A high performance permanent magnet motor based on a magnetized knee-point silicon steel structure

Abstract

The present invention discloses a high-performance permanent magnet motor based on a heteromagnetized knee silicon steel structure, which is composed of a permanent magnet alternating pole rotor, a stator core and an armature winding, and is characterized in that the rotor core poles and stator tooth tops of the motor are composed of a heteromagnetized knee silicon steel structure, wherein the heteromagnetized knee silicon steel structure is manufactured from three silicon steel materials with different silicon contents. Based on the three-dimensional spatial distribution characteristics of the magnetic field inside the traditional permanent magnet motor, the rotor core poles and the stator tooth tops are divided into magnetic density equal difference areas with a fixed magnetic density value as the magnetic density equal difference spacing, and according to the distribution characteristics of the magnetic density values ​​from high to low in the magnetic density equal difference areas, silicon steel materials with silicon contents from high to low are arranged respectively and manufactured to form a heteromagnetized knee silicon steel structure. The motor of the present invention has high magnetic saturation induction intensity and strong torque output capability, and is suitable for applications such as electric vehicles and industrial robot joint drives that require high torque density and high power density output of the motor.

Description

Technical Field

[0001] The invention belongs to the field of motor design and manufacturing, and in particular relates to a high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure. Background Art

[0002] The permanent magnet synchronous motor can output stable torque after the armature magnetic field in the motor is coupled with the rotating magnetic field of the rotor permanent magnet excitation. It is a high-performance, high-reliability AC motor with the advantages of low manufacturing cost, high power factor and high torque density. It has become an important choice to replace traditional electromagnetic motors and is widely used in aerospace, space exploration, industrial production and other fields.

[0003] In recent years, permanent magnet synchronous motors have made great progress in electromagnetic structure design. Based on the four-quadrant hybrid system, researchers have proposed three different four-quadrant energy converter mechanical topology composite structures, so that the internal magnetic field coupling of the motor occurs not only between radial and radial, but also between axial and axial, and between axial and radial. The composite structure has the advantages of compact structure, high torque density and high power density output. However, compared with the traditional permanent magnet synchronous motor, the composite structure is more complex and has problems of winding overheating and internal circulation.

[0004] The researchers proposed a new Halbach structure with unequal height poles and established a magnetic field analytical model for the T-shaped pole motor. By comparing it with the traditional Halbach magnetized poles and radial magnetized poles, they found that the T-shaped poles have the advantages of large output torque and small torque pulsation. Each pole of the double-layer convex Halbach permanent magnet array is composed of two parallel magnetized permanent magnets, which has the advantages of simple structure and strong overall performance. Both of the above motor structures can increase the output torque of the motor and reduce torque pulsation. However, these two motor structures increase the amount of permanent magnets, resulting in higher motor manufacturing costs and increased risk of saturation of ferromagnetic materials.

[0005] At present, optimizing the motor structure and increasing the amount of permanent magnets can effectively improve the torque density of permanent magnet motors. However, the use of a large number of permanent magnets for excitation in the motor will inevitably increase the risk of magnetic saturation in the motor and affect the performance of the motor. The saturation of local ferromagnetic materials will weaken the effect of the excitation permanent magnets on the output torque, making it difficult to increase the output torque of the motor after reaching a certain value. The high saturation of the magnetic circuit will increase the torque pulsation of the permanent magnet motor and reduce the stability of the output torque. The saturation of the stator tooth flux density will affect the harmonic changes of the magnetic permeance, thereby affecting the electromagnetic performance of the motor.

[0006] In order to solve the problem caused by magnetic saturation in the motor, researchers proposed to use silicon steel materials with high magnetic saturation induction intensity to conduct subtractive manufacturing of high calculated magnetic density and easy saturation structures such as the stator and rotor core in the motor. The most representative silicon steel material is FeSi6.5 (silicon steel with a silicon content of 6.5%). FeSi6.5 has the advantages of high magnetic permeability and low iron loss, which enables silicon steel to have a higher magnetic induction intensity under a weaker magnetic field and improves the working efficiency of the motor. However, high silicon steel is brittle and has poor load and impact resistance.

