CN111884460B - Axial magnetic flux hybrid excitation memory motor - Google Patents

Abstract

The invention discloses an axial magnetic flux hybrid excitation memory motor, comprising a stator disk and a rotor disk with a Halbach structure. The stator disk is composed of a stator iron core and a three-phase armature winding, wherein the stator iron core includes a stator yoke and a stator. teeth, a stator slot is formed between two adjacent stator teeth, and the three-phase armature windings are wound on the stator teeth; the rotor disk satisfies the Halbach composite array, and its outer side is excited by a plurality of AlNiCo permanent magnets and a plurality of pulsed excitations in series. Winding composition, the magnetization directions of two adjacent AlNiCo permanent magnets are opposite, and a soft magnetic material is arranged between the AlNiCo permanent magnets, and the pulse excitation winding is wound around the AlNiCo permanent magnets; NdFeB permanent magnets The magnets are attached to the inner side of the rotor disk at a certain angle, and the magnetization directions of two adjacent NdFeB permanent magnets are opposite. The invention has a compact structure, can realize flexible adjustment of the air-gap magnetic field of the motor, and has a wider range of speed regulation and the performance of low speed and high torque.

Description

An Axial Flux Hybrid Excitation Memory Motor

technical field

The invention relates to an axial magnetic flux hybrid excitation memory motor, which belongs to the technical field of motors.

Background technique

In recent years, with the continuous advancement of science and technology, the performance of permanent magnets made of rare earth materials has been continuously improved. Permanent magnet motors have been greatly sought after due to their high efficiency and high power density. fields have been widely used. In real life, the structure of the permanent magnet motor is not single. Among all kinds of permanent magnet motors, the axial magnetic field permanent magnet motor, also known as the disc motor, not only has a small size, a very compact structure, It has the characteristics of short size, high torque density and high efficiency, and has more obvious advantages in some special working environments. Axial magnetic field permanent magnet motors are mainly used for motion control, and have been widely used in some direct-drive occasions that need to meet the requirements of small axial size and large enough torque at the same time.

When the permanent magnet motor is used for driving occasions, when the permanent magnet motor is in the low-speed constant-torque region, the air-gap magnetic field should be large enough to achieve a high internal energy index. When the permanent magnet motor is in the high-speed constant power region, the air-gap magnetic field should be reduced enough to allow the motor to have a wide enough speed regulation range. In common permanent magnet motors, due to the inherent characteristics of permanent magnet materials such as NdFeB, the air gap magnetic field of the motor is basically constant, which greatly limits its application scenarios. In order to make the air gap of the permanent magnet motor adjustable, a motor that realizes the air gap adjustment by changing the magnetization level of the permanent magnet is gradually gaining popularity. This motor uses a new permanent magnet material-AlNiCo, which It has the characteristics of high remanence and low coercivity. Its magnetization state can be changed instantaneously by applying a pulse current to it, and its magnetization level can be memorized, thereby realizing the flexible adjustment of the air gap magnetic field. This air-gap magnetic field adjustment method hardly produces electrical excitation loss, and does not sacrifice other performance indicators of the motor. It can be regarded as a very simple and efficient magnetic adjustment scheme.

Lin Heyun et al. of Southeast University mentioned an axial magnetic field flux switching surface-mounted permanent magnet memory motor in the article on the research review and latest progress of memory motors. , and then control the adjustment of the air gap magnetic field, and this type of motor has the advantages of high back EMF sine, small positioning torque and torque ripple, high power density and high fault tolerance, but due to the use of low coercivity AlNiCo Permanent magnets will cause the maximum air gap magnetic flux to fail to reach the required level of NdFeB permanent magnet motors, resulting in a decrease in the overall performance of the motor.

In order to obtain a hybrid permanent magnet memory motor with higher power density, controllable magnetic flux, and excellent heat dissipation performance, the Chinese Patent Publication No. CN206237285U, named "A Halbach Concentrating Type Axial Magnetic Field Hybrid Permanent Magnet Motor" adopts A double-stator and single-rotor motor structure is proposed, but the double-stator structure is adopted, which makes the motor structure more complex and the motor is not compact enough.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art. The present invention provides an axial magnetic flux hybrid excitation memory motor to obtain a motor with high power density, adjustable magnetism, light weight, small size, and heat dissipation performance. Excellent permanent magnet memory motor.

