CN106787307B - Rotor adjustable magnetic type flux switch motor - Google Patents

Abstract

The invention discloses a magnetic flux switching motor of a rotor magnetic adjustment type, which comprises a stator and a rotor, both of which adopt a salient pole structure; the rotor comprises: a rotor magnetic pole module (1), a magnetic isolation block (4), A magnetic block (5) and a shaft (6); the rotor pole module (1) includes two rotor teeth (2) and a permanent magnet (3), and the permanent magnet (3) is embedded in the two rotor teeth (2) Between them, the permanent magnets (3) are magnetized tangentially, and the magnetization direction of the adjacent permanent magnets (3) is consistent; a magnetic spacer block (4) is embedded between the adjacent rotor pole modules (1). The rotor magnetic flux switching motor of the present invention has the advantages of high power density, strong torque output capability and adjustable magnetic field, and has multiple magnetic modulation working modes, effectively widening the working range and operating characteristics of the motor.

Description

Rotor flux switching motor

technical field

The invention relates to a brushless motor based on the magnetic flux switching principle and the magnetic field adjustment mechanism, in particular to a rotor magnetic flux switching motor, which belongs to the technical field of motor manufacturing.

Background technique

The permanent magnets and armature windings of traditional stator permanent magnet flux switching motors are placed on the stator side, and the rotor is only composed of iron cores. It has a simple structure and high mechanical strength, and is suitable for high-speed operation and harsh environments. The motor has the advantages of high torque (power) density, low loss, etc., and the single-phase permanent magnet flux linkage and no-load induced potential harmonic content are low, effectively suppressing torque ripple.

However, in the application fields of wind power generation, new energy electric vehicles, industrial drives, multi-electric aircraft/ships, etc., not only the motors are required to have good torque output characteristics, but also the motor speed regulation range and working range have higher requirements. to meet the changing operating conditions of the equipment. However, the disadvantage of the stator permanent magnet flux switching motor is that the amount of permanent magnets is large and the utilization rate of permanent magnets is low. The permanent magnet on the stator side and the armature winding form a space competition relationship, which reduces the area of the armature slot, which affects the torque output capability of the motor to a certain extent, and the armature magnetic field and the permanent magnetic field work together to make the magnetic density in the stator core Oversaturation limits the motor's overload capability. In addition, the stator permanent magnet flux switching motor is excited by permanent magnets, and the excitation magnetic field cannot be adjusted, which in turn affects the speed regulation range of the motor.

In recent years, the stator permanent magnet hybrid excitation flux switching motor has been proposed, which has solved the problem that the excitation field of the traditional stator permanent magnet flux switching motor cannot be adjusted. However, since the field winding is added on the stator side based on the existing structure of the original armature winding and permanent magnet, the space for the armature winding or permanent magnet is greatly reduced, thereby further limiting the torque output capability of the motor.

Document CN104201852A proposes a rotor permanent magnet flux switching motor with complementary windings. The permanent magnet is transplanted on the rotor side and separated from the armature winding, which effectively improves the space utilization of the rotor side and releases the armature winding space on the stator side. The torque density and power density of the motor are improved. The armature magnetic field is separated from the permanent magnetic field, which alleviates the saturation of the stator tooth magnetic field and improves the overload capacity of the motor.

However, the document CN104201852A proposes a rotor permanent magnet flux switching motor with complementary windings, which has the following disadvantages: a single permanent magnet is used for excitation, and the permanent magnetic field cannot be adjusted, thereby affecting the field-weakening speed regulation range of the motor; The hybrid excitation flux switching motor adopts a hybrid excitation structure, and a brush slip ring needs to be added on the rotor side to provide DC excitation current. However, the brush slip ring has a complex structure and requires regular maintenance.

Contents of the invention

Technical problem: The technical problem to be solved by the present invention is to address the deficiencies in the prior art. The present invention proposes a rotor flux-modulating flux switching motor with high torque (power) density, high efficiency, and strong torque output capability. On the premise of not introducing a brush slip ring structure, the permanent magnet magnetic field adjustment is realized, the field-weakening speed regulation range and working range of the motor are widened, and it has different working modes.

Technical solution: In order to solve the above technical problems, the present invention provides a magnetic flux switching motor with rotor flux modulation, including a stator and a rotor, both of which adopt a salient pole structure; the rotor includes: a rotor magnetic pole module, a spacer Magnetic block, magnetic adjustment block and shaft; the rotor magnetic pole module includes two rotor teeth and a permanent magnet, the permanent magnet is embedded between the two rotor teeth, the permanent magnet is magnetized tangentially, and is adjacent to the permanent magnet The direction of magnetization is consistent; the magnetic spacers are embedded between the adjacent rotor pole modules,

The rotor magnetic pole module and the magnetic isolation block together form an annular rotor structure, and the annular rotor is fixed to the motor shaft through the magnetic isolation end ring, and forms an annular magnetic adjustment air gap with the shaft; the magnetic adjustment air gap is embedded with a magnetic adjustment Magnetic block; the magnetic adjustment block slides relative to the rotor magnetic pole module in the magnetic adjustment air gap.

