阅读说明：本技术 不对称型变磁通记忆电机 (Asymmetric variable flux memory motor ) 是由 华浩 周子成 于 2021-08-20 设计创作，主要内容包括：本发明提供了一种不对称型变磁通记忆电机,包括定子铁心、定子绕组、转子铁心、低矫顽力可变磁通永磁体；所述定子绕组安装在所述定子铁心上,所述低矫顽力可变磁通永磁体安装在所述转子铁心上,所述不对称型变磁通记忆电机所具有的转子的一对或多对磁极上设置有低矫顽力可变磁通永磁体,低矫顽力可变磁通永磁体的中心线与转子磁极中心轴线不重合；本发明所述的不对称型变磁通记忆电机,由于低矫顽力可变磁通永磁体的中心线与转子磁极中心轴线不重合,且在电机转子正向旋转情况下交轴电枢反应磁场将正向流过低矫顽力可变磁通永磁体,故所述不对称型变磁通记忆电机可以在正向旋转情况下避免交轴电枢电流造成的意外退磁问题。(The invention provides an asymmetric variable magnetic flux memory motor, which comprises a stator iron core, a stator winding, a rotor iron core and a low-coercivity variable magnetic flux permanent magnet, wherein the stator iron core is arranged on the rotor iron core; the asymmetric variable magnetic flux memory motor is characterized in that the stator winding is arranged on the stator iron core, the low-coercive-force variable magnetic flux permanent magnet is arranged on the rotor iron core, the low-coercive-force variable magnetic flux permanent magnet is arranged on one or more pairs of magnetic poles of a rotor of the asymmetric variable magnetic flux memory motor, and the central line of the low-coercive-force variable magnetic flux permanent magnet is not overlapped with the central axis of the magnetic poles of the rotor; according to the asymmetric variable magnetic flux memory motor, the central line of the low-coercivity variable magnetic flux permanent magnet is not overlapped with the central axis of the rotor magnetic pole, and the cross-axis armature reaction magnetic field flows through the low-coercivity variable magnetic flux permanent magnet in the forward direction under the condition that the motor rotor rotates in the forward direction, so that the asymmetric variable magnetic flux memory motor can avoid the problem of accidental demagnetization caused by cross-axis armature current under the condition of forward rotation.)

1. An asymmetric variable magnetic flux memory motor is characterized by comprising a stator iron core (1), a stator winding (2), a rotor iron core (3) and a low-coercive-force variable magnetic flux permanent magnet (4);

the stator winding (2) is arranged on the stator iron core (1), the low-coercivity variable magnetic flux permanent magnet (4) is arranged on the rotor iron core (3), the low-coercivity variable magnetic flux permanent magnet (4) is arranged on one or more pairs of magnetic poles of a rotor of the asymmetric variable magnetic flux memory motor, and the central line of the low-coercivity variable magnetic flux permanent magnet (4) is not overlapped with the central axis of the magnetic poles of the rotor;

a first gap is formed between the stator core (1) and the rotor core (3).

2. The asymmetric variable flux memory motor according to claim 1, further comprising a high coercive force constant flux permanent magnet (5), the low coercive force variable flux permanent magnet (4) and the high coercive force constant flux permanent magnet (5) being mounted on the rotor core (3);

each magnetic pole of a rotor on the asymmetric variable magnetic flux memory motor is provided with a low-coercivity variable magnetic flux permanent magnet (4) and a high-coercivity constant magnetic flux permanent magnet (5); or only a part of the rotor magnetic poles are provided with the low-coercivity variable magnetic flux permanent magnet (4) and the high-coercivity constant magnetic flux permanent magnet (5), and only the high-coercivity constant magnetic flux permanent magnet (5) is arranged on the rest rotor magnetic poles; the low-coercivity variable magnetic flux permanent magnet (4) and the high-coercivity constant magnetic flux permanent magnet (5) on the same magnetic pole are connected in a parallel magnetic circuit mode;

the center line of the low-coercive-force variable-flux permanent magnet (4) is not coincident with the central axis of the rotor magnetic pole.

3. The asymmetric variable flux memory motor according to claim 1, further comprising a high coercive force constant flux permanent magnet (5), the low coercive force variable flux permanent magnet (4) and the high coercive force constant flux permanent magnet (5) being mounted on the rotor core (3); the low-coercivity variable magnetic flux permanent magnet (4) and the high-coercivity constant magnetic flux permanent magnet (5) on the same magnetic pole are connected in a parallel magnetic circuit mode; the center line of the low-coercivity variable-magnetic-flux permanent magnet (4) is not coincident with the central axis of the rotor magnetic pole;

only a part of magnetic poles of the rotor are provided with low-coercivity variable magnetic flux permanent magnets (4), and the other part of magnetic poles of the rotor are provided with low-coercivity variable magnetic flux permanent magnets (4) and high-coercivity constant magnetic flux permanent magnets (5); the residual part of the magnetic pole of the rotor is only provided with a high-coercivity constant magnetic flux permanent magnet (5);

only a part of magnetic poles of the rotor are provided with low-coercivity variable magnetic flux permanent magnets (4), and the rest of magnetic poles of the rotor are provided with high-coercivity constant magnetic flux permanent magnets (5); or

Only the low-coercivity variable magnetic flux permanent magnet (4) is arranged on one part of the magnetic poles of the rotor, and the low-coercivity variable magnetic flux permanent magnet (4) and the high-coercivity constant magnetic flux permanent magnet (5) are arranged on the rest part of the rotor.