The present invention specifically adopts the following technical solutions to solve the above-mentioned technical problems:

An axial magnetic flux hybrid excitation memory motor includes a stator disk and a rotor disk with a Halbach structure, a single-sided air gap structure is formed between the stator disk and the rotor disk, and is coaxially mounted on a mounting shaft, and the mounting shaft is connected by a bearing. Fixed on the casing of the motor, the stator disc is composed of a stator iron core and a three-phase armature winding, wherein the stator iron core includes a stator yoke and stator teeth, a stator slot is formed between two adjacent stator teeth, and the three-phase armature winding is wound. On the stator teeth; the rotor disk satisfies the Halbach composite array, the outer side of which is composed of a plurality of AlNiCo permanent magnets and a plurality of pulsed excitation windings connected in series with each other, the magnetization directions of two adjacent AlNiCo permanent magnets are opposite, and the aluminum Soft magnetic materials are arranged between the nickel-cobalt permanent magnets, and pulse excitation windings are wound around the alnico permanent magnets; the neodymium-iron-boron permanent magnets are attached to the inner side of the rotor disk at a certain angle, and the two adjacent neodymium-iron The magnetization direction of boron permanent magnets is opposite.

Further, as a preferred technical solution of the present invention: the number of NdFeB permanent magnets on the rotor disk, the number of AlNiCo permanent magnets and the number of stator teeth on the stator disk are equal, all being an integer multiple of 6.

Further, as a preferred technical solution of the present invention, the number of NdFeB permanent magnets, the number of AlNiCo permanent magnets, and the number of stator teeth are all six.

Further, as a preferred technical solution of the present invention: the NdFeB permanent magnet is attached to the surface of the soft magnetic material, the AlNiCo permanent magnet and the soft magnetic material are spliced into a rotor ring, and the center of the NdFeB permanent magnet is Align with the center of the stator teeth.

Further, as a preferred technical solution of the present invention: two three-phase armature winding coils with a difference of 180 degrees are connected in series to form a single phase, with a total of three phases; all pulse excitation windings are connected in series. Magnetic modulation is performed by means of DC pulses.

Further, as a preferred technical solution of the present invention, the stator yoke and the stator teeth are both formed by lamination of cold-rolled non-oriented silicon steel sheets.

Further, as a preferred technical solution of the present invention: the rotor disk includes a non-magnetically conductive ring, 6 rotor core teeth arranged at equal intervals along the circumferential direction of the non-magnetically conductive ring, and 6 inner and outer NdFeB permanent magnets and AlNiCo permanent magnets are arranged at equal intervals.

Further, as a preferred technical solution of the present invention, the three-phase armature winding and the pulse excitation winding are both concentrated windings.

Further, as a preferred technical solution of the present invention, the NdFeB permanent magnets, the AlNiCo permanent magnets and the rotor core teeth are all sector-shaped.

Further, as a preferred technical solution of the present invention, the NdFeB permanent magnets are magnetized in the axial direction, and the AlNiCo permanent magnets are magnetized in the circumferential direction, forming a Halbach structure.

The present invention adopts the above-mentioned technical scheme, and can produce the following technical effects:

1. The present invention not only has the characteristics of disk permanent magnet motor and memory motor, but also includes the advantages of Halbach type motor. The motor includes a stator disk and a rotor disk, and the rotor disk is equipped with NdFeB permanent magnets and aluminum alloys. Nickel-cobalt permanent magnet, the excitation winding is wound around the alnico permanent magnet, and the magnetization method is pulsed magnetic adjustment. The magnetization state of the alnico permanent magnet is adjusted by controlling the magnitude and direction of the pulse current, and then the air gap of the permanent magnet motor is adjusted. Magnetic field; while having the advantages of memory motor, the motor still retains the advantages of compact structure and small magnetic flux leakage of the disk type permanent magnet motor.

2. There are no permanent magnets on the stator disk of the present invention, so that the structure of the stator disk is simpler and the weight is lighter, and both the stator and the soft magnet are made of cold-rolled non-oriented silicon steel sheet material, which reduces the eddy current effect and magnetic flux leakage, and The manufacturing cost of the motor is reduced.

3. The excitation mode of the present invention is a self-excitation mode, which improves the working efficiency of the permanent magnet motor by adding a DC power supply and a pulse generating device to the rotor disk for magnetic regulation.

4. The main excitation source of the present invention is two types of permanent magnets: NdFeB permanent magnets and AlNiCo permanent magnets. The speed regulation range of the motor can be determined by controlling the consumption relationship of these two permanent magnet materials. The magnitude of the pulse current is used to control the magnetization and working point of the AlNiCo permanent magnet, thereby realizing the flexible adjustment of the air-gap magnetic field of the motor, so that the motor has a wider speed regulation range and has the performance of low speed and high torque.

