Asymmetric multi-magnetic-circuit variable-flux memory motor with magnetic field offset effect

Abstract

The invention discloses an asymmetric multi-magnetic-circuit variable-flux memory motor with a magnetic field offset effect, which comprises a stator, an armature winding and a rotor, the rotor comprises a plurality of poles, each pole is provided with a first permanent magnet layer and a second permanent magnet layer, the first permanent magnet layer comprises a plurality of first low-coercivity permanent magnets, and the second permanent magnet layer comprises a plurality of second low-coercivity permanent magnets. The second layer of permanent magnets comprises high-coercive-force permanent magnets and second low-coercive-force permanent magnets, and the first layer of permanent magnets of each pole are located between the high-coercive-force permanent magnets and the second low-coercive-force permanent magnets of the second layer of permanent magnets of the pole; and the high-coercivity permanent magnets of the second layer of permanent magnets of each pole are adjacent to the second low-coercivity permanent magnets of the second layer of permanent magnets of the adjacent pole. Through the double-layer permanent magnet structure and the asymmetric magnetic circuit design, the problems of magnetic flux saturation and sharp output torque drop of the conventional symmetric magnetic circuit memory motor in a weak magnetic state are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of permanent magnet synchronous motors, and in particular relates to an asymmetric multi-magnetic circuit variable flux memory motor with a magnetic field offset effect. Background Art

[0002] In recent years, with the development of new energy technologies and the growing demand for high-efficiency motors, variable flux memory motors have been increasingly used in electric vehicles, industrial automation, smart homes and other fields. Variable flux memory motors have become one of the research hotspots because they can adjust the magnetic circuit state under different working conditions, showing excellent efficiency adjustment capabilities and outstanding performance stability.

[0003] Traditional variable flux memory motor designs mostly use a symmetrical magnetic circuit structure, which is a relatively mature structural design that can provide reliable performance in a variety of application scenarios. The advantages of the symmetrical magnetic circuit design are that it has a simple structure, is easy to manufacture and control, and exhibits good consistency and controllability in terms of magnetization and magnetic stabilization. However, with the complexity of application scenarios and the improvement of motor performance requirements, the bottlenecks of existing symmetrical magnetic circuit memory motors under some specific working conditions are gradually emerging.

[0004] In general, the bottleneck of existing symmetrical magnetic circuit memory motors is mainly concentrated on the problem of magnetic flux saturation in the weak magnetic state. This magnetic flux saturation limits the magnetic adjustment range of the motor, which means that the memory motor still has considerable potential for improvement in this regard. In addition, compared with the magnetic flux enhancement state, the output torque of the memory motor in the magnetic flux weakening state drops sharply, resulting in a relatively narrow working area in the weak magnetic state, which in turn weakens the efficiency improvement benefit of the magnetization work in the high-speed zone. Summary of the invention

[0005] The main purpose of the present invention is to provide an asymmetric multi-magnetic circuit variable flux memory motor with a magnetic field offset effect to solve the problems of magnetic flux saturation and a sharp drop in output torque in the existing symmetrical magnetic circuit memory motor under weak magnetic state, thereby improving the efficiency of the motor's magnetic adjustment range and high-efficiency working area.

[0006] To achieve the aforementioned invention objectives, the technical solution adopted by the present invention includes: an asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect, including a stator, an armature winding and a rotor, the armature winding is wound on the stator, and the rotor is located on the inner side of the stator and rotates relative to the stator; the rotor includes a plurality of poles arranged on the rotor core, the plurality of poles are evenly distributed on the rotor core along the circumference of the rotor shaft, each pole is provided with a first layer of permanent magnets and a second layer of permanent magnets, the first layer of permanent magnets includes a plurality of first low coercive force permanent magnets, the second layer of permanent magnets includes high coercive force permanent magnets and second low coercive force permanent magnets, the first layer of permanent magnets of each pole is located between the high coercive force permanent magnets and the second low coercive force permanent magnets of the second layer of permanent magnets of the pole, and the high coercive force permanent magnets of the second layer of permanent magnets of each pole are arranged adjacent to the second low coercive force permanent magnets of the second layer of permanent magnets of the adjacent pole.

