CN113839481B - Novel rhombus modulation pole vernier permanent magnet motor - Google Patents

Abstract

The invention relates to the technical field of low-speed direct-drive large-torque motors, in particular to a novel rhombic modulation pole vernier permanent magnet motor which comprises a stator and a rotor, wherein an air gap is formed between the stator and the rotor; the stator comprises a stator core and an armature winding; the stator iron core comprises armature teeth, fault-tolerant teeth, modulation poles and a stator yoke; the armature teeth and the fault-tolerant teeth are alternately and uniformly distributed in the circumferential direction, the tips of the armature teeth and the fault-tolerant teeth are provided with modulation electrodes, the modulation electrodes are in a diamond shape, and the modulation electrodes are arranged oppositely in pairs and uniformly distributed at intervals along the circumferential surface; the modulation pole of the stator adopts a diamond structure, the winding adopts a single-layer concentrated winding, the rotor adopts a surface-mounted permanent magnet rotor structure in a radial magnetizing mode, and the motor can be an inner rotor structure or an outer rotor structure. Compared with the traditional rectangular modulation pole vernier permanent magnet motor, the novel rhombic modulation pole structure can obviously increase the air gap flux density of the vernier permanent magnet motor, so that the torque density of the vernier permanent magnet motor is improved.

Description

A Novel Diamond Modulated Pole Vernier Permanent Magnet Motor

technical field

The invention relates to the technical field of low-speed direct-drive high-torque motors, in particular to a novel diamond-shaped modulated pole vernier permanent magnet motor.

Background technique

With the high-quality development of society and the advancement of modern industrial processes, permanent magnet motors are increasingly used in aerospace, military equipment, electric vehicles, wind power generation, oilfield mining and other fields. Among them, in low-speed and high-torque applications, the electric direct drive system can remove the gearbox, eliminate the noise and faults caused by gear transmission, and help improve system efficiency and reliability. If the traditional permanent magnet synchronous motor is directly driven, it will inevitably lead to an increase in its volume and a decrease in torque density. In recent years, a vernier permanent magnet (VPM) motor with high torque density based on the "magnetic gear effect" has attracted the attention of scholars. Based on the magnetic field modulation effect, the modulation pole is used to modulate the stator air-gap magnetic field with a low rotation speed into a high-speed stator air-gap magnetic field, so as to achieve the so-called "self-acceleration" effect and achieve the essential requirements of low-speed and high-torque direct drive systems. The fractional-slot concentrated winding is introduced into the VPM motor, and by optimizing the configuration of the armature teeth and the tooth width of the fault-tolerant teeth, the motor can provide a large torque density while maximizing the phase-to-phase independence of the windings to achieve the main goal of high fault-tolerance performance of the VPM motor. However, the magnetic field modulation effect of the traditional rectangular modulated pole VPM motor is limited, it is difficult to maximize its torque density, and it is difficult to effectively improve the power factor.

At present, most of the enhanced magnetic field modulation motors are based on the double stator or double rotor structure. The multi-layer air gap structure undoubtedly increases the complexity of the motor, and it is difficult to guarantee the mechanical strength and the reliability of the whole machine. The advantage of independence. Therefore, improving the torque density and power factor of the VPM motor without increasing the complexity of the motor and retaining the high fault-tolerant performance has important practical significance for the high-performance operation of the entire direct drive system.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides a novel diamond-shaped modulated pole vernier permanent magnet motor, which can significantly increase the air gap magnetic density of the vernier permanent magnet motor, thereby improving its torque density.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A novel rhombus modulated pole vernier permanent magnet motor includes a stator and a rotor, and an air gap is provided between the stator and the rotor;

The stator includes a stator core and an armature winding;

The stator core includes armature teeth, fault-tolerant teeth, modulation poles and a stator yoke; the armature teeth and fault-tolerant teeth are alternately and evenly distributed in the circumferential direction, and modulation poles are provided at the tops of the armature teeth and fault-tolerant teeth. The modulation poles are in the shape of a rhombus, and the modulation poles are arranged opposite to each other and evenly spaced along the circumferential surface;

the rotor includes a rotor core and a permanent magnet;

The permanent magnet adopts a radial magnetization method, and the surface of the permanent magnet is attached to the inner surface of the rotor core.

