A dual-rotor hybrid excitation flux-switching permanent magnet motor with double-C staggered teeth and leakage flux control

Abstract

This invention relates to the field of permanent magnet motor technology, and more particularly to a dual-rotor hybrid excitation flux-switching permanent magnet motor with double-C staggered tooth and leakage flux control. It includes an outer rotor, a middle stator, and an inner rotor, with the middle stator positioned between the outer and inner rotors. The outer rotor has a plurality of first salient poles evenly distributed, and the inner rotor has a plurality of second salient poles evenly distributed. The middle stator includes m double-C staggered tooth iron cores, m rectangular leakage magnet cores, n tangentially magnetized Type I permanent magnets, an armature winding, a first set of excitation windings, and a second set of excitation windings. This invention not only retains the advantages of a compact structure and high efficiency of a dual-rotor flux-switching permanent magnet motor, but also, through the addition of the electrically excited excitation windings, makes the air gap magnetic field smooth and adjustable, effectively solving the problem of magnetic field coupling when the inner and outer motors work simultaneously. This also broadens the speed regulation range when the inner and outer motors work individually to a certain extent. Furthermore, the addition of leakage magnet cores solves the problem of strong permanent magnet magnetomotive force and difficulty in weakening the magnetomotive force.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, and in particular to a dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control. Background Technology

[0002] The drive motor is a key power component of new energy electric vehicles, and its performance directly affects the overall vehicle performance. Currently, hybrid electric vehicles, which combine the advantages of internal combustion engine vehicles and electric vehicles, are developing extremely rapidly and have become a hot topic in new energy vehicle development. In hybrid electric vehicle research, in order to overcome the problems of complex system structure, high energy consumption, and the lack of coordination between the engine and other system components in series and parallel drive devices, research is being conducted.

[0003] Chinese patent application number 201510755061.3 proposes a dual-rotor flux-switching permanent magnet motor for vehicles, which not only inherits the advantages of flux-switching permanent magnet motors such as high power density and high reliability, but also has the advantages of dual-rotor motors such as compact structure, flexible control and diverse performance.

[0004] However, these motors use permanent magnet excitation, which has a very strong magnetomotive force, making it difficult to weaken. Furthermore, this constant magnetic field limits the adjustable range of the air gap magnetic field, restricting its speed regulation range and hindering its widespread application in wide-speed drive systems. To achieve effective adjustment of the air gap magnetic field in a dual-rotor flux-switching permanent magnet motor, Chinese patent application number 201010520285.3 proposes an internal and external dual-rotor hybrid excitation doubly salient pole motor. This motor utilizes an additional electrically excited winding to form a dual-rotor hybrid excitation flux-switching motor, achieving a wider speed regulation range while ensuring high motor efficiency.

[0005] However, this dual-rotor flux-switching permanent magnet motor shares a single stator in its geometry, and both the electrical and magnetic loads are concentrated on the middle stator. This structure theoretically leads to magnetic coupling between the inner and outer motors. This phenomenon severely affects the motor's electromagnetic performance. Therefore, low magnetic coupling becomes a prerequisite for the high-performance operation of the dual-rotor flux-switching permanent magnet motor.

[0006] It is evident that when existing dual-rotor hybrid excitation flux switching motors are applied to hybrid electric vehicles, there are still problems that urgently need to be solved, such as the effective adjustment and control of the motor's air gap magnetic field, the widening of the motor's speed range, the regulation of the permanent magnet magnetomotive force, and ensuring low magnetic coupling during motor operation. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a dual-rotor hybrid excitation flux-switching permanent magnet motor with double-C staggered teeth and leakage flux control. By controlling the magnitude and direction of the excitation current, the internal and external air gap magnetic fields of the motor are smoothly adjustable. This not only widens the speed range when the internal and external motors are working individually, but more importantly, it significantly reduces magnetic field coupling when the internal and external motors are working simultaneously. Furthermore, the addition of a leakage magnet core solves the problem of strong permanent magnet magnetomotive force and difficulty in weakening the magnetomotive force.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control includes an outer rotor, an intermediate stator and an inner rotor. The intermediate stator is located between the outer rotor and the inner rotor. A plurality of first salient poles are evenly distributed on the outer rotor and a plurality of second salient poles are evenly distributed on the inner rotor.

[0010] The intermediate stator includes m double-C staggered tooth iron cores, m rectangular leakage magnet cores, n tangentially magnetized Type I permanent magnets, armature windings, a first set of excitation windings and a second set of excitation windings.

