An interior permanent magnet modular flux switching motor

Abstract

The disclosure relates to the technical field of magnetic flux switching motor, and proposes an internal permanent magnet modular magnetic flux switching motor. The motor stator adopts a modular design. The permanent magnets in each stator module are arranged in the interior of the iron core. The adjacent stator modules are connected by yokes, so that the motor stator iron core is a whole structure that is through everywhere and made of the same material. The stator comprises radial permanent magnets and tangential permanent magnets. Each stator module comprises two armature coils. The two armature coils in the same module can adopt a series or parallel structure. The motor structure constraint relationship is simple and clear, can meet the design requirements of different phase numbers and different pole numbers, and can always ensure the symmetry of the motor phase windings.

Description

Technical Field

[0001] This disclosure relates to the technical field of flux-switching motors, specifically to a modular flux-switching motor with a built-in permanent magnet. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] The permanent magnet flux switching motor belongs to the stator permanent magnet type brushless motor. The stator permanent magnet type brushless motor is a new type of permanent magnet brushless motor in which both the permanent magnet and the armature winding are 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.

[0004] The inventors discovered in their research that existing literature generally employs a split structure for the stator core of flux-switching motors, resulting in low overall structural strength. Permanent magnets are typically placed radially, leading to poor excitation performance; therefore, rare-earth-containing permanent magnets are commonly used, resulting in higher economic costs. Furthermore, since the permanent magnets are radially placed between two stator core segments, using a narrow outer magnetic bridge to connect them significantly reduces the overall structural strength of the motor stator core. Using a wider magnetic bridge would severely weaken the excitation magnetic field of the permanent magnets. Additionally, the motor winding connection method is relatively fixed, with only one armature coil in each stator module, lacking flexibility and failing to meet the design requirements for different high-voltage and low-voltage applications, thus limiting its applicability. Summary of the Invention

[0005] To address the aforementioned issues, this disclosure proposes a modular flux-switching motor with a built-in permanent magnet, which improves the overall structure of the stator core and effectively reduces economic costs while ensuring excitation performance.

[0006] To achieve the above objectives, the present disclosure adopts the following technical solution:

[0007] One or more embodiments provide a built-in permanent magnet modular flux switching motor, including a stator and a rotor, wherein the stator includes multiple stator modules with identical structures;

[0008] The stator module includes two nested stator cores, with tangential and radial permanent magnets positioned between the inner and outer stator cores. Stator teeth are formed at both ends of each stator core. After multiple stator modules are connected, the stator teeth form an arc structure opposite to the rotor, and the stator teeth and rotor form a predetermined air gap.

[0009] Compared with the prior art, the beneficial effects of this disclosure are as follows:

[0010] The stator module in this disclosure adopts an inner and outer nested core structure, which allows permanent magnets to be placed inside the core. The permanent magnets are embedded inside the core, resulting in better excitation effect. In addition to the permanent magnets that are placed radially and tangentially magnetized, permanent magnets that are placed tangentially and radially magnetized are also added, further improving the excitation effect. Permanent magnets with low energy product or without rare earth materials can be used for excitation, which can effectively reduce economic costs while ensuring the excitation effect.

[0011] The advantages of this disclosure, as well as its additional advantages, will be described in detail in the following specific embodiments. Attached Figure Description

[0012] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute a limitation thereof.

[0013] Figure 1 This is a schematic diagram of the unfolded structure of a single stator module 5 of a flux-switching motor according to an embodiment of the present disclosure;

[0014] Figure 2 This is a schematic diagram of the rotor 10 part of the flux-switching motor according to an embodiment of the present disclosure;

[0015] Figure 3 This is a schematic diagram of the cross-sectional structure of the flux switching motor according to an embodiment of the present disclosure;

[0016] Figure 4 This is a schematic diagram of the motor structure according to the motor parameter design scheme of this disclosure;

