Rotor structure of Halbach array type permanent magnet auxiliary synchronous reluctance motor

Abstract

The invention discloses a Halbach array type permanent magnet auxiliary synchronous reluctance motor rotor structure, and relates to the technical field of motor rotors. The rotor structure comprises three layers of magnetic barrier structures. The three-layer magnetic barrier structure comprises a first-layer U-shaped structure, a second-layer U-shaped structure and a third-layer double-J-shaped structure; wherein each layer of structure comprises Halbach array segments formed by permanent magnets and air slots which are arranged at intervals, and the included angle between every two adjacent permanent magnets in each layer is a fixed angle. Through the design of the three-layer magnetic barrier structure, each layer of permanent magnet is divided into a plurality of sections, and the magnetizing direction of the permanent magnet is changed by adjusting the included angle between each section of permanent magnet, so that a Halbach array structure is formed, and the torque ripple is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motor rotors, and in particular to a Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure. Background Art

[0002] Permanent magnet-assisted synchronous reluctance motors have the advantages of high efficiency, high reliability, and a wide speed regulation range, and have broad application prospects in the field of new energy vehicles. However, the high torque pulsation inherent in permanent magnet-assisted synchronous reluctance motors seriously affects the smoothness of the torque pulsation output, causing the motor to generate periodic impact force during operation, thereby generating vibration and noise. Long-term vibration may cause the motor and its connecting parts to loosen and wear, which will reduce the reliability and service life of the equipment. Therefore, without reducing the performance advantages of permanent magnet-assisted synchronous reluctance motors, how to reduce torque pulsation has become a difficult problem that motor designers must face. Summary of the invention

[0003] The purpose of the present invention is to provide a Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, which can divide each layer of permanent magnets into several segments through a three-layer magnetic barrier structure design, and change the magnetization direction by adjusting the angle between each segmented permanent magnet to form a Halbach array structure, thereby reducing torque pulsation.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure comprises: a three-layer magnetic barrier structure; the three-layer magnetic barrier structure comprises a first layer U-shaped structure, a second layer U-shaped structure and a third layer double J-shaped structure; wherein each layer structure comprises a Halbach array segment formed by permanent magnets and air slots arranged at intervals, and the angle between adjacent permanent magnets in each layer is a fixed angle.

[0006] Optionally, the first layer of U-shaped structure includes 5 permanent magnets, the second layer of U-shaped structure includes 7 permanent magnets, and the third layer of double J-shaped structure includes 10 permanent magnets. The 10 permanent magnets are evenly divided into two J-shaped structures, and the two J-shaped structures are symmetrically arranged and not connected to each other.

[0007] Optionally, the widths of adjacent permanent magnets in each layer structure are different, and the widths of spaced permanent magnets are the same.

[0008] Optionally, the width of the spacing air grooves in the first layer of U-shaped structure is the same as the width of the spacing air grooves in the second layer of U-shaped structure, and the width of the spacing air grooves in the third layer of double J-shaped structure is smaller than the width of the spacing air grooves in the first layer of U-shaped structure and the second layer of U-shaped structure; the spacing air grooves are air grooves other than the edge air grooves.

[0009] Optionally, the angle of the permanent magnets in the second layer of U-shaped structure is the same as the angle of the permanent magnets in the third layer of double J-shaped structure, and the angle of the permanent magnets in the first layer of U-shaped structure is smaller than the angles of the permanent magnets in the second layer of U-shaped structure and the third layer of double J-shaped structure.

[0010] Optionally, the magnetization directions of the permanent magnets in each layer structure are different and are perpendicular to the lower boundary of the corresponding permanent magnet.

[0011] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0012] The present invention discloses a Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, wherein the rotor structure comprises a three-layer magnetic barrier structure, including a first layer U-shaped structure, a second layer U-shaped structure and a third layer double J-shaped structure; wherein each layer structure comprises a Halbach array segment formed by permanent magnets and air slots arranged at intervals, and the angle between adjacent permanent magnets in each layer is a fixed angle. The present invention can divide each layer of permanent magnets into several segments through the design of a three-layer magnetic barrier structure, and change the magnetization direction of each segmented permanent magnet by adjusting the angle between the segmented permanent magnets to form a Halbach array structure, thereby reducing torque pulsation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1 This is a schematic diagram of the rotor structure designed with a 1 / 8 Halbach array in this embodiment;

[0015] Figure 2 Schematic diagram of the angle and magnetization direction of the Halbach array design in this embodiment;

[0016] Figure 3 This is a schematic diagram of the original rotor structure motor in this embodiment;

[0017] Figure 4 The magnetic density cloud diagram of the motor load in this embodiment;

[0018] Figure 5 The output torque diagram of the motor designed with the original rotor structure and the motor designed with the Halbach array in this embodiment;

[0019] Figure 6 This is the motor efficiency MAP diagram of the Halbach array design in this embodiment.