[0007] The combination of silicon steel materials with different knee points of the magnetization curve can improve the magnetic saturation induction intensity without reducing the toughness of the material. However, the traditional method of manufacturing multi-metal material structures leads to complex production processes and increases the production cost of motors. Additive manufacturing technology has the advantages of realizing complex geometric shapes, printing with multiple materials at the same time, and accurately controlling the material composition. It can solve the problem of combined additive manufacturing of multiple metal materials and reduce the production cost of motors.

[0008] The present invention proposes a high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure, which effectively reduces the risk of magnetic saturation in the motor. Summary of the invention

[0009] To solve the above problems, the present invention discloses a high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure, which can output high performance under rated and short-term overload conditions, has high magnetic saturation induction intensity and high line load, strong load capacity and strong torque output capacity, and is suitable for applications such as electric vehicles, industrial robot joint drives, etc. that require high torque density and high power density output of the motor.

[0010] To achieve the above object, the technical solution of the present invention is as follows:

[0011] A high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure comprises a rotor and a stator. The rotor comprises a shaft, a rotor core, permanent magnet poles and core poles, wherein a circumferential array of permanent magnet poles and core poles is mounted on the surface of the rotor core. The stator comprises a stator core, stator tooth tops and an armature winding, wherein the stator tooth tops are arranged on stator teeth on the stator core side close to an air gap.

[0012] Among them, the core poles and stator tooth tops are composed of a heteromagnetized knee-point silicon steel structure arranged according to the magnetic density distribution characteristics in the three-dimensional space of the motor. The heteromagnetized knee-point silicon steel structure is composed of three types of silicon steel materials: FeSi6.5, FeSi5.5 and FeSi4.5.

[0013] Furthermore, the arrangement and structure of the three silicon steel materials in the differently magnetized knee silicon steel structure are determined based on the three-dimensional magnetic field distribution characteristics of the motor whose stator and rotor cores are made of the same silicon steel material. A fixed value is set as the magnetic flux arithmetic interval, and the rotor core poles and stator tooth tops are divided into magnetic flux arithmetic intervals; according to the distribution characteristics of the magnetic flux values ​​in the magnetic flux arithmetic intervals in the three-dimensional space from high to low, FeSi6.5, FeSi5.5 and FeSi4.5 with high to low silicon content are arranged respectively.

[0014] Furthermore, the heteromagnetized knee-point silicon steel structure is an axially laminated structure, and the arrangement of the three silicon steel materials in the laminate is determined according to the radial distribution of the three-dimensional spatial distribution characteristics of the magnetic field in the motor at the axial position.

[0015] Furthermore, the distribution of the three silicon steel materials in the laminations at different axial positions in the heteromagnetized knee silicon steel structure may be different or the same; the simplest structure is that the distribution of the three silicon steel materials in each layer of laminations is the same.

[0016] Furthermore, FeSi6.5 with the highest magnetic saturation induction intensity in the heteromagnetized knee silicon steel structure is located close to the air gap and the permanent magnet; the magnetic saturation induction intensity from FeSi6.5 to FeSi4.5 decreases successively, and each material is connected successively. The alloy ratio between adjacent materials is slightly different, which is easy to connect by laser sintering.

[0017] Furthermore, the magnetic density contour lines for dividing the magnetic density areas of the core poles and stator tooth tops into equal differences in magnetic density can be regular curves or irregular curves. When the magnetic density contour lines are regular curves, the heteromagnetized knee silicon steel structure can be formed by wire cutting; when the magnetic density contour lines are irregular curves, the heteromagnetized knee silicon steel structure needs to be formed by additive manufacturing.