4. An asymmetric type variable flux memory motor according to claim 1, wherein only the low coercive force variable flux permanent magnet (4) is provided on all the poles of the rotor;

the center line of the low-coercive-force variable-flux permanent magnet (4) is not coincident with the central axis of the rotor magnetic pole.

5. The asymmetric type variable flux memory motor according to any one of claims 1 to 4, wherein the asymmetric type variable flux memory motor takes an inner rotor form or an outer rotor form.

6. An asymmetric type variable flux memory motor according to any one of claims 1-4, wherein the asymmetric type variable flux memory motor takes any one of the following forms:

a radial magnetic field rotating electrical machine;

an axial magnetic field rotating electrical machine;

a linear motor.

7. An asymmetric variable flux memory motor according to any of claims 1-4, characterized in that the stator winding (2) of the motor is a multi-phase symmetric AC armature winding;

the stator winding (2) of the motor is loaded with direct-axis armature current or quadrature-axis armature current;

the stator winding (2) of the motor adopts an integer slot winding form or a fractional slot winding form.

8. An asymmetric variable flux memory motor according to any one of claims 1 to 4, wherein the low coercive force variable flux permanent magnet (4) and the high coercive force constant flux permanent magnet (5) distributed on the same rotor pole have the same magnetizing direction, but the magnetizing directions of the low coercive force variable flux permanent magnet (4) and the high coercive force constant flux permanent magnet (5) are respectively opposite to the magnetizing directions of the low coercive force variable flux permanent magnet (4) and the high coercive force constant flux permanent magnet (5) on the adjacent rotor poles.

The low-coercivity variable-flux permanent magnets (4) on two adjacent different rotor magnetic poles are opposite in magnetizing direction.

9. The asymmetric variable flux memory motor as claimed in claim 4, wherein the rotor of the asymmetric variable flux memory motor is an embedded permanent magnet structure.

10. The asymmetric variable flux memory motor according to any one of claims 1 to 3, wherein the rotor of the asymmetric variable flux memory motor has a surface-mounted permanent magnet structure or an embedded permanent magnet structure.

Technical Field

The invention relates to the field of permanent magnet synchronous motor equipment, in particular to a variable flux memory motor, and particularly relates to an asymmetric permanent magnet variable flux memory motor.

Background

Compared with the traditional motor, the permanent magnet synchronous motor has received more and more attention by virtue of the advantages of high power density, high efficiency, high power factor, high design freedom degree and the like, and becomes a mainstream scheme in a high-performance driving occasion. However, applications such as electric vehicle driving, wind power generation, and high-end machine tool spindle motors have high requirements for the rotation speed range and the constant power region range of the driving motor, and it is desirable that the motor maintain good operation performance in a wide rotation speed range.

For the permanent magnet synchronous motor, because the remanence of the adopted high-coercivity constant-flux permanent magnet is relatively stable, the no-load air gap magnetic field is basically constant, and the magnetic regulation difficulty is high. Although the field weakening control of the permanent magnet synchronous motor can be realized by loading negative direct-axis armature current along with the development of the motor control technology, the efficiency and the power factor of the motor are sacrificed by continuously applying field weakening current, and the advantages of the permanent magnet synchronous motor in the application occasions of wide rotating speed are weakened.

To address this problem, the concept of a variable flux memory motor has been proposed. Compared with a common permanent magnet synchronous motor, the variable flux memory motor has the same basic structure, and is characterized in that a special low-coercivity variable flux permanent magnet is adopted, the remanence of the variable flux permanent magnet can be adjusted on line by loading direct-axis armature current, and the permanent magnet can memorize a corresponding magnetization state after the current is removed, namely, the direct-axis armature current is utilized to complete an active magnetic adjustment function. Thus, the magnetization intensity of the low-coercivity variable-flux permanent magnet can be enhanced by loading the forward direct-axis armature current, and the no-load air gap flux density is increased, so that the motor meets the requirements of low-speed large-torque output; the magnetization intensity of the low-coercivity variable-flux permanent magnet can be weakened by loading negative direct-axis armature current, and the no-load air gap flux density is reduced, so that the motor meets the high-speed flux weakening requirement.