[0011] The m double-C staggered tooth iron cores are distributed in a circumferential shape, and adjacent double-C staggered tooth iron cores are connected by a rectangular leakage magnet core; n tangentially magnetized Type I permanent magnets are distributed in a circumferential shape, and tangentially magnetized Type I permanent magnets are provided between adjacent double-C staggered tooth iron cores; the armature winding, the first set of excitation windings and the second set of excitation windings are respectively wound on the double-C staggered tooth iron cores.

[0012] Preferably, each of the double-C staggered tooth type iron cores is spliced ​​together from an inner grooved iron core, an outer grooved iron core, and a middle rectangular magnetic bridge; the inner grooved iron core and the outer grooved iron core are connected by the middle rectangular magnetic bridge, which is located at one end of the inner grooved iron core and connected to it.

[0013] Preferably, the Type I permanent magnet is a ferrite permanent magnet, which includes an inner ring Type I permanent magnet and an outer ring Type I permanent magnet. The inner ring Type I permanent magnet is disposed between two adjacent inner ring grooved iron cores, and the outer ring Type I permanent magnet is disposed between two adjacent outer ring grooved iron cores. The inner ring Type I permanent magnet and the outer ring Type I permanent magnet are staggered.

[0014] Preferably, the magnetization directions of two adjacent inner ring type I permanent magnets are opposite, and the magnetization directions of two adjacent outer ring type I permanent magnets are opposite.

[0015] Preferably, the first set of excitation windings is wound on both sides of the middle rectangular magnetic bridge; the second set of excitation windings is wound on both sides of the rectangular leakage magnetic core; the armature winding is wound on the stator pole composed of two adjacent inner ring grooved iron cores or two outer ring grooved iron cores, and the inner ring type I permanent magnet or outer ring type I permanent magnet sandwiched in the middle.

[0016] Preferably, the width of the intermediate rectangular magnetic bridge and the rectangular leakage magnetic core are both 3mm-5mm, and the height of the intermediate rectangular magnetic bridge and the rectangular leakage magnetic core are both 10mm-15mm.

[0017] Preferably, the pole arc width of the inner ring type I permanent magnet is αi, and the pole arc width of the outer ring type I permanent magnet is αo, satisfying αi≈αo.

[0018] Preferably, the first set of excitation windings and the second set of excitation windings are connected in parallel.

[0019] Preferably, the number of first salient poles on the outer rotor is 16 to 22, and the number of second salient poles on the inner rotor is 7 to 10.

[0020] By adopting the above technical solution, this invention not only prevents the significant damage to permanent magnets during rotation in traditional rotor permanent magnet motors, but also, by adding an excitation winding, compared to traditional dual-rotor hybrid excitation flux-switching permanent magnet motors, it not only solves the problem of narrow speed range when the inner and outer motors work independently, but also greatly reduces magnetic field coupling when the inner and outer motors work simultaneously, improving the utilization rate of permanent magnets and increasing motor efficiency. Furthermore, the addition of a leakage magnet core solves the difficulty of weakening the strong magnetomotive force of permanent magnets.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention sets all permanent magnets on the stator, making the motor a stator permanent magnet type dual rotor motor. It not only inherits the advantages of stator type permanent magnet motors such as high power density and high reliability, but also has the advantages of dual rotor motors such as compact structure, flexible control and diverse performance.

[0023] 2. The DC excitation winding of the present invention is placed on both sides of the magnetic bridge and both sides of the leakage magnet core, which has high space utilization and compact structure. Furthermore, the electric excitation magnetic circuit and the permanent magnet working magnetic circuit are connected in parallel and are independent of each other, which reduces excitation loss and improves motor working efficiency.

[0024] 3. By changing the magnitude and direction of the current in the first set of electric excitation windings, the present invention makes the air gap magnetic field smooth and adjustable, effectively solving the problem of magnetic field coupling when the inner and outer motors work simultaneously, and to a certain extent expanding the speed regulation range when the inner and outer motors work alone.

[0025] 4. By controlling the magnitude and direction of the current in the second set of electrically excited windings, the present invention changes the magnetic saturation level in the leakage magnet core, which can effectively solve the problem of strong permanent magnet potential and difficulty in weakening the magnet. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the motor of the present invention;

[0027] Figure 2 (a) is a schematic diagram of the structure of the double-C staggered tooth iron core of the present invention; (b) is a schematic diagram of a small unit composed of the double-C staggered tooth iron core and the surrounding permanent magnets; (c) is an overall schematic diagram of the double-C staggered tooth iron core.

