CN113489274B - Bilateral Alternating Pole Hybrid Excitation Brushless Motor - Google Patents

Abstract

The invention discloses a bilateral alternating pole type hybrid excitation brushless motor, comprising a stator and rotor, a stator and a rotor, an armature winding and an annular DC excitation winding; the stator and rotor are arranged in parallel and parallel in the axial direction; 1 includes stator 1 and rotor 1; stator and rotor 2 includes stator 2 and rotor 2; stator 1 and stator 2 together constitute a stator, and both stator core poles and stator permanent magnet poles are evenly and alternately arranged in the circumferential direction; rotor 1 and rotor 2 share The rotor is formed, and the rotor core poles and rotor permanent magnet poles are uniformly and alternately arranged in the circumferential direction; the armature winding is wound in the stator slot; the annular DC excitation winding is arranged in the axial air gap between the first stator and the second stator. By arranging the annular DC excitation winding between the first stator and the second stator, the invention has no space constraint with the armature winding in the stator slot, and solves the mutual restriction between the output capability and the magnetic adjustment capability of the traditional stator permanent magnet type hybrid excitation motor. problem, and the magnetic modulation efficiency is high.

Description

Bilateral Alternating Pole Hybrid Excitation Brushless Motor

technical field

The invention relates to the field of motor design and manufacture, in particular to a bilateral alternating pole type hybrid excitation brushless motor.

Background technique

Permanent magnet motors have the advantages of high torque/power density, high efficiency and high power factor, and have been widely used in many occasions such as household appliances, electric vehicles and aerospace. According to the classification of permanent magnet positions, permanent magnet motors are divided into rotor permanent magnet motors and stator permanent magnet motors, both of which are unilateral permanent magnet motors.

At present, the rotor permanent magnet motor is the most commonly used. The stator permanent magnet motor has been a research hotspot for more than ten years. Its permanent magnets and armature windings are located on the stator, and there are neither windings nor permanent magnets on the rotor. Due to its simple structure, reliable operation, easy heat dissipation, and high torque density, high efficiency, and strong fault tolerance, it has a good application prospect. However, since the permanent magnet magnetic field is a constant magnetic field, both the rotor permanent magnet motor and the stator permanent magnet motor face an inherent problem—the limited ability to adjust the magnetic field.

Therefore, the hybrid excitation motor with two kinds of magnetomotive force sources (excitation winding and permanent magnet) emerges as the times require. This type of motor not only inherits the advantages of high power density and high efficiency of the permanent magnet motor, but also inherits the magnetic field regulation of the electric excitation motor. The advantage of convenience is that only lower excitation power (smaller excitation power converter) is required to achieve effective regulation of the air-gap magnetic field. Therefore, the hybrid excitation motor has great application potential in wide speed range driving occasions (such as electric vehicles) and constant voltage power generation occasions (such as aviation power supply).

Similar to the permanent magnet motor, the hybrid excitation motor can also be divided into a rotor permanent magnet type hybrid excitation motor and a stator permanent magnet type hybrid excitation motor.

For the rotor permanent magnet hybrid excitation motor, brushless excitation (note: brushes and slip rings will introduce many unfavorable factors) is a key technology. There are three main solutions: (1) With the help of additional magnetic circuits and magnetic conductive components to build Electric excitation circuit. (2) Adopt special auxiliary excitation winding and rotating rectifier to realize brushless excitation. (3) Combine the stator electric excitation motor and the rotor permanent magnet motor in parallel in the axial direction.

The DC excitation winding of the stator permanent magnet hybrid excitation motor is set in the stator slot, and the brushless excitation is simple and reliable. However, there are space constraints in the armature winding and the excitation winding, which results in the mutual restriction of the output capability and the magnetic adjustment capability of the motor.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is aimed at the deficiencies of the above-mentioned prior art, and provides a bilateral alternating pole type hybrid excitation brushless motor. There is no space constraint between it and the second stator, and the armature winding in the stator slot, which solves the problem of mutual restriction between the output capability and the magnetic regulation capability of the traditional stator permanent magnet type hybrid excitation motor. At the same time, a single annular DC excitation winding (coil) can simultaneously generate the magnetic flux of the core pole on the entire circumference, and the magnetic regulation efficiency is high.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A bilateral alternating-pole hybrid excitation brushless motor comprises a stator and rotor, a stator and rotor two, an armature winding, an annular DC excitation winding and a rotating shaft.