However, since the variable magnetic flux motor needs to be loaded with the quadrature armature current when outputting the electromagnetic torque in a normal operation, it is desirable that the magnetization state of the low coercive force variable magnetic flux permanent magnet in the variable magnetic flux motor is not affected by the quadrature armature current. Otherwise, when the motor loads the quadrature armature current and normally outputs the torque, if the cross armature reaction magnetic field causes the reduction of the magnetization intensity of the low-coercivity variable-flux permanent magnet, namely, the accidental demagnetization occurs, the torque output capability of the motor can be obviously reduced, and the comprehensive performance of the variable-flux memory motor is seriously sacrificed.

In a traditional permanent magnet synchronous motor and a variable flux memory motor, common permanent magnets or low-coercivity variable flux permanent magnets are placed on a rotor and are symmetrically distributed based on the central axis of a magnetic pole of the rotor (namely the straight axis of the rotor). At this time, the quadrature-axis armature reaction magnetic field inevitably flows into the rotor from one tangential side end of the permanent magnet and flows out of the rotor from the other tangential side end, causing the risk of accidental demagnetization of the permanent magnet at one tangential side end.

On the other hand, it is worth noting that in many motor operating situations such as electric vehicle drive, industrial drive, etc., the main rotational direction of the motor is unique, or the motor does not need to maintain the same operating performance in both rotational directions.

Patent document CN109660042B discloses a series hybrid permanent magnet flux-changing motor, which includes a stator, an armature winding wound on the stator, and a rotor core, where three permanent magnets that are not directly contacted and separately placed are provided under each pole of the rotor core, where a second permanent magnet is placed outside in a "one" shape, two first permanent magnets are placed inside in a "V" shape, the second permanent magnet is a high coercivity permanent magnet or a low coercivity permanent magnet, and the first permanent magnet is a high coercivity permanent magnet or a low coercivity permanent magnet. The scheme can improve the working point and the magnetization degree of the low-coercivity permanent magnet, improve the torque output capacity, reduce the magnetizing current of the motor, and still solve the problem of accidental demagnetization.

Disclosure of Invention

In view of the defects in the prior art, the invention aims to provide an asymmetric variable flux memory motor.

The invention provides an asymmetric variable magnetic flux memory motor which comprises a stator iron core, a stator winding, a rotor iron core and a low-coercivity variable magnetic flux permanent magnet, wherein the stator iron core is arranged on the rotor iron core;

the asymmetric variable magnetic flux memory motor is characterized in that the stator winding is arranged on the stator iron core, the low-coercive-force variable magnetic flux permanent magnet is arranged on the rotor iron core, the low-coercive-force variable magnetic flux permanent magnet is arranged on one or more pairs of magnetic poles of a rotor of the asymmetric variable magnetic flux memory motor, and the central line of the low-coercive-force variable magnetic flux permanent magnet is not overlapped with the central axis of the magnetic poles of the rotor;

a first gap is formed between the stator core and the rotor core.

Preferably, the permanent magnet rotor further comprises a high-coercivity constant-magnetic-flux permanent magnet, and the low-coercivity variable-magnetic-flux permanent magnet and the high-coercivity constant-magnetic-flux permanent magnet are both mounted on the rotor core;

each magnetic pole of a rotor on the asymmetric variable magnetic flux memory motor is provided with a low-coercivity variable magnetic flux permanent magnet and a high-coercivity constant magnetic flux permanent magnet; or only a part of the rotor magnetic poles are provided with the low-coercivity variable magnetic flux permanent magnet and the high-coercivity constant magnetic flux permanent magnet, and only the high-coercivity constant magnetic flux permanent magnet is placed on the rest rotor magnetic poles; the low-coercivity variable magnetic flux permanent magnet and the high-coercivity constant magnetic flux permanent magnet on the same magnetic pole are connected in a parallel magnetic circuit mode;

the central line of the low-coercivity variable-magnetic-flux permanent magnet is not coincident with the central axis of the rotor magnetic pole;

preferably, the permanent magnet rotor further comprises a high-coercivity constant-magnetic-flux permanent magnet, and the low-coercivity variable-magnetic-flux permanent magnet and the high-coercivity constant-magnetic-flux permanent magnet are both mounted on the rotor core; the low-coercivity variable magnetic flux permanent magnet and the high-coercivity constant magnetic flux permanent magnet on the same magnetic pole are connected in a parallel magnetic circuit mode; the center line of the low-coercivity variable-magnetic-flux permanent magnet does not coincide with the central axis of the rotor magnetic pole;

only the low-coercivity variable magnetic flux permanent magnet is arranged on one part of the magnetic poles of the rotor, and the low-coercivity variable magnetic flux permanent magnet and the high-coercivity constant magnetic flux permanent magnet are arranged on the other part of the magnetic poles of the rotor; the residual part of the magnetic pole of the rotor is only provided with a high-coercivity constant magnetic flux permanent magnet;

only low-coercivity variable magnetic flux permanent magnets are arranged on one part of magnetic poles of the rotor, and only high-coercivity constant magnetic flux permanent magnets are arranged on the rest part of magnetic poles of the rotor; or

Only the low-coercivity variable magnetic flux permanent magnet is arranged on one part of the magnetic poles of the rotor, and the low-coercivity variable magnetic flux permanent magnet and the high-coercivity constant magnetic flux permanent magnet are arranged on the rest part of the rotor.

