CN113193670B

CN113193670B - Modularized magnetic flux reversing motor

Info

Publication number: CN113193670B
Application number: CN202110548806.4A
Authority: CN
Inventors: 苏鹏; 申怡; 王一维; 李永建; 胡艳芳
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2023-06-16
Anticipated expiration: 2041-05-20
Also published as: CN113193670A

Abstract

The invention discloses a modularized magnetic flux reversing motor, which comprises a plurality of modularized units distributed along the axial direction; each modular unit includes a stator core and a rotor module. According to the invention, through the modularized design, the positioning torque waveforms of two adjacent modularized units differ by 180 degrees, no-load positioning torques generated by the two modularized units are mutually offset when the same rotor is positioned, the peak value of the positioning torque of the motor is reduced, the torque pulsation is restrained, and the motor is more suitable for high-speed operation. According to the invention, through a modularized design, the amplitude of the no-load flux linkage of the motor is increased, meanwhile, the motor has winding complementarity and even harmonic cancellation, the sine of the permanent magnetic flux linkage of the motor is optimized, the counter-potential harmonic content of the motor is reduced, and the output torque pulsation of the motor is restrained. The invention has the advantages of high torque density and power density and small torque pulsation.

Description

Modularized magnetic flux reversing motor

Technical Field

The invention belongs to the technical field of motor manufacturing, and particularly relates to a modularized magnetic flux reversing motor.

Background

The permanent magnet of the traditional magnetic Flux reversing motor (Flux-Reversal Permanent Magnet Machine, FRPM) is attached to the surface of the stator teeth, and the armature winding is wound on the stator teeth, so that the cooling and heat dissipation are easy. The rotor is only composed of salient pole iron cores, has no winding or permanent magnet, has simple structure and is suitable for high-speed operation.

The traditional 6-slot/4-pole flux reversing motor can reduce fundamental frequency requirements and high-frequency related losses when running at high speed, but the 6-slot/4-pole topological structure has larger second order and other even harmonics in flux linkage and counter electromotive force, so that the torque pulsation is higher, and the vibration noise of the motor is larger in the running process. The literature 'Stator-Slot/Rotor-Pole Pair Combinations of Flux-Reversal Permanent Magnet Machine' proposes a Stator Slot/Rotor pole pair combination principle of a flux reversing permanent magnet motor, and the principle considers a magnetization mode and a magnetic leakage effect at the same time, but indicates that the counter potential waveform of the 6 Slot/4 pole flux reversing motor is seriously asymmetric, and the torque pulsation is overlarge, so that the use is not recommended.

The Chinese patent of application number 201310119939.5 discloses a stator surface-mounted doubly salient permanent magnet motor of a modularized rotor, which reduces the consumption of permanent magnets, simultaneously ensures that the permanent magnet flux of each coil of an armature winding is bipolar, improves the reliability of the motor, but has larger torque pulsation, and has unilateral magnetic pulling force of odd pole rotors, thereby influencing the high-speed operation of the motor.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a modularized magnetic flux reversing motor.

The technical scheme for solving the technical problems is that a modularized magnetic flux reversing motor is provided, which is characterized by comprising a plurality of modularized units distributed along the axial direction; each modular unit comprises a stator core and a rotor module;

the stator core is provided with a plurality of stator teeth, and the stator teeth are uniformly distributed in the circumferential direction of the stator core; all stator cores are arranged along the axial direction and completely coincide; the stator teeth at the same position of all the stator cores are provided with an armature winding which is wound along the axial direction;

one side surface of each stator tooth is provided with two permanent magnets along the circumferential direction of the stator core in a sticking way, and the magnetizing directions of the two permanent magnets are opposite; in one stator core, the permanent magnets on all stator teeth are mounted in the same way; the magnetizing directions of permanent magnets at the same positions on stator teeth at the same positions of two adjacent stator cores are opposite;

a magnetism isolating ring is arranged between the stator cores; magnetic isolation rings are arranged between the permanent magnets on different modularized units;

the axes of all the rotor modules are collinear; each rotor module consists of a plurality of mutually independent rotor teeth, the rotor teeth are uniformly distributed along the circumferential direction, and a gap is reserved between two adjacent rotor teeth; the positioning moment waveforms of two adjacent modularized units differ by 180 degrees; permanent magnet flux linkage phases in armature windings at the same position on two adjacent modular units are 180 degrees different; an air gap is formed between the permanent magnets and the rotor module.