Preferably, the stator includes a stator core and an armature winding, the armature winding is arranged on the armature teeth of the stator core, adopts a concentrated winding structure, and each of the armature coils is separated from its central angle by 90° and 180° respectively. ° and 270 ° three armature coils constitute a phase armature winding.

Preferably, the stator core is arranged outside the rotor magnetic pole module to form an outer stator structure, or arranged inside the rotor magnetic pole module to form an inner stator structure.

Preferably, the stator core has a straight slot structure or an inclined slot structure.

Preferably, the rotor teeth, magnetic adjustment block and stator core are all magnetically permeable materials.

Preferably, the permanent magnet is neodymium iron boron or samarium cobalt or ferrite permanent magnet material.

Beneficial effect: compared with prior art, the beneficial effect of the present invention is:

1) The rotor magnetic flux switching motor has the advantages of high torque (power) density, strong torque overload capability, and high efficiency of the traditional rotor permanent magnet flux switching motor.

2) By changing the position of the magnetic adjustment block, the adjustment of the permanent magnetic field is realized, and the speed regulation range of the motor's field weakening is improved.

3) The magnetic adjustment block is placed in the magnetic adjustment air gap, and does not form a space competition relationship with the permanent magnet in space, so it does not affect the torque (power) density of the motor.

4) The magnetic modulation is realized through the magnetic modulation block, which is different from the traditional field winding magnetic modulation method, and does not require a brush slip ring structure, which improves the reliability and stability of the motor operation.

5) When the magnetic field of the motor is weakened, the magnetic field adjustment magnetic circuit is connected in parallel with the main magnetic circuit, which effectively prevents the permanent magnet from demagnetizing during the process of weakening the permanent magnetic field.

6) There are a variety of magnetic adjustment methods, and the magnetic adjustment effects are different. According to the requirements of the working conditions, an appropriate magnetic adjustment method can be selected to improve the operating characteristics of the motor drive system.

7) The armature windings of each phase have complementary characteristics. The higher harmonics in the permanent magnet flux linked by the two sets of coil groups of each phase winding, especially the even harmonics, can cancel each other, which optimizes the sinusoidal nature of the permanent magnet flux and suppresses the no-load induced potential. Harmonic content.

8) In the rotor magnetic flux switching motor of the present invention, due to the complementary characteristics, the magnetic field energy in the main magnetic circuit where the two complementary coil groups are located is opposite to the derivative of the relative position of the stator and rotor, canceling each other out, effectively reducing the The size of the positioning torque suppresses the output torque ripple.

9) The rotor magnetic flux switching motor of the present invention is characterized in that the motor can be used for both electric operation and power generation operation.

Description of drawings

Fig. 1 is a structural schematic diagram of a rotor magnetic flux switching motor of the present invention;

Fig. 2a is a magnetic circuit diagram of the rated operating condition of the rotor magnetic flux switching motor of the present invention;

Fig. 2b is a magnetic circuit diagram of working condition 1 of field-weakening operation of the rotor field-adjusting type flux-switching motor of the present invention;

Fig. 2c is a magnetic circuit diagram of the second magnetic circuit diagram of the rotor flux-tuning type flux switching motor of the present invention in the field-weakening operation condition;

Fig. 3 is the three-phase permanent magnet flux linkage in the armature winding under the normal working condition of the rotor magnetic flux switching motor of the present invention and different magnetic modulation modes;

Fig. 4 is the torque and speed curves of the rotor flux-adjusting type flux-switching motor of the present invention under normal working conditions and field-weakening working conditions.

In the figure: 1. Rotor magnetic pole module, 2. Rotor teeth, 3. Permanent magnet, 4. Magnetic isolation block, 5. Magnetic adjustment block, 6. Shaft, 7. Magnetic adjustment air gap, 8. Stator core, 9. Electric Pivot winding, 10, main magnetic circuit, 11, magnetic modulation magnetic circuit 1, 12, magnetic modulation magnetic circuit 2.

Detailed ways

The present invention is a flux-switching motor with rotor flux modulation. The specific implementation of the present invention will be described in detail below by taking a three-phase rotor flux-modulation flux switching motor as an example.