[0017] Figure 5 This is a schematic diagram of the motor structure of motor parameter design scheme two according to an embodiment of this disclosure;

[0018] Figure 6 This is a simulation result of the motor flux linkage of the motor parameter design scheme according to an embodiment of this disclosure;

[0019] Figure 7 This is the simulation result of the motor flux linkage of motor parameter design scheme two in this embodiment of the present disclosure;

[0020] 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 Implementation

[0021] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0023] It should be noted that the terminology used herein is for descriptive purposes only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be noted that, without conflict, the various embodiments and features within those embodiments can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0024] Example 1

[0025] In one or more of the technical solutions disclosed in the embodiments, such as Figures 1 to 7 As shown, a built-in permanent magnet modular flux switching motor includes: a stator 12 and a rotor 10, wherein the stator includes multiple stator modules 5 with the same structure;

[0026] The stator module 5 includes two nested stator cores, with tangential and radial permanent magnets 8 arranged between the inner and outer 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 the stator teeth and rotor form a set air gap 14.

[0027] In this embodiment, the stator module adopts an inner and outer nested core structure, which allows the permanent magnet 8 to be placed inside the core. The permanent magnet is embedded inside the core, resulting in better excitation effect. In addition to the permanent magnet placed radially and tangentially magnetized, a permanent magnet placed tangentially and radially magnetized is also added, further enhancing the excitation effect. Permanent magnets with low energy product or without rare earth materials can be used for excitation, effectively reducing economic costs while ensuring excitation effect.

[0028] like Figure 3 As shown, according to the conventional definition of a rotating electrical machine, the motor involved in this embodiment consists of a stator and a rotor, with an air gap between the stator and the rotor. The direction from the center point of the shaft to the outside of the motor along the motor radius is the positive radial direction, and the counterclockwise direction perpendicular to the radial direction along the circumference of the motor is the positive tangential direction.

[0029] Optionally, two nested stator cores can be used. The stator cores can be any structure that allows permanent magnets to be arranged in different directions and form two stator teeth opposite to the rotor.

[0030] One feasible structure is a stator core that can be a semi-circular structure with two arc-shaped arms. A permanent magnet T3 is tangentially arranged at the bottom of the arc-shaped structure, and permanent magnets T1 and T2 are radially arranged between the two arms of the inner and outer stator cores.

[0031] Another possible structure is a U-shaped stator core, such as... Figure 1 As shown, permanent magnets 8 are arranged tangentially and radially between the inner and outer double U-shaped iron cores. A permanent magnet 8 is tangentially arranged at the bottom end of the U-shaped core, and permanent magnets 8 are radially arranged on the two sidewalls of the U-shaped core. The stator iron core contains four primary teeth tangentially, namely, first stator tooth 1, second stator tooth 2, third stator tooth 3, and fourth stator tooth 4. Each stator module contains at least three permanent magnet segments 8, namely, permanent magnet T1, permanent magnet T2, and permanent magnet T3. Permanent magnet T1 is radially positioned between the first stator tooth 1 and the second stator tooth 2; permanent magnet T2 is radially positioned between the third stator tooth 3 and the fourth stator tooth 4; and permanent magnet T3 is positioned along the tangential centerline.

[0032] Furthermore, the stator core of the stator module has a symmetrical structure, with the stator core of a single stator module being symmetrical about its own central axis L.

[0033] In some embodiments, two stator cores nested inside and outside the stator module are connected into a continuous whole by a narrow magnetic bridge 9.

[0034] Optionally, adjacent stator modules are connected using a connecting yoke 13.

[0035] In this embodiment, an extremely narrow connecting magnetic bridge is placed inside the iron core, and a wide yoke is used between adjacent stator modules. Figure 4 The connection of the connecting yoke 13 shown in the figure forms a fully integrated stator core, which achieves high overall structural strength and excitation magnetic field of the stator core.