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

1) According to the invention, through the modularized design, no-load positioning moment waveforms of two adjacent modularized units differ by 180 degrees, no-load positioning moment generated by the two modularized units are opposite to each other and offset when the same rotor is positioned, so that the peak value of the motor positioning moment is reduced through the cooperation between the modularized units, the motor output torque pulsation is restrained, smaller vibration and noise are generated when the motor is operated, and the motor is more suitable for high-speed operation.

2) According to the invention, through a modularized design, the amplitude of the no-load flux linkage of the motor is increased, meanwhile, the motor has winding complementarity, even harmonic components in the single coil permanent magnet flux linkage and induced potential are greatly reduced or offset, even harmonic offset is performed, the sine of the motor permanent magnet flux linkage is optimized, the counter potential harmonic content of the motor is reduced, and the output torque pulsation of the motor is inhibited.

3) The rotor of the invention also adopts a modularized design, and has less material and less iron loss.

4) The armature windings are in a centralized ring topology and separated from the permanent magnets, one armature winding is shared by a plurality of modularized units and is only wound on one stator tooth along the axial direction, so that the length of the end winding is reduced, copper consumption is reduced, and the operating efficiency of the motor is improved.

5) The permanent magnet is not provided with an armature winding, so that the influence of winding temperature rise in the traditional magnetic flux reversing motor on the permanent magnet is reduced, and the high-temperature demagnetization of the permanent magnet caused by the heating of the winding is avoided. In addition, the permanent magnet and the armature winding are arranged on the stator side, which is beneficial to cooling and heat dissipation. In the high-speed running process, the iron loss and the permanent magnet eddy current loss are effectively reduced.

6) The motor can be used for electric operation and power generation operation.

7) The motor provided by the invention belongs to a stator permanent magnet motor, and has the advantages of high torque density and high efficiency.

8) The rotor has no permanent magnet or armature winding, is only made of magnetic conductive materials, has simple structure and high mechanical strength, and is suitable for high-speed operation.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a motor according to embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of a modular unit according to embodiment 1 of the present invention;

FIG. 3 is a schematic view of another modular unit adjacent to the modular unit of FIG. 2 according to embodiment 1 of the present invention;

fig. 4 is a waveform diagram of the positioning moment of each modular unit and the entire motor in accordance with embodiment 1 of the present invention when the motor is empty.

In the figure: 1. modular unit, 2, stator core, 3, separate magnetic ring, 4, permanent magnet, 5, armature winding, 6, rotor module, 7, stator tooth, 8, rotor tooth.

511. A phase A positive armature winding; 512. a phase A negative armature winding; 521. a B-phase positive armature winding; 522. a phase B negative armature winding; 531. a C-phase positive armature winding; 532. and C-phase negative electrode armature winding.

Detailed Description

Specific examples of the present invention are given below. The specific examples are provided only for further elaboration of the invention and do not limit the scope of the claims of the present application.

The invention provides a modularized magnetic flux reversing motor (motor for short), which is characterized by comprising a plurality of modularized units 1 distributed along the axial direction; each modular unit 1 comprises a stator core 2 and a rotor module 6;

the stator core 2 is provided with a plurality of stator teeth 7, and the stator teeth 7 are uniformly distributed in the circumferential direction of the stator core 2; all stator cores 2 are arranged axially and completely coincide; the stator teeth 7 at the same position of all the stator cores 2 are provided with an armature winding 5 which is wound along the axial direction;

one side surface of each stator tooth 7 is provided with two permanent magnets 4 along the circumferential direction of the stator core 2 in a mounted manner, and the magnetizing directions of the two permanent magnets 4 are opposite (one is outwards along the radial direction of the stator tooth 7, and the other is inwards along the radial direction of the stator tooth 7); in one stator core 2, the permanent magnets 4 on all the stator teeth 7 are mounted in the same way (i.e. the magnetizing directions of adjacent permanent magnets 4 on adjacent stator teeth 7 are opposite); the magnetizing directions of the permanent magnets 4 at the same positions on the stator teeth 7 at the same positions of the two adjacent stator cores 2 are opposite;