Preferably, only the low coercive force variable magnetic flux permanent magnet is arranged on all the magnetic poles of the rotor;

the central line of the low-coercivity variable-magnetic-flux permanent magnet is not coincident with the central axis of the rotor magnetic pole;

preferably, the asymmetric variable flux memory motor is in an inner rotor form or an outer rotor form;

preferably, the asymmetric type variable flux memory motor takes any one of the following forms:

a radial magnetic field rotating electrical machine;

an axial magnetic field rotating electrical machine;

a linear motor.

Preferably, the stator winding of the motor is a multi-phase symmetrical alternating current armature winding;

the stator winding of the motor is loaded with direct-axis armature current or quadrature-axis armature current;

the stator winding of the motor adopts an integer slot winding form or a fractional slot winding form.

Preferably, the magnetizing directions of the low-coercivity variable-flux permanent magnet and the high-coercivity constant-flux permanent magnet distributed on the same rotor magnetic pole are the same, but the magnetizing directions of the low-coercivity variable-flux permanent magnet and the high-coercivity constant-flux permanent magnet are respectively opposite to the magnetizing directions of the low-coercivity variable-flux permanent magnet and the high-coercivity constant-flux permanent magnet on the adjacent rotor magnetic pole.

The low-coercivity variable-flux permanent magnets on two adjacent different rotor magnetic poles are opposite in magnetizing direction.

Preferably, the asymmetric variable flux memory motor has a rotor with an embedded permanent magnet structure.

Preferably, the asymmetric variable flux memory motor has a rotor with a surface-mounted permanent magnet structure or an embedded permanent magnet structure.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the asymmetric variable magnetic flux memory motor, the central line of the low-coercivity variable magnetic flux permanent magnet is not overlapped with the central axis of the rotor magnetic pole, and the cross-axis armature reaction magnetic field flows through the low-coercivity variable magnetic flux permanent magnet in the forward direction under the condition that the motor rotor rotates in the forward direction, so that the asymmetric variable magnetic flux memory motor can avoid the problem of accidental demagnetization caused by cross-axis armature current under the condition of forward rotation.

2. The asymmetric variable magnetic flux memory motor adopts the variable magnetic flux permanent magnet with low coercive force, so that active magnetization and active demagnetization can be completed by using direct-axis armature current pulses, and the on-line adjustment of the air gap magnetic field intensity is realized.

3. The asymmetric variable flux memory motor is based on the improvement of a permanent magnet synchronous motor, has the advantages of high power density, high efficiency, high power factor and wide application range of the permanent magnet synchronous motor, and is flexible and various in motor phase number, pole slot number matching, winding forms and the like.

4. The asymmetric variable flux memory motor has high degree of freedom of rotor structure design, and can adopt an embedded permanent magnet structure or a surface-mounted permanent magnet structure.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a cross-sectional view of 1/8 symmetrical model in accordance with example 4 of the present invention;

FIG. 2 is a schematic flow diagram of 1/8 symmetric model quadrature-axis armature reaction magnetic field according to example 4 of the present invention;

fig. 3 is a schematic diagram of the magnitude of the no-load counter electromotive force after the direct-axis or quadrature-axis armature current is loaded in embodiment 4 of the present invention.

The figures show that:

a stator core 1;

a stator winding 2;

a rotor core 3;

a low coercive force variable magnetic flux permanent magnet 4;

a high coercive force constant flux permanent magnet 5.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1:

example 1 is a basic example:

an asymmetric variable magnetic flux memory motor comprises a stator iron core 1, a stator winding 2, a rotor iron core 3 and a low-coercive-force variable magnetic flux permanent magnet 4;

the stator winding 2 is arranged on the stator core 1, the low-coercivity variable-magnetic-flux permanent magnet 4 is arranged on the rotor core 3, the low-coercivity variable-magnetic-flux permanent magnet 4 is arranged on one or more pairs of magnetic poles of a rotor of the asymmetric variable-magnetic-flux memory motor, and the central line of the low-coercivity variable-magnetic-flux permanent magnet 4 is not overlapped with the central axis of the magnetic poles of the rotor;

a first gap is provided between the stator core 1 and the rotor core 3.

The center line of the low-coercivity variable-magnetic-flux permanent magnet 4 is not coincident with the central axis of the rotor magnetic pole, namely, the low-coercivity variable-magnetic-flux permanent magnet 4 is not symmetrical along the central axis of the rotor magnetic pole, so the motor is called as an asymmetrical variable-magnetic-flux memory motor.