[0020] Reference numerals:

[0021] 1. Air slots on the edge; 2. Air slots on the first layer; 3. Air slots on the second layer; 4. Air slots on the third layer; 5. Any permanent magnet in the first layer; 6. Adjacent permanent magnets in the first layer; 7. Any permanent magnet in the second layer; 8. Adjacent permanent magnets in the second layer; 9. Any permanent magnet in the third layer; 10. Adjacent permanent magnets in the third layer; 11. Air slots on the edge of the original motor rotor; 12. Permanent magnets on the first layer of the original motor rotor; 13. Permanent magnets on the second layer of the original motor rotor; 14. Permanent magnets on the left side of the third layer of the original motor rotor; 15. Permanent magnets on the right side of the third layer of the original motor rotor. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The purpose of the present invention is to provide a Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, which can divide each layer of permanent magnets into several segments through a three-layer magnetic barrier structure design, and change the magnetization direction by adjusting the angle between each segmented permanent magnet to form a Halbach array structure, thereby reducing torque pulsation.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, the present invention provides a Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, including: a three-layer magnetic barrier structure, including a first layer U-shaped structure, a second layer U-shaped structure and a third layer double J-shaped structure; wherein each layer of the structure includes a Halbach array segment formed by permanent magnets and air slots arranged at intervals, and the angle between adjacent permanent magnets in each layer is a fixed angle.

[0026] As a specific implementation, the number of permanent magnets in the first layer is five, the number of permanent magnets in the second layer is seven, and the number of permanent magnets on both sides of the third layer is five, for a total of ten, forming a Halbach array segment.

[0027] The widths of adjacent permanent magnets in each layer are different, while the widths of adjacent permanent magnets remain the same, that is, the lateral widths of any permanent magnet 5 in the first layer are different from those of the adjacent permanent magnet 6 in the first layer, the lateral widths of any permanent magnet 7 in the second layer are different from those of the adjacent permanent magnet 8 in the second layer, and the lateral widths of any permanent magnet 9 in the third layer are different from those of the adjacent permanent magnet 10 in the third layer. This design of width variation is intended to adjust the magnetic field distribution by utilizing the changes in the content of different permanent magnets, thereby effectively increasing the magnetic field distribution density.

[0028] In each layer, except for the air slot 1 at the edge of each layer, the width of the air slots on both sides of a single permanent magnet remains the same. Specifically, the width of the air slots in the first and second layers is the same. However, due to space limitations, the width of the air slots in the third layer is designed to be smaller than the first two layers, that is, the width of the air slots 2 in the first layer and the air slots 3 in the second layer are the same, and the width of the air slots 4 in the third layer is smaller than the width of the air slots 2 in the first layer and the air slots 3 in the second layer. This difference in the design of the air slots can change the magnetic field distribution inside the motor.

[0029] like Figure 2 As shown, the angles of adjacent permanent magnets in the second and third layers are the same, and the angles of adjacent permanent magnets in the first layer are smaller than those in the second and third layers, that is, the angle a of adjacent permanent magnets in the first layer is smaller than the angle b of adjacent permanent magnets in the second layer and the angle c of adjacent permanent magnets in the third layer, and the angle b of adjacent permanent magnets in the second layer and the angle c of adjacent permanent magnets in the third layer are the same. Changing the angle of the permanent magnets changes the magnetization direction of the permanent magnets, thereby changing the direction of the magnetic field, making the distribution more uniform and increasing the magnetic field density.

[0030] In each layer, the magnetization direction of each permanent magnet is different, and the magnetization direction is always perpendicular to the lower boundary of the permanent magnet, that is, the direction of the magnetization direction arrows e1, e2 and e3 is perpendicular to the boundary at the beginning of the arrow. When the angle of the permanent magnet changes, its magnetization direction will also adjust accordingly. The arrangement of permanent magnets that constitute the Halbach array makes the magnetic field more concentrated in space, thereby generating a high-intensity magnetic field.