[0036] In this embodiment, the motor stator adopts a modular design, with each module having an identical structure. Adjacent stator module cores are connected by yoke 13 to form an integrated, robust stator core. Based on stator module 5, multi-phase symmetrical motor designs with different pole numbers can be quickly realized.

[0037] In some embodiments, tangentially arranged permanent magnets are magnetized radially, and radially arranged permanent magnets are magnetized tangentially.

[0038] One feasible implementation scheme is as follows: the permanent magnets T1 and T2, which are arranged radially, are magnetized tangentially, wherein permanent magnet T1 is magnetized in the positive tangential direction and permanent magnet T2 is magnetized in the negative tangential direction, while permanent magnet T3, which is arranged tangentially, is magnetized in the negative radial direction.

[0039] Another possible implementation scheme is as follows: permanent magnet T1 is magnetically charged in the negative tangential direction, permanent magnet T2 is magnetically charged in the positive tangential direction, and permanent magnet T3 is magnetically charged in the positive radial direction.

[0040] Optionally, the stator module includes two centralized armature coils, namely 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.

[0041] Furthermore, coil I6 and coil II7 have the same number of turns and belong to the same phase; the two coils can be connected in series or in parallel; for example... Figure 1 The ⊙ end is the beginning of the coil, and the ⊕ end is the end of the coil. If the two coils are connected in series, they should be connected from beginning to end. If they are connected in parallel, they should be connected from beginning to beginning and from end to end.

[0042] In this embodiment, in the modular flux switching motor, one stator module contains two armature coils. The two armature coils can be connected in series or in parallel, which is flexible and makes it easier to meet the different application design requirements of high voltage and low voltage.

[0043] Optionally, the rotor 10 consists only of a rotor core, with the protruding part near the air gap being the rotor teeth 11. The width of adjacent rotor teeth 11 along the tangential direction is equal, and the distance between adjacent rotor teeth 11 along the tangential direction is equal.

[0044] In some embodiments, motors with different numbers of phases and poles can be obtained by setting motor parameters, i.e., by adjusting the tangential space occupied by the stator teeth, the rotor tooth pitch, and the dimensions of the connecting yoke.

[0045] The motor structure design in this embodiment is flexible, and the design relationship between the stator and rotor tooth pitches is clear, ensuring that the induced electromotive force of each phase of the motor is always symmetrical. Based on the design formula, symmetrical structures with different numbers of phases and poles can be formed. Specifically, the improved motor parameter design of this embodiment is exemplified as follows:

[0046] 1. The four stator teeth of stator module 5 have equal widths along the tangential direction, and the tooth width is w. t The tangential distance between two adjacent teeth is equal, with a spacing of θ. t And satisfy w t <θ t ;

[0047] 2. Taking the center lines 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 =2θt 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 is satisfied. s ;

[0048] 3. The tangential width of 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 satisfy w r <θ r ,like Figure 2 As shown.

[0049] 4. The motor has m phases, and each phase contains N stator modules. There are two parameter design schemes to ensure symmetrical flux linkage in the armature windings of each phase:

[0050] (1) Motor parameter design scheme one, which makes the tangential space Δθ occupied by a stator module greater than the tangential space 2θ of all stator teeth of that stator module. s Rotor tooth pitch θ r Equal to the tangential space θ of the two stator teeth s ,Right now:

[0051] When parameters Δθ, θ s θ r When equation (1) is satisfied, the motor has a symmetrical structure;

[0052]

[0053] When m = 3, N = 2, and "±" is taken as "+" in equation system (1), we have Δθ = π / 3, θ r =θ s =π / 7, at this time it is Figure 4 As shown, the motor stator contains 6 modules, with 2 modules per phase, and adjacent modules are connected by a connecting yoke, so that the stator core forms a whole, and the rotor contains 14 teeth.

[0054] Figure 6 The simulation results of the motor flux linkage corresponding to the first design scheme for motor parameters show that the motor has a three-phase symmetrical structure.