[0007] In a preferred embodiment, the low coercive force permanent magnets of the first layer of permanent magnets and the second layer of permanent magnets of each pole change their magnetization states under the action of the d-axis pulse current, and the low coercive force permanent magnets of the first layer of permanent magnets of each pole together with the high coercive force permanent magnets of the same level or the adjacent pole, the low coercive force permanent magnets of the second layer of permanent magnets and the high coercive force permanent magnets of the adjacent pole form multiple series magnetic circuit structures to achieve different motor operating states.

[0008] In a preferred embodiment, the second low-coercive force permanent magnet of the second permanent magnetic layer of each pole also forms a parallel magnetic circuit structure with the high-coercive force permanent magnet of the pole.

[0009] In a preferred embodiment, when the motor is in a weak magnetic field operating state, the magnetization directions of the first low coercive force permanent magnet of the first permanent magnet layer and the high coercive force permanent magnet of the second permanent magnet layer are opposite, and the magnetization directions of the second low coercive force permanent magnet of the second permanent magnet layer and its high coercive force permanent magnet are also opposite.

[0010] In a preferred embodiment, the second layer of permanent magnets of each pole is designed as a V-shaped permanent magnet with an opening expanding outward, and the high coercive force permanent magnets and the second low coercive force permanent magnets of the second layer of permanent magnets are both in a straight line extending in the direction of the motor shaft.

[0011] In a preferred embodiment, the first layer of permanent magnets is distributed on a side close to the air gap of the motor, and the first layer of permanent magnets includes at least three first low-coercive force permanent magnets.

[0012] In a preferred embodiment, the first layer of permanent magnets is generally distributed in a U-shape that protrudes toward the rotation axis of the motor.

[0013] In a preferred embodiment, the rotor core of the motor is q An air magnetic barrier area is arranged on one side of the shaft close to the air gap.

[0014] In a preferred embodiment, the materials of the low coercive force permanent magnets of the first layer of permanent magnets and the second layer of permanent magnets are both AlNiCo; and the material of the high coercive force permanent magnets of the second layer of permanent magnets is NdFeB.

[0015] In a preferred embodiment, the stator and the rotor are connected via a magnetic circuit to form a closed link.

[0016] Compared with the prior art, the beneficial effects of the present invention are at least: 1. The present invention introduces a magnetic field offset effect in the non-magnetization state through asymmetric magnetic circuit design, reducing d Axis and q The angle between the shafts optimizes the magnetic field distribution. This design improves the torque output capacity of the motor, especially when running at high speed, showing better performance.

[0017] 2. The present invention realizes flexible magnetic adjustment of the motor under different working conditions through a double-layer permanent magnet structure and an asymmetric magnetic circuit design. The series and parallel magnetic circuit structures between the first layer of permanent magnets and the second layer of permanent magnets enable the motor to maintain efficient operation under both weak and strong magnetic conditions, significantly broadening the magnetic adjustment range.

[0018] 3. The present invention is achieved by q The rotor pole clipping structure is designed on the side of the shaft close to the air gap, which effectively reduces the torque pulsation of the motor in the multi-magnetization state and improves the stability and reliability of the motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of the magnetization state of the motor of the present invention, wherein the direction of the arrow indicates the magnetization direction of the permanent magnet; Figure 2 is a schematic diagram of the weak magnetic state of the motor of the present invention, wherein the direction of the arrow indicates the magnetization direction of the permanent magnet; Figure 3 is a magnetic flux path diagram of the motor of the present invention in a magnetization state; Figure 4 is a magnetic flux path diagram of the motor of the present invention in a weak magnetic state; Figure 5 The output torque waveform of the motor of the present invention when the motor is in a magnetizing state and a weakening magnetic state; Figure 6 It is the air gap flux density waveform of the motor of the present invention when the motor is in the magnetization state and the weakening magnetic state.