The first stator and rotor and the second stator and rotor are arranged in parallel and juxtaposed along the axial direction of the rotating shaft.

The first stator and the rotor include a first stator, a first rotor and an air gap arranged therebetween.

The second stator and the rotor include a second stator, a second rotor and an air gap disposed therebetween.

The first stator and the second stator together constitute a stator, and the sides of the first stator and the second stator facing the air gap are uniformly and alternately arranged with stator iron core poles and stator permanent magnet poles along the circumferential direction.

Rotor 1 and rotor 2 together constitute a rotor, and rotor iron core poles and rotor permanent magnet poles are uniformly and alternately arranged along the circumferential direction on the sides of rotor 1 and rotor 2 facing the air gap.

The armature windings are wound in the stator slots of the stator.

There is an axial air gap between the first stator and the second stator, and the annular DC excitation winding is arranged in the axial air gap.

The number of stator pole pairs _ps , the number of rotor pole pairs _pr and the number of pole pairs p _a of the armature windings satisfy the following formula:

p _r =|p _a ± _ps |

and p _s =k×Ns

Among them, k is a positive integer, and Ns is the number of stator slots.

The flux linkage generated by the permanent magnet poles of the stator in the armature winding and the flux linkage generated by the permanent magnet poles of the rotor in the armature winding should be superimposed positively. The winding flux linkage should also be superimposed in a positive direction; therefore, the first and second stators and rotors must meet the following conditions at the same time:

a. The polarities of the permanent magnet poles of stator one and rotor one are the same, and the polarities of the permanent magnet poles of stator two and rotor two are the same.

b. The polarity of the permanent magnet poles in the first stator and rotor is opposite to that of the permanent magnet poles in the second stator and rotor, and the first and second rotors are offset by a pole pitch in the circumferential direction, and the first and second rotors rotate coaxially.

c. The center line of the permanent magnet pole of the first stator is axially aligned with the center line of the permanent magnet pole of the second stator.

By controlling the current size and direction of the annular DC excitation winding, the bidirectional regulation of magnetization and weakening in the air-gap magnetic field is realized.

During magnetization, the magnetic flux direction generated by the electric excitation of the annular DC excitation winding on the iron core pole is opposite to the polarity of the adjacent permanent magnet poles; when the magnetic field is weakened, the magnetic flux direction generated by the electric excitation of the annular DC excitation winding on the iron core pole is in the opposite direction. The same polarity as the adjacent permanent magnet poles.

Adjust the size of the axial air gap between the first stator and the second stator according to the required ampere-turns of the annular DC excitation winding.

The rotating shaft adopts magnetic conductive material or non-magnetic conductive material; when the rotating shaft adopts non-magnetic conductive material, a solid magnetic conductive yoke portion of the rotor is also arranged between the rotating shaft and the rotor.

It also includes a casing set on the outer circumferences of the first stator and rotor and the second rotor, and the casing is made of magnetically conductive material or non-magnetically conductive material; A solid magnetic conducting yoke is also arranged between.

The stator slots of the first stator and the second stator are axially aligned, and the stator slots of the first stator and the second stator are axially aligned, so that the armature windings can be uniformly wound in the stator slots of the first stator and the second stator.

The permanent magnet poles in the stator and rotor are surface-mounted permanent magnets or built-in permanent magnets.

The present invention has the following beneficial effects:

1. The annular DC excitation winding of the present invention is located between the two parts of the stator, and there is no space constraint with the armature winding in the stator slot, which solves the problem that the output capability and the magnetic regulation capability of the traditional stator permanent magnet hybrid excitation motor are mutually restricted. .

2. A single annular DC excitation winding (coil) can adjust the magnetic flux of the core pole on the entire circumference at the same time, and the magnetic adjustment efficiency is high.