[0031] Compared to Figure 3The original rotor structure motor shown in the figure (the original motor rotor edge air slot 11, the original motor rotor first layer permanent magnet 12, the original motor rotor second layer permanent magnet 13, the original motor rotor third layer left permanent magnet 14 and the original motor rotor third layer right permanent magnet 15), the Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure of the present invention, firstly, the permanent magnet is segmented, and air slots are added between them, and then the angle between adjacent permanent magnets is adjusted, which not only optimizes the layout of the permanent magnets, but also further adjusts the magnetic field distribution by introducing air slots. This design significantly enhances the magnetic field strength on one side of the array, while the other side is relatively weakened, making the air gap magnetic density closer to the sine wave. This feature significantly reduces the harmonic component and reduces the torque pulsation; the Halbach array adjusts the magnetization direction of the motor, and can enhance the air gap magnetic density without adding additional permanent magnet materials, thereby improving the torque density of the motor; the Halbach array optimizes the magnetic field distribution, effectively improves the high-efficiency operation range of the motor, and thus achieves a significant improvement in the motor efficiency.

[0032] The Halbach array design significantly increases the air gap magnetic field of the motor by segmenting the permanent magnets and changing the magnetization direction. Figure 4 As shown in the load magnetic density cloud diagram, in each layer of the U-shaped structure, the magnetic field line density on the outside of each layer is sparser than that on the inside, forming a specific magnetic field gradient. This design optimizes the distribution of the magnetic field, improves the air gap magnetic density of the motor, and enhances the magnetic field strength of the motor in the air gap.

[0033] The rotor structure of the Halbach array design improves the output torque of the motor. Figure 5 The output torques of the two motors are shown in Figure 2. Comparing the output torques of the two motors, the permanent magnet assisted synchronous reluctance motor with Halbach array design has an output torque of 345.09 N·m, while the output torque of the original rotor structure motor without Halbach array design is 328.7 N·m.

[0034] The rotor structure of the Halbach array design increases the proportion of high efficiency of the motor. Figure 6 As shown in the motor efficiency MAP, it can be seen that the motor with Halbach array design has a larger high efficiency area. Halbach array design greatly improves the magnetic field distribution inside the motor, making the energy conversion process more efficient and making the motor more inclined to operate stably in its high efficiency area.

[0035] The specific advantage comparison data analysis is shown in Table 1.

[0036] Table 1 Analysis results

[0037]

[0038]

[0039] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0040] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, characterized in that: include: A three-layer magnetic barrier structure; the three-layer magnetic barrier structure includes a first-layer U-shaped structure, a second-layer U-shaped structure and a third-layer double J-shaped structure; wherein each layer of the structure includes a Halbach array segment formed by permanent magnets and air slots arranged at intervals, and the angle between adjacent permanent magnets in each layer is a fixed angle.

2. The Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure according to claim 1, characterized in that: The first layer of U-shaped structure includes 5 permanent magnets, the second layer of U-shaped structure includes 7 permanent magnets, and the third layer of double J-shaped structure includes 10 permanent magnets. The 10 permanent magnets are evenly divided into two J-shaped structures, and the two J-shaped structures are symmetrically arranged and not connected to each other.

3. The Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure according to claim 2 is characterized in that: The widths of adjacent permanent magnets in each layer structure are different, and the widths of spaced permanent magnets are the same.

4. The Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure according to claim 1, characterized in that: The width of the spacing air groove in the first layer of U-shaped structure is the same as that of the spacing air groove in the second layer of U-shaped structure, and the width of the spacing air groove in the third layer of double J-shaped structure is smaller than the width of the spacing air groove in the first layer of U-shaped structure and the second layer of U-shaped structure; the spacing air groove is the air groove other than the edge air groove.

5. The Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure according to claim 2, characterized in that: The angle of the permanent magnets in the second layer of U-shaped structure is the same as the angle of the permanent magnets in the third layer of double J-shaped structure, and the angle of the permanent magnets in the first layer of U-shaped structure is smaller than the angles of the permanent magnets in the second layer of U-shaped structure and the third layer of double J-shaped structure.

6. The Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure according to claim 2, characterized in that: The magnetization directions of the permanent magnets in each layer structure are different and are perpendicular to the lower boundary of the corresponding permanent magnet.

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