Fundamental wave ratio magnetic conductance maximized salient pole reluctance rotor switch flux linkage motor

Abstract

The invention provides a salient pole reluctance rotor switch flux linkage motor with maximum fundamental wave ratio magnetic conductance, which belongs to the technical field of stator permanent magnet synchronous motors and comprises a stator iron core, permanent magnets, armature windings and a salient pole reluctance rotor. The stator iron core is composed of a plurality of identical U-shaped iron cores. The permanent magnets are arranged between two adjacent U-shaped iron cores; the armature windings are wound on the adjacent U-shaped iron cores; the salient pole reluctance rotor is arranged in the stator core, and the overall dimension of the salient pole reluctance rotor is calculated and determined according to the inner diameter of the stator, the length of an air gap and the number of poles of the stator, so that the salient pole reluctance rotor is of a salient pole rotor structure with the maximum fundamental wave ratio magnetic conductance, and the torque pulsation of the switched flux linkage motor is reduced. The motor has the advantages of low torque pulsation, simple structure, high reliability and the like, and is suitable for occasions with high requirements on motor torque pulsation performance, such as numerical control machine tools, intelligent robots and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of stator permanent magnet synchronous motor, more particularly, to a maximum fundamental ratio magnetic conductance convex pole reluctance rotor switched flux motor. BACKGROUND

[0002] Permanent magnet synchronous motor has the advantages of high torque density, high power density and high efficiency, so that it has smaller volume and weight under the premise of meeting the demand of driving system. Permanent magnet synchronous motor includes stator permanent magnet type synchronous motor and rotor permanent magnet type synchronous motor. Compared with rotor permanent magnet type synchronous motor, stator permanent magnet type synchronous motor has simple rotor structure (similar to switched reluctance motor, convex pole reluctance type core rotor), high reliability and easy heat dissipation (permanent magnet and winding are on the stator), so it has been widely noticed. Among them, the stator permanent magnet type synchronous motor includes switched flux motor, doubly salient motor, flux switching motor, hybrid excitation motor, etc., among which the switched flux motor has great application potential in industrial servo system, electric vehicle driving, aerospace and household appliances due to its high magnetic field utilization rate and strong reliability.

[0003] However, the traditional convex pole reluctance rotor structure used by switched flux motor faces the problem of nonlinear change of magnetic reluctance. The sudden change of magnetic reluctance leads to the sharp fluctuation of magnetic field energy with the rotor position, which further makes the switched flux motor have the characteristic of large torque ripple. The shape of the convex pole reluctance type core is the key factor to determine the air gap ratio magnetic conductance distribution, and the air gap ratio magnetic conductance distribution directly affects the performance of motor torque. Therefore, the convex pole reluctance type core needs to be optimized and designed to make the air gap ratio magnetic conductance distribution more sinusoidal, reduce the harmonic content, and achieve the goal of reducing torque ripple. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a maximum fundamental ratio magnetic conductance convex pole reluctance rotor switched flux motor, which solves the technical problem of large torque ripple of stator permanent magnet type switched flux motor.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a maximum fundamental ratio magnetic conductance convex pole reluctance rotor switched flux motor is provided, which comprises: a stator core, a permanent magnet, an armature winding and a convex pole reluctance rotor. The stator core is composed of a plurality of identical U-shaped cores; the permanent magnet is arranged between two adjacent U-shaped cores; and the armature winding is arranged in the adjacent U-shaped cores. The convex pole reluctance rotor is arranged in the stator core, and the profile size of the convex pole reluctance rotor is determined according to the inner diameter of the stator, the air gap length and the number of stator poles, so that the convex pole reluctance rotor is a maximum fundamental ratio magnetic conductance convex pole rotor structure, thereby reducing the torque ripple of the switched flux motor.

[0006] Preferably, the profile size of the salient pole reluctance rotor is calculated by wherein, D si is the inner diameter of the stator, N r is the number of rotor poles, r and θ are the pole radius and angle of the salient pole reluctance rotor in polar coordinates, respectively.

[0007] Preferably, the number of rotor poles N r is calculated by wherein, N s is the number of stator poles, m is the number of motor phases, n is 1 or 2.

[0008] Preferably, the four corners of the U-shaped core of the stator core are provided with a buckle structure for fixing the permanent magnets.