3. The bilateral alternating pole structure of the present invention can enhance the magnetic field modulation effect and realize the positive superposition of the armature winding phase flux linkages generated by the rotor permanent magnet and the stator permanent magnet, thereby effectively improving the torque density and power density of the motor.

4. Using the high magnetic permeability characteristics of the iron core poles on both sides of the air gap, combined with the annular DC excitation winding, the magnetic conductive casing (or the solid magnetic conductive yoke), and the rotor solid magnetic conductive yoke (or the magnetic conductive shaft), a parallel magnetic field is formed. The circuit-type hybrid excitation brushless motor not only realizes the flexible adjustment of the air gap magnetic field, but also reduces the risk of irreversible demagnetization of the permanent magnet.

Description of drawings

FIG. 1 is a three-dimensional overall view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 1 of the present invention.

FIG. 2 is a three-dimensional exploded view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 1 of the present invention.

FIG. 3 is a first three-dimensional partial view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 1 of the present invention.

FIG. 4 is a second three-dimensional partial view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 1 of the present invention.

FIG. 5 is a cross-sectional view of the first stator and rotor in Embodiment 1 of the present invention.

FIG. 6 is a cross-sectional view of the second stator and rotor in Embodiment 1 of the present invention.

FIG. 7 is a diagram of the magnetic flux distribution generated by the permanent magnet poles of the rotor alone in Embodiment 1 of the present invention.

FIG. 8 is a diagram of the magnetic flux distribution generated by the permanent magnet poles of the stator alone in Embodiment 1 of the present invention.

FIG. 9 is a graph showing the change of the phase flux linkage of the armature winding and the position of the rotor in Embodiment 1 of the present invention.

FIG. 10 is a three-dimensional overall view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 2 of the present invention.

11 is a three-dimensional exploded view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 2 of the present invention.

12 is a first three-dimensional partial view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 2 of the present invention.

13 is a second three-dimensional partial view of a bilateral alternating pole type hybrid excitation brushless motor in Embodiment 2 of the present invention.

FIG. 14 is a cross-sectional view of the first stator and rotor in Embodiment 2 of the present invention.

FIG. 15 is a cross-sectional view of the second stator and rotor in Embodiment 2 of the present invention.

Including:

10. Stator rotor one;

11. Stator one; 111. Stator iron core pole one; 112. Stator permanent magnet pole one; 113. Stator iron core one;

12. Rotor one; 121. Rotor core pole one; 122. Rotor permanent magnet pole one; 123. Rotor core one;

13. Air gap one;

20. Two stators and rotors;

21. Stator II; 211. Stator iron core pole II; 212. Stator permanent magnet pole II; 213. Stator iron core II;

22. Rotor II; 221. Rotor Core Pole II; 222. Rotor Permanent Magnet Pole II; 223. Rotor Core II;

23. Air gap two;

30. Armature winding; 40. Ring DC excitation winding;

50. Rotating shaft; 51. Rotor solid magnetic conducting yoke;

60. Chassis.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and specific preferred embodiments.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "left side", "right side", "upper", "lower part", etc. are based on the orientation or positional relationship shown in the drawings, only For the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a particular orientation, be constructed and operate in a particular orientation, "first", "second", etc. importance, and therefore should not be construed as a limitation to the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the protection scope of the present invention.

In the inner rotor of Example 1, take three-phase m=3, Ns=6 (k=2), p _a =2, p _s =12, _pr =10 as an example

As shown in FIG. 1 to FIG. 6 , a bilateral alternating-pole hybrid excitation brushless motor includes a stator and rotor 10 , a stator and rotor 2 20 , an armature winding 30 , an annular DC excitation winding 40 , a rotating shaft 50 and a casing 60 .

The above-mentioned casing is set on the outer circumference of the first stator and the second rotor, and the casing is made of magnetically conductive material or non-magnetically conductive material; A solid magnetic conductive yoke is provided.

The first stator and rotor and the second stator and rotor are arranged in parallel and juxtaposed along the axial direction of the rotating shaft, wherein the rotating shaft is made of magnetically conductive material.