[0018] Furthermore, the heteromagnetized knee-point silicon steel structure may be made of a combination of various materials such as iron-cobalt alloy, iron-nickel alloy, and soft magnetic composite material.

[0019] Furthermore, the heteromagnetized knee-point silicon steel structure can replace the high calculated magnetic density core part in the motor, and its structure and manufacturing method are suitable for motors, relays and other equipment based on the principle of electromagnetic induction.

[0020] Furthermore, the rotor of the high-performance permanent magnet motor adopts an alternating pole structure, the N pole is made of neodymium iron boron material, and the S pole is replaced by an iron core.

[0021] Furthermore, the high-performance permanent magnet motor adopts fractional-slot concentrated winding.

[0022] Beneficial effects: Compared with the prior art, the motor provided by the patent of this invention has the following significant advantages:

[0023] (1) High magnetic saturation induction intensity. By using silicon steel structures with different silicon contents to manufacture and form the parts with high calculated magnetic density and prone to magnetic saturation in the motor, the magnetic saturation induction intensity of the motor can be improved and the risk of magnetic saturation of the motor can be reduced.

[0024] (2) High motor line load, strong load capacity and torque output capacity. The magnetized knee silicon steel structure can increase the main magnetic flux without changing the excitation magnetomotive force, increase the motor line load, and enhance the motor load capacity and torque output capacity.

[0025] (3) High applicability. The heteromagnetized knee-point silicon steel structure can replace the high calculated magnetic density core part in the motor. Its structure and manufacturing method are suitable for motors, relays and other equipment based on the principle of electromagnetic induction, and have a very broad industrial application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the cross-sectional structure along the axis of a high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure provided in the embodiments of the present invention;

[0027] Figure 2 It is a schematic diagram of the radial cross-sectional structure of a high-performance permanent magnet motor based on a heteromagnetized knee-point silicon steel structure provided in the embodiments of the present invention;

[0028] Figure 3 It is a schematic diagram of the three-dimensional structure of the rotor core and the core pole in a high-performance permanent magnet motor based on a heteromagnetized knee silicon steel structure provided in the embodiment of the present invention;

[0029] Figure 4 It is a schematic diagram of a different magnetization knee point silicon steel structure in a high performance permanent magnet motor based on a different magnetization knee point silicon steel structure provided in the embodiment of the present invention, wherein the structure uses a regular curve to divide the magnetic flux density equal difference regions;

[0030] Figure 5 It is a schematic diagram of a different magnetization knee point silicon steel structure in a high-performance permanent magnet motor based on a different magnetization knee point silicon steel structure provided in the embodiment of the present invention, and the structure uses irregular curves to divide the magnetic flux density equal difference areas.

[0031] In the figure: 1-rotor, 101-shaft, 102-rotor core, 103-permanent magnet pole, 104-core pole, 2-statator, 201-stator core, 202-stator tooth top, 203-armature winding, 3-different magnetization knee point silicon steel structure, 301-FeSi6.5, 302-FeSi5.5, 303-FeSi4.5. DETAILED DESCRIPTION

[0032] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0033] like Figure 1 and Figure 2 As shown, the present invention discloses a high-performance permanent magnet motor based on a heteromagnetized knee silicon steel structure, comprising: a rotor 1, a stator 2 and a heteromagnetized knee silicon steel structure 3, wherein the rotor 1 comprises a shaft 101, a rotor core 102, a permanent magnet pole 103 and a core pole 104, and the stator 2 comprises a stator core 201, a stator tooth top 202 and an armature winding 203, as shown in FIG. Figure 2 and Figure 3 As shown, the core pole 104 and the stator tooth top 202 are formed by a heteromagnetized knee silicon steel structure 3 arranged according to the magnetic flux distribution characteristics in the three-dimensional space of the motor. The heteromagnetized knee silicon steel structure 3 is composed of three silicon steel materials: FeSi6.5 material 301, FeSi5.5 material 302 and FeSi4.5 material 303.