Preferably, the stator core is formed by laminating silicon steel sheets, the inner radius of the stator core is r ₄ , the outer radius of the stator core is r ₁ , the modulating pole bottom radius is r ₂ , and the stator The radius of the yoke is r ₃ , the tooth width of the armature is w _ATT , and the width of the fault-tolerant tooth is w _FTT .

Preferably, the ratio r ₄ /r ₁ of the inner radius to the outer radius of the stator core is 0.417, the ratio r ₂ /r ₁ of the radius of the modulation pole bottom to the outer radius of the stator core is 0.933, the radius of the stator yoke and the stator The inner radius ratio r ₃ /r ₄ of the iron core is 1.4, and the armature tooth width and the fault-tolerant tooth width ratio w _ATT /w _FTT are 1.27.

Preferably, the central angle corresponding to the notch of the modulation electrode and the bottom ends of two adjacent modulation electrodes is θ ₁ , the central angle corresponding to the two ends of the side of the modulation electrode is θ ₂ , and the modulation electrode is close to the air gap. The central angle corresponding to the two end points of the side edge is θ ₁ +θ ₂ , and the slot pitch angle of the modulation pole is θ ₃ .

Preferably, the central angles θ ₁ , θ ₂ , and θ ₃ corresponding to the modulation poles satisfy the relational expression 4 (θ ₁ +θ ₂ )=θ ₃ , where θ ₁ /θ ₂ =0.8.

Preferably, the armature windings are collectively wound on the armature teeth, and the span of the armature windings is 1.

Preferably, the permanent magnet is made of NdFeB material, and the pole arc coefficient of the permanent magnet is 1.

Preferably, the number of poles of the modulation pole is N _m , the number of pole pairs of the armature winding is N _w , the number of pole pairs of the permanent magnet is N _p , the number of poles of the modulation pole N _m , the number of pole pairs of the armature winding The number of pole pairs N _w and the number of pole pairs N _p of the permanent magnet satisfy the theoretical relationship of magnetic field modulation, that is, N _m −N _w =N _p .

By adopting the above technical solutions: the stator modulation pole adopts a rhombus structure, the winding adopts a single-layer concentrated winding, and the rotor adopts a surface-mounted permanent magnet rotor structure with radial magnetization, and the motor can be an inner rotor structure or an outer rotor structure. Compared with the traditional rectangular modulated pole vernier permanent magnet motor, the novel diamond modulated pole structure of the present invention can significantly increase the air gap magnetic density of the vernier permanent magnet motor, thereby improving its torque density. At the same time, the novel diamond-shaped modulation pole structure of the present invention can also increase its power factor.

Beneficial effects of the present invention:

The present invention only changes the shape of the modulation pole, and can effectively improve the magnetic field modulation effect of the VPM motor without increasing the structural complexity of the VPM motor and retaining high fault-tolerant performance, thereby improving its torque density and power factor.

Description of drawings

Fig. 1 is the sectional view of the novel diamond-shaped modulating pole VPM motor of the present invention;

FIG. 2 is a schematic diagram of the structure of the novel diamond-shaped modulation pole of the present invention;

Fig. 3 is a schematic diagram of the structure of a conventional rectangular modulating pole stator and a dimensioning diagram;

4 is a schematic structural diagram and a dimensioning diagram of the novel diamond-shaped modulating pole stator of the present invention;

5 is a no-load back EMF waveform diagram of a traditional rectangular modulating pole VPM motor and a novel rhombus modulating pole VPM motor of the present invention;

FIG. 6 is a torque waveform diagram of the conventional rectangular modulated pole VPM motor and the novel rhombic modulated pole VPM motor of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that those skilled in the art can better understand the advantages and features of the present invention, and thus make the protection scope of the present invention clearer definition. The described embodiments of the present invention are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without creative work For example, all belong to the protection scope of the present invention.

Referring to FIG. 1 , a new type of rhombus modulated pole vernier permanent magnet motor includes a stator 1 and a rotor 2 , an air gap is formed between the stator 1 and the rotor 2 , and the thickness of the air gap is 0.5 mm.