Description of drawings

FIG. 1 is a schematic three-dimensional structure diagram of an axial magnetic flux hybrid excitation memory motor of the present invention.

Fig. 2(a) is a schematic diagram of the inner side structure of the rotor disk of the present invention, and Fig. 2(b) is a schematic diagram of the outer side structure of the stator disk of the present invention.

FIG. 3( a ) is a schematic diagram of the outer structure of the rotor disk of the present invention, and FIG. 3( b ) is a schematic diagram of the inner structure of the stator disk of the present invention.

FIG. 4 is a schematic diagram of a magnetizing magnetic circuit of the present invention.

FIG. 5 is a schematic diagram of the demagnetization magnetic circuit of the present invention.

In the figure: 1, rotor core teeth; 2, stator yoke; 2.1, stator teeth; 2.2, stator slots; 3.1, three-phase armature winding; 3.2, pulse excitation winding; 4, AlNiCo permanent magnet; 4.1, clockwise AlNiCo permanent magnets magnetized in the circumferential direction; 4.2. AlNiCo permanent magnets magnetized in the counterclockwise direction; 5. NdFeB permanent magnets; ; 5.2. NdFeB permanent magnets magnetized axially perpendicular to the paper face outwards; 6. Non-magnetic conductive ring.

Detailed ways

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the present invention designs an axial magnetic flux hybrid excitation memory motor, which includes a stator disk and a rotor disk with a Halbach structure. A single-sided air gap structure is formed between the stator disk and the rotor disk and is installed coaxially. On the installation shaft, the installation shaft is fixed on the casing of the motor through the bearing. The stator disc is composed of the stator iron core and the three-phase armature winding 3.1. At the same time, the stator iron core includes the stator yoke 2 and the stator teeth 2.1, and the two adjacent stators are A stator slot 2.2 is formed between the teeth 2.1, and the three-phase armature windings 3.1 are wound on the stator teeth 2.1. The outer and inner structures are shown in Figure 2(b) and Figure 3(a); the rotor disk satisfies the Halbach composite array structure, Its outer side is composed of a plurality of AlNiCo permanent magnets 4 and a plurality of pulse excitation windings 3.2 connected in series with each other. The magnetization directions of the two adjacent AlNiCo permanent magnets 4 are opposite, and the AlNiCo permanent magnets 4 are placed between each other. With soft magnetic material, the pulse excitation winding 3.2 is wound on the AlNiCo permanent magnet 4; the NdFeB permanent magnet 5 is attached to the inner side of the rotor disk at a certain angle, and the The magnetization direction is also reversed.

Wherein, the number of NdFeB permanent magnets 5 and AlNiCo permanent magnets 4 on the rotor disk and the number of stator teeth 2.1 on the stator disk are all equal, which are integer multiples of 6, preferably 6 in this embodiment. And the NdFeB permanent magnet 5 is attached to the surface of the soft magnetic material, the AlNiCo permanent magnet 4 is spliced with the soft magnetic material to form a rotor ring, and the center of the NdFeB permanent magnet 5 is aligned with the center of the stator teeth 2.1.

The stator disk is only composed of a stator iron core and an armature winding. Since there is no permanent magnet on the stator disk, the structure of the stator disk is relatively simple and easy to process. The difference between the two is 180 ^. The three-phase armature winding coils are connected in series to form a single phase, for a total of three phases.

The rotor disk is designed according to the Halbach composite array. The outer side of the rotor disk is composed of 6 circumferentially magnetized AlNiCo permanent magnets and a plurality of pulse excitation windings. The pulse excitation windings are wound on 3.2 groups of AlNiCo permanent magnets 4. The magnetization directions of two adjacent AlNiCo permanent magnets 4 are opposite. As shown in Figure 2(a), the adjacent two are AlNiCo permanent magnets 4.1 magnetized circumferentially in the clockwise direction and aluminum magnetized circumferentially in the counterclockwise direction. Nickel-Cobalt Permanent Magnets 4.2. The inner side is attached to 6 NdFeB permanent magnets 5 at a certain angle. The NdFeB permanent magnets 5 are magnetized axially, and the magnetization directions of any two adjacent NdFeB permanent magnets are opposite, as shown in Figure 2 As shown in (a), it includes two NdFeB permanent magnets 5.1 and 5.3 which are axially magnetized inwards perpendicular to the paper surface, and a NdFeB permanent magnet 5.2 which is axially magnetized perpendicular to the outer surface of the paper surface.

