CN116073541A - A Modular Flux Switching Motor with Built-in Permanent Magnet - Google Patents

Abstract

The disclosure relates to the technical field of flux switching motors, and proposes a modular flux switching motor with built-in permanent magnets. The stator of the motor adopts a modular design, and the permanent magnets in each stator module are placed inside the iron core, and the adjacent stator modules The yoke connection is used to make the motor stator core a whole structure with the same material everywhere; the stator contains radially placed and tangentially magnetized permanent magnets, and tangentially placed and radially magnetized permanent magnets; each stator The module contains two armature coils, and the two armature coils in the same module can adopt a series or parallel structure; the structural constraints of the motor are simple and clear, which can meet the design requirements of different phase numbers and different pole numbers, and can always guarantee The windings of each phase of the motor are symmetrical.

Description

A modular flux switching motor with internal permanent magnet

Technical Field

The present disclosure relates to the technical field related to flux switching motors, and in particular, to a built-in permanent magnet modular flux switching motor.

Background Art

The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

The permanent magnet flux switching motor belongs to the stator permanent magnet brushless motor. The stator permanent magnet brushless motor is a new type of permanent magnet brushless motor in which the permanent magnet and the armature winding are both located on the stator side. The rotor is composed only of an iron core. There are neither permanent magnets nor windings on the rotor. The structure is simple and reliable and suitable for high-speed operation. This type of motor has the characteristics of high power density, high efficiency, good fault tolerance and flexible control.

The inventors found in the research that in the existing literature, the stator core of the flux switching motor generally adopts a split structure, and the overall structural strength is low; the permanent magnets are generally placed radially, and the excitation effect is poor, so permanent magnets containing rare earth materials are generally used, which has a high economic cost; and the permanent magnets are all placed radially between two sections of the stator core. If the two sections of the stator core are connected by a narrow outer magnetic bridge, the overall structural strength of the motor stator core is obviously low. If a wider magnetic bridge is used to connect the two sections of the stator core, the excitation magnetic field of the permanent magnet will be seriously weakened; at the same time, the motor winding connection method is relatively fixed, and a stator module contains only one armature coil, which is not flexible enough and cannot meet the different application design requirements for high voltage and low voltage, and has a narrow scope of application.

Summary of the invention

In order to solve the above problems, the present disclosure proposes a built-in permanent magnet modular flux switching motor, which improves the overall structure of the stator core and can effectively reduce the economic cost while ensuring the excitation effect.

In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

One or more embodiments provide an internal permanent magnet modular flux switching motor, comprising a stator and a rotor, wherein the stator comprises a plurality of stator modules having the same structure;

The stator module includes two stator cores nested inside and outside, and permanent magnets arranged tangentially and radially are arranged between the two stator cores; stator teeth are formed at both ends of each stator core, and after multiple stator modules are connected, the stator teeth form an arc structure opposite to the rotor, and a set air gap is formed between the stator teeth and the rotor.

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

The stator module in the present disclosure adopts an iron core structure with inner and outer nesting, and the permanent magnet can be arranged inside the iron core. The permanent magnet is embedded inside the iron core, and the excitation effect is better. In addition to the permanent magnets placed radially and magnetized tangentially, permanent magnets placed tangentially and magnetized radially are added, and the excitation effect is better. Permanent magnets with low magnetic energy product or no rare earth materials can be used for excitation, which can effectively reduce economic costs while ensuring the excitation effect.

The advantages of the present disclosure and additional aspects will be described in detail in the following specific embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure but do not constitute a limitation of the present disclosure.

FIG1 is a schematic structural diagram of a single stator module 5 of a flux switching motor according to an embodiment of the present disclosure;

FIG2 is a schematic diagram of a partial structure of a rotor 10 of a flux switching motor according to an embodiment of the present disclosure;

FIG3 is a schematic diagram of a cross-sectional structure of a flux switching motor according to an embodiment of the present disclosure;

FIG4 is a schematic diagram of a motor structure of a motor parameter design solution 1 according to an embodiment of the present disclosure;

FIG5 is a schematic diagram of a motor structure of a second motor parameter design scheme according to an embodiment of the present disclosure;

FIG6 is a motor flux simulation result of a motor parameter design solution 1 according to an embodiment of the present disclosure;

FIG. 7 is a motor flux simulation result of a second motor parameter design scheme according to an embodiment of the present disclosure;

Among them: 1. first stator tooth, 2. second stator tooth, 3. third stator tooth, 4. fourth stator tooth, 5. stator module, 6. coil I, 7. coil II, 8. permanent magnet, 9. narrow magnetic bridge, 10. rotor, 11. rotor tooth, 12. stator, 13. connecting yoke, 14. air gap.