In a preferred example, the asymmetric variable flux memory motor further comprises a high-coercivity constant flux permanent magnet 5, and the low-coercivity variable flux permanent magnet 4 and the high-coercivity constant flux permanent magnet 5 are both mounted on the rotor core 3; each magnetic pole of a rotor on the asymmetric variable magnetic flux memory motor is provided with a low-coercivity variable magnetic flux permanent magnet 4 and a high-coercivity constant magnetic flux permanent magnet 5; or the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are arranged on only part of the rotor magnetic poles, and the high coercive force constant magnetic flux permanent magnet 5 is arranged on the rest of the rotor magnetic poles. The magnetic poles provided with the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are present in pairs, and the magnetic poles provided with only the high coercive force constant magnetic flux permanent magnet 5 are also present in pairs. For example, the rotor has 8 poles, the magnetic poles provided with the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are 2 magnetic poles that appear in pairs, and the remaining 6 magnetic poles that appear in pairs are all the magnetic poles on which only the high coercive force constant magnetic flux permanent magnet 5 is placed. The low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 on the same rotor magnetic pole are connected in a parallel magnetic circuit mode; the center line of the low coercive force variable magnetic flux permanent magnet 4 does not coincide with the rotor magnetic pole center axis. In this preferred embodiment, the rotor of the asymmetric variable flux memory motor is of a surface-mount permanent magnet structure or an embedded permanent magnet structure.

In another preferred embodiment, the asymmetric variable flux memory motor further includes a high coercive force constant flux permanent magnet 5, and the low coercive force variable flux permanent magnet 4 and the high coercive force constant flux permanent magnet 5 are both mounted on the rotor core 3; the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 on the same magnetic pole are connected in a parallel magnetic circuit mode; the central line of the low-coercivity variable-magnetic-flux permanent magnet 4 is not coincident with the central axis of the rotor magnetic pole;

only the low-coercivity variable magnetic flux permanent magnet 4 is arranged on one part of the magnetic poles of the rotor, and the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 are arranged on the other part of the magnetic poles of the rotor; the residual part of the magnetic pole of the rotor is only provided with a high-coercivity constant magnetic flux permanent magnet 5; the magnetic poles provided only with the low coercive force variable magnetic flux permanent magnets 4 are present in pairs; the magnetic poles provided with the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 also appear in pairs; the magnetic poles provided with only the high coercive force constant magnetic flux permanent magnet 5 are also present in pairs, for example, the rotor has 8 poles, the magnetic poles provided with only the low coercive force variable magnetic flux permanent magnet 4 are 2 magnetic poles present in pairs, and the magnetic poles provided with the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are 2 magnetic poles present in pairs; the remaining 4 magnetic poles appearing in pairs are magnetic poles on which only the high-coercivity constant-flux permanent magnet 5 is placed; or

Only the low-coercivity variable magnetic flux permanent magnet 4 is arranged on one part of the magnetic poles of the rotor, only the high-coercivity constant magnetic flux permanent magnet 5 is arranged on the rest magnetic poles of the rotor, and the magnetic poles only provided with the low-coercivity variable magnetic flux permanent magnets 4 appear in pairs; the magnetic poles provided only with the high coercive force constant flux permanent magnet 5 are also present in pairs; if the rotor has 8 poles, the magnetic poles only provided with the low-coercivity variable magnetic flux permanent magnets 4 are 2 magnetic poles which appear in pairs, and the remaining 6 magnetic poles which appear in pairs are all the magnetic poles only provided with the high-coercivity constant magnetic flux permanent magnets 5; or

Only the low-coercivity variable magnetic flux permanent magnet 4 is arranged on one part of the magnetic poles of the rotor, the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 are arranged on the rest part of the rotor, and the magnetic poles only provided with the low-coercivity variable magnetic flux permanent magnet 4 appear in pairs; the magnetic poles provided with the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 also appear in pairs; if the rotor has 8 poles, the magnetic poles provided with only the low coercive force variable magnetic flux permanent magnets 4 are 2 magnetic poles appearing in pairs, and the remaining 6 magnetic poles appearing in pairs are all the magnetic poles provided with the low coercive force variable magnetic flux permanent magnets 4 and the high coercive force constant magnetic flux permanent magnets 5.

In this preferred embodiment, the rotor of the asymmetric variable flux memory motor is of a surface-mount permanent magnet structure or an embedded permanent magnet structure.

In yet another preferred example, only the low coercive force variable magnetic flux permanent magnet 4 is provided on all the poles of the rotor; the central line of the low-coercivity variable-flux permanent magnet 4 is not coincident with the central axis of the rotor magnetic pole; in this preferred embodiment, the rotor of the asymmetric variable flux memory motor has an embedded permanent magnet structure.