The stator 1 includes a stator core 11 and an armature winding 12 .

The stator core 11 includes armature teeth 11-I, fault-tolerant teeth 11-II, modulation poles 11-III, and a stator yoke 11-IV; the armature teeth 11-I and fault-tolerant teeth 11-II are alternately uniform in the circumferential direction. distribution, the top of the armature teeth 11-I and the fault-tolerant teeth 11-II are provided with modulation poles 11-III, the modulation poles 11-III are diamond-shaped, and the modulation poles 11-III are arranged opposite to each other and along the The circumferential surface is evenly spaced.

The rotor 2 includes a rotor core 21 and a permanent magnet 22;

The permanent magnets 22 are radially magnetized, and the surfaces of the permanent magnets 22 are attached to the inner surface of the rotor core 21 .

Specifically, the stator core 11 is formed by laminating silicon steel sheets, the inner radius of the stator core 11 is r ₄ , the outer radius of the stator core 11 is r ₁ , and the bottom radius of the modulation pole 11-III is r ₂ , the radius of the stator yoke 11-IV is r ₃ , the width of the armature teeth 11-I is w _ATT , and the width of the fault-tolerant teeth 11-II is w _FTT .

The ratio r ₄ /r ₁ of the inner radius to the outer radius of the stator core 11 is 0.417, the ratio r ₂ /r ₁ of the bottom radius of the modulating pole 11-III to the outer radius of the stator core 11 is 0.933, and the stator The ratio r ₃ /r ₄ of the radius of the yoke 11-IV to the inner radius of the stator core 11 is 1.4, and the width ratio w _ATT /w _FTT of the armature tooth 11-I and the tolerance tooth 11-II is 1.27.

Specifically, the central angle corresponding to the notch of the modulation electrode 11-III and the bottom ends of two adjacent modulation electrodes is θ ₁ , and the central angle corresponding to the two ends of the side of the modulation electrode 11-III is θ ₂ , so The central angle corresponding to the two ends of the modulation electrode 11-III close to the side of the air gap is θ ₁ +θ ₂ , and the slot pitch angle of the modulation electrode 11-III is θ ₃ .

Specifically, the central angles θ ₁ , θ ₂ , and θ ₃ corresponding to the modulation poles 11-III satisfy the relational expression 4 (θ ₁ +θ ₂ )=θ ₃ , where θ ₁ /θ ₂ =0.8.

Specifically, the armature windings 12 are collectively wound on the armature teeth 11-I, and the span of the armature windings 12 is 1.

Specifically, the permanent magnet 22 is made of NdFeB material, and the pole arc coefficient of the permanent magnet 22 is 1.

Specifically, the number of poles of the modulation pole 11-III is N _m , the number of pole pairs of the armature winding 12 is N _w , the number of pole pairs of the permanent magnet 22 is N _p , and the number of pole pairs of the modulation pole 11-III is N m . The number of poles N _m , the number of pole pairs N _w of the armature winding 12 and the number of pole pairs N _p of the permanent magnet 22 satisfy the theoretical relationship of magnetic field modulation, that is, N _m −N _w =N _p .

In this embodiment, the stator modulation pole adopts a rhombus structure, the winding adopts a single-layer concentrated winding, and the rotor adopts a surface-mounted permanent magnet rotor structure with radial magnetization. The motor can be an inner rotor structure or an outer rotor structure. Compared with the traditional rectangular modulated pole vernier permanent magnet motor, the novel diamond modulated pole structure of the present invention can significantly increase the air gap magnetic density of the vernier permanent magnet motor, thereby improving its torque density. At the same time, the novel diamond-shaped modulation pole structure of the present invention can also increase its power factor.

Referring to FIG. 2 , it is a schematic diagram of the structure of the novel rhombus-shaped modulation electrode of the present invention. The number N _m of modulation electrodes 11-III is 40, and they are arranged opposite to each other along the circumferential surface.

Referring to FIG. 3 , it is a schematic diagram and dimension drawing of a conventional rectangular modulation pole stator. The modulation poles 11-III are rectangular, the modulation pole number N _m is 40, and the modulation pole duty ratio θ ₄ /2θ ₄ is always 0.5, and the same as the slot. The pitch angle θ ₃ satisfies the relationship 4θ ₄ =θ ₃ , and the slot pitch angle θ ₃ is 18°.

