CN113193670B - Modularized magnetic flux reversing motor - Google Patents

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

A Modular Flux Reversal Motor

technical field

The invention belongs to the technical field of motor manufacturing, in particular to a modular magnetic flux reversal motor.

Background technique

The permanent magnets of the traditional Flux-Reversal Permanent Magnet Machine (FRPM) are mounted on the surface of the stator teeth, and the armature windings are wound on the stator teeth, which is easy to cool and dissipate heat. The rotor is only composed of a salient pole core, without windings or permanent magnets, with a simple structure and suitable for high-speed operation.

Conventional 6-slot/4-pole flux reversal motors can reduce fundamental frequency requirements and high-frequency related losses at high speeds, but the 6-slot/4-pole topology has large second-order and other couplings in flux linkage and back EMF Subharmonic, which makes its torque ripple higher, resulting in greater vibration and noise of the motor during operation. The literature "Stator-Slot/Rotor-Pole PairCombinations of Flux-Reversal Permanent Magnet Machine" puts forward the principle of stator slot/rotor pole pair combination of flux-reversed permanent magnet motor, which considers the magnetization mode and flux leakage effect at the same time, but It is pointed out in the article that the back EMF waveform of the 6-slot/4-pole flux reversal motor is seriously asymmetrical, and the torque ripple is too large, so it is not recommended to use it.

The Chinese patent application number 201310119939.5 discloses a surface-mounted double salient pole permanent magnet motor with a modular rotor stator. While reducing the amount of permanent magnets, the permanent magnet flux linkage of each coil of the armature winding is still bipolar. Changes, and improve the reliability of the motor, but the torque ripple of the motor is large, and there is a unilateral magnetic pull on the odd-numbered pole rotor, which affects the high-speed operation of the motor.

Contents of the invention

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a modular flux reversal motor.

The technical solution of the present invention to solve the technical problem is to provide a modular flux reversal motor, which is characterized in that the motor includes several modular units distributed along the axial direction; each modular unit includes a stator core and a rotor module;

The stator core has several stator teeth, and the stator teeth are evenly distributed in the circumferential direction of the stator core; all the stator cores are arranged in the axial direction and completely coincident; all the stator teeth at the same position of the stator core are provided with an electric motor wound along the axial direction. pivot winding;

One side surface of each stator tooth is mounted with two permanent magnets along the circumferential direction of the stator core, and the magnetization direction of the two permanent magnets is opposite; in a stator core, the permanent magnets on all stator teeth are mounted in the same way ; The magnetization directions of the permanent magnets at the same position on the stator teeth at the same position on two adjacent stator cores are opposite;

A magnetic isolation ring is set between the stator cores; a magnetic isolation ring is set between the permanent magnets on different modular units;

The axis centers of all rotor modules are collinear; each rotor module is composed of several mutually independent rotor teeth, and the rotor teeth are evenly distributed along the circumference, and there is a gap between two adjacent rotor teeth; the adjacent two modular units The positioning torque waveforms differ by 180°; the phases of the permanent magnet flux linkages in the armature windings at the same position on two adjacent modular units differ by 180°; an air gap is formed between the permanent magnets and the rotor module.

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

1) In the present invention, through the modular design, the no-load positioning torque waveforms of two adjacent modular units differ by 180°, and the no-load positioning torques generated by the two modular units at the same rotor position are opposite to each other to offset each other, so by The cooperation between the modular units reduces the peak-to-peak value of the positioning torque of the motor, thereby suppressing the output torque ripple of the motor, generating less vibration and noise when the motor is running, and is more suitable for high-speed operation.

2) The present invention increases the amplitude of the no-load flux linkage of the motor through the modular design, and at the same time, the motor has winding complementarity, which greatly reduces or cancels the even-order harmonic components in the permanent magnet flux-linkage and induced potential of a single coil, and the even-order Harmonic cancellation optimizes the sinusoidal nature of the permanent magnet flux linkage of the motor, reduces the harmonic content of the motor's back EMF, and suppresses the output torque ripple of the motor.

3) The rotor of the present invention also adopts a modular design, which requires less material and less iron consumption.