The first stator and rotor include a stator one 11, a rotor one 12 and an air gap disposed between them.

The second stator and rotor include a second stator 21 , a second rotor 22 and an air gap disposed therebetween.

The first stator and the second stator have the same structural parameters, and the two together constitute the stator. The stator core poles and the stator permanent magnet poles are evenly arranged alternately along the circumferential direction on the side of the stator one and the stator two facing the air gap. Specifically:

The first stator core pole 111 and the stator permanent magnet pole 1 112 are uniformly and alternately arranged along the circumferential direction on the side of the first stator facing the air gap.

Two stator iron core poles 211 and two stator permanent magnet poles 212 are evenly and alternately arranged along the circumferential direction on the side of the second stator facing the air gap.

Rotor 1 and rotor 2 have the same structural parameters, and they together constitute a rotor. Rotor iron core poles and rotor permanent magnet poles are evenly arranged alternately along the circumferential direction on the side of rotor 1 and rotor 2 facing the air gap. Specifically:

The first rotor core pole 121 and the rotor permanent magnet pole 1 122 are evenly and alternately arranged along the circumferential direction on the side of the first rotor facing the air gap.

Two rotor iron core poles 221 and two rotor permanent magnet poles 222 are evenly arranged alternately along the circumferential direction on the side of the second rotor facing the air gap.

That is, permanent magnet poles and iron core poles are arranged on the stator and rotor on both sides of the air gap, thereby forming a bilateral alternating pole structure.

In Embodiment 1, the stator permanent magnet pole one 112, the stator permanent magnet pole two 212, the rotor permanent magnet pole one 122 and the rotor permanent magnet pole two 222 are preferably surface-mounted permanent magnets. Alternatively, built-in permanent magnets can also be used.

The armature winding is wound in the stator slot of the stator. The specific winding method is as follows: the stator slots of stator one and stator two are axially aligned, and the stator slots of stator one and stator two are axially aligned to facilitate the armature winding. It can be uniformly wound in the stator slots of stator one and stator two.

In this embodiment 1, the number of stator slots is Ns=6, and the armature winding is three-phase, that is, m=3; the armature winding includes A, B, and C three-phase windings, wherein the A phase can be formed by connecting A1 and A2 coils in series, It can also be formed by parallel connection of A1 and A2; B phase and C phase and so on.

There is an axial air gap between the first stator and the second stator, and the annular DC excitation winding is arranged in the axial air gap, so there is no space constraint with the armature winding in the stator slot.

The number of stator pole pairs _ps , the number of rotor pole pairs _pr and the number of pole pairs p _a of the armature windings satisfy the following formula:

p _r =|p _a ± _ps |

and p _s =k×Ns

Among them, k is a positive integer, and Ns is the number of stator slots.

In this embodiment 1, the preferred values are: Ns=6 (k=2), p _a =2, p _s =12, and _pr =10.

In order to effectively improve the flux linkage of the armature winding (and thus improve the torque density and power density of the motor), the flux linkage generated by the stator permanent magnet poles in the armature winding and the flux linkage generated by the rotor permanent magnet poles in the armature winding should be positive. At the same time, the armature winding flux linkage generated by the first stator and rotor and the armature winding flux linkage generated by the stator and rotor two should also be superimposed in the positive direction. Therefore, the two sets of stators and rotors need to meet the following conditions at the same time:

a. The magnetization directions (polarities) of the permanent magnet poles of the first stator and the first rotor are the same, and the magnetization directions (polarities) of the permanent magnet poles of the second stator and the second rotor are the same.

b. The magnetization directions (polarities) of the permanent magnet poles of the first and second stators and rotors are opposite, and the first and second rotors are offset by a pole pitch in the circumferential direction (that is, the centerline of the permanent magnet poles of the first rotor and the iron core of the second rotor pole-neutral line is axially aligned). The first rotor and the second rotor rotate coaxially.

c. The center line of the permanent magnet pole of stator one is axially aligned with the center line of the permanent magnet pole of stator two (that is, the center line of the iron core pole of stator one is axially aligned with the center line of the iron core pole of stator two)

FIG. 7 is a magnetic flux distribution diagram produced by the rotor permanent magnet alone, and FIG. 8 is a magnetic flux distribution diagram produced by the stator permanent magnet alone. It can be seen that the permanent magnets on both sides generate 4-pole magnetic fluxes on the stator core, which are superimposed in a positive direction. Therefore, the armature winding phase flux linkage is effectively improved, as shown in Figure 9.

