CN114400855B

CN114400855B - Stator-rotor double-module permanent magnet synchronous motor

Info

Publication number: CN114400855B
Application number: CN202210080187.5A
Authority: CN
Inventors: 王秀平; 杨帅; 曲春雨; 郭子琦; 姚舜禹; 胡永壮; 刘万明; 王雅慧; 王长华
Original assignee: Shenyang Institute of Engineering
Current assignee: Shenyang Institute of Engineering
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2023-06-16
Anticipated expiration: 2042-01-24
Also published as: CN114400855A

Abstract

The application provides a stator-rotor double-module permanent magnet synchronous motor, which comprises a shell, a stator module unit, a rotor module unit, a permanent magnet assembly and a rotating shaft. The permanent magnet assembly comprises ferrite and a rare earth permanent magnet, and a dislocation angle is formed between the ferrite and the rare earth permanent magnet. The double-modular structure of the stator module unit and the rotor module unit effectively reduces the dimension parameter of the unit element of the high-power wind driven generator and reduces the transportation cost and difficulty of the wind driven generator. The dislocation angle between ferrite and rare earth permanent magnet can form air magnetic barrier to prevent from causing a large amount of magnetic leakage. In summary, the present application can solve the problems that when a part of the rare earth permanent magnet is replaced with ferrite, the rare earth permanent magnet and ferrite form magnetic leakage and the motor efficiency and power factor are low.

Description

Stator-rotor double-module permanent magnet synchronous motor

Technical Field

The application relates to the technical field of motor manufacturing, in particular to a stator-rotor double-module permanent magnet synchronous motor.

Background

The permanent magnet direct-drive wind generating set has the advantages of low maintenance cost, high wind energy conversion efficiency, wide operating wind speed range, long service life, good low-high voltage ride through performance and the like, and the technical development is rapid in recent years. However, with the increase of single power of the wind generating set, the diameter of the direct-driven generator is increased, production and manufacturing equipment and transportation become the biggest bottleneck problems restricting the technology, and the power density of the motor and the modularization level of production and manufacturing are improved, so that the direct-driven generator is a necessary trend of industry development. Currently, the maximum width limit of land transportation is about 5m, and exceeding the transportation limit greatly increases the transportation cost and is even impossible, thus bringing a great challenge to the economic design of the motor.

In recent years, due to the limitation of exploitation of rare earth permanent magnet materials, the supply amount is limited, the purchase price rises year by year, and more researchers begin to research motors capable of replacing permanent magnet synchronous motors, or attempt to design high-performance motors using materials such as ferrite or the like with low performance or without permanent magnets.

However, the simple adoption of ferrite to replace part of permanent magnets can lead to the formation of magnetic leakage between the permanent magnets and the ferrite, and meanwhile, the permanent magnet synchronous motor does not have any excitation, so that in order to obtain larger electromagnetic torque, a stator side is required to improve larger excitation current, and the efficiency and the power factor of the motor are lower.

Disclosure of Invention

The utility model provides a stator-rotor double-module permanent magnet synchronous motor, can solve and can lead to rare earth permanent magnet and ferrite to form the magnetic leakage and motor efficiency and power factor lower problem when replacing partial rare earth permanent magnet with ferrite.

The technical scheme of this application is a stator-rotor bimodulation PMSM, includes: the shell is circular and extends along the axial direction;

the stator module units are uniformly arranged on the inner peripheral surface of the shell around the axial direction, and a stator module gap is arranged between two adjacent stator module units; two stator slots are symmetrically arranged in the stator module unit, and windings which axially penetrate through the stator slots are arranged in the stator slots;

the rotor module units are uniformly arranged in an inner ring formed by encircling all the stator module units around the axial direction, and a rotor module gap is formed between two adjacent rotor module units; a stator-rotor module gap is arranged between the stator module unit and the rotor module unit;

the permanent magnet assemblies are uniformly arranged in all circular rings formed by encircling the rotor module units around the axial direction and are close to one side of the stator module units; the permanent magnet assembly is V-shaped, and the V-shaped opening faces the stator module unit; the permanent magnet assembly comprises ferrite positioned at the V-shaped tip and permanent magnets symmetrically arranged at two sides of the ferrite, and a dislocation angle is formed between the ferrite and two adjacent rare earth permanent magnets;

the rotating shaft is arranged in an inner ring formed by encircling the rotor module unit and extends along the axial direction;

one of the stator slots in the stator module unit is provided with a stator groove at a side close to the casing; two rotor grooves are symmetrically formed in one side, close to the stator module unit, of the rotor module unit;

the permanent magnet assembly is arranged between two adjacent rotor grooves;

the rotor groove is trapezoidal;

the width of the ferrite on the side close to the stator module unit should be smaller than the width of the ferrite on the side close to the rotating shaft.