DETAILED DESCRIPTION

The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof. It should be noted that, in the absence of conflict, the various embodiments in the present disclosure and the features in the embodiments can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

Example 1

In the technical solution disclosed in one or more embodiments, as shown in FIG. 1 to FIG. 7 , a built-in permanent magnet modular flux switching motor includes: a stator 12 and a rotor 10 , wherein the stator includes a plurality of stator modules 5 having the same structure;

The stator module 5 includes two stator cores nested inside and outside, and permanent magnets 8 are arranged tangentially and radially between the two stator cores; stator teeth are formed at both ends of each stator core, and after multiple stator modules are connected, the stator teeth form an arc structure opposite to the rotor, and a set air gap 14 is formed between the stator teeth and the rotor.

The stator module in this embodiment adopts an iron core structure with inner and outer nesting, and the permanent magnet 8 can be arranged inside the iron core. The permanent magnet is embedded in the iron core, and the excitation effect is better. In addition to the permanent magnets placed radially and magnetized tangentially, permanent magnets placed tangentially and magnetized radially are added, and the excitation effect is better. Permanent magnets with low magnetic energy product or without rare earth materials can be used for excitation. While ensuring the excitation effect, the economic cost can be effectively reduced.

As shown in FIG3 , according to the definition convention of rotating electrical machines, the motor involved in this embodiment is composed of a stator and a rotor, with an air gap between the stator and the rotor. The direction along the motor radius from the center point of the shaft to the outside of the motor is the positive radial direction, and the counterclockwise direction along the circumference of the motor perpendicular to the radial direction is the positive tangential direction.

Optionally, the two stator cores are nested inside and outside, and the stator core can be any structure that can realize the permanent magnets being arranged in different directions and form two stator teeth opposite to the rotor.

A structure that can be realized is that the stator core can be a semicircular structure, the two arms of the core are arc-shaped structures, the permanent magnet T3 is tangentially arranged at the bottom end of the arc-shaped structure, and the permanent magnets T1 and T2 are radially arranged between the two arms of the inner and outer stator cores.

Another structure that can be realized is that the stator core can adopt a U-shaped structure, as shown in Figure 1, a permanent magnet 8 is set tangentially and radially between the inner and outer U-shaped cores, the bottom of the U-shaped core is set tangentially with a permanent magnet 8, and the two side walls of the U-shaped core are respectively set radially with permanent magnets 8; the stator core includes 4 primary teeth along the tangent direction, namely the first stator tooth 1, the second stator tooth 2, the third stator tooth 3 and the fourth stator tooth 4. Each stator module contains at least 3 sections of permanent magnets 8, namely permanent magnet T1, permanent magnet T2 and permanent magnet T3; wherein permanent magnet T1 is placed radially between the first stator tooth 1 and the second stator tooth 2, permanent magnet T2 is placed radially between the third stator tooth 3 and the fourth stator tooth 4, and permanent magnet T3 is placed along the tangential midline position;

Furthermore, the stator core of the stator module is a symmetrical structure, and the stator core of a single stator module is bilaterally symmetrical along its own central axis L.

In some embodiments, the two stator cores nested inside and outside the stator module are connected to form a through whole through a narrow magnetic bridge 9 .

Optionally, adjacent stator modules are connected by a connecting yoke 13 .

In this embodiment, an extremely narrow connecting magnetic bridge is placed inside the core, and adjacent stator modules are connected by a wide yoke, namely the connecting yoke 13 shown in FIG. 4 , to form an integrated stator core that is connected everywhere, while achieving a very high overall structural strength of the stator core and an excitation magnetic field.

In this embodiment, the motor stator adopts a modular design, the structures of each module are exactly the same, and the adjacent stator module cores form an integrated, structurally strong stator core through the connecting yoke 13. Based on the stator module 5, a multi-phase symmetrical motor design with different pole numbers can be quickly realized.

In some embodiments, the tangentially arranged permanent magnets are magnetized radially, and the radially arranged permanent magnets are magnetized tangentially.