The rotor magnetic flux switching motor provided by the present invention includes a stator and a rotor, both of which adopt a salient pole structure; the rotor includes: a rotor magnetic pole module 1, a magnetic isolation block 4, a magnetic modulation block 5 and a shaft 6. The rotor pole module 1 includes two rotor teeth 2 and a permanent magnet 3, the permanent magnet 3 is embedded between the two rotor teeth 2, the permanent magnet 3 is magnetized tangentially, and is adjacent to the permanent magnet 3 The magnetization direction is the same; the magnetic spacer 4 is embedded between the adjacent rotor pole modules 1,

The rotor magnetic pole module 1 and the magnetic isolation block 4 jointly form an annular rotor structure, and the annular rotor is fixed to the motor shaft through the magnetic isolation end ring, and forms an annular magnetic adjustment air gap 7 with the shaft 6; A magnetic modulation block 5 is embedded in the gap 7 ; the magnetic modulation block 5 slides in the magnetic modulation air gap 7 relative to the rotor pole module 1 .

The stator includes a stator core 8 and an armature winding 9, the armature winding 9 is arranged on the armature teeth of the stator core 8, adopts a concentrated winding structure, and each of the armature coils 9 and its central angle are separated by 90° , 180° and 270° three armature coils 9 form a phase armature winding.

The stator core 8 is arranged outside the rotor pole module 1 to form an outer stator structure, or arranged inside the rotor pole module 1 to form an inner stator structure.

The stator core 8 is a straight slot structure or an oblique slot structure.

The rotor teeth 2, the magnetic adjustment block 5 and the stator core 8 are all magnetically conductive materials.

The permanent magnet 3 is NdFeB or SmCo or ferrite permanent magnet material.

As shown in Figure 1, the rotor magnetic flux switching motor of the present invention includes a stator and a rotor, both of which are salient pole structures with an air gap between them; the rotor is composed of a rotor magnetic pole module 1 , Magnetic isolation block 4, magnetic adjustment block 5 and shaft 6 constitute. The rotor pole module 1 is composed of two rotor teeth 2 and a permanent magnet 3, the permanent magnet 3 is embedded between the two rotor teeth 2, the permanent magnet 3 is magnetized tangentially, and the magnetization direction is consistent. A magnetic isolation block 4 is embedded between the adjacent rotor magnetic pole modules 1, and the magnetic isolation block 4 is connected as a whole through the magnetic isolation end ring at the end of the motor. It is characterized in that the rotor magnetic pole module 1 and the magnetic isolation block 4 are jointly formed. An annular rotor structure, the annular rotor is fixed to the motor shaft through a magnetic isolation end ring, and forms an annular magnetic modulation air gap 8 with the shaft 6 . The magnetic modulation block 5 is embedded in the annular magnetic modulation air gap 8 . The magnetic adjustment block 5 can slide relative to the rotor magnetic pole module 1 in the annular magnetic adjustment air gap 8 . Each magnetic modulation block 5 is connected by a magnetic modulation end ring at the end of the motor to form an integral magnetic modulation component, which is convenient for processing and realizes magnetic modulation control.

The stator is composed of a stator core 8 and an armature winding 9 . The armature winding 9 is arranged on the armature teeth of the stator core 8 and adopts a concentrated winding structure. In the described A-phase armature winding, the armature coil 911 and the armature coils 912, 913, 914 have a central angle difference of 90°, 180° and 270° respectively; The phases of the permanent magnet flux linkages of the inner turn links are the same, and the flux linkage changes are consistent. Similarly, the armature coils 912 and 914 are radially opposite, and the permanent magnet flux linkage changes of the inner turn links of the armature coils are also consistent; The central angles of the coils 911 and 912 differ by 90°, the phases of the permanent magnet flux linkages in the armature coils differ by 180°, and the flux linkage changes are complementary, so they are connected in series in the forward direction to form the first coil group. Similarly, the armature coil 913 The central angle of the spatial position of 914 is 90° apart, and the change of flux linkage is also complementary, so the second coil group is connected in series in the forward direction; the first coil group and the second coil group are connected in series or parallel in the forward direction. Similarly, the armature coils 921, 922, 923 and 924 constitute the B-phase armature winding, and the armature coils 931, 932, 933 and 934 constitute the C-phase armature winding.

The rotor teeth 2, the magnetic adjustment block 5 and the stator core 10 are all magnetically permeable materials. The permanent magnet 3 is NdFeB, SmCo and ferrite permanent magnet materials.

The three-phase rotor magnetic flux switching motor has the advantages of high torque (power) density, strong torque overload capability, and high efficiency of the traditional rotor permanent magnet flux switching motor. The armature windings of each phase have complementary characteristics, which offset the high-order harmonics of the permanent magnet flux linkage linked by the two sets of coil groups in each phase winding, especially the even-order harmonics, optimize the sinusoidal nature of the permanent magnet flux linkage, and suppress Harmonic content of no-load induced EMF.