[0021] Reference numerals: 1. Stator, 11. Stator teeth, 12. Stator yoke, 2. Armature winding, 3. Rotor, 4. First layer of permanent magnets, 41 / 42 / 43. First low coercive force permanent magnets, 5. Second layer of permanent magnets, 51. Second low coercive force permanent magnets, 52. High coercive force permanent magnets, 6. Air magnetic barrier region. DETAILED DESCRIPTION

[0022] The present invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are only exemplary of the present invention, which can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be interpreted as limiting, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in virtually any appropriate detailed embodiment.

[0023] The present invention discloses an asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect. The asymmetric magnetic circuit design introduces the magnetic field offset effect in the non-magnetization state, thereby reducing d Axis and q The angle between the axes is reduced, thereby optimizing the magnetic field distribution. This design improves the torque output capacity of the motor, especially when running at high speed, showing better performance. And through the double-layer permanent magnet structure and asymmetric magnetic circuit design, the motor can be flexibly adjusted in different working conditions. The series and parallel magnetic circuit structure between the first layer of permanent magnets 4 and the second layer of permanent magnets 5 enables the motor to maintain efficient operation in both weak and strong magnetic conditions, significantly widening the magnetic adjustment range.

[0024] like Figure 1 and Figure 2 As shown, an asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect disclosed in an embodiment of the present invention specifically includes a stator 1, an armature winding 2, a rotor 3, a first layer of permanent magnets 4 and a second layer of permanent magnets 5, wherein the armature winding 2 is installed in the stator 1, the rotor 3 is located inside the stator 1 and rotates relative to the stator 1, and the first layer of permanent magnets 4 and the second layer of permanent magnets 5 are arranged on the rotor 3. The combination and configuration of these components enable the motor to have a variety of magnetic circuit structures and magnetic adjustment capabilities.

[0025] Specifically, in this embodiment, the stator 1 specifically includes a stator yoke 12 and a stator tooth 11, and the stator yoke 12 and the stator tooth 11 are both made of conventional silicon steel materials to ensure the structural strength and magnetic flux guiding capability of the stator 1. The stator yoke 12 is also provided with a stator slot (not shown), and the armature winding 2 is installed in the stator slot to generate an induced electromotive force during the operation of the motor.

[0026] The rotor 3 includes a plurality of poles, which are arranged on the rotor core (not shown) and are evenly distributed around the motor shaft on the rotor core. Each pole includes at least one first-layer permanent magnet 4 and at least one second-layer permanent magnet 5. In this embodiment, the rotor 3 includes four poles evenly distributed around the motor shaft, each pole includes a first-layer permanent magnet 4 and a second-layer permanent magnet 5, and the first-layer permanent magnet 4 and the second-layer permanent magnet 5 are specifically embedded in the rotor core. The arrangement of these permanent magnets and the selection of magnetic materials determine the magnetic circuit structure and magnetic adjustment capability of the motor. The stator and the rotor are connected by a magnetic circuit to form a closed magnetic circuit, thereby enhancing the flux control capability of the motor.

[0027] The first layer of permanent magnets 4 of each pole is distributed on one side close to the air gap of the motor, and specifically includes at least one low coercive force permanent magnet. In the present embodiment, each first layer of permanent magnets 4 specifically includes three low coercive force permanent magnets. For the convenience of description, the three low coercive force permanent magnets are defined as the first low coercive force permanent magnet 41, the first low coercive force permanent magnet 42 and the first low coercive force permanent magnet 43, wherein the first low coercive force permanent magnet 42 is located between the first low coercive force permanent magnet 41 and the first low coercive force permanent magnet 43, and each first layer of permanent magnets 4 is U-shaped as a whole, specifically protruding toward the direction close to the center of the shaft.