One possible implementation scheme is that the permanent magnet magnetization direction scheme is: the radially arranged permanent magnet T1 and the permanent magnet T2 are magnetized along the tangential direction, wherein the permanent magnet T1 is magnetized along the positive tangential direction, and the permanent magnet T2 is magnetized along the negative tangential direction. At the same time, the tangentially arranged permanent magnet T3 is magnetized along the negative radial direction.

Another possible implementation scheme is that the permanent magnet magnetization direction scheme is: the radial permanent magnet T1 is magnetized along the negative tangential direction, the radial permanent magnet T2 is magnetized along the positive tangential direction, and at the same time, the permanent magnet T3 is magnetized along the positive radial direction.

Optionally, the stator module includes two centralized armature coils, the armature coils include coil I6 and coil II7, coil I6 is wound around the first stator tooth 1 and the second stator tooth 2, and coil II7 is wound around the third stator tooth 3 and the fourth stator tooth 4; coil I6 and coil II7 can be connected in series or in parallel.

Furthermore, the number of turns of coil I6 and coil II7 are equal and belong to the same phase, and the two coils can be connected in series or in parallel; as shown in Figure 1, the end marked with ⊙ is the head end of the coil, and the other end marked with ⊕ is the tail end of the coil. If the two coils are connected in series, they should be connected head to tail, and if they are connected in parallel, they should be connected head to head and tail to tail.

In this embodiment, in the modular flux switching motor, one stator module contains two armature coils, and the two armature coils can be connected in series or in parallel. The connection method is flexible and can more easily meet different application design requirements for high voltage and low voltage.

Optionally, the rotor 10 is only composed of a rotor core, and the protruding portion close to the air gap is the rotor teeth 11, and the widths of adjacent rotor teeth 11 along the tangential direction are equal, and the distances between adjacent rotor teeth 11 along the tangential direction are equal.

In some embodiments, motors with different numbers of phases and poles can be obtained by setting motor parameters, that is, by adjusting the tangential space occupied by the stator teeth, the rotor tooth pitch, and the size of the connecting yoke.

The motor structure design of this embodiment is flexible, and the design relationship between the stator and rotor pitches is clear, which ensures that the induced electromotive force of each phase of the motor is always symmetrical. Based on the design formula, a symmetrical structure with different phase numbers and different pole numbers can be formed. Specifically, the improved motor parameter design of this embodiment is as follows:

1. The tangential widths of the four stator teeth of the stator module 5 are equal, and the tooth width is w _t ; the tangential distances between two adjacent teeth are equal, and the spacing is θ _t ; and w _t <θ _t is satisfied;

2. Taking the midline of two adjacent teeth as the boundary, the tangential space occupied by each stator tooth is θ _t , the tangential space occupied by the first stator tooth 1 and the second stator tooth 2 is θ _s =2θ _t , the tangential space occupied by the third stator tooth 3 and the fourth stator tooth 4 is θ _s =2θ _t ; the tangential space occupied by the stator module is Δθ; and Δθ≥2θ _s is satisfied;

3. The tangential width of the rotor teeth 11, i.e. the tooth width, is w _r ; the tangential distance between two adjacent rotor teeth 11, i.e. the tooth pitch, is θ _r ; and w _r <θ _r is satisfied, as shown in FIG. 2 .

4. The number of motor phases is m, and the number of stator modules contained in each phase is N. There are two parameter design schemes to ensure the symmetry of the magnetic flux of each phase armature winding:

(1) Motor parameter design scheme 1 makes the tangential space Δθ occupied by a stator module larger than the tangential space 2θ _s of all stator teeth of the stator module, and the rotor tooth pitch θ _r is equal to the tangential space θ _s of two stator teeth, that is:

When the parameters Δθ, θ _s , θ _r satisfy equation group (1), the motor is a symmetrical structure;

When m＝3, N＝2 in equation group (1), and “±” is “+”, Δθ＝π/3, θ _r ＝θ _s ＝π/7, as shown in FIG4 . At this time, the motor stator includes 6 modules, each phase includes 2 modules, and adjacent modules are connected by connecting yokes, so that the stator core forms a whole, and the rotor includes 14 teeth.

FIG6 is a simulation result of the motor flux corresponding to the motor parameter design scheme 1. According to the result, it can be seen that the motor has a three-phase symmetrical structure.