In summary, on the rotor poles of the asymmetric variable magnetic flux memory motor, the number of the low coercive force variable magnetic flux permanent magnets 4 is flexible, and only 1 or more pairs of the low coercive force variable magnetic flux permanent magnets need to be satisfied; the total number of the high-coercivity constant-flux permanent magnets is flexible and is only required to be more than or equal to 0 pair.

The asymmetric variable flux memory motor can adopt an inner rotor form or an outer rotor form.

The stator winding 2 can be loaded with direct or quadrature armature currents.

The asymmetric variable magnetic flux memory motor adopts any one of the following forms:

a radial magnetic field rotating electrical machine;

an axial magnetic field rotating electrical machine;

a linear motor.

The stator winding 2 of the machine may be in the form of an integer slot winding or a fractional slot winding.

The stator winding 2 may be a multi-phase symmetrical ac armature winding, and particularly, the stator winding 2 is a three-phase symmetrical ac armature winding.

The magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 distributed on the same rotor magnetic pole are consistent, but the magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are respectively opposite to the magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 on the adjacent rotor magnetic poles.

The low-coercivity variable-flux permanent magnets 4 on two adjacent different rotor poles are oppositely charged.

Example 2:

example 2 is a preferred example of example 1.

All the magnetic poles of the rotor are only provided with low-coercivity variable magnetic flux permanent magnets 4;

the embodiment comprises a stator core 1, a stator winding 2, a rotor core 3 and a low-coercivity variable-flux permanent magnet 4. The stator winding 2 is arranged on a stator iron core 1, the low-coercivity variable magnetic flux permanent magnet 4 is arranged on the rotor iron core 3, each rotor magnetic pole of the asymmetric variable magnetic flux memory motor is only provided with the low-coercivity variable magnetic flux permanent magnet 4, and the central line of the low-coercivity variable magnetic flux permanent magnet 4 is not overlapped with the central axis of the rotor magnetic pole; a first gap is provided between the stator core 1 and the rotor core 3. The low-coercivity variable-flux permanent magnets 4 on two adjacent different magnetic poles on the rotor are opposite in magnetizing direction. The central axis of the rotor magnetic pole can be called as a rotor straight shaft. In this preferred embodiment, the rotor of the asymmetric variable flux memory motor has an embedded permanent magnet structure.

When the asymmetric variable magnetic flux memory motor needs to change the magnetization state of the low coercive force variable magnetic flux permanent magnet 4 to further adjust the air gap magnetic field strength, a direct axis armature current can be loaded to the stator winding 2, and a generated direct axis armature reaction magnetic field can enhance or weaken the magnetization state of the low coercive force variable magnetic flux permanent magnet 4. When the negative direction direct axis armature current is loaded, the direction of the direct axis armature reaction magnetic field is opposite to the direction of the magnetic field of the low coercive force variable magnetic flux permanent magnet 4, the magnetization state of the low coercive force variable magnetic flux permanent magnet 4 is weakened, and active demagnetization occurs. That is, in the present invention, the magnetization state of the low coercive force variable magnetic flux permanent magnet 4 can be actively adjusted using a direct axis armature current pulse of a magnetizing or demagnetizing property.

When the quadrature-axis armature current is loaded to the stator winding 2 to output electromagnetic torque, the motor rotor rotates in a certain direction, the direction is recorded as positive rotation, and the generated quadrature-axis armature reaction magnetic field flows in from one tangential side end of each rotor magnetic pole and flows out from the other tangential side end. The placing positions of the low-coercivity variable-flux permanent magnets 4 are ingeniously arranged, the positions of the low-coercivity variable-flux permanent magnets 4 relative to the central axis of the magnetic pole are included, the low-coercivity variable-flux permanent magnets 4 are designed based on the central axis of the magnetic pole of the rotor in an asymmetrical mode, the fact that the cross-axis armature reaction magnetic field only flows through the low-coercivity variable-flux permanent magnets 4 in the forward direction can be guaranteed, namely the direction of the cross-axis armature reaction magnetic field in the area is consistent with the direction of the magnetic field of the low-coercivity variable-flux permanent magnets 4, at the moment, the cross-axis armature reaction magnetic field can enhance the magnetization state of the low-coercivity variable-flux permanent magnets 4, and the cross-axis armature reaction magnetic field actually helps the low-coercivity variable-flux permanent magnets 4 to maintain the working point to avoid accidental demagnetization. However, after the placement position of the low coercive force variable magnetic flux permanent magnet 4 is determined, if the rotation direction of the motor rotor is reversed, the generated quadrature axis armature reaction magnetic field reversely flows through the low coercive force variable magnetic flux permanent magnet 4. However, it should be noted that in many motor operation occasions such as electric vehicle driving, industrial dragging, etc., the main rotation direction of the motor is unique, or the motor does not need to maintain the same operation performance in both rotation directions, so the present embodiment has greatly reduced the risk of accidental demagnetization by avoiding the accidental demagnetization when the motor rotates in the forward direction.