[0028] The second layer of permanent magnets 5 of each pole specifically includes at least one high coercive force permanent magnet and at least one low coercive force permanent magnet. In this embodiment, the second layer of permanent magnets 5 of each pole specifically includes a second low coercive force permanent magnet 51 and a high coercive force permanent magnet 52, and the second layer of permanent magnets 5 in each pole is designed as a V-shaped permanent magnet with an opening expanding outward, wherein the high coercive force permanent magnet 52 and the second low coercive force permanent magnet 51 are both in a straight line extending in the direction of the rotating shaft of the motor. The first layer of permanent magnets 4 of each pole is located between the high coercive force permanent magnet 52 and the second low coercive force permanent magnet 51 of the second layer of permanent magnets 5 of the pole, and the high coercive force permanent magnet 52 of the second layer of permanent magnets 5 of each pole is arranged adjacent to the second low coercive force permanent magnet 51 of the second layer of permanent magnets 5 of the adjacent pole. That is, the adjacent poles are spaced in the order of high coercive force permanent magnet 52, first layer permanent magnet 4, second low coercive force permanent magnet 51, high coercive force permanent magnet 52, first layer permanent magnet 4, second low coercive force permanent magnet 51.

[0029] The motor of the present invention realizes the switching of multiple magnetic circuit structures through the ingenious magnetic circuit design between the first layer of permanent magnets 4 and the second layer of permanent magnets 5, and these magnetic circuit structures can be dynamically adjusted according to the operating state of the motor, so as to realize different magnetization states and magnetic flux distributions. Specifically, the low coercive force permanent magnets of the first layer of permanent magnets 4 and the second layer of permanent magnets 5 of each pole change their magnetization states under the action of the d-axis pulse current, and through magnetic coupling, the low coercive force permanent magnets 41 of the first layer of permanent magnets 4 of each pole are all connected with the high coercive force permanent magnets 52 of the same level or the adjacent pole, and the low coercive force permanent magnets 51 of the second layer of permanent magnets 5 and the high coercive force permanent magnets 52 of the adjacent poles form a plurality of series magnetic circuit structures to realize different motor operating states. Specifically, as in this embodiment, the three first low-coercive force permanent magnets 41 of each pole can respectively form a plurality of series magnetic circuit structures with the high-coercive force permanent magnets 52 of the pole or the adjacent pole, and the second low-coercive force permanent magnet 51 can also form a series magnetic circuit structure with the high-coercive force permanent magnet 52 of the adjacent pole. d Under the action of the axial pulse current, the magnetization states of the first low coercive force permanent magnet 41, the first low coercive force permanent magnet 42, the first low coercive force permanent magnet 43 and the second low coercive force permanent magnet 51 can be changed, thereby adjusting the magnetic flux distribution of the motor. This design not only enhances the load magnetic stabilization capability of the motor, but also effectively reduces the torque pulsation.

[0030] The second low coercive force permanent magnet 51 of the second permanent magnetic layer 5 of each pole can independently form a parallel magnetic circuit structure with the high coercive force permanent magnet 52 of the pole. The existence of the multi-magnetic circuit structure can significantly improve the magnetic adjustment capability of the motor.

[0031] Specifically, when the motor is in operation, the magnetization directions of the three first low-coercive force permanent magnets 41, 42, 43 of the first layer of permanent magnets 4 and the second low-coercive force permanent magnet 51 of the second layer of permanent magnets 5 can be changed by pulse current, so that the motor is in a strong magnetic state or a weak magnetic state. Specifically, when the motor is in a strong magnetic state, the magnetization direction of the low-coercive force permanent magnets 41, 42, and 43 of the first layer of permanent magnets 4 is the same as the magnetization direction of the high-coercive force permanent magnet 52 of the second layer of permanent magnets 5 by pulse current, and the magnetization direction of the second low-coercive force permanent magnet 51 of the second layer of permanent magnets 5 is also the same as the magnetization direction of the high-coercive force permanent magnet 52 thereof. Figure 3 Schematic diagram of the distribution of the magnetic lines of force of the motor in the magnetization state. At this time, the magnetic flux convergence direction of the three first low-coercive force permanent magnets of the first layer of permanent magnets 4 and the second low-coercive force permanent magnets 51 of the second layer of permanent magnets 5 is the same as the magnetic flux convergence direction of the high-coercive force permanent magnets 52 of the second layer of permanent magnets 5, ensuring the efficient operation of the motor.