The electric excitation and the permanent magnet of the hybrid excitation brushless motor of the present invention are in a parallel magnetic circuit relationship. The main magnetic flux generated by the electric excitation passes through "stator iron core one 113 → stator iron core pole one 111 → air gap one (air gap between stator one and rotor one) → rotor iron core pole one 121 → rotor iron core one 123 → rotor solid guide. Magnetic yoke part (or magnetic shaft) → rotor core 2 → rotor core pole 2 → air gap 2 (air gap between stator 2 and rotor 2) → stator core pole 2 → stator core 2 → magnetic conductive casing (or Solid magnetic conducting yoke) → stator core 1" loop is closed without going through permanent magnet poles. The magnetic conductive casing (or solid magnetic conductive yoke), the solid magnetic conductive yoke of the rotor (or magnetic conductive shaft) and the iron cores on both sides of the air gap provide a low reluctance path for the electric excitation magnetic field, which is not only conducive to the flexible adjustment of the air gap magnetic field , also reduces the risk of irreversible demagnetization of permanent magnets.

Further, the present invention realizes the bidirectional adjustment of magnetization and weakening in the air gap magnetic field by controlling the current size and direction of the annular DC excitation winding.

During magnetization, the direction of the magnetic flux generated by the electric excitation of the annular DC excitation winding on the core pole is opposite to the magnetization direction (polarity) of the adjacent permanent magnet poles; when the magnetic field is weakened, the electric excitation of the annular DC excitation winding is on the core pole. The direction of the generated magnetic flux is the same as the magnetization direction (polarity) of the adjacent permanent magnet poles.

Further, the stator core and the rotor core are made of magnetically conductive materials. In order to reduce core loss (increase efficiency), the stator core and rotor core can be laminated in the axial direction by laminations.

In addition, according to different applications and requirements, the number of pole pairs of the armature winding, the alternating poles on the stator side and the rotor, as well as the specific structural form of each magnetic pole can be flexibly selected. The gap between the first stator and the second stator can be adjusted according to the design requirements, so as to adjust the ampere-turns of the annular DC excitation winding.

Further, the rotor of the present invention may also be an outer rotor.

Example 2 takes three-phase m=3, Ns=12 (k=1), p _a =2, p _s =12, _pr =10 as an example

It is basically the same as Embodiment 1, except that as shown in Figure 10 to Figure 15 , the rotating shaft is made of non-magnetic conductive material, and a solid magnetic conductive yoke is provided on the inner side of the rotating shaft.

The armature winding includes A, B, C three-phase windings, of which the A phase can be formed by A1, A2, A3, A4 coils in series, or A1-A2, A3-A4 can be connected in series and then in parallel; And so on.

The main magnetic flux generated by the electric excitation passes through "stator core 1 → stator core pole 1 → air gap 1 → rotor core pole 1 → rotor core 1 → rotor solid magnetic yoke → rotor core 2 → rotor core pole 2 → air gap 2. →Stator core pole 2→Stator core 2→Magnetic conductive housing (or solid magnetic conductive yoke)→Stator core 1" loop is closed without going through the permanent magnet pole.

The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention. These equivalent transformations All belong to the protection scope of the present invention.