[0009] Preferably, the permanent magnets are all parallel magnetized, and the magnetization directions of adjacent permanent magnets are opposite.

[0010] Preferably, the permanent magnets are embedded between two U-shaped cores and directly participate in the flux linkage switching.

[0011] Preferably, the armature winding is a concentrated winding, and a single coil is wound on the core teeth of two U-shaped cores and embedded on the permanent magnets between the two U-shaped cores.

[0012] Preferably, the ends of the armature winding are arranged in a regular manner and the armature winding is concentrated on the core teeth.

[0013] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects: 1. The salient pole reluctance rotor switched flux motor with maximum fundamental ratio permeance of the present application has a rotor profile that is calculated by the inner diameter of the stator, the air gap length, and the number of stator poles to obtain a salient pole rotor structure with maximum fundamental ratio permeance, which greatly reduces the motor torque ripple, has the advantages of low torque ripple, simple structure, high reliability, and is suitable for occasions with high requirements for motor torque ripple performance, such as numerical control machine tools, intelligent robots, etc.

[0014] 2. The salient pole reluctance rotor switched flux motor with maximum fundamental ratio permeance of the present application has a stator core composed of multiple identical U-shaped cores, and the modular stator core structure is simple, reliable, and easy to process and manufacture. ​​

[0015] 3. The invention provides a fundamental wave ratio magnetic guide maximum salient pole reluctance rotor switched flux motor, the armature winding adopts centralized winding, reduces the winding complexity, reduces the end winding length, improves the motor efficiency, and reduces the axial space occupation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the structural schematic diagram of the fundamental wave ratio magnetic guide maximum salient pole reluctance rotor switched flux motor of the invention. Figure 2 is the structural schematic diagram of the rotor structure of the traditional reluctance rotor switched flux motor. Figure 3 is the torque fluctuation performance comparison diagram of the fundamental wave ratio magnetic guide maximum salient pole reluctance rotor switched flux motor of the invention and the traditional reluctance rotor switched flux motor.

[0017] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein: 1, stator core; 2, permanent magnet; 3, armature winding; 4, salient pole reluctance rotor. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the invention clearer, the invention is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the invention and do not limit the invention. In addition, the technical features involved in each embodiment of the invention described below can be combined with each other as long as they do not conflict with each other.

[0019] As shown in Figure 1 , the invention provides a fundamental wave ratio magnetic guide maximum salient pole reluctance rotor switched flux motor, which specifically comprises: a stator core 1, a permanent magnet 2, an armature winding 3 and a salient pole reluctance rotor 4.

[0020] In the embodiment of the invention, the stator core 1 is composed of multiple stator cores with the same shape and size and separated from each other, and the shape is U-shaped, which is called U-shaped core.

[0021] Further, in the embodiment of the invention, the number of U-shaped cores is 12, and the modular stator structure avoids the complexity of traditional overall assembly of the stator, reducing the processing difficulty.

[0022] Further explanation, in the embodiment of the invention, the permanent magnet 2 is rectangular in shape, all of which are parallel magnetized, and the magnetization directions of the two adjacent permanent magnets 2 are opposite, and the number of the permanent magnets 2 in the embodiment of the invention is 12.

[0023] Further, the permanent magnet 2 is embedded between two U-shaped cores, the permanent magnet 2 directly participates in flux linkage switching, the magnetic field path is short, the magnetic flux leakage is small, and the magnetic energy utilization rate is high.

[0024] Further, the four corners of the U-shaped core are designed with a buckle structure in the embodiment of the application, so that the permanent magnet can be fixed without affecting the electromagnetic performance of the motor.

[0025] Further, the armature winding 3 is a concentrated winding in the embodiment of the application, a single coil is wound on the adjacent teeth of the two U-shaped cores and the permanent magnet embedded therein, the winding end is short and arranged regularly, and the winding complexity is greatly reduced.

[0026] Further, the copper consumption of the armature winding 3 end winding is reduced, the motor efficiency is improved, the coil of the armature winding 3 is concentrated on the tooth portion, the axial space occupation is reduced, and the motor structure is more compact.

[0027] The salient pole reluctance rotor 4 in the embodiment of the application is a salient pole rotor structure with maximum fundamental ratio magnetic permeability, the rotor structure is determined according to the selected stator size, stator pole number and air gap length.