[0034] Among them, the arrangement and structure of the three silicon steel materials in the heteromagnetized knee silicon steel structure 3 are determined based on the three-dimensional magnetic field distribution characteristics of the motor whose stator and rotor cores are made of the same silicon steel material, and a fixed value is set as the magnetic flux arithmetic interval to divide the rotor core pole 104 and the stator tooth top 202 into magnetic flux arithmetic intervals. According to the distribution characteristics of the magnetic flux values ​​of the magnetic flux arithmetic intervals in the three-dimensional space from high to low, the FeSi6.5 material 301, the FeSi5.5 material 302, and the FeSi4.5 material 303 with high to low silicon content are arranged respectively.

[0035] like Figure 3 As shown, the heteromagnetized knee silicon steel structure 3 is an axially laminated structure, and the arrangement of the three silicon steel materials in the laminate is determined according to the radial distribution of the three-dimensional spatial distribution characteristics of the magnetic field in the motor at the axial position.

[0036] like Figure 3 As shown, the distribution of the three silicon steel materials in the laminations at different axial positions in the heteromagnetized knee silicon steel structure 3 may be different or the same; the simplest structure is that the distribution of the three silicon steel materials in each lamination layer is the same.

[0037] like Figure 2 As shown, the FeSi6.5 material 301 with the highest magnetic saturation induction intensity in the heteromagnetized knee silicon steel structure 3 is located close to the air gap and the permanent magnet; the magnetic saturation induction intensity from the FeSi6.5 material 301 to the FeSi4.5 material 303 decreases successively, and each material is connected successively, and the alloy ratio between adjacent materials is slightly different, which is easy to be connected by laser sintering.

[0038] like Figure 4 and Figure 5As shown, the magnetic flux density contour lines for dividing the magnetic flux density areas of the core pole 104 and the stator tooth top 202 into equal differences in magnetic flux density may be regular curves or irregular curves.

[0039] like Figure 4 As shown, when the magnetic density contour lines are regular curves, the heteromagnetized knee point silicon steel structure 3 can be formed by wire cutting method.

[0040] like Figure 5 As shown, when the magnetic density contour line is an irregular curve, the heteromagnetized knee point silicon steel structure 3 needs to be formed by an additive manufacturing method.

[0041] like Figure 2 As shown, the heteromagnetized knee-point silicon steel structure 3 can be made of a combination of various materials such as iron-cobalt alloy, iron-nickel alloy, and soft magnetic composite material.

[0042] like Figure 2 As shown, the heteromagnetized knee point silicon steel structure 3 can replace the high calculated magnetic density core part in the motor, and its structure and manufacturing method are suitable for motors, relays and other equipment based on the electromagnetic induction principle.

[0043] like Figure 2 As shown, the rotor 1 adopts an alternating pole structure, which utilizes the characteristic of the permeable core to gather magnetic lines of force to form magnetic poles, thereby replacing some permanent magnetic poles with iron core poles to form a hybrid magnetic pole structure, the N poles are made of neodymium iron boron material, and the S poles are all replaced by iron cores. By appropriately increasing the pole arc coefficient and magnetic steel thickness of the permanent magnetic poles, the alternating pole motor can significantly reduce the use of permanent magnets with a smaller torque loss, effectively reducing the production cost of the motor.

[0044] like Figure 2 As shown, the armature winding 303 adopts a fractional slot concentrated winding, which is wound on the stator teeth. In this embodiment, since the end of the fractional slot concentrated winding is shorter than the end of the traditional distributed winding, the copper loss is low, which is conducive to reducing the temperature rise of the motor when it is working under load.

[0045] When the motor is unloaded, the high-performance permanent magnet motor has a no-load back electromotive force waveform with a relatively high sinusoidality; when the motor is loaded, the high-performance permanent magnet motor has a high magnetic saturation induction intensity and a high motor line load, which improves the motor's load capacity and torque output capacity, and is suitable for applications such as electric vehicles and industrial robot joint drives that require high torque density and high power density output of the motor.