[0032] When the motor is in a weak magnetic state, a pulse current is used to make the magnetizing direction of the first low coercive force permanent magnets 41, 42 and 43 of the first layer of permanent magnets 4 opposite to the magnetizing direction of the high coercive force permanent magnet 52 of the second layer of permanent magnets 5, thereby forming a magnetic flux short circuit. At the same time, the magnetizing direction of the second low coercive force permanent magnet 51 of the second layer of permanent magnets 5 is also opposite to that of the high coercive force permanent magnet 52. Figure 4 This is a schematic diagram of the distribution of the motor's magnetic field lines in a weak magnetic state. At this time, the flux convergence directions of the three first low coercive force permanent magnets of the first layer of permanent magnets 4 and the second low coercive force permanent magnets 51 of the second layer of permanent magnets 5 are opposite to the flux convergence directions of the high coercive force permanent magnets 52 of the second layer of permanent magnets 5, which helps the motor to achieve sufficient short-circuiting of the permanent magnetic flux in a weak magnetic state, thereby significantly reducing the air gap flux and effectively widening the magnetic adjustment range of the motor.

[0033] Another example Figure 5 As shown in FIG. 1 , the output torque waveform of the motor of the present invention in the magnetizing state and the weak magnetic state is shown. It can be seen from the figure that compared with the magnetizing state, the torque of the motor in the weak magnetic state is reduced to a certain extent, which is due to the decrease in the air gap magnetic flux amplitude. Figure 6 As shown, the air gap flux density waveform of the motor of the present invention is in the magnetization state and the weak magnetic state. It can be seen from the figure that the air gap flux density fundamental wave of the motor in the magnetization state is significantly higher than that in the low magnetization state, which proves that the proposed motor can achieve a wider magnetic adjustment range.

[0034] In addition, in the present embodiment, the three first low coercive force permanent magnets 41, 42, 43 of the first layer of permanent magnets 4 and the second low coercive force permanent magnet 51 of the second layer of permanent magnets 5 are made of the same material, namely, aluminum nickel cobalt, so as to realize flexible adjustment of the magnetic circuit; the material of the high coercive force permanent magnet 52 in the second layer of permanent magnets 5 is neodymium iron boron, so as to provide greater magnetic field strength and stable magnetic load capacity.

[0035] Since the present invention adopts an asymmetric magnet arrangement structure, there is a magnetic field offset effect inside the motor in the non-magnetization state. Specifically, this offset effect can reduce the d Axis and q The angle between the axes is reduced, thereby optimizing the magnetic field distribution of the motor and improving the torque output.

[0036] More preferably, the present invention is in the rotor core of the motor q The shaft is designed with pole cutting on the side close to the air gap. q An air magnetic barrier area 6 is provided on the side of the shaft close to the air gap. This design increases the air gap length from the rotor to the stator, forms an air magnetic barrier, increases the sinusoidality of the air gap, and can effectively reduce the torque pulsation of the motor and improve the stability and reliability of the motor under complex working conditions.