Optionally, the winding is a three-phase symmetric stator winding.

The permanent magnet assembly is characterized in that optionally, protrusions matched with the rotor module gaps are uniformly distributed on the peripheral surface of the rotating shaft;

the rotating shaft is provided with a circular groove between two adjacent bulges and at one side close to the shell.

The application provides a stator-rotor double-module permanent magnet synchronous motor, which comprises a shell, a stator module unit, a rotor module unit, a permanent magnet assembly and a rotating shaft. A stator module gap is arranged between two adjacent stator module units. A rotor module gap is arranged between two adjacent rotor module units. A stator-rotor module gap is arranged between the stator module unit and the rotor module unit. Because the application adopts the double-module structure of the stator module unit and the rotor module unit, the unit element size parameter of the high-power wind driven generator is effectively reduced, and the transportation cost and difficulty of the wind driven generator are reduced. The stator and rotor module gaps can play a role of magnetic barriers, the stator module gaps can enable the stator magnetic circuit to be supersaturated, electromagnetic torque output by the motor is reduced, the rotor module gaps play a role of restraining magnetic force lines, low-order non-working harmonic waves are weakened, rotor quality is reduced, and the size of the motor is further reduced. Besides, the rare earth permanent magnet part in the prior art is replaced by ferrite, and the ferrite is magnetized by the rare earth permanent magnets at two sides, so that the cost of the motor is saved. In addition, the ferrite forms the dislocation angle with two adjacent rare earth permanent magnets, can form the air magnetic barrier, avoids the rare earth permanent magnet to send the magnet wire and directly form the return circuit through ferrite, prevents to cause a large amount of magnetic leakage phenomenon, can solve when replacing partial rare earth permanent magnet with ferrite this application and can lead to permanent magnet and ferrite to form the magnetic leakage and problem that motor efficiency and power factor are lower to this application has the advantage that the performance is excellent, novel structure, low cost, reliable operation, be convenient for transport, industrialization are convenient etc. in the aspect of comparing prior art.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic structural diagram of a stator-rotor dual-module permanent magnet synchronous motor in an embodiment of the present application;

FIG. 2 is a schematic view of a stator module unit without windings in an embodiment of the present application;

FIG. 3 is a schematic diagram of a sub-module unit in an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a ferrite assembly according to an embodiment of the present application;

FIG. 5 is a graph comparing the no-load back electromotive force of a motor under different structures;

fig. 6 is a schematic diagram of winding arrangement in an embodiment of the present application;

FIG. 7 is a schematic diagram of a structure of a rotor in an embodiment of the present application;

wherein, 1-shell; 2-stator module units; 21-stator module gap; 22-stator slots; 221. 221a, 221b, 221c, 221d, 221e, 221f, 221g, 221h, 221i, 221j, 221k and 221 l-windings; 222-stator grooves; 3-rotor module unit; 31-rotor module clearance; 32-stator-rotor module gap; 33-rotor grooves; 4-permanent magnet assembly; 41-ferrite; 42-rare earth permanent magnets; 43-dislocation angle; 5-rotating shaft; 51-bump; 52-round groove.

Detailed Description

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the present application. Merely as examples of systems and methods consistent with some aspects of the present application as detailed in the claims.

The application provides a stator-rotor double-module permanent magnet synchronous motor, as shown in fig. 1, fig. 1 is a schematic structural diagram of the stator-rotor double-module permanent magnet synchronous motor in the embodiment of the application, and the motor comprises a casing 1, a stator module unit 2, a rotor module unit 3, a permanent magnet assembly 4 and a rotating shaft 5.

Wherein the casing 1 is circular and extends in an axial direction.

The stator module units 2 are uniformly arranged on the inner peripheral surface of the casing 1 around the axial direction, and a stator module gap 21 is arranged between two adjacent stator module units 2. Two stator slots 22 are symmetrically arranged in the stator module unit 2, and windings 221 penetrating the stator slots 22 in the axial direction are arranged in the stator slots 22. Referring specifically to fig. 2, fig. 2 is a schematic structural diagram of a stator module unit in an embodiment of the present application without windings.

The rotor module units 3 are uniformly arranged in an inner ring formed by encircling all the stator module units 2 around the axial direction, and a rotor module gap 31 is arranged between two adjacent rotor module units 3. A stator-rotor module gap 32 is provided between the stator module unit 2 and the rotor module unit 3. Referring specifically to fig. 3, fig. 3 is a schematic structural diagram of a rotor module unit in an embodiment of the present application.