[0028] First, the rotor pole number is determined according to the stator pole number, the relationship is as follows:

[0029] Among them, N r The rotor pole number is n, N s The stator pole number is p, m The motor phase number is q, n The natural number (usually the value is 1 or 2) is m, and considering that the minimum inductance value is reduced as much as possible and the operating frequency is reduced, generally, the front part adopts a “-” sign, that is, the rotor pole number is generally less than the stator pole number.

[0030] After the rotor pole number n is determined N r The specific outer contour size of the salient pole reluctance rotor can be calculated through the following formula:

[0031] In the formula,

[0032] Among them, D si The stator inner diameter is D, g The air gap length is g, r And θ The pole diameter and the angle of the salient pole reluctance rotor outer contour in the polar coordinate are r and a respectively,α and β is a function of the inner diameter of the stator D si , the air gap length g and the optimal core height h smax , the optimal core h smax represents the difference between the outermost point radius and the innermost point radius of the outer profile of the reluctance rotor, and the equation satisfied is:

[0033] The number of rotor poles N r is 10 in the embodiment of the present application, and the convex pole rotor structure with the maximum fundamental ratio permeance can be obtained by combining the above formula.

[0034] Figure 2 is a two-dimensional cross-sectional schematic view of a switched flux motor with a traditional reluctance structure of the rotor.

[0035] In the embodiment, two motor structures are designed according to the motor structures shown in Figure 1 and Figure 2 , one is the motor designed in the present application (denoted as motor A), and the other is the motor with a traditional reluctance rotor structure based on the present application (denoted as motor B).

[0036] The simulation analysis is performed on the two motors, and the torque performance is referred to Figure 3 . Under the premise of the same size of the stator structure, the same material properties of the motor and the same current excitation, the torque ripple of the motor of the present application is 0.99%, and the torque fluctuation of the motor with the traditional reluctance rotor structure is 13.31%. The torque ripple performance of the present application is obviously better than that of the traditional structure, which proves the correctness of the theory of the present application.

[0037] The switched flux motor with the convex pole reluctance rotor structure with the maximum fundamental ratio permeance has the advantages of low torque ripple, simple structure, high reliability and the like, and is suitable for occasions with high requirements on the torque ripple performance of the motor, such as numerical control machine tools, intelligent robots and the like.

[0038] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A salient-pole reluctance rotor switched flux motor with maximized fundamental frequency ratio permeability, characterized in that, include: Stator core (1), permanent magnet (2), armature winding (3) and salient pole reluctance rotor (4); The stator core (1) is composed of multiple identical U-shaped cores; the permanent magnet (2) is disposed between two adjacent U-shaped cores; the armature winding (3) is wound around the adjacent U-shaped cores; The salient pole reluctance rotor (4) is disposed inside the stator core (1). The outline size of the salient pole reluctance rotor (4) is calculated and determined according to the stator inner diameter, air gap length and stator pole number so that the salient pole reluctance rotor (4) is a salient pole rotor structure with maximized fundamental wave ratio permeability, thereby reducing the torque pulsation of the switched magnet motor.

2. The fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 1, characterized in that, The outline dimensions of the salient pole reluctance rotor (4) are obtained through Calculations show that in, D si The inner diameter of the stator. N r The number of rotor poles, r and θ These represent the polar diameter and angle of the salient pole reluctance rotor in polar coordinates.

3. The fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 2, characterized in that, The number of rotor poles N r pass Calculations show that in, N s For the stator pole number, m This represents the number of phases of the motor. n It can be 1 or 2.

4. The fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 1, characterized in that, The stator core (1) has a buckle structure at the four corners of the U-shaped core, which is used to fix the permanent magnet (2).

5. The fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 1, characterized in that, The permanent magnets (2) are all magnetized in parallel and adjacent permanent magnets are magnetized in opposite directions.

6. A fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 5, characterized in that, The permanent magnet (2) is embedded between two U-shaped iron cores and directly participates in the switching of magnetic flux.

7. A fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 1, characterized in that, The armature winding (3) is a concentrated winding, with a single coil wound around the core teeth of two U-shaped iron cores and embedded in the permanent magnet between the two U-shaped iron cores.

8. A fundamental frequency ratio permeability maximized salient pole reluctance rotor switched flux motor according to claim 7, characterized in that, The ends of the armature winding (3) are arranged regularly and the armature winding (3) is concentrated in the iron core teeth.

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