[0055] (2) Motor parameter design scheme two, which makes the tangential space Δθ occupied by a stator module 5 equal to the tangential space 2θ of the stator teeth of that stator module. s The rotor tooth spacing is equal to the tangential space between the two stator teeth, that is:

[0056] When parameters Δθ, θ s θ rWhen equation (2) is satisfied, the motor has a symmetrical structure;

[0057]

[0058] When m = 3, N = 2, and "±" takes the value "-" in equation system (2), we have Δθ = π / 3, θ s =π / 6, θ r =π / 5, at this time it is Figure 5 As shown, the motor stator contains 6 modules, with 2 modules per phase, and adjacent modules are connected by a connecting yoke, so that the stator core forms a whole, and the rotor contains 10 teeth.

[0059] Figure 7 The simulation results of the motor flux linkage corresponding to the second design scheme for motor parameters show that the motor has a three-phase symmetrical structure.

[0060] As can be seen, the motor design constraints in this embodiment are simple and clear, which can meet the design requirements of different numbers of phases and different numbers of poles, and always ensure that the windings of each phase of the motor are symmetrical.

[0061] The stator core of the motor in this embodiment has a more robust structure, eliminating the risk of permanent magnet detachment; it is more economical in cost, as it can use permanent magnets with low energy product or without rare earth elements; the winding design is more flexible, making it easier to meet different application requirements; thus, this invention has a promising application prospect in industrial electric drive systems.

[0062] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

[0063] While the specific embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this disclosure. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this disclosure are still within the scope of protection of this disclosure.

Claims

1. A modular flux-switching motor with built-in permanent magnet, characterized in that: It includes a stator and a rotor, and the stator includes multiple stator modules with the same structure; The stator module includes two nested stator cores, with tangential and radial permanent magnets positioned between the inner and outer 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 the stator teeth and rotor form a predetermined air gap. Two 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 contains at least three permanent magnets, including permanent magnet T1, permanent magnet T2, and permanent magnet T3. Permanent magnet T1 is radially positioned between the first and second stator teeth, permanent magnet T2 is radially positioned between the third and fourth stator teeth, and permanent magnet T3 is positioned along the tangential centerline. Each stator module contains two concentrated armature coils, including coil I and coil II. Coil I is wound around the first and second stator teeth, and coil II is wound around the third and fourth stator teeth. Coil I and coil II are connected in series or in parallel. Two stator cores nested inside and outside the stator module are connected into a continuous whole by a narrow magnetic bridge; adjacent stator modules are connected by a connecting yoke; by adjusting the tangential space occupied by the stator teeth, the rotor tooth pitch, and the size of the connecting yoke, motors with different numbers of phases and poles can be obtained.

2. The built-in permanent magnet modular flux switching motor as described in claim 1, characterized in that: The stator core adopts a U-shaped structure, with permanent magnets tangentially arranged at the bottom end of the U-shape and permanent magnets radially arranged on the two side walls of the U-shape.

3. The built-in permanent magnet modular flux switching motor as described in claim 1, characterized in that: Tangentially arranged permanent magnets are magnetized radially, and radially arranged permanent magnets are magnetized tangentially.

4. The built-in permanent magnet modular flux switching motor as described in claim 3, characterized in that: The magnetization direction scheme for permanent magnets is as follows: permanent magnet T1 is magnetized along the positive tangential direction, permanent magnet T2 is magnetized along the negative tangential direction, and at the same time, permanent magnet T3, which is set tangentially, is magnetized along the negative radial direction. Alternatively, the permanent magnet magnetization direction scheme is as follows: permanent magnet T1 is magnetized radially along the negative tangential direction, permanent magnet T2 is magnetized radially along the positive tangential direction, and permanent magnet T3 is magnetized radially along the positive radial direction.

5. The built-in permanent magnet modular flux switching motor as described in claim 1, characterized in that: The stator core of the stator module has a symmetrical structure, and the stator core of a single stator module is symmetrical about its own central axis.

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