a magnetism isolating ring 3 is arranged between the stator cores 2, and isolation between the stator cores 2 is realized through the magnetism isolating ring 3; a magnetism isolating ring 3 is arranged between the permanent magnets 4 on different modularized units 1;

the axes of all the rotor modules 6 are collinear; each rotor module 6 is composed of a plurality of mutually independent rotor teeth 8, the rotor teeth 8 are uniformly distributed along the circumferential direction, and a gap with the same size is formed between two adjacent rotor teeth 8; the no-load positioning torque waveforms of two adjacent modularized units 1 differ by 180 degrees; the permanent magnet flux linkage phases in the armature windings 5 at the same position on two adjacent modular units 1 are 180 degrees different; an air gap is formed between the permanent magnets 4 and the rotor module 6.

Preferably, each armature winding 5 and the armature winding 5 radially opposite thereto constitute a one-phase armature winding.

Preferably, the stator core 2 has a salient pole structure.

Preferably, the rotor module 6 is disposed inside the stator core 2 to form an inner rotor structure, or disposed outside the stator core 2 to form an outer rotor structure; when the inner rotor structure is formed, the two permanent magnets 4 are attached to the inner side surfaces of the stator teeth 7 along the circumferential direction of the stator core 2, and the magnetizing directions of the two permanent magnets 4 are opposite; when the outer rotor structure is formed, two permanent magnets 4 are attached to the outer side surfaces of the stator teeth 7 along the circumferential direction of the stator core 2, and the magnetizing directions of the two permanent magnets 4 are opposite.

Preferably, the rotor module 6 is of straight or skewed slot configuration.

Preferably, the stator core 2 and the rotor module 6 are made of magnetic conductive materials such as silicon steel sheets.

Preferably, the permanent magnet 4 is made of neodymium-iron-boron, samarium-cobalt or ferrite permanent magnet material.

Preferably, the armature winding 5 is a concentrated armature winding.

Preferably, the rotor teeth 8 are wrapped around the rotor shaft by clips made of non-magnetically conductive material during installation.

Example 1

In the embodiment, the 6-slot/4-pole magnetic flux reversing motor with an inner rotor structure is adopted, two modularized units 1 are adopted, and the effective length of the whole motor is 75mm as shown in fig. 1.

In each modularized unit 1, the number of stator teeth 7 is 6, the stator teeth are uniformly distributed in the circumferential direction of the stator core 2 by adopting a salient pole structure, the stator pole arc is 40.5 degrees, the inner diameter of the stator core 2 is 70.4mm, and the outer diameter of the stator core 2 is 128mm. The thickness of the permanent magnet in the magnetizing direction is 1.6mm, and the pole arc of the permanent magnet is 18deg.

In each modular unit 1, the armature winding 5 has 6 concentrated ring windings, namely an a-phase positive armature winding 511, an a-phase negative armature winding 512, a B-phase positive armature winding 521, a B-phase negative armature winding 522, a C-phase positive armature winding 531 and a C-phase negative armature winding 532; the permanent magnet flux linkage in all armature windings 5 is bipolar change;

according to the star vector diagram of the slot conductor, compared with other cases, when the A-phase positive armature winding 511 and the A-phase negative armature winding 512 are connected in series to form an A-phase coil group, the flux linkage amplitude is maximum, at this time, the A-phase positive armature winding 511 and the A-phase negative armature winding 512 are opposite in radial direction (namely, the space position central angles are 180 degrees different), the permanent magnet flux linkage phases of the inner turn links of the armature windings are the same, and the amplitude is the same. Similarly, the B-phase positive armature winding 521 and the B-phase negative armature winding 522 are connected in series to form a B-phase coil group, and the C-phase positive armature winding 531 and the C-phase negative armature winding 532 are connected to form a C-phase coil group.

In each modularized unit 1, the rotor module 6 is formed by uniformly distributing four fan-shaped rotor teeth 8 along the circumferential direction, the inner diameter of each rotor tooth 8 is 44.5mm, the outer diameter of each rotor tooth 8 is 66.5mm, and the rotor pole arc is 55 degrees; the clearance angle between two adjacent rotor teeth 8 is 35 °. The rotor teeth 8 on adjacent two rotor modules 6 differ by 45 ° (i.e. after the adjacent two rotor modules 6 are fully coincident, one rotor is rotated 45 ° clockwise or counter-clockwise with respect to the other rotor and the direction of rotation of all rotor modules 6 is the same).