Referring to FIG. 4, it is a schematic structural diagram and dimensioning diagram of the novel diamond-shaped modulation pole stator of the present invention, wherein the modulation poles 11-III are rhombus-shaped, the modulation pole number N _m is 40, and the central angles θ ₁ and θ ₂ in the figure satisfy the relational expression 4(θ ₁ +θ ₂ )=18°, where θ ₁ /θ ₂ =0.8.

Referring to FIG. 5 , it is a no-load back-EMF waveform diagram of the traditional rectangular-modulated-pole VPM motor and the novel rhombic-modulated-pole VPM motor of the present invention. As shown in the figure, the new diamond-shaped modulated pole VPM motor of the present invention can greatly improve the no-load back EMF of the motor, and the third harmonic in the no-load back EMF is increased.

Referring to FIG. 6 , it is a torque waveform diagram of a conventional rectangular-modulated-pole VPM motor and a novel diamond-shaped modulated-pole VPM motor of the present invention. In comparison, the torque of the novel diamond-shaped modulating pole VPM motor of the present invention is increased by about 34.6%, and the torque ripple is almost unchanged.

The embodiments of the present invention have been described in detail above, but the above contents are only preferred embodiments of the present invention, and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still belong to the scope of the patent of the present invention.

Claims (2)

1. The utility model provides a novel rhombus modulation pole vernier permanent-magnet machine, includes stator and rotor, its characterized in that: an air gap is arranged between the stator and the rotor;

the stator comprises a stator core and an armature winding;

the stator iron core comprises armature teeth, fault-tolerant teeth, modulation poles and a stator yoke; the armature teeth and the fault-tolerant teeth are alternately and uniformly distributed in the circumferential direction, the top ends of the armature teeth and the fault-tolerant teeth are respectively provided with a modulation electrode, the modulation electrodes are in a diamond shape, and the modulation electrodes are arranged in pairs in opposite mode and are uniformly distributed at intervals along the circumferential surface;

the rotor includes a rotor core and a permanent magnet;

the permanent magnet adopts a radial magnetizing mode, and the surface of the permanent magnet is attached to the inner surface of the rotor core;

the stator iron core is formed by laminating silicon steel sheets, and the inner radius of the stator iron core is r₄The outer radius of the stator core isr₁The radius of the bottom of the modulation electrode is r₂The radius of the stator yoke is r₃The width of the armature teeth is w_ATTSaid fault-tolerant tooth width is w_FTT；

The inner radius and the outer radius ratio r of the stator core₄/r₁0.417, the ratio of the bottom radius of the modulation pole to the outer radius of the stator core r₂/r₁Is 0.933, the ratio of the radius of the stator yoke to the radius of the inner diameter of the stator core r₃/r₄1.4, the armature tooth width and fault-tolerant tooth width ratio w_ATT/w_FTTIs 1.27;

the central angle between the notch of the modulation electrode and the bottom end of the two adjacent modulation electrodes is theta₁The central angle corresponding to two end points of the side edge of the modulation electrode is theta₂The central angle corresponding to two end points of the modulation electrode close to the air gap side is theta₁+θ₂The groove pitch angle of the modulation pole is theta₃；

Central angle theta corresponding to the modulation pole₁，θ₂，θ₃Satisfies the relation 4 (theta)₁+θ₂)＝θ₃Wherein, theta₁/θ₂＝0.8；

The armature winding is wound on the armature teeth in a concentrated mode, and the span of the armature winding is 1;

the permanent magnet is formed by processing neodymium iron boron materials, and the pole arc coefficient of the permanent magnet is 1.

2. The novel diamond modulated pole vernier permanent magnet machine of claim 1, wherein: the number of the modulation poles is N_mThe number of pole pairs of the armature winding is N_wThe number of pole pairs of the permanent magnet is N_pNumber of poles N of said modulation pole_mThe number of pole pairs of the armature winding is N_wAnd the number of pole pairs N of the permanent magnet_pSatisfy the theoretical relationship of magnetic field modulation, namely N_m-N_w＝N_p。

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