Specifically, the stator module unit 2 and the rotor module unit 3 are each made of silicon steel sheets. The stator module units 2, the stator slots 22 and the rotor module units 3 are all fan-shaped, and all the rotor module units 3 are embedded on the rotating shaft 5. The width of the sector stator slot 22 is equal to the width of one rotor pole. The stator module gap 21 has a width of 2mm in the circumferential direction, and the rotor module gap 31 has a width of 1mm in the circumferential direction. The stator module units 2 are connected through magnetic bridges, and the rotor module units 3 are connected through rotating shafts, so that the assembly and disassembly are convenient. The stator poles of the stator module unit in the anticlockwise direction are wound with windings 221, and all windings 221 have the same winding direction and are concentrated windings. The pole arc coefficient of the rotor pole is 0.52, and the pole width of the rotor pole is 0.24 times that of the stator pole. The rotor module unit 3 is provided with a rotor magnetic pole, and the top of the rotor module unit 3 is in arc shape and matched with the stator module unit 2.

The permanent magnet assemblies 4 are uniformly arranged in the circular rings formed by all the rotor module units 3 in a surrounding manner around the axial direction and are close to one side of the stator module units 2. The permanent magnet assembly 4 is V-shaped with the V-shaped opening facing the stator module unit 2. The permanent magnet assembly 4 includes ferrite 41 at the V-shaped tip and rare earth permanent magnets 42 symmetrically disposed at both sides of the ferrite 41, and a dislocation angle 43 is formed between the ferrite 41 and the adjacent two rare earth permanent magnets 42.

Specifically, as shown in fig. 1 and fig. 4, fig. 4 is a schematic structural diagram of a ferrite assembly in the embodiment of the present application, where ferrite 41 and rare earth permanent magnet 42 are V-shaped and embedded in rotor module unit 3, where ferrite 41 is located at the tip of V-shaped permanent magnet assembly 4, and is magnetized by pot rare earth permanent magnet 42, so as to replace rare earth permanent magnet 42 in the prior art, and save motor cost. In some embodiments, the rare earth permanent magnet 42 is made of neodymium-iron-boron, samarium-cobalt, or ferrite permanent magnet material. The ferrite 41 and the adjacent two rare earth permanent magnets 42 form a dislocation angle 43, which can form an air magnetic barrier, prevent the rare earth permanent magnets 42 from sending out magnetic wires to directly form a loop through the ferrite 41, and prevent a large amount of magnetic leakage. The rare earth permanent magnets 42 are distributed in a blocking and anisotropic magnetizing way, the magnetizing direction of the rare earth permanent magnets is changed in a sinusoidal way, so that the permanent magnetic field close to the gap is more concentrated, the magnetic flux density distribution of the motor gap is more similar to the sinusoidal distribution, the harmonic content is less, the magnetic density distribution is more uniform, and the electromagnetic torque output capability and the utilization rate of the rare earth permanent magnets 42 can be further improved. The number of the rotor poles is small, and the iron loss and the eddy current loss of the rare earth permanent magnet 42 can be effectively reduced in the high-speed running process of the motor.

The rotary shaft 5 is disposed in an inner ring formed around the rotor module unit 3 and extends in the axial direction.

Specifically, the rotor module units 3 are each embedded on the rotation shaft 5.

The motor in the embodiments of the present application operates following the principle of minimum reluctance, and the flux linkage of the armature winding turns will vary from maximum to minimum periodically for each revolution of the rotor module through one pole, with the flux from the rare earth permanent magnet 42 being linked to the windings 221 through two gaps. The winding 221 changes the traditional distributed winding into a fractional slot concentrated winding, has the advantages of being convenient to wind and convenient to divide slots, saves the winding at the end of the motor, can save copper wires at the end, reduces copper consumption of the motor and improves the efficiency of the motor; the saving in end space may also increase the effective length of the motor, thereby increasing the torque density of the motor. The embodiment of the present application, although adding the rotor module unit 3 compared with the prior art, is due to the rotor

The modular unit 3 reduces the rotor mass, constrains the rotor magnet wires, and thus the output torque and power density of the motor can be significantly improved.

Referring specifically to fig. 5, fig. 5 is a comparison diagram of the no-load back electromotive force of the motor under different structures. The comparative analysis shows that after the stator of the permanent magnet motor is modularized, the non-working harmonic content is increased, the working harmonic content is reduced, and the no-load counter potential is obviously reduced. After topological structure optimization, the air magnetic barrier effectively restricts the trend of magnetic lines and weakens the content of non-working harmonic waves. The electromagnetic performance of the motor is obviously optimized, and the no-load counter potential amplitude is effectively improved.