4) The armature winding is a centralized ring topology, which is separated from the permanent magnet. One armature winding is shared by multiple modular units and is only wound on one stator tooth in the axial direction, which reduces the length of the end winding and reduces the Reduce copper consumption and improve the operating efficiency of the motor.

5) There is no armature winding on the permanent magnet, which reduces the influence of the temperature rise of the winding on the permanent magnet in the traditional flux reversal motor, and avoids the high temperature demagnetization of the permanent magnet caused by the heating of the winding. In addition, the permanent magnets and armature windings are placed on the stator side, which is conducive to cooling and heat dissipation. During high-speed operation, the iron loss and permanent magnet eddy current loss are effectively reduced.

6) The motor of the present invention can be used for both electric operation and power generation operation.

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

8) There is neither permanent magnet nor armature winding on the rotor, it is only made of magnetically conductive material, with simple structure and high mechanical strength, suitable for high-speed operation.

Description of drawings

1 is a schematic diagram of the overall structure of the motor according to Embodiment 1 of the present invention;

Fig. 2 is a schematic structural diagram of a modular unit in Embodiment 1 of the present invention;

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

Fig. 4 is a waveform diagram of the positioning torque of each modular unit and the whole motor in the first embodiment of the present invention when it is unloaded.

In the figure: 1. Modular unit, 2. Stator core, 3. Magnetic isolation ring, 4. Permanent magnet, 5. Armature winding, 6. Rotor module, 7. Stator teeth, 8. Rotor teeth.

511. Phase A positive armature winding; 512. Phase A negative armature winding; 521. Phase B positive armature winding; 522. Phase B negative armature winding; 531. Phase C positive armature winding; 532. Phase C negative armature winding.

Detailed ways

Specific examples of the present invention are given below. The specific embodiments are only used to further describe the present invention in detail, and do not limit the protection scope of the claims of the present application.

The present invention provides a modular magnetic flux reversal motor (referred to as motor), which is characterized in that the motor includes several modular units 1 distributed along the axial direction; each modular unit 1 includes a stator core 2 and a rotor module 6;

The stator core 2 has several stator teeth 7, and the stator teeth 7 are evenly distributed in the circumferential direction of the stator core 2; all the stator cores 2 are arranged in the axial direction and completely overlap; all the stator teeth 7 at the same position of the stator core 2 are provided with an axially wound armature winding 5;

One side surface of each stator tooth 7 is mounted with two permanent magnets 4 along the circumferential direction of the stator core 2 and the magnetization directions of the two permanent magnets 4 are opposite (one is outward along the radial direction of the stator tooth 7, and the other is along the radial direction of the stator tooth 7 radially inward); in a stator core 2, the mounting method of the permanent magnets 4 on all stator teeth 7 is the same (that is, the magnetization direction of the adjacent permanent magnets 4 on the adjacent stator teeth 7 On the contrary); the magnetization directions of the permanent magnets 4 at the same positions on the stator teeth 7 at the same positions of the adjacent two stator cores 2 are opposite;

A magnetic isolation ring 3 is arranged between the stator cores 2, and the isolation between the stator cores 2 is realized through the magnetic isolation ring 3; a magnetic isolation ring 3 is arranged between the permanent magnets 4 on different modular units 1;

The axis centers of all the rotor modules 6 are collinear; each rotor module 6 is composed of several mutually independent rotor teeth 8, the rotor teeth 8 are evenly distributed along the circumferential direction, and there are gaps of the same size between two adjacent rotor teeth 8; The no-load detent torque waveforms of two adjacent modular units 1 differ by 180°; the phases of the permanent magnet flux linkage in the armature winding 5 at the same position on two adjacent modular units 1 differ by 180°; the permanent magnet 4 and An air gap is formed between the rotor modules 6 .

Preferably, each armature winding 5 and the armature winding 5 diametrically opposite to it form a phase armature winding.

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

Preferably, the rotor module 6 is arranged inside the stator core 2 to form an inner rotor structure, or arranged outside the stator core 2 to form an outer rotor structure; Install two permanent magnets 4 and the magnetization directions of the two permanent magnets 4 are opposite; 4 is magnetized in the opposite direction.

Preferably, the rotor module 6 is a straight slot structure or a skewed slot structure.

Preferably, both the stator core 2 and the rotor module 6 are magnetically permeable 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 adopts a centralized armature winding.

