Halbach array type permanent magnet motor rotor structure for new energy vehicle

Abstract

The invention discloses a Halbach array type permanent magnet motor rotor structure for a new energy vehicle, and relates to the technical field of new energy vehicle synchronous motors. And a second layer of No.1 permanent magnet, a second layer of No.2 permanent magnet, a second layer of No.3 permanent magnet, a second layer of No.4 permanent magnet, a second layer of No.5 permanent magnet, a second layer of No.6 permanent magnet and a second layer of No.7 permanent magnet are fixedly mounted on the inner side wall of the rotor silicon steel sheet. The number of effective magnetic poles of the rotor can be increased through the double-layer structure, magnetic leakage of a magnetic field in air gaps can be reduced, the efficiency of the motor is improved, the magnetizing angles of the permanent magnets are different, the magnetic field is more concentrated in a needed area through the design of the magnetic poles with different widths, and the uniformity of the magnetic field is further improved. And the magnetic field fluctuation during the operation of the motor is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of synchronous motors for new energy vehicles, and particularly to a rotor structure of a Halbach array permanent magnet motor for new energy vehicles. Background Art

[0002] Interior permanent magnet synchronous motors are widely used in the field of new energy vehicles due to their advantages such as high power density, high working efficiency, and wide speed regulation range. However, the widely adopted symmetric permanent magnet arrangement exposes several key technical defects during the actual vehicle operation, restricting the further improvement of the overall vehicle performance.

[0003] Existing interior permanent magnet synchronous motors generally adopt a symmetrically distributed permanent magnet layout, making the magnetic field inside the motor highly symmetric. Although this design can maintain stable operation under general working conditions, it shows significant deficiencies under typical new energy vehicle working conditions such as high speed and high load: First, the symmetric magnetic field structure is difficult to effectively adapt to the frequently changing working condition requirements, resulting in enhanced air-gap magnetic density fluctuations, unstable torque output, and large torque ripples; Second, due to the uneven distribution of magnetic field energy and insufficient local magnetic flux density, the magnetic energy utilization rate decreases, further exacerbating the problems of torque ripple and efficiency loss; More seriously, torque ripple will cause obvious vibrations and abnormal noises in the vehicle during low-speed driving and acceleration, affecting driving smoothness and comfort, and may lead to increased mechanical vibrations, increased noise, and shortened lifespan of the motor, thereby affecting the overall vehicle reliability and user experience of new energy vehicles.

[0004] To address the above technical problems, the present invention is committed to solving two core issues: (1) How to effectively suppress torque ripple through innovative magnetic circuit design and improve the running smoothness of the whole vehicle; (2) How to optimize the magnetic field energy distribution to enhance the torque output stability of the motor while ensuring controllable costs. The breakthrough of these problems will significantly improve the comprehensive performance and application value of permanent magnet synchronous motors in new energy vehicles. Summary of the Invention

[0005] The purpose of the present invention is to provide a rotor structure of a Halbach array permanent magnet motor for new energy vehicles.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A rotor structure of a Halbach array permanent magnet motor for new energy vehicles, including rotor silicon steel sheets, and the inner side walls of the rotor silicon steel sheets are respectively fixedly installed with a second-layer No. 1 permanent magnet, a second-layer No. 2 permanent magnet, a second-layer No. 3 permanent magnet, a second-layer No. 4 permanent magnet, a second-layer No. 5 permanent magnet, a second-layer No. 6 permanent magnet, and a second-layer No. 7 permanent magnet.

[0007] As a further solution of the present invention: The rotor silicon steel sheets are provided with a plurality of outer magnetic isolation grooves on each layer.

[0008] As a further solution of the present invention: four magnetic isolation grooves are provided between adjacent permanent magnets in the second layer on the rotor silicon steel sheet.

[0009] As a further solution of the present invention: a first-layer No. 1 permanent magnet, a first-layer No. 2 permanent magnet, and a first-layer No. 3 permanent magnet are respectively and fixedly installed on the inner side wall of the rotor silicon steel sheet.