In summary, the motor in the embodiment of the application adopts a double-modular structure of the stator module unit 2 and the rotor module unit 3, so that the unit element size parameter of the high-power wind driven generator is effectively reduced, and the transportation cost and difficulty of the wind driven generator are reduced. Wherein, stator and rotor module clearance 32 can play the effect of magnetic barrier, and stator module clearance 21 can make stator magnetic circuit supersaturation, has reduced the electromagnetic torque of motor output, and rotor module clearance 31 has played the effect of restraint magnetic line of force, has weakened low order non-working harmonic, lightens rotor quality, further reduces the motor size. In addition, in the embodiment of the application, the rare earth permanent magnet part in the prior art is replaced by ferrite 41, and the ferrite 41 is magnetized by utilizing the rare earth permanent magnets 42 on two sides, so that the cost of the motor is saved. The ferrite 41 and the adjacent two rare earth permanent magnets 42 form a dislocation angle 43, which can form an air magnetic barrier, prevent the rare earth permanent magnets 42 from sending out magnetic wires to directly form a loop through the ferrite 41, and prevent a large amount of magnetic leakage.

In some embodiments, the number of stator module units 2 is six; the number of the rotor module units 3 is five; the number of the permanent magnet assemblies 4 is ten.

In some embodiments, one of the stator slots 22 in the stator module unit 2 is provided with a stator groove 222 on a side close to the casing 1.

Specifically, a stator groove 222 is formed in one side of the stator groove 22, which is close to the casing 1, and the width of the stator groove 222 in the axial direction is 2mm, namely, a magnetic barrier is added to the yoke part of the stator, so that the trend of magnetic wires can be restrained, the cogging torque can be reduced, and the vibration influence during the load operation of the motor can be prevented.

In some embodiments, the windings 221 are three-phase symmetric stator windings.

Specifically, as shown in fig. 6, fig. 6 is a schematic diagram of winding arrangement in the embodiment of the present application, so 221a, 221b, 221c, 221d, 221e, 221f, 221g, 221h, 221i, 221j, 221k, and 221l are used for designating in order to distinguish windings 221 at different positions. Wherein

windings

221a and 221f are positive windings around the A phase, windings 221g and 221l are negative windings around the A phase,

windings

221k and 221d are negative windings around the B phase, and

windings

221e and 221j are positive windings around the B phase; windings 221b and 221i are positive windings around the C phase and windings 221C and 221h are negative windings around the C phase; the three-phase symmetrical stator windings are sequentially connected end to form symmetrical three-phase armature windings.

In some embodiments, the rotor module unit 3 is symmetrically provided with two rotor grooves 33 at a side close to the stator module unit 2; the permanent magnet assembly 4 is disposed between two adjacent rotor grooves 33. The rotor groove 33 is trapezoidal and has a radial depth of 1.5mm.

Specifically, two rotor grooves 33 are symmetrically arranged on one side of the rotor module unit 3, which is close to the stator module unit 2, the rotor grooves 33 are arranged to be trapezoid through comparison of different shapes and different groove depths, the width of the rotor grooves 33 in the axial direction is 1.5mm, rotor side magnetic wires are restrained, and higher non-working harmonic waves are weakened, so that electromagnetic torque is improved, and modular motor cogging torque is reduced.

In some embodiments, the width of the ferrite 41 on the side close to the stator module unit 2 should be smaller than the width of the ferrite 41 on the side close to the rotation shaft 5.

Specifically, the width of the ferrite 41 near the stator module unit 2 should be smaller than the width of the ferrite 41 near the rotating shaft 5, so as to facilitate magnetization.

In some embodiments, the protrusions 51 matching with the rotor module gaps 31 are uniformly distributed on the outer circumferential surface of the rotating shaft 5; the rotating shaft 5 is provided with a circular groove 52 between two adjacent protrusions 51 and at a side close to the casing 1. Specifically, as shown in fig. 7, fig. 7 is a schematic structural diagram of the rotating shaft in the embodiment of the present application, where the protrusions 51 may enable the rotating shaft 5 to be connected with the rotor module unit 3 more tightly, so as to facilitate installation of the rotor module unit 3, and meanwhile, a groove matched with the protrusions 51 is also formed in the rotor module unit 3; the arrangement of the circular groove 52 can reduce the weight of the motor, enhance the rigidity of the motor rotating shaft 5 and enhance the reliability of the rotating part. In some embodiments, the number of protrusions 51 and rounded grooves 52 is 5.