(2) Motor parameter design scheme 2 makes the tangential space Δθ occupied by a stator module 5 equal to the tangential space 2θ _s of the stator teeth of the stator module, and the rotor tooth spacing equals the tangential space of two stator teeth, that is:

When the parameters Δθ, θ _s , θ _r satisfy equation group (2), the motor is a symmetrical structure;

When m＝3, N＝2 in equation group (2), and “±” is “-”, Δθ＝π/3, θ _s ＝π/6, θ _r ＝π/5, as shown in FIG5 . At this time, the motor stator includes 6 modules, each phase includes 2 modules, and adjacent modules are connected by connecting yokes, so that the stator core forms a whole, and the rotor includes 10 teeth.

FIG7 is a simulation result of the motor flux corresponding to the motor parameter design scheme 2. According to the result, it can be seen that the motor has a three-phase symmetrical structure.

It can be seen that the motor design constraint relationship of this embodiment is simple and clear, which can meet the design requirements of different numbers of phases and poles, and always ensure the symmetry of the windings of each phase of the motor.

The structure of the motor stator core of this embodiment is more solid, and there is no risk of permanent magnets falling off; the cost is more economical, and permanent magnets with low magnetic energy product or no rare earth elements can be used; the winding design is more flexible and easy to meet different application requirements; this makes the invention have a good application prospect in industrial electric traction systems.

The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims (10)

1. An interior permanent magnet modularization magnetic flux switching motor is characterized in that: the stator comprises a plurality of stator modules with the same structure;

the stator module comprises two inner and outer nested stator cores, and a tangential permanent magnet and a radial permanent magnet are arranged between the inner and outer stator cores; stator teeth are formed at two ends of each stator core, a plurality of stator modules are connected, the stator teeth form an arc structure opposite to the rotor, and the stator teeth and the rotor form a set air gap.

2. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: the stator core adopts a U-shaped structure, the bottom of the U-shaped structure is provided with permanent magnets in a tangential mode, and two side walls of the U-shaped structure are provided with permanent magnets in a radial mode respectively.

3. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: the two inner and outer nested stator cores form four stator teeth, including a first stator tooth, a second stator tooth, a third stator tooth and a fourth stator tooth; each stator module at least comprises three sections of permanent magnets, including a permanent magnet T1, a permanent magnet T2 and a permanent magnet T3; the permanent magnet T1 is radially arranged between the first stator tooth and the second stator tooth, the permanent magnet T2 is radially arranged between the third stator tooth and the fourth stator tooth, and the permanent magnet T3 is arranged along the tangential central line.

4. A permanent magnet-built-in modular flux switching motor as defined in claim 3, wherein: the stator module comprises two centralized armature coils, wherein the armature coils comprise coils I and coils II, the coils I are wound around the first stator teeth and the second stator teeth, and the coils II are wound around the third stator teeth and the fourth stator teeth; the coil I and the coil II are connected in series or in parallel.

5. A permanent magnet-built-in modular flux switching motor as defined in claim 3, wherein: the tangentially arranged permanent magnets are magnetized according to the radial direction, and the radially arranged permanent magnets are magnetized according to the tangential direction.

6. An interior permanent magnet modular flux switching motor as defined in claim 5, wherein:

the magnetizing direction scheme of the permanent magnet is as follows: the permanent magnet T1 is magnetized along the tangential positive direction, the permanent magnet T2 is magnetized along the tangential negative direction, and meanwhile, the tangentially arranged permanent magnet T3 is magnetized along the radial negative direction;

or, the scheme of the magnetizing direction of the permanent magnet is as follows: the permanent magnet T1 is radially arranged to magnetize along the tangential negative direction, the permanent magnet T2 is radially arranged to magnetize along the tangential positive direction, and meanwhile, the permanent magnet T3 is radially arranged to magnetize along the positive direction.

7. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: the stator core of the stator module is of a symmetrical structure, and the stator core of the single stator module is bilaterally symmetrical along the central axis of the stator core.

8. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: the two stator cores nested inside and outside the stator module are connected into a through whole through a narrow magnetic bridge.

9. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: adjacent stator modules are connected by connecting yokes.

10. An interior permanent magnet modular flux switching motor as defined in claim 1, wherein: by adjusting the tangential space occupied by the stator teeth, the tooth pitch of the rotor and the size of the connecting yoke, motors with different phases and different pole numbers are obtained.

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