Example 3:

embodiment 3 is another preferred embodiment of embodiment 1. Each magnetic pole of the rotor of the asymmetric variable magnetic flux memory motor is provided with a low-coercivity variable magnetic flux permanent magnet 4 and a high-coercivity constant magnetic flux permanent magnet 5.

The main differences between example 2 and example 1 are: the permanent magnet rotor also comprises a high-coercivity constant magnetic flux permanent magnet 5, wherein the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 are arranged on the rotor core 3; each rotor magnetic pole on the asymmetric variable magnetic flux memory motor is provided with a low-coercivity variable magnetic flux permanent magnet 4 and a high-coercivity constant magnetic flux permanent magnet 5; the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 on the same magnetic pole are connected in a parallel magnetic circuit mode; the low-coercivity variable magnetic flux permanent magnets 4 are distributed in an asymmetric mode relative to the center axis of the rotor magnetic pole, and the low-coercivity variable magnetic flux permanent magnets 4 are only arranged on one side of the center axis of the rotor magnetic pole. The low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 distributed on the same magnetic pole have flexible magnetizing directions, for example, radial magnetizing may be adopted, or parallel magnetizing or other manners may be adopted, and it is noted that the magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 distributed on the same magnetic pole are the same, but the magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are respectively opposite to the magnetizing directions of the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 on the adjacent magnetic pole.

The rotor of the asymmetric variable magnetic flux memory motor adopts a surface-mounted permanent magnet structure or an embedded permanent magnet structure.

Example 4:

example 4 is a preferred example of example 3.

In this embodiment, the asymmetric variable magnetic flux memory motor is in a radial magnetic field form, the rotor is in a surface-mounted permanent magnet structure, and 48 slots of the stator/8 poles of the rotor, fig. 1 shows a schematic cross-sectional structure view of a symmetric model 1/8 in this embodiment, a stator core 1 is located outside a rotor core 3, and a physical air gap is formed between the two; the stator winding 2 is an integer slot distributed winding type three-phase symmetrical alternating current armature winding, and the stator winding 2 is arranged on the stator core 1; the low-coercivity variable-flux permanent magnet 4 and the high-coercivity constant-flux permanent magnet 5 are of surface-mounted structures, the radially magnetized low-coercivity variable-flux permanent magnet 4 can be an alnico permanent magnet, for example, and the radially magnetized high-coercivity constant-flux permanent magnet 5 can be a neodymium-iron-boron permanent magnet, for example, which are mounted in parallel on each pole of the rotor core 3, and in fig. 1, the magnetization directions of the low-coercivity variable-flux permanent magnet 4 and the high-coercivity constant-flux permanent magnet 5 are directed radially outward. The whole body formed by the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 is symmetrically arranged along the central axis of a magnetic pole, the variable magnetic flux permanent magnet 4 is only arranged on one side of the central axis of the magnetic pole of the rotor, but not arranged on the other side of the central axis of the magnetic pole of the rotor, and the lengths of the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 in the surface direction of the rotor core 3 are different, so that the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 are asymmetrically distributed in the tangential direction, and the low-coercivity variable magnetic flux permanent magnet 4 is asymmetrically distributed based on the central axis of the magnetic pole of the rotor and is only arranged on one side of the central axis of the magnetic pole of the rotor.

Example 4 ofPrinciple of operationThe following were used:

the counterclockwise rotation of the rotor in fig. 1 is defined as the positive direction of rotation of the rotor. It can be found that, when the rotor rotates in the positive direction, the low coercive force variable magnetic flux permanent magnet 4 is arranged in the direction of the leading end of the rotor in the circumferential direction of rotation, and the high coercive force constant magnetic flux permanent magnet 5 is arranged in the direction of the trailing end of the rotor in the circumferential direction of rotation, and the low coercive force variable magnetic flux permanent magnet 4 is mounted only on one side of the central axis of the rotor magnetic pole. At this time, when the quadrature armature current is applied to the stator winding 2 to output the forward electromagnetic torque, the flow direction of the quadrature armature reaction magnetic field is as shown in fig. 2, and it is found that the magnetic lines of the quadrature armature reaction magnetic field flow into the rotor from the end of the magnetic poles and flow out of the rotor from the end of the magnetic poles. In the rotor magnetic pole, the magnetizing directions of the low-coercivity variable magnetic flux permanent magnet 4 and the high-coercivity constant magnetic flux permanent magnet 5 are outward along the radial direction, namely the direction of the permanent magnets flowing out of the rotor, so that the direction of the quadrature axis armature reaction magnetic field is consistent with the direction of the magnetic field of the low-coercivity variable magnetic flux permanent magnet 4, namely the quadrature axis armature reaction magnetic field helps the low-coercivity variable magnetic flux permanent magnet 4 to maintain the magnetization state, and accidental demagnetization is avoided.