The permanent magnets on the rotor disk are all surface-mounted structures, and anaerobic glue is used to make the permanent magnets stick to the surface of the disk, which can not only reduce the production cost but also further reduce the magnetic flux leakage, which greatly improves the utilization rate of the permanent magnets. In this way, the heat dissipation of the permanent magnet is also helped, and the operation efficiency of the permanent magnet motor is improved.

The axial magnetic flux hybrid excitation memory motor is a single-stator and single-rotor motor. The NdFeB permanent magnets 5 on the rotor disk are attached to the inner side of the rotor according to a certain interval, and the adjacent NdFeB permanent magnets 5 are attached to the inner side of the rotor. There is a circumferentially magnetized AlNiCo permanent magnet 4 in between. All the pulse excitation windings are connected in series, and the DC pulse is applied for magnetic regulation.

The stator yoke 2 and the stator teeth 2.1 are both formed by laminating cold-rolled non-oriented silicon steel sheets, thereby reducing eddy current effects, reducing magnetic flux leakage and reducing manufacturing costs.

Preferably, as shown in FIG. 3( b ), the rotor disk includes a non-magnetically conductive ring 6 , 6 rotor core teeth 1 arranged at equal intervals along the circumference of the non-magnetically conductive ring, and 6 inner and outer And the NdFeB permanent magnets and AlNiCo permanent magnets are arranged at equal intervals. The rotor core teeth are part of the rotor disk. The rotor core teeth 1 and the AlNiCo permanent magnets 4 are arranged at equal intervals along the circumference of the non-magnetically conductive ring 6, and are fixed with anaerobic glue and bolts. Ring 6 is made of heat-resistant polyurethane plastic material.

The three-phase armature windings 3.1 and the excitation windings 3.2 are both concentrated windings, and the two coils of the six armature windings 3.1, which are separated by 180 degrees, are connected in series to form three three-phase alternating current outputs. All the excitation windings 3.2 are connected in series, and the magnetization is adjusted by passing in DC pulses.

In addition, the NdFeB permanent magnets 5, the AlNiCo permanent magnets 4 and the rotor core teeth 1 are all fan-shaped. The magnetization method of the NdFeB permanent magnet 5 is axial magnetization, and the magnetization method of the AlNiCo permanent magnet 4 is circumferential magnetization, which together constitute a Halbach structure, which has a magnetization effect.

The working principle of the axial magnetic flux hybrid excitation memory motor of the present invention is as follows:

As shown in Figure 4, when the motor needs to operate with increased output power, by applying a forward rated DC pulsed magnetizing current to the pulsed excitation winding, the alnico permanent magnet has and maintains a circumferential magnetization level, and the NdFeB on the rotor disk The permanent magnets generate a constant axial magnetic field, which together with the circumferential magnetic field of the AlNiCo permanent magnets on the outer side of the rotor disc constitutes a Halbach magnetic concentrating structure; at this time, the magnetic lines of force start from the AlNiCo permanent magnets and pass through the rotor iron core teeth, NdFeB permanent magnets. The magnets, the air gap, reach the three-phase armature windings on the stator disc, producing the largest air gap magnetic field.

As shown in Figure 5, when the motor is running with reduced output power, the reverse rated DC pulse magnetizing current is applied through the pulse excitation winding to reduce the circumferential magnetization level of the AlNiCo permanent magnet and reduce the generation of the AlNiCo permanent magnet. At this time, the air gap magnetic flux is only generated by the circumferential magnetic field of the NdFeB permanent magnet, which reduces the air gap magnetic field. Therefore, the size of the air-gap magnetic field can be adjusted by applying different degrees of DC pulse magnetizing current. This method has less loss to the motor, and can improve the motor's field weakening ability and constant power operation efficiency.

