Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure

Abstract

The application 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 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 of the structure comprises a Halbach array segment formed by interval arranged permanent magnets and air slots, and the included angle of each layer of adjacent permanent magnets is a fixed angle. The application can divide each layer of permanent magnets into several segments through three-layer magnetic barrier structure design, and can change the magnetizing direction of the segments by adjusting the included angle between the segments, so that a Halbach array structure is formed, and torque ripple is reduced.

Description

Technical Field

[0001] This invention relates to the field of motor rotor technology, and in particular to a rotor structure for a Halbach array type permanent magnet assisted synchronous reluctance motor. Background Technology

[0002] Permanent magnet assisted synchronous reluctance motors (PMRMs) offer advantages such as high efficiency, high reliability, and a wide speed range, making them promising for applications in the new energy vehicle sector. However, the inherent high torque ripple of PMRMs significantly affects the smoothness of torque output, leading to periodic impact forces during operation and consequently vibration and noise. Prolonged vibration can cause loosening and accelerated wear of the motor and its connecting components, reducing equipment reliability and lifespan. Therefore, reducing torque ripple without compromising the performance advantages of PMRMs has become a critical challenge for motor designers. Summary of the Invention

[0003] The purpose of this 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 their magnetization direction by adjusting the included angle between each segment of permanent magnets to form a Halbach array structure, thereby reducing torque pulsation.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure includes: 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 structure includes Halbach array segments formed by spaced permanent magnets and air slots, and the included angle between adjacent permanent magnets in each layer is a fixed angle.

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

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

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

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

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

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

[0012] This invention discloses a Halbach array-type permanent magnet assisted synchronous reluctance motor rotor structure. The rotor structure includes a three-layer magnetic barrier structure, comprising a first-layer U-shaped structure, a second-layer U-shaped structure, and a third-layer double-J-shaped structure. Each layer includes Halbach array segments formed by spaced permanent magnets and air slots, with a fixed angle between adjacent permanent magnets in each layer. This invention, through its three-layer magnetic barrier structure design, divides each layer of permanent magnets into several segments and adjusts the angle between these segments to change their magnetization direction, thus forming a Halbach array structure and reducing torque ripple. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0015] Figure 2 This is a schematic diagram showing 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 This is a magnetic flux density cloud diagram of the motor load in this embodiment;

[0018] Figure 5 The output torque diagrams for the original rotor structure design motor and the Halbach array design motor in this embodiment are shown.

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

[0020] Figure label:

[0021] 1. Edge air slot; 2. First layer spaced air slot; 3. Second layer spaced air slot; 4. Third layer spaced air slot; 5. Any permanent magnet in the first layer; 6. Adjacent permanent magnet in the first layer; 7. Any permanent magnet in the second layer; 8. Adjacent permanent magnet in the second layer; 9. Any permanent magnet in the third layer; 10. Adjacent permanent magnet in the third layer; 11. Edge air slot of the original motor rotor; 12. Permanent magnet in the first layer of the original motor rotor; 13. Permanent magnet in the second layer of the original motor rotor; 14. Permanent magnet on the left side of the third layer of the original motor rotor; 15. Permanent magnet on the right side of the third layer of the original motor rotor. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this 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 their magnetization direction by adjusting the included angle between each segment of permanent magnets to form a Halbach array structure, thereby reducing torque pulsation.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be 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 structure includes Halbach array segments formed by spaced permanent magnets and air slots, and the included angle between adjacent permanent magnets in each layer is a fixed angle.

[0026] In one specific implementation, the first layer has five permanent magnets, the second layer has seven permanent magnets, and the third layer has five permanent magnets on each of the left and right sides, for a total of ten, forming a Halbach array segment.

[0027] In each layer, the widths of adjacent permanent magnets vary, while the widths of the next adjacent permanent magnets remain consistent. Specifically, the lateral width of any permanent magnet 5 in the first layer differs from that of its adjacent permanent magnet 6; the lateral width of any permanent magnet 7 in the second layer differs from that of its adjacent permanent magnet 8; and the lateral width of any permanent magnet 9 in the third layer differs from that of its adjacent permanent magnet 10. This design of varying widths aims to adjust the magnetic field distribution by changing the amount of different permanent magnets, thereby effectively increasing the magnetic field density.