However, when the motor rotor rotates in the reverse direction, if the quadrature armature current is applied to the stator winding 2 to output the electromagnetic torque, the direction of the quadrature armature reaction magnetic field is reversed. Since the installation position and the initial magnetizing direction of the low coercive force variable magnetic flux permanent magnet 4 are not changed, the direction of the quadrature axis armature reaction magnetic field is opposite to the direction of the magnetic field of the low coercive force variable magnetic flux permanent magnet 4, that is, the quadrature axis armature reaction magnetic field tends to weaken the magnetization state of the low coercive force variable magnetic flux permanent magnet 4, and thus, accidental demagnetization is easy to occur. However, it should be noted that in many motor operation situations such as electric vehicle driving, industrial dragging, etc., the main rotation direction of the motor is unique, or the motor does not need to maintain the same operation performance in both rotation directions, and the rotation direction of the asymmetric flux change memory motor is unique or set to be unique, so the present embodiment has greatly reduced the risk of accidental demagnetization by avoiding accidental demagnetization when the motor rotates in the forward direction.

When the direct-axis armature current is applied to the stator winding 2 during forward rotation or reverse rotation, the generated direct-axis armature reaction magnetic field flows through the low-coercive-force variable-flux permanent magnet 4 in the forward direction or the reverse direction, that is, the direction of the direct-axis armature reaction magnetic field is consistent with or opposite to the magnetization direction of the low-coercive-force variable-flux permanent magnet 4, so that the effect of the direct-axis armature reaction magnetic field on enhancing or weakening the magnetization state of the low-coercive-force variable-flux permanent magnet 4 is achieved. Specifically, when a positive direct-axis armature current is loaded, the direction of the direct-axis armature reaction magnetic field is consistent with the direction of the magnetic field of the low-coercive-force variable-magnetic-flux permanent magnet 4, and the magnetization state of the low-coercive-force variable-magnetic-flux permanent magnet 4 is enhanced, that is, active magnetization occurs; when negative direct-axis armature current is loaded, the direction of a direct-axis armature reaction magnetic field is opposite to the direction of the magnetic field of the low-coercivity variable-magnetic-flux permanent magnet 4, and the magnetization state of the low-coercivity variable-magnetic-flux permanent magnet 4 is weakened, namely, active demagnetization occurs.

To better illustrate the implementation effect of the invention, fig. 3 shows the change of the magnitude of the no-load back emf fundamental wave after loading the quadrature-axis armature current or the reverse direct-axis armature current in the embodiment 3. In fig. 3, the abscissa represents the magnitude of the loaded armature current, and the ordinate represents the magnitude of the no-load counter potential of the armature winding after the armature current is loaded and removed. The three sets of curves in fig. 3 represent: loading negative direct axis armature current under the condition that the rotor rotates in the positive direction to carry out active demagnetization, and then obtaining the back electromotive force; the counter electromotive force after the quadrature axis armature current is loaded under the condition that the rotor rotates in the positive direction is large; and the counter electromotive force after accidental demagnetization of the loaded quadrature axis armature current under the condition of reverse rotation of the rotor.

As shown in fig. 3, the loaded negative direct-axis armature current can effectively reduce the no-load back electromotive force of the motor, and a good active demagnetization effect is realized to improve the high-speed weak magnetic performance. When the motor rotates in the positive direction and the quadrature axis armature current is loaded to output the electromagnetic torque, the no-load counter electromotive force of the motor is basically kept constant, namely the magnetization state of the low-coercive variable-flux permanent magnet 4 is kept stable, and accidental demagnetization cannot occur, so that the power density and the loading capacity of the motor are favorably improved. When the motor rotates in the opposite direction, the loaded quadrature axis armature current can obviously reduce the no-load back electromotive force of the motor, namely, the unexpected demagnetization occurs, namely, the loading capacity of the motor in the rotating direction is weaker.

Example 5

Example 5 is a variation of example 4.

The structure of the variable magnetic flux memory motor is basically the same as that of the asymmetric variable magnetic flux memory motor in embodiment 3, and the difference is that the rotor adopts an embedded permanent magnet structure, namely, a slot is formed in the rotor core 3, the low coercive force variable magnetic flux permanent magnet 4 and the high coercive force constant magnetic flux permanent magnet 5 are embedded in the slot of the rotor core 3, and the corresponding magnetizing directions can adopt parallel magnetizing. It is emphasized that within each rotor pole, the low coercive force variable magnetic flux permanent magnet 4 is placed asymmetrically with respect to the pole center axis, and the low coercive force variable magnetic flux permanent magnet 4 is only on a single side of the rotor pole center axis. Thus, under the condition of forward rotation, the direction of the quadrature-axis armature reaction magnetic field can be consistent with the magnetic field direction of the low-coercivity variable-magnetic-flux permanent magnet 4, the low-coercivity variable-magnetic-flux permanent magnet 4 is helped to maintain the working point, and accidental demagnetization is avoided.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.