The invention not only has the characteristics of the disk type permanent magnet motor and the memory motor, but also includes the advantages of the Halbach type magnetic concentrating motor, including a stator disk and a rotor disk, the three-phase armature winding is wound on the stator disk, and the It is composed of AlNiCo permanent magnets, NdFeB permanent magnets, and pulse excitation windings wound on AlNiCo permanent magnets. The magnetization state of AlNiCo permanent magnets can be adjusted by controlling the magnitude and direction of the pulse current. The size of the air-gap magnetic field; at the same time, there is no permanent magnet on the stator disk, which makes the structure of the stator disk simpler and lighter. At the same time, both the stator and the soft magnet are made of cold-rolled non-oriented silicon steel sheet material, which reduces the eddy current effect and magnetic flux leakage. , and the manufacturing cost of the motor is reduced; the excitation mode of the motor of the present invention is a self-excitation mode, and a DC power supply and a pulse generating device are added to the rotor disk for magnetic regulation, which improves the working efficiency of the permanent magnet motor; the present invention The main excitation source of the motor is two types of permanent magnets: NdFeB permanent magnets and AlNiCo permanent magnets. The speed regulation range of the motor can be determined by controlling the amount of these two permanent magnet materials. The size of the AlNiCo permanent magnet can be controlled to control the magnetization and working point of the AlNiCo permanent magnet, so as to realize the flexible adjustment of the air gap magnetic field of the motor, so that the motor has a wider speed regulation range and has the performance of low speed and high torque.

The above description is only to illustrate the essential content of the present invention, but does not limit the protection scope of the patent of the present invention. For those of ordinary skill in the art, the technical solutions of the present invention can be improved or equivalently replaced, but these improvements and equivalent replacements should also be regarded as the protection scope of the present invention.

Claims (9)

1. an axial magnetic flux hybrid excitation memory motor is characterized in that, comprising a stator disk and a rotor disk of a Halbach structure, a unilateral air gap structure is formed between the stator disk and the rotor disk and is coaxially installed on the installation shaft , the installation shaft is fixed on the casing of the motor through the bearing, the stator disc is composed of a stator iron core and a three-phase armature winding, wherein the stator iron core includes a stator yoke and stator teeth, and a stator slot is formed between two adjacent stator teeth, The three-phase armature windings are wound on the stator teeth; the rotor disk satisfies the Halbach composite array, and its outer side is composed of a plurality of AlNiCo permanent magnets and a plurality of pulse excitation windings connected in series. The magnetic directions are opposite, and a soft magnetic material is arranged between the AlNiCo permanent magnets, and the pulse excitation windings are wound around the AlNiCo permanent magnets; the NdFeB permanent magnets are attached to the inner side of the rotor disk at a certain angle, and The magnetizing directions of two adjacent NdFeB permanent magnets are opposite; wherein, the NdFeB permanent magnets are attached to the surface of the soft magnetic material, the AlNiCo permanent magnets and the soft magnetic material are spliced into a rotor ring, and the NdFeB permanent magnets are attached to the surface of the soft magnetic material. The center of the boron permanent magnet is aligned with the center of the stator teeth. 2. The axial magnetic flux hybrid excitation memory motor according to claim 1, wherein the number of NdFeB permanent magnets, the number of AlNiCo permanent magnets and the number of stator teeth on the stator disk are equal on the rotor disk , which are multiples of 6. 3. The axial magnetic flux hybrid excitation memory motor according to claim 1, wherein the number of the NdFeB permanent magnets, the number of AlNiCo permanent magnets, and the number of stator teeth are all 6 . 4. The axial magnetic flux hybrid excitation memory motor according to claim 1, characterized in that: two three-phase armature winding coils with a difference of 180 degrees are connected in series to form a single phase, a total of three phases; all pulse excitation The windings are all connected in series, and the magnetism is adjusted by means of DC pulses. 5 . The axial magnetic flux hybrid excitation memory motor according to claim 1 , wherein the stator yoke and the stator teeth are both laminated by cold-rolled non-oriented silicon steel sheets. 6 . 6 . The axial magnetic flux hybrid excitation memory motor according to claim 1 , wherein the rotor disk comprises a non-magnetic-conducting ring and 6 rotors arranged at equal intervals along the circumference of the non-magnetic-conducting ring. 7 . Iron core teeth, and 6 inner and outer NdFeB permanent magnets and AlNiCo permanent magnets arranged at equal intervals. 7 . The axial magnetic flux hybrid excitation memory motor according to claim 1 , wherein the three-phase armature winding and the pulse excitation winding are both concentrated windings. 8 . 8 . The axial magnetic flux hybrid excitation memory motor according to claim 6 , wherein the NdFeB permanent magnets, the AlNiCo permanent magnets and the rotor core teeth are all sector-shaped. 9 . 9 . The axial magnetic flux hybrid excitation memory motor according to claim 1 , wherein the NdFeB permanent magnets are axially magnetized, and the AlNiCo permanent magnets are circumferentially magnetized to form a Halbach structure. 10 .

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