Through the change of the position of the magnetic flux of the three-phase rotor magnetic flux switching motor, the permanent magnetic field adjustment is realized, and the speed regulation range of the motor's field weakening is improved. There are a variety of magnetic modulation methods, and the magnetic modulation effects are different. The appropriate magnetic modulation method can be selected according to the working conditions to improve the characteristics of the motor drive system. The magnetic adjustment block is placed in the magnetic adjustment air gap, and does not form a space competition relationship with the permanent magnet in space, so it does not affect the torque (power) density of the motor. This magnetic modulation method is different from the traditional field winding magnetic modulation method, and does not require a brush slip ring structure, which improves the reliability and stability of the motor operation. When the magnetic field of the motor is weakened, the magnetic adjustment magnetic circuit is connected in parallel with the main magnetic circuit, as shown in Figure 2, which effectively prevents the permanent magnet from demagnetizing during the process of weakening the permanent magnetic field.

Due to the complementary characteristics, the magnetic field energy in the main magnetic circuit where the two complementary coil groups are located is opposite to the derivative of the relative position of the stator and rotor, canceling each other out, effectively reducing the magnitude of the positioning torque and suppressing the output torque ripple.

The rotor magnetic flux switching motor has the following characteristics when operating under different working conditions:

1. Pure permanent magnet operation: At this time, the motor relies on the permanent magnet to generate the excitation magnetic field, and the output torque, power density and speed regulation performance of the motor are adjusted by controlling the armature current.

2. Magnetic adjustment mode 1 operation: The magnetic adjustment block is located at the bottom of the rotor magnetic pole module, and forms a parallel branch on the main magnetic circuit, so that the magnetic flux of the main magnetic circuit is reduced, and the speed of the weak magnetic field is realized. Since the structure of the main magnetic circuit is directly changed, the maximum field weakening capability can be obtained, as shown in Figure 3 and Figure 4.

3. Magnetic adjustment mode 2 operation: The magnetic adjustment block is located at the bottom of the magnetic isolation block, which increases the interpolar magnetic flux leakage between adjacent rotor magnetic pole modules, thereby weakening the magnetic flux of the main magnetic circuit, and realizing weak magnetic field speed expansion. The magnetic adjustment characteristics are as follows: Figure 3 and Figure 4 show.

The above are only specific application examples of the present invention, and do not constitute any limitation to the protection scope of the present invention. In addition to the above-mentioned embodiments, the present invention can also have other implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims (6)

1. A rotor magnetic modulation type flux switching motor, comprising a stator and a rotor, the stator and the rotor all adopt a salient pole structure; the rotor comprises: a rotor magnetic pole module (1), a magnetic isolation block (4), a magnetic modulation block (5) and shaft (6); the rotor pole module (1) includes two rotor teeth (2) and a permanent magnet (3), and the permanent magnet (3) is embedded between the two rotor teeth (2) The permanent magnets (3) are magnetized tangentially, and the magnetization direction of the adjacent permanent magnets (3) is consistent; the magnetic spacers (4) are embedded between the adjacent rotor pole modules (1), which are characterized in that , The rotor magnetic pole module (1) and the magnetic isolation block (4) together form an annular rotor structure, and the annular rotor is fixed to the shaft (6) through the magnetic isolation end ring, and an annular magnetic adjustment gas is formed between the shaft (6). Gap (7); the magnetic modulation block (5) is embedded in the magnetic modulation air gap (7); the magnetic modulation block (5) slides in the magnetic modulation air gap (7) relative to the rotor magnetic pole module (1) in a circle. 2. The rotor magnetic flux switching motor according to claim 1, characterized in that, the stator includes a stator core (8) and an armature winding (9), and the armature winding (9) is arranged on On the armature teeth of the stator core (8), a concentrated winding structure is adopted, and each armature winding (9) and three armature windings (9) whose central angles are respectively 90°, 180° and 270° form a phase armature winding. 3. The rotor magnetic flux switching motor according to claim 2, characterized in that, the stator core (8) is arranged outside the rotor pole module (1) to form an outer stator structure, or is arranged on the rotor pole module ( 1) The inner stator structure is formed inside. 4. The rotor magnetic flux switching motor according to claim 1, characterized in that, the stator core (8) has a straight slot structure or an inclined slot structure. 5 . The rotor magnetic flux switching motor according to claim 1 , characterized in that, the rotor teeth ( 2 ), the magnetic modulation block ( 5 ), and the stator core ( 8 ) are all magnetically conductive materials. 6 . 6. The rotor magnetic flux switching motor according to claim 1, characterized in that, the permanent magnet (3) is made of NdFeB or SmCo or ferrite permanent magnet material.