[0037] The present invention has the following advantages: 1. The present invention introduces a magnetic field offset effect in a non-magnetization state through an asymmetric magnetic circuit design, thereby reducing d Axis and q The angle between the two axes is optimized to optimize the magnetic field distribution. This design improves the torque output capacity of the motor, especially when running at high speeds, showing better performance. 2. The present invention realizes flexible magnetic adjustment of the motor under different working conditions through a double-layer permanent magnet structure and an asymmetric magnetic circuit design. The series and parallel magnetic circuit structures between the first layer of permanent magnets and the second layer of permanent magnets enable the motor to maintain high efficiency in both weak and strong magnetic conditions, significantly broadening the magnetic adjustment range. 3. The present invention achieves flexible magnetic adjustment of the motor under different working conditions through a double-layer permanent magnet structure and an asymmetric magnetic circuit design. The series and parallel magnetic circuit structures between the first layer of permanent magnets and the second layer of permanent magnets enable the motor to maintain high efficiency in both weak and strong magnetic conditions, significantly broadening the magnetic adjustment range. q The rotor pole clipping structure is designed on the side of the shaft close to the air gap, which effectively reduces the torque pulsation of the motor in the multi-magnetization state and improves the stability and reliability of the motor operation.

[0038] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0039] The use of headings and sections in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.

Claims

1. An asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect, characterized in that: The motor includes a stator, an armature winding and a rotor, wherein the armature winding is wound on the stator, and the rotor is located on the inner side of the stator and rotates relative to the stator; the rotor includes a plurality of poles arranged on a rotor core, wherein the plurality of poles are evenly distributed on the rotor core along the circumference of the rotor shaft, and each pole is provided with a first layer of permanent magnets and a second layer of permanent magnets, wherein the first layer of permanent magnets includes a plurality of first low-coercive force permanent magnets, and the second layer of permanent magnets includes high-coercive force permanent magnets and second low-coercive force permanent magnets, and the first layer of permanent magnets of each pole is located between the high-coercive force permanent magnets and the second low-coercive force permanent magnets of the second layer of permanent magnets of the pole, and the high-coercive force permanent magnets of the second layer of permanent magnets of each pole are arranged adjacent to the second low-coercive force permanent magnets of the second layer of permanent magnets of the adjacent pole.

2. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The low-coercive force permanent magnets of the first layer of permanent magnets and the second layer of permanent magnets of each pole change their magnetization states under the action of the d-axis pulse current, and the low-coercive force permanent magnets of the first layer of permanent magnets of each pole together with the high-coercive force permanent magnets of the same level or the adjacent pole, the low-coercive force permanent magnets of the second layer of permanent magnets and the high-coercive force permanent magnets of the adjacent pole form multiple series magnetic circuit structures to achieve different motor operating states.

3. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 2, characterized in that: The second low-coercive force permanent magnet of the second permanent magnetic layer of each pole also forms a parallel magnetic circuit structure with the high-coercive force permanent magnet of the same level.

4. An asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to any one of claims 1 to 3, characterized in that: When the motor is in a weak magnetic field operating state, the magnetization directions of the first low coercive force permanent magnet of the first permanent magnet layer and the high coercive force permanent magnet of the second permanent magnet layer are opposite, and the magnetization directions of the second low coercive force permanent magnet of the second permanent magnet layer and the high coercive force permanent magnet are also opposite.

5. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The second layer of permanent magnets of each pole is designed as a V-shaped permanent magnet with an opening expanding outward, and the high coercive force permanent magnets and the second low coercive force permanent magnets of the second layer of permanent magnets are both in a straight line extending toward the shaft direction of the motor.

6. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The first layer of permanent magnets is distributed on a side close to the air gap of the motor, and the first layer of permanent magnets includes at least three first low-coercive force permanent magnets.

7. An asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1 or 6, characterized in that: The first layer of permanent magnets is generally distributed in a U-shape protruding toward the rotation axis of the motor.

8. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The rotor core of the motor is q An air magnetic barrier area is arranged on one side of the shaft close to the air gap.

9. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The materials of the low coercive force permanent magnets of the first layer of permanent magnets and the second layer of permanent magnets are both AlNiCo; the material of the high coercive force permanent magnets of the second layer of permanent magnets is NdFeB.

10. The asymmetric multi-magnetic circuit variable flux memory motor with magnetic field offset effect according to claim 1, characterized in that: The stator and the rotor are connected via a magnetic circuit to form a closed link.

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