[0028] Figure 3 The diagram shows the anti-coupling and leakage flux control operation principle of the internal and external motors when they are running together; (a) shows the anti-coupling operation principle of the internal and external motors when they are running together; (b) shows the operation principle of the permanent magnet circuit and leakage flux circuit when the internal and external motors are running together.

[0029] Figure 4 The diagrams show the principle of magnetization and demagnetization operation when the external motor is running alone; (a) shows the principle of magnetization operation when the external motor is running alone; (b) shows the principle of demagnetization operation when the external motor is running alone.

[0030] Figure 5 (a) is a schematic diagram of the magnetization and demagnetization operation principle of the internal motor when it is running alone; (b) is a schematic diagram of the magnetization operation principle of the internal motor when it is running alone.

[0031] Figure 6 The diagram shows the operating principle of the demagnetization and leakage flux control when the internal and external motors are running independently; (a) shows the operating principle of the demagnetization and leakage flux control when the internal motor is running independently; (b) shows the operating principle of the demagnetization and leakage flux control when the external motor is running independently. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the scope of protection of the present invention. The embodiments described in this invention are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] A dual-rotor hybrid excitation flux switching permanent magnet motor with double C staggered teeth and leakage flux control includes an outer rotor 1, an intermediate stator 2 and an inner rotor 3. The intermediate stator 2 is located between the outer rotor 1 and the inner rotor 3. A plurality of first salient poles 11 are evenly distributed on the outer rotor 1 and a plurality of second salient poles 12 are evenly distributed on the inner rotor 3.

[0034] The intermediate stator 2 includes m double-C staggered tooth iron cores 4, m rectangular leakage magnet cores 9, n tangentially magnetized Type I permanent magnets 5, armature windings 6, a first set of excitation windings 7 and a second set of excitation windings 10.

[0035] The m double-C staggered tooth iron cores 4 are distributed in a circumferential shape, and adjacent double-C staggered tooth iron cores 4 are connected by a rectangular leakage magnet core 9; n tangentially magnetized type I permanent magnets 5 are distributed in a circumferential shape, and tangentially magnetized type I permanent magnets 5 are provided between adjacent double-C staggered tooth iron cores 4; the armature winding 6, the first set of excitation windings 7 and the second set of excitation windings 10 are respectively wound on the double-C staggered tooth iron cores 4.

[0036] Specifically, each of the double-C staggered tooth type iron cores 4 is composed of an inner grooved iron core 14, an outer grooved iron core 13, and a middle rectangular magnetic bridge 8; the inner grooved iron core 14 and the outer grooved iron core 13 are connected by the middle rectangular magnetic bridge 8, which is located at one end of the inner grooved iron core 14 and connected to it.

[0037] Specifically, the Type I permanent magnet 5 is a ferrite permanent magnet. The Type I permanent magnet 5 includes an inner ring Type I permanent magnet 16 and an outer ring Type I permanent magnet 15. The inner ring Type I permanent magnet 16 is disposed between two adjacent inner ring grooved iron cores 14, and the outer ring Type I permanent magnet 15 is disposed between two adjacent outer ring grooved iron cores 13. The inner ring Type I permanent magnet 16 and the outer ring Type I permanent magnet 15 are staggered.

[0038] Specifically, the magnetization directions of two adjacent inner ring type I permanent magnets 16 are opposite, and the magnetization directions of two adjacent outer ring type I permanent magnets 15 are opposite.

[0039] In this embodiment, both the inner ring type I permanent magnet and the outer ring type I permanent magnet are set on the stator, making the motor a stator permanent magnet type dual rotor motor. It not only inherits the advantages of stator type permanent magnet motors such as high power density and high reliability, but also has the advantages of dual rotor motors such as compact structure, flexible control and diverse performance.

[0040] Specifically, the first set of excitation winding 7 is wound on both sides of the middle rectangular magnetic bridge 8; the second set of excitation winding 10 is wound on both sides of the rectangular leakage magnetic core 9; the armature winding 6 is wound on the stator pole composed of two adjacent inner ring grooved iron cores or two outer ring grooved iron cores, and the inner ring type I permanent magnet or outer ring type I permanent magnet sandwiched in the middle.

[0041] In this embodiment, the first set of excitation winding 7 and the second set of excitation winding 10 are placed on both sides of the magnetic bridge and on both sides of the leakage magnet core, which makes the space utilization rate high and the structure compact. The electric excitation magnetic circuit and the permanent magnet working magnetic circuit are connected in parallel and are independent of each other, which reduces excitation loss and improves the motor working efficiency.