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

[0029] like Figure 2 As shown, the angles between adjacent permanent magnets in the second and third layers are the same, while the angles between adjacent permanent magnets in the first layer are smaller than those in the second and third layers. Specifically, the angle 'a' between adjacent permanent magnets in the first layer is smaller than the angle 'b' in the second layer and the angle 'c' in the third layer. Meanwhile, the angles 'b' and 'c' between adjacent permanent magnets in the second and third layers are the same. Changing the angles of the permanent magnets alters their magnetization direction, thus changing the direction of the magnetic field, making its distribution more uniform and increasing its 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 directions of the magnetization direction arrows e1, e2, and e3 are perpendicular to the starting boundary of the arrow. When the angle of the permanent magnet changes, its magnetization direction will also adjust accordingly. The arrangement of permanent magnets in 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 (original rotor edge air slot 11, original rotor first layer permanent magnet 12, original rotor second layer permanent magnet 13, original rotor third layer left permanent magnet 14, and original rotor third layer right permanent magnet 15) of this invention, the Halbach array type permanent magnet assisted synchronous reluctance motor rotor structure, firstly segments the permanent magnets and adds air slots between them, then adjusts the included angle between adjacent permanent magnets. This not only optimizes the layout of the permanent magnets, but also further adjusts the magnetic field distribution through the introduction of air slots. This design significantly enhances the magnetic field strength on one side of the array, while relatively weakening it on the other side, making the air gap magnetic flux density closer to a sine wave. This characteristic significantly reduces harmonic components and lowers torque ripple. The Halbach array adjusts the magnetization direction of the motor, which can enhance the air gap magnetic flux density without adding additional permanent magnet material, thereby improving the torque density of the motor. The Halbach array optimizes the magnetic field distribution, effectively improving the high-efficiency operating range of the motor, thus achieving a significant improvement in motor efficiency.

[0032] The Halbach array design significantly increases the air gap magnetic field of the motor by segmenting the permanent magnets and changing their magnetization direction. For example... Figure 4 As shown in the load magnetic flux density cloud diagram, in each U-shaped structure, the magnetic field line density on the outer side of each U-shape is sparser than that on the inner side, forming a specific magnetic field gradient. This design optimizes the magnetic field distribution, thereby increasing the air gap magnetic flux density of the motor and enhancing the magnetic field strength of the motor in the air gap.

[0033] The rotor structure designed with Halbach arrays improves the motor's output torque. For example... Figure 5 The output torques of the two motors are shown. 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 original rotor structure motor without Halbach array design has an output torque of 328.7 N·m.

[0034] The rotor structure designed with Halbach arrays increases the proportion of high efficiency in the motor. For example... Figure 6 As shown in the motor efficiency MAP, the motor using the Halbach array design has a larger high-efficiency region. The Halbach array design greatly improves the magnetic field distribution inside the motor, making the energy conversion process more efficient and causing the motor to operate stably within its high-efficiency region.

[0035] The specific advantages are compared and analyzed in Table 1.

[0036] Table 1 Analysis Results

[0037]

[0038]

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

[0040] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A rotor structure for a Halbach array-type permanent magnet assisted synchronous reluctance motor, 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 structure includes Halbach array segments formed by spaced permanent magnets and air slots, and the included angle between adjacent permanent magnets in each layer is a fixed angle; The air gaps in the first U-shaped structure and the second U-shaped structure have the same width, and the air gaps in the third double J-shaped structure are smaller than the widths of the air gaps in the first and second U-shaped structures; the air gaps are air gaps other than the edge air gaps.

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

3. The rotor structure of the Halbach array type permanent magnet assisted synchronous reluctance motor according to claim 2, characterized in that, In each layer of the structure, the width of adjacent permanent magnets is different, while the width of the spaced-out permanent magnets is the same.

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

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

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