[0046] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A high-performance permanent magnet motor based on a magnetized knee-point silicon steel structure, comprising a rotor (1) and a stator (2), wherein: The rotor (1) comprises a shaft (101), a rotor core (102), permanent magnet poles (103) and iron core poles (104), wherein the permanent magnet poles (103) and iron core poles (104) are circumferentially arrayed on the surface of the rotor core (102); the stator (2) comprises a stator core (201), stator tooth tops (202) and an armature winding (203), wherein the stator tooth tops (202) are arranged on stator teeth on the stator core (201) near the air gap side; The invention is characterized in that: the core pole (104) and the stator tooth top (202) are composed of a heteromagnetized knee silicon steel structure (3) arranged according to the magnetic flux distribution characteristics in the three-dimensional space of the motor; the heteromagnetized knee silicon steel structure (3) is composed of three silicon steel materials: FeSi6.5 (301), FeSi5.5 (302), and FeSi4.5 (303); The arrangement and structure of the three silicon steel materials in the heteromagnetized knee silicon steel structure (3) are determined based on the three-dimensional magnetic field distribution characteristics of the motor whose stator and rotor cores are made of the same silicon steel material, and a fixed value is set as the magnetic flux arithmetic interval to divide the rotor core poles (104) and the stator tooth tops (202) into magnetic flux arithmetic intervals; according to the distribution characteristics of the magnetic flux values ​​of the magnetic flux arithmetic intervals in the three-dimensional space from high to low, FeSi6.5 (301), FeSi5.5 (302), and FeSi4.5 (303) with silicon content from high to low are arranged respectively; The heteromagnetized knee silicon steel structure (3) is an axially laminated structure, and the arrangement of the three silicon steel materials in the laminate is determined according to the radial distribution of the three-dimensional spatial distribution characteristics of the magnetic field in the motor at the axial position.

2. A high performance permanent magnet motor based on a magnetized knee point silicon steel structure according to claim 1, characterized in that: In the differently magnetized knee silicon steel structure (3), the distribution of the three silicon steel materials in the laminations at different axial positions is different or the same; the simplest structure is that the distribution of the three silicon steel materials in each lamination is the same.

3. A high performance permanent magnet motor based on a magnetized knee point silicon steel structure according to claim 1, characterized in that: In the magnetized knee silicon steel structure (3), FeSi6.5 (301) with the highest magnetic saturation induction intensity is located close to the air gap and the permanent magnet; the magnetic saturation induction intensity from FeSi6.5 (301) to FeSi4.5 (303) decreases successively, and each material is connected successively. The alloy ratio between adjacent materials is small, which is easy to connect by laser sintering.

4. A high performance permanent magnet motor based on a magnetized knee point silicon steel structure according to claim 1, characterized in that: The magnetic flux density contour lines for dividing the magnetic flux density areas of the core pole (104) and the stator tooth top (202) into equal differences in magnetic flux density are regular curves or irregular curves; When the magnetic density contour line is a regular curve, the heteromagnetized knee point silicon steel structure (3) is formed by a wire cutting method; when the magnetic density contour line is an irregular curve, the heteromagnetized knee point silicon steel structure (3) needs to be formed by an additive manufacturing method.

5. A high performance permanent magnet motor based on a magnetized knee point silicon steel structure according to claim 1, characterized in that: The heteromagnetized knee-point silicon steel structure (3) can be made of a combination of various materials such as iron-cobalt alloy, iron-nickel alloy and soft magnetic composite material.

6. A high performance permanent magnet motor based on a magnetized knee point silicon steel structure according to claim 1, characterized in that: The heteromagnetized knee point silicon steel structure (3) can replace the high calculated magnetic density core part in the motor, and its structure and manufacturing method are suitable for motors, relays and other devices based on the electromagnetic induction principle.

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