[0042] By changing the magnitude and direction of the current in the first set of electrically excited windings, the air gap magnetic field becomes smooth and adjustable, effectively solving the problem of magnetic field coupling when the internal and external motors work simultaneously, and to some extent widening the speed regulation range when the internal and external motors work independently. By controlling the magnitude and direction of the current in the second set of electrically excited windings, the magnetic saturation degree in the leakage magnet core is changed, effectively solving the problem of strong permanent magnet magnetomotive force and difficulty in weakening the magnetomotive force.

[0043] Specifically, the width of the intermediate rectangular magnetic bridge 8 and the rectangular leakage magnetic core 9 is 3mm-5mm, and the height of the intermediate rectangular magnetic bridge 8 and the rectangular leakage magnetic core 9 is 10mm-15mm.

[0044] Specifically, the pole arc width of the inner ring type I permanent magnet is αi, and the pole arc width of the outer ring type I permanent magnet is αo, satisfying αi≈αo.

[0045] Specifically, the first set of excitation windings 7 and the second set of excitation windings 10 are connected in parallel.

[0046] Specifically, the number of first salient poles 11 on the outer rotor 1 is 16 to 22, and the number of second salient poles 12 on the inner rotor 3 is 7 to 10.

[0047] Example

[0048] like Figure 1 As shown, in the intermediate stator structure of this motor, double-C staggered silicon steel sheets are connected by leakage magnet cores and arranged alternately with ferrite permanent magnets.

[0049] like Figure 2 As shown in (a), this is a small unit consisting of a double-C staggered tooth iron core and surrounding permanent magnets. Figure 2 As shown in (b), the stator core is formed by splicing the middle rectangular magnetic bridge 8 in the double C staggered tooth type core 4 with the rectangular leakage magnetic core 9 that connects the adjacent double C staggered tooth cores. The rectangular leakage magnetic core 9 not only provides space to wind the second set of excitation windings, but also plays a role in strengthening the mechanical strength of the stator.

[0050] Specifically, when the internal and external motors work simultaneously, such as Figure 3 As shown in (a), the first excitation winding 7 and the second excitation winding 10 are supplied with excitation currents in the same direction. The outer solid line represents the magnetic flux path of the outer permanent magnet, and the inner solid line represents the magnetic flux path of the inner permanent magnet. The two do not affect each other. Figure 3 As shown in (b), the first set of excitation windings 7 and the second set of excitation windings 10 are supplied with excitation currents in opposite directions. The outer solid line is the magnetic flux path of the outer permanent magnet, the inner solid line is the magnetic flux path of the inner permanent magnet, and the two closed dashed lines are the leakage magnetic paths generated by the inner and outer permanent magnets, respectively.

[0051] Therefore, by controlling the magnitude and direction of the current in the two sets of excitation windings, the magnetic saturation of the rectangular magnetic bridge and the leakage magnetic core can be changed, which not only effectively prevents the magnetic coupling phenomenon between the internal and external motors, but also achieves the effect of weakening the field and increasing speed as needed.

[0052] When the excitation current flowing through the first set of excitation windings is positive and the leakage magnet core is saturated, such as Figure 4 (a) and Figure 5 As shown in (a), the solid line represents the permanent magnet flux path, and the dashed line represents the excitation flux path. Both are in the same direction. The excitation flux and the permanent magnet flux together form and enhance the air gap magnetic field, and the motor operates in magnetization mode. At the same rotor position, changing the direction of the excitation current, i.e., making the excitation current flowing through the excitation winding negative, is as follows: Figure 4 (b) and Figure 5 As shown in (b), the excitation current and the permanent magnet flux are in opposite directions, and together they form and weaken the air gap magnetic field, causing the motor to operate in demagnetization mode. The excitation magnetomotive force and the permanent magnet magnetomotive force are connected in parallel on the magnetic circuit. The magnetic flux generated by the excitation winding does not directly pass through the permanent magnet, so there is no demagnetization problem. By adjusting the direction and magnitude of the excitation current, the excitation magnetic field can be changed, thereby adjusting the armature winding flux linkage and enabling the motor to operate within a wide constant power speed range.

[0053] like Figure 6 As shown in (a) and (b), the external and internal motors, respectively, in the demagnetized state, change the current direction of the second set of excitation windings to provide a path for the leakage flux of the permanent magnet, thereby reducing the effective magnetic flux generated by the permanent magnet and enabling the motor to better achieve the effect of field weakening and speed expansion.

