024] Reference numerals:

[0025] 1. Stator; 11. Stator yoke; 12. Stator teeth; 13. Stator slots; 2. Armature winding; 3. Permanent magnet rotor; 31. Rotor core; 32. First permanent magnet; 33. Magnetic barrier; 34. Second permanent magnet; 4. Rotating shaft. DETAILED DESCRIPTION

[0026] 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.

[0027] The present invention introduces "asymmetric permanent magnet design" into the field of built-in permanent magnet motors, thereby proposing a new type of motor based on the magnetic field offset effect. Compared with traditional symmetrical motors, the new magnetic field offset motor can offset the permanent magnet axis through an asymmetric topology, thereby reducing the optimal current angle difference corresponding to the permanent magnet torque and reluctance torque, improving the utilization rate of the two torque components, and effectively improving the motor torque density. In order to verify the applicability of "asymmetric permanent magnet design technology" in the field of built-in permanent magnet motors, the optimal permanent magnet design scheme is explored, and its inherent torque enhancement mechanism is further explored based on the magnetic field offset effect. Based on the basic topology of a type of built-in permanent magnet motor with an asymmetric rotor design, the influence of different permanent magnet arrangements on the magnetic field offset effect and the motor torque enhancement capability is analyzed, and the optimized permanent magnet design is screened.

[0028] See also Figure 1 The present invention provides a technical solution: an asymmetric circumferentially arranged internal permanent magnet motor, comprising:

[0029] Stator 1, on which armature winding 2 is mounted;

[0030] The permanent magnet rotor 3 is rotatably connected to the inner side of the stator 1. A rotating shaft 4 is installed at the center of the permanent magnet rotor 3. The rotating shaft 4 is made of a non-magnetic material.

[0031] The permanent magnet rotor 3 includes a rotor core 31, on which multiple magnetic pole assemblies are installed to reduce the magnetic field offset effect; every two magnetic pole assemblies are set as a group, and the two magnetic pole assemblies in the same group are distributed in mirror symmetry, and the multiple groups of magnetic pole assemblies are distributed circumferentially asymmetrically as a whole.

[0032] It should be noted that the magnetic pole assembly includes multiple magnetic barriers 33 and a first permanent magnet 32 ​​and a second permanent magnet 34 installed on the rotor core 31. The multiple magnetic barriers 33 are opened outward and are evenly distributed in the circumference of the rotor core 31. The first permanent magnet 32 ​​and the second permanent magnet 34 are embedded in the left and right sides of the magnetic barriers 33. An angle is formed between the first permanent magnet 32 ​​and the second permanent magnet 34. For the technical solution of this application, the angle is an obtuse angle; the multiple magnetic barriers 33 are distributed asymmetrically in the circumferential direction as a whole, and an adjacent pair of magnetic barriers 33 are mirror-symmetrical.

[0033] Furthermore, a series magnetic circuit is formed between two mirror-symmetrical first permanent magnets 32 in the same group of magnetic pole assemblies, and a parallel magnetic circuit is formed between two adjacent second permanent magnets 34 in two adjacent groups of magnetic pole assemblies.

[0034] In addition, the stator 1 includes a stator yoke 11, and stator teeth 12 are arranged between the stator yoke 11 and the permanent magnet rotor 3. A cavity is formed between two adjacent stator teeth 12, which is a stator slot 13 for placing the three-phase armature winding 2 wound on the stator teeth 12. An air gap is left between the stator 1 and the permanent magnet rotor 3.

[0035] The operating principle of the asymmetric circumferentially arranged interior permanent magnet motor disclosed in the present invention is as follows:

[0036] The magnetic field lines of the motor are distributed as follows Figure 2 As shown, the magnetic path of the permanent magnet flux is from the permanent magnet N pole to the air gap, stator tooth 12, stator yoke 11, stator tooth 12, air gap, permanent magnet S pole in sequence, and then returns to the permanent magnet N pole through the yoke of the permanent magnet rotor 3 to form a closed path. The armature winding 2 is supplied with a three-phase AC current with the same speed as the permanent magnet rotor 3. The rotating magnetic fields formed by the stator 1 and the permanent magnet rotor 3 interact with each other, thereby generating permanent magnet torque. The difference between the quadrature and direct-axis magnetic circuits of the permanent magnet rotor 3 leads to a large difference in the quadrature and direct-axis inductances, thereby generating reluctance torque.

[0037] The magnitudes of the permanent magnet torque and the reluctance torque both vary sinusoidally with the change of the current angle, and the permanent magnet torque peak is obtained when the current angle is 0°, and the reluctance torque peak is obtained when the current angle is about 45°. The present invention uses the asymmetry of the permanent magnet to achieve the closeness of the corresponding current angles when the two peak torques are obtained, thereby improving the torque utilization rate and the total output torque, ensuring that a larger torque is output with the same amount of permanent magnets.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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. An asymmetric circumferentially arranged interior permanent magnet motor, comprising: A stator (1), wherein an armature winding (2) is mounted on the stator (1); a permanent magnet rotor (3), the permanent magnet rotor (3) being rotatably connected to the inner side of the stator (1), and a rotating shaft (4) being installed at the center of the permanent magnet rotor (3); The permanent magnet rotor (3) includes a rotor core (31), and a plurality of magnetic pole assemblies are mounted on the rotor core (31) for reducing the magnetic field offset effect; every two magnetic pole assemblies are arranged as a group, and the two magnetic pole assemblies in the same group are distributed in a mirror-image symmetric manner, and the plurality of magnetic pole assemblies are distributed in an asymmetric manner in the circumferential direction as a whole; a magnetic pole assembly is composed of a first permanent magnet (32), a second permanent magnet (34) and a magnetic barrier (33), and the plurality of magnetic barriers (33) are distributed in an asymmetric manner in the circumferential direction as a whole; the two pairs of magnetic barriers (33) in two adjacent groups of magnetic pole assemblies are in a mirror-image symmetric manner; The first permanent magnet (32) and the second permanent magnet (34) are respectively arranged on both sides of the magnetic barrier (33), and an angle is formed between the first permanent magnet (32) and the second permanent magnet (34), the angle being an obtuse angle, and the length of the first permanent magnet (32) is greater than that of the second permanent magnet (34); A series magnetic circuit is formed between two first permanent magnets (32) in the same group of magnetic pole components that are mirror-symmetrical; A parallel magnetic circuit is formed between two adjacent second permanent magnets (34) in two adjacent groups of magnetic pole assemblies.

2. The asymmetric circumferential arrangement type interior permanent magnet motor according to claim 1, characterized in that: The stator (1) comprises a stator yoke (11), stator teeth (12) are arranged between the stator yoke (11) and the permanent magnet rotor (3), and stator slots (13) are formed between two adjacent stator teeth (12).

3. The asymmetric circumferential arrangement type interior permanent magnet motor according to claim 2, characterized in that: The armature winding (2) is three-phase, and the armature winding (2) is mounted on the teeth of the stator (1).

4. The asymmetric circumferential arrangement type interior permanent magnet motor according to claim 1, characterized in that: An air gap is left between the radial inner side of the stator (1) and the radial outer side of the permanent magnet rotor (3).

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