Preferably, during installation, the rotor teeth 8 can be covered on the rotor shaft with a hoop made of a non-magnetic material.

Example 1

In this embodiment, a 6-slot/4-pole flux reversal motor with an inner rotor structure is adopted, and there are two modular units 1, as shown in FIG. 1 , and the overall effective length of the motor is 75 mm.

In each modular unit 1, there are 6 stator teeth 7, which adopt a salient pole structure and are evenly distributed in the circumferential direction of the stator core 2. The stator pole arc is 40.5°, the inner diameter of the stator core 2 is 70.4 mm, and the outer diameter of the stator core 2 is 128mm. The thickness of the permanent magnet magnetization 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 centralized ring windings, which are respectively A-phase positive pole armature winding 511, A-phase negative pole armature winding 512, B-phase positive pole armature winding 521, and B-phase negative pole winding. Armature winding 522, C-phase positive pole armature winding 531 and C-phase negative pole armature winding 532; the permanent magnet flux linkages in all armature windings 5 are bipolar changes;

According to the star-shaped vector diagram of the slot conductor, compared with other situations, when the A-phase positive armature winding 511 and the A-phase negative armature winding 512 are connected in series to form the A-phase coil group, the flux linkage amplitude is the largest. The armature winding 511 is diametrically opposed to the A-phase negative armature winding 512 (that is, the central angle of the spatial position differs by 180°). 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 modular unit 1, the rotor module 6 is composed of four fan-shaped rotor teeth 8 uniformly distributed along the circumferential direction, the inner diameter of the rotor teeth 8 is 44.5mm, the outer diameter of the rotor teeth 8 is 66.5mm, and the rotor pole arc is 55°; The gap angle between two adjacent rotor teeth 8 is 35°. The difference between the rotor teeth 8 on two adjacent rotor modules 6 is 45° (that is, after two adjacent rotor modules 6 are completely overlapped, one rotor rotates 45° clockwise or counterclockwise relative to the other rotor, and all rotor modules 6 in the same direction of rotation).

During the measurement, the positioning torque waveforms output by the two modular units and the entire motor under no load are measured respectively, as shown in Figure 4. It can be seen from Fig. 4 that the peak-to-peak value of the positioning torque is reduced from 2.1Nm to 0.9Nm through the cooperation between the modular units. Since the torque ripple of the magnetic flux reversal motor is mainly caused by the positioning torque, the rotational speed of the motor of the present invention Torque ripple is significantly reduced.

The difference between the rotor teeth 8 on two adjacent rotor modules 6 is 45°, so the phase difference of the permanent magnet flux linkage in the armature winding 5 at the same position on two adjacent modular units 1 is 180°; The magnetization directions of the permanent magnets 4 at the same positions on the stator teeth 7 at the same positions of the two modular units 1 are opposite, so the flux linkage amplitudes in the armature coils 5 at the same positions on two adjacent modular units 1 are opposite; The phase difference of the flux linkage is 180° and the amplitude of the flux linkage is opposite, so the amplitude of the no-load flux linkage of the motor can be increased. At the same time, the flux linkage changes of two adjacent modular units 1 are complementary, and the even harmonics are cancelled, which optimizes the motor The sinusoidal nature of the permanent magnet flux linkage reduces the harmonic content of the back EMF of the motor and suppresses the output torque ripple of the motor.

The difference between the rotor teeth 8 on two adjacent rotor modules 6 is 45°, so the no-load detent torque waveforms of two adjacent modular units 1 differ by 180°, and the no-load torque generated by the two modular units at the same rotor position The positioning torque is opposite to each other, so the peak-to-peak value of the positioning torque of the motor is reduced through the cooperation between the modular units, thereby suppressing the output torque ripple of the motor, generating less vibration and noise when the motor is running, and more suitable for high-speed operation.

The motor of the present invention has the following characteristics during operation:

The motor only relies on the permanent magnet 4 to generate an excitation magnetic field, and the output torque, power density and speed regulation performance of the motor are adjusted by controlling the armature current. During high-speed operation, the iron loss and permanent magnet eddy current loss are effectively reduced.

What is not mentioned in the present invention is applicable to the prior art.

Claims (8)

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 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; 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.

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