[0054] In summary, this invention not only prevents the significant damage to permanent magnets during rotation in traditional rotor permanent magnet motors, but also, by adding an excitation winding, solves the problem of narrow speed range when the inner and outer motors operate independently compared to traditional dual-rotor hybrid excitation flux-switching permanent magnet motors. Furthermore, it greatly reduces magnetic field coupling when the inner and outer motors operate simultaneously, improving the utilization rate of the permanent magnets and increasing motor efficiency. Simultaneously, the addition of a leakage magnet core overcomes the difficulty of weakening the strong magnetomotive force of permanent magnets.

[0055] The descriptions and practices disclosed in this invention are readily apparent and understandable to those skilled in the art, and various modifications and refinements can be made without departing from the principles of this invention. Therefore, any modifications or improvements made without departing from the spirit of this invention should also be considered within the scope of protection of this invention.

Claims

1. A dual-rotor hybrid excitation flux-switching permanent magnet motor with double-C staggered teeth and leakage flux control, characterized in that, It includes an outer rotor (1), an intermediate stator (2) and an inner rotor (3). The intermediate stator (2) is located between the outer rotor (1) and the inner rotor (3). A plurality of first salient poles (11) are evenly distributed on the outer rotor (1) and a plurality of second salient poles (12) are evenly distributed on the inner rotor (3). The intermediate stator (2) includes m double C staggered tooth iron cores (4), m rectangular leakage magnet cores (9), n tangentially magnetized type I permanent magnets (5), armature windings (6), a first set of excitation windings (7) and a second set of excitation windings (10). m double-C staggered tooth iron cores (4) are distributed in a circular shape, and adjacent double-C staggered tooth iron cores (4) are connected by a rectangular leakage magnet core (9); n tangentially magnetized type I permanent magnets (5) are distributed in a circular shape, and tangentially magnetized type I permanent magnets (5) are provided between adjacent double-C staggered tooth iron cores (4); the armature winding (6), the first set of excitation windings (7) and the second set of excitation windings (10) are respectively wound on the double-C staggered tooth iron cores (4); Each of the double C staggered tooth type iron cores (4) is spliced ​​together by an inner grooved iron core (14), an outer grooved iron core (13) and a middle rectangular magnetic bridge (8); the inner grooved iron core (14) and the outer grooved iron core (13) are connected by the middle rectangular magnetic bridge (8), which is located at one end of the inner grooved iron core (14) and connected to it; The type I permanent magnet (5) is a ferrite permanent magnet. The type I permanent magnet (5) includes an inner ring type I permanent magnet (16) and an outer ring type I permanent magnet (15). The inner ring type I permanent magnet (16) is located between two adjacent inner ring grooved iron cores (14), and the outer ring type I permanent magnet (15) is located between two adjacent outer ring grooved iron cores (13). The inner ring type I permanent magnet (16) and the outer ring type I permanent magnet (15) are staggered. The magnetization directions of two adjacent inner ring type I permanent magnets are opposite, and the magnetization directions of two adjacent outer ring type I permanent magnets are opposite; The first set of excitation windings (7) is wound on both sides of the middle rectangular magnetic bridge (8); the second set of excitation windings (10) is wound on both sides of the rectangular leakage magnetic core (9); the armature winding (6) is wound on the stator pole composed of two adjacent inner ring grooved iron cores or two outer ring grooved iron cores, and the inner ring type I permanent magnet or outer ring type I permanent magnet sandwiched in the middle.

2. The dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control according to claim 1, characterized in that, The width of the intermediate rectangular magnetic bridge (8) and the rectangular leakage magnetic core (9) is 3mm-5mm, and the height of the intermediate rectangular magnetic bridge (8) and the rectangular leakage magnetic core (9) is 10mm-15mm.

3. The dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control according to claim 1, characterized in that, The inner ring type I permanent magnet (16) has a pole arc width of αi, and the outer ring type I permanent magnet (15) has a pole arc width of αo, satisfying αi≈αo.

4. The dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control according to claim 1, characterized in that, The first set of excitation windings (7) and the second set of excitation windings (10) are connected in parallel.

5. A dual-rotor hybrid excitation flux switching permanent magnet motor with double-C staggered teeth and leakage flux control according to claim 1, characterized in that, The number of first salient poles (11) on the outer rotor (1) is 16 to 22, and the number of second salient poles (12) on the inner rotor (3) is 7 to 10.

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