The embodiment of the application provides a stator-rotor double-module permanent magnet synchronous motor, which comprises a shell 1, a stator module unit 2, a rotor module unit 3, a permanent magnet assembly 4 and a rotating shaft 5. A stator module gap 21 is provided between two adjacent stator module units 2. A rotor module gap 31 is provided between two adjacent rotor module units 3. A stator-rotor module gap 32 is provided between the stator module unit 2 and the rotor module unit 3. Because the embodiment of the application adopts the double-module structure of the stator module unit 2 and the rotor module unit 3, the unit element size parameter of the high-power wind driven generator is effectively reduced, and the transportation cost and difficulty of the wind driven generator are reduced. Wherein, stator and rotor module clearance 32 can play the effect of magnetic barrier, and stator module clearance 21 can make stator magnetic circuit supersaturation, has reduced the electromagnetic torque of motor output, and rotor module clearance 31 has played the effect of restraint magnetic line of force, has weakened low order non-working harmonic, lightens rotor quality, further reduces the motor size. In addition, in the embodiment of the application, the rare earth permanent magnet part in the prior art is replaced by ferrite 41, and the ferrite 41 is magnetized by utilizing the rare earth permanent magnets 42 on two sides, so that the cost of the motor is saved. In addition, the ferrite 41 and two adjacent rare earth permanent magnets 42 form a dislocation angle 43, an air magnetic barrier can be formed, the phenomenon that a magnetic wire emitted by the rare earth permanent magnets 42 directly passes through the ferrite 41 to form a loop is avoided, a large amount of magnetic leakage phenomenon is prevented from being caused, and in conclusion, the problem that the rare earth permanent magnets and the ferrite form magnetic leakage and the motor efficiency and the power factor are lower when part of the rare earth permanent magnets are replaced by the ferrite can be solved.

The foregoing detailed description of the embodiments of the present application has been provided for the purpose of illustrating the preferred embodiments of the present application and is not to be construed as limiting the scope of the present application. All equivalent changes and modifications within the scope of the present application should be made within the scope of the present application.

Claims

1. A stator-rotor dual-modular permanent magnet synchronous motor, characterized in that the motor comprises: the shell (1) is round and extends along the axial direction;

the stator module units (2) are uniformly arranged on the inner peripheral surface of the shell (1) around the axial direction, and a stator module gap (21) is arranged between two adjacent stator module units (2); two stator slots (22) are symmetrically arranged in the stator module unit (2), and windings (221) which axially penetrate through the stator slots (22) are arranged in the stator slots (22);

the rotor module units (3) are uniformly arranged in an inner ring formed by encircling all the stator module units (2) around the axial direction, and rotor module gaps (31) are arranged between two adjacent rotor module units (3); a stator-rotor module gap (32) is arranged between the stator module unit (2) and the rotor module unit (3);

the permanent magnet assemblies (4) are uniformly arranged in all the circular rings formed by encircling the rotor module units (3) around the axial direction and are close to one side of the stator module units (2); the permanent magnet assembly (4) is V-shaped and the V-shaped opening faces the stator module unit (2); the permanent magnet assembly (4) comprises a ferrite (41) positioned at the V-shaped tip and rare earth permanent magnets (42) symmetrically arranged at two sides of the ferrite (41), wherein a dislocation angle (43) is formed between the ferrite (41) and two adjacent rare earth permanent magnets (42);

a rotating shaft (5) which is disposed in an inner ring formed around the rotor module unit (3) and extends in the axial direction;

one of the stator slots (22) in the stator module unit (2) is provided with a stator groove (222) at a side close to the casing (1);

two rotor grooves (33) are symmetrically formed in one side, close to the stator module unit (2), of the rotor module unit (3);

the permanent magnet assembly (4) is arranged between two adjacent rotor grooves (33);

the rotor groove (33) is trapezoidal;

the width of the ferrite (41) on the side close to the stator module unit (2) should be smaller than the width of the ferrite (41) on the side close to the rotating shaft (5).

2. A stator and rotor double modular permanent magnet synchronous motor according to claim 1, characterized in that the windings (221) are three-phase symmetrical stator windings.

3. A stator-rotor dual-module permanent magnet synchronous motor according to claim 1, characterized in that protrusions (51) matched with the rotor module gaps (31) are uniformly distributed on the outer peripheral surface of the rotating shaft (5);

the rotating shaft (5) is provided with a circular groove (52) between two adjacent protrusions (51) and at one side close to the machine shell (1).