During measurement, the positioning moment waveforms output by the two modularized units and the whole motor when in no-load are respectively measured, as shown in fig. 4. As can be seen from fig. 4, the peak-to-peak value of the detent torque is reduced from 2.1Nm to 0.9Nm by the cooperation between the modular units, and the torque ripple of the flux reversing motor is significantly reduced because the torque ripple is mainly caused by the detent torque.

The rotor teeth 8 on adjacent two rotor modules 6 differ by 45 ° and thus the permanent magnet flux linkage in the armature windings 5 in the same position on adjacent two modular units 1 differ by 180 °; the magnetizing directions of the permanent magnets 4 at the same positions on the stator teeth 7 at the same positions of the adjacent two modularized units 1 are opposite, so that the flux linkage magnitudes in the armature coils 5 at the same positions on the adjacent two modularized units 1 are opposite; the flux linkage phase is 180 degrees different and the flux linkage amplitude is opposite, so that the motor no-load flux linkage amplitude is increased, meanwhile, the flux linkage changes of two adjacent modularized units 1 have complementarity, even harmonic cancellation is carried out, the sine of the motor permanent magnet flux linkage is optimized, the counter potential harmonic content of the motor is reduced, and the motor output torque pulsation is restrained.

The rotor teeth 8 on two adjacent rotor modules 6 differ by 45 degrees, so that no-load positioning torque waveforms of two adjacent modularized units 1 differ by 180 degrees, no-load positioning torques generated by the two modularized units are opposite to each other in the same rotor position, and therefore, peak and peak values of motor positioning torque are reduced through cooperation between the modularized units, so that motor output torque pulsation is restrained, smaller vibration and noise are generated when the motor operates, and the motor is more suitable for high-speed operation.

The motor of the invention has the following characteristics when in operation:

the motor only depends on the permanent magnet 4 to generate an excitation magnetic field, and the output torque, the power density and the speed regulation performance of the motor are regulated by controlling the armature current. In the high-speed running process, the iron loss and the permanent magnet eddy current loss are effectively reduced.

The invention is applicable to the prior art where it is not described.

Claims

1. A modular flux reversing motor, comprising a plurality of modular units distributed axially; each modular unit comprises a stator core and a rotor module;

the axes of all the rotor modules are collinear; each rotor module consists of a plurality of mutually independent rotor teeth, the rotor teeth are uniformly distributed along the circumferential direction, and a gap is reserved between two adjacent rotor teeth; after the adjacent two rotor modules are completely overlapped, one rotor rotates 45 degrees clockwise or anticlockwise relative to the other rotor, and the rotation directions of all the rotor modules are the same, so that the rotor teeth on the adjacent two rotor modules are different by 45 degrees; the positioning moment waveforms of two adjacent modularized units differ by 180 degrees; permanent magnet flux linkage phases in armature windings at the same position on two adjacent modular units are 180 degrees different; an air gap is formed between the permanent magnets and the rotor module.

2. The modular flux reversing motor of claim 1, wherein the stator core is of salient pole construction.

3. The modular flux reversing motor of claim 1, wherein the rotor module is disposed inside the stator core to form an inner rotor structure or disposed outside the stator core to form an outer rotor structure; when the inner rotor structure is formed, two permanent magnets are attached to the inner side surfaces of the stator teeth along the circumferential direction of the stator core, and the magnetizing directions of the two permanent magnets are opposite; when the outer rotor structure is formed, two permanent magnets are attached to the outer side surfaces of the stator teeth along the circumferential direction of the stator core, and magnetizing directions of the two permanent magnets are opposite.

4. The modular flux reversing motor of claim 1, wherein the rotor module is a straight slot structure or a skewed slot structure.

5. The modular flux reversing motor of claim 1, wherein the stator core and the rotor module are each of magnetically permeable material.

6. The modular flux reversing motor of claim 1, wherein the permanent magnet is a neodymium-iron-boron, samarium-cobalt, or ferrite permanent magnet material.

7. The modular flux reversing motor of claim 1, wherein the armature winding is a concentrated armature winding.

8. The modular flux reversing motor of claim 1, wherein the rotor teeth are sector-ring shaped in shape.