Claims (9)

1. The utility model provides a bilateral alternating pole type hybrid excitation brushless motor which characterized in that: the permanent magnet synchronous motor comprises a stator-rotor I, a stator-rotor II, an armature winding, an annular direct current excitation winding and a rotating shaft;

the first stator and the second rotor are arranged in parallel along the axial direction of the rotating shaft;

the stator-rotor I comprises a stator I, a rotor I and an air gap arranged between the stator I and the rotor I;

the stator II and the rotor II comprise a stator II, a rotor II and an air gap arranged between the stator II and the rotor II;

the first stator and the second stator form a stator together, and stator iron core poles and stator permanent magnet poles are uniformly and alternately distributed on one sides of the first stator and the second stator facing the air gap along the circumferential direction;

the first rotor and the second rotor jointly form a rotor, and one sides of the first rotor and the second rotor, which face the air gap, are uniformly and alternately distributed with rotor iron core poles and rotor permanent magnet poles along the circumferential direction;

the armature winding is wound in a stator slot of the stator;

an axial air gap is formed between the first stator and the second stator, and the annular direct-current excitation winding is arranged in the axial air gap;

the flux linkage generated by the stator permanent magnet pole in the armature winding and the flux linkage generated by the rotor permanent magnet pole in the armature winding are superposed in the positive direction, and meanwhile, the armature winding flux linkage generated by the stator and the rotor I and the armature winding flux linkage generated by the stator and the rotor II are superposed in the positive direction; therefore, the first stator and the second rotor need to satisfy the following conditions:

a. the polarity of the permanent magnet poles of the first stator and the first rotor is the same, and the polarity of the permanent magnet poles of the second stator and the second rotor is the same;

b. the polarity of the permanent magnet pole in the first stator and rotor is opposite to that of the permanent magnet pole in the second stator and rotor, the first rotor and the second rotor are offset by a pole distance along the circumferential direction, and the first rotor and the second rotor coaxially rotate;

c. the central line of the permanent magnet pole of the first stator is axially aligned with the central line of the permanent magnet pole of the second stator.

2. The double-sided alternating-pole hybrid excitation brushless motor according to claim 1, characterized in that: number of stator pole pairs p _s Number of pole pairs p of rotor _r And number p of pole pairs of armature winding _a And satisfies the following formula:

p _r ＝|p _a ±p _s |

and p is _s ＝k×Ns

Wherein k is a positive integer and Ns is the number of stator slots.

3. The double-sided alternating pole type hybrid excitation brushless motor according to claim 1, characterized in that: the bidirectional regulation of the magnetism increase and the magnetism weakening in the air gap magnetic field is realized by controlling the current magnitude and the current direction of the annular direct current excitation winding.

4. The double-sided alternating-pole hybrid excitation brushless motor according to claim 3, characterized in that: when the magnetism is increased, the direction of magnetic flux generated on the iron core pole by the electric excitation of the annular direct current excitation winding is opposite to the polarity of the adjacent permanent magnet pole; when the magnetic field is weak, the magnetic flux generated on the iron core pole by the electric excitation of the annular direct current excitation winding has the same direction as the polarity of the adjacent permanent magnet pole.

5. The double-sided alternating pole type hybrid excitation brushless motor according to claim 1, characterized in that: and adjusting the size of an axial air gap between the first stator and the second stator according to the required ampere turns of the annular direct-current excitation winding.

6. The double-sided alternating pole type hybrid excitation brushless motor according to claim 1, characterized in that: the rotating shaft is made of a magnetic conductive material or a non-magnetic conductive material; when the rotating shaft adopts a non-magnetic conducting material, a rotor solid magnetic conducting yoke part is also arranged between the rotating shaft and the rotor.

7. The double-sided alternating pole type hybrid excitation brushless motor according to claim 1, characterized in that: the shell is sleeved on the peripheries of the stator-rotor I and the stator-rotor II and is made of a magnetic material or a non-magnetic material; when the machine shell adopts a non-magnetic material, a solid magnetic yoke part is also arranged between the machine shell and the first stator and the second rotor.

8. The double-sided alternating-pole hybrid excitation brushless motor according to claim 1, characterized in that: the stator slots of the first stator and the second stator are axially aligned, and the stator slot notches of the first stator and the second stator are axially aligned, so that the armature windings can be uniformly wound in the stator slots of the first stator and the second stator.

9. The double-sided alternating-pole hybrid excitation brushless motor according to claim 1, characterized in that: permanent magnet poles in the stator and the rotor adopt surface-mounted permanent magnets or built-in permanent magnets.

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