[0010] As a further solution of the present invention: two magnetic isolation grooves are provided between adjacent permanent magnets in the first layer on the rotor silicon steel sheet.

[0011] As a further solution of the present invention: the first-layer No. 1 permanent magnet, the first-layer No. 2 permanent magnet, and the first-layer No. 3 permanent magnet have the same size value of w3, where w3 = 4.7 mm.

[0012] As a further solution of the present invention: the second-layer No. 2 permanent magnet, the second-layer No. 4 permanent magnet, and the second-layer No. 6 permanent magnet have the same size value of w2, and the second-layer No. 1 permanent magnet, the second-layer No. 3 permanent magnet, the second-layer No. 5 permanent magnet, and the second-layer No. 7 permanent magnet have the same size value of w1, where w2 = 6.4 mm and w1 = 3.95 mm.

[0013] As a further solution of the present invention: the radial magnetization angles of the first-layer No. 2 permanent magnet with the first-layer No. 1 permanent magnet and the first-layer No. 3 permanent magnet on the left and right sides are both 25°.

[0014] As a further solution of the present invention: the arrangement angles of the second-layer No. 1 permanent magnet, the second-layer No. 2 permanent magnet, the second-layer No. 3 permanent magnet, the second-layer No. 4 permanent magnet, the second-layer No. 5 permanent magnet, the second-layer No. 6 permanent magnet, and the second-layer No. 7 permanent magnet from left to right are 25°, 25°, 20°, 20°, 25°, 25° in sequence.

[0015] Adopting the above technical solutions, compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. Through the double-layer U-shaped structure design of the present invention, compared with the single-layer structure, the double-layer structure can increase the effective number of magnetic poles of the rotor, reduce the magnetic leakage of the magnetic field in the air gap, improve the efficiency of the motor, the permanent magnets are arranged in a segmented manner in the rotor core, improving the utilization rate of the permanent magnets and making the motor structure more compact. The Halbach array type permanent magnet distribution is adopted, and the permanent magnets are radially magnetized, and the magnetization angles of each permanent magnet are different. Through the unequal-width magnetic pole design, the magnetic field is more concentrated in the required area, further improving the magnetic field uniformity and effectively reducing the magnetic field fluctuation during the operation of the motor;

[0017] 2. The present invention demonstrates the advantage of significantly reducing torque ripple through the Halbach array structure. In terms of torque characteristics, it maintains the stability of torque output, significantly reduces torque pulsation, and reduces the vibration and noise problems caused by torque pulsation.

[0018] 3. In terms of energy efficiency performance, the present invention can operate with higher efficiency within a wider range of operating points through the Halbach array rotor structure, thereby reducing energy consumption, decreasing heat generation, improving motor performance, and enhancing the stability and market competitiveness of the system.

[0019] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the overall rotor silicon steel sheet in the embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the intercepted 1 / 8 rotor silicon steel sheet in the embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the Halbach array rotor in the embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the design parameters in the embodiment of the present invention;

[0024] Figure 5 Schematic diagram of the original rotor structure in the embodiment of the present invention;

[0025] Figure 6 Magnetic cloud diagram of the motor load in the embodiment of the present invention;

[0026] Figure 7 Torque diagram of the Halbach array rotor structure and the original rotor structure in the embodiment of the present invention;

[0027] Figure 8 Cogging torque diagram of the Halbach array rotor structure and the original rotor structure in the embodiment of the present invention;

[0028] Figure 9 Efficiency map of the Halbach array interior permanent magnet motor in the embodiment of the present invention.

[0029] In the figure: 1. Rotor silicon steel sheet; 2. The first permanent magnet of the second layer; 3. Magnetic isolation groove between adjacent permanent magnets of the second layer; 4. The second permanent magnet of the second layer; 5. The third permanent magnet of the second layer; 6. The fourth permanent magnet of the second layer; 7. The fifth permanent magnet of the second layer; 8. The sixth permanent magnet of the second layer; 9. The seventh permanent magnet of the second layer; 10. The first permanent magnet of the first layer; 11. Magnetic isolation groove between adjacent permanent magnets of the first layer; 12. The second permanent magnet of the first layer; 13. The third permanent magnet of the first layer; 14. Magnetic isolation groove on the outer side of each layer. Detailed implementation manners

[0030] The following further describes the detailed implementation manners of the present invention in conjunction with the accompanying drawings. It should be noted here that the description of these implementation manners is used to help understand the present invention, but does not constitute a limitation to the present invention.

[0031] In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Please refer to the attached Figure 1 - attached Figure 9 , the rotor structure of the Halbach array type permanent magnet motor for new energy vehicles of the present invention.

[0033] Embodiment 1 includes a rotor silicon steel sheet 1. The inner side walls of the rotor silicon steel sheet 1 are respectively fixedly installed with the first permanent magnet 2 of the second layer, the second permanent magnet 4 of the second layer, the third permanent magnet 5 of the second layer, the fourth permanent magnet 6 of the second layer, the fifth permanent magnet 7 of the second layer, the sixth permanent magnet 8 of the second layer, and the seventh permanent magnet 9 of the second layer. The rotor silicon steel sheet 1 is provided with a plurality of magnetic isolation grooves 14 on the outer side of each layer. The rotor silicon steel sheet 1 is provided with four magnetic isolation grooves 3 between adjacent permanent magnets of the second layer. The inner side walls of the rotor silicon steel sheet 1 are also respectively fixedly installed with the first permanent magnet 10 of the first layer, the second permanent magnet 12 of the first layer, and the third permanent magnet 13 of the first layer. The rotor silicon steel sheet 1 is provided with two magnetic isolation grooves 11 between adjacent permanent magnets of the first layer;

[0034] Specifically, this Halbach array type structure consists of two layers. The layer close to the rotor outer edge is the first layer, and the layer close to the shaft position is the second layer. A double-layer U-shaped structure design is adopted. Compared with the single-layer structure, the double-layer structure can increase the effective number of magnetic poles of the rotor, reduce the magnetic leakage of the magnetic field in the air gap, improve the efficiency of the motor, and the permanent magnets are arranged in segments. The number of permanent magnets in the first layer is less, and the number of permanent magnets in the second layer is more, thereby improving the utilization rate of the permanent magnets and making the motor structure more compact.

[0035] Both layers of permanent magnets are wrapped by magnetic isolation grooves to ensure their stable positions. Each permanent magnet is wrapped by magnetic isolation grooves. The first layer adopts an integral design, with three permanent magnets placed in the magnetic isolation grooves, effectively controlling the magnetic flux distribution and reducing the torque ripple caused by uneven magnetic resistance. The second layer adopts a rectangular groove design, with three magnetic isolation grooves arranged in an overall layout. Two permanent magnets on each side of the left and right regions share one magnetic isolation groove to appropriately control the magnetic flux coupling and improve the demagnetization resistance. The three permanent magnets in the middle share one magnetic isolation groove, and a magnetic isolation bridge is added between adjacent permanent magnets to prevent magnetic flux short - circuit and improve the magnetic field stability. On both sides of the second layer near the No. 6 permanent magnet, the distance between adjacent permanent magnets is smaller than that of other permanent magnets, that is, the length of the corresponding magnetic isolation groove is reduced. This design helps to concentrate the magnetic field in the middle region, thus forming a magnetic concentration effect and further enhancing the magnetic field strength in this region. By observing the magnetic force line distribution, it can be seen that the magnetic field is mainly concentrated between the two layers of permanent magnets, with a higher magnetic flux density along the magnetization direction and a weaker magnetic field in the opposite direction. This design makes full use of the Halbach array principle, enhances the field strength in the magnetization direction, makes the magnetic field more concentrated in the required regions, enhances the magnetic flux density in these regions, and thus helps the drive motor to work more efficiently. More magnetic force lines enter the stator and form a closed loop, thereby reducing energy loss. This structure can optimize the magnetic field distribution, thus improving the efficiency of the motor; in terms of torque characteristics, the Halbach array - type structure shows a significant advantage in reducing torque ripple. It can be seen from the comparison of the torque of the Halbach permanent magnet array - type structure and the original structure that the average torque of the Halbach array - type rotor structure is basically the same as that of the symmetric structure. At the same time, the torque ripple of the Halbach array - type rotor structure is only 1.163%, significantly lower than 2.85% of the symmetric structure. Through the comparison of data, it can be known that this design makes full use of the advantages of the Halbach array, maintains the stability of torque output, and significantly reduces torque ripple, reducing the vibration and noise problems caused by torque ripple; in terms of energy efficiency performance, the peak efficiency of the Halbach array - type rotor structure is 97.67%, which is 0.73% higher than 96.96% of the original structure. In terms of the proportion of the high - efficiency region, the efficiency range of the Halbach array - type rotor structure is significantly expanded. Especially in the efficiency range greater than 96%, its proportion is higher than that of the original structure. This shows that the structure of this invention can operate with higher efficiency in a wider range of operating points, thereby reducing energy consumption, reducing heat generation, improving the performance of the motor, and enhancing the stability and market competitiveness of the system; thus effectively solving the problems of traditional permanent magnet synchronous motors in terms of torque ripple, cogging torque, and material consumption through the Halbach array - type rotor structure, while improving the efficiency and operating stability of the motor, meeting the requirements of modern motor design for high efficiency, low noise, and low vibration, and having significant technical advantages and application prospects.

[0036] Embodiment 2. The sizes of the No. 1 permanent magnet 10, No. 2 permanent magnet 12, and No. 3 permanent magnet 13 in the first layer are the same, with a value of w3, where w3 = 4.7 mm. The sizes of the No. 2 permanent magnet 4, No. 4 permanent magnet 6, and No. 6 permanent magnet 8 in the second layer are the same, with a value of w2. The sizes of the No. 1 permanent magnet 2, No. 3 permanent magnet 5, No. 5 permanent magnet 7, and No. 7 permanent magnet 9 in the second layer are the same, with a value of w1, where w2 = 6.4 mm and w1 = 3.95 mm. The radial magnetization angles of the No. 2 permanent magnet 12 in the first layer with the No. 1 permanent magnet 10 and the No. 3 permanent magnet 13 on the left and right sides are both 25°. The arrangement angles of the No. 1 permanent magnet 2, No. 2 permanent magnet 4, No. 3 permanent magnet 5, No. 4 permanent magnet 6, No. 5 permanent magnet 7, No. 6 permanent magnet 8, and No. 7 permanent magnet 9 in the second layer from left to right are 25°, 25°, 20°, 20°, 25°, 25° in sequence.

[0037] Specifically, the large permanent magnets act as main magnetic poles, and the small permanent magnets act as auxiliary magnetic poles. Specifically, the No. 2 permanent magnet 4, No. 4 permanent magnet 6, and No. 6 permanent magnet 8 in the second layer act as main magnetic poles, and the No. 1 permanent magnet 2, No. 3 permanent magnet 5, No. 5 permanent magnet 7, and No. 7 permanent magnet 9 in the second layer act as auxiliary magnetic poles. The permanent magnets are radially magnetized. Through the design of unequal-width magnetic poles, the magnetic field is more concentrated in the required area, further improving the magnetic field uniformity and effectively reducing the magnetic field fluctuation during the operation of the motor. Moreover, the magnetization angles of the permanent magnets are different, and their different permanent magnet array arrangements form different magnetization directions, constituting a Halbach-type permanent magnet array. Due to the small gap between the permanent magnets and the stator, the interaction between the permanent magnets and the stator generates cogging torque, further optimizing the operation performance of the motor. On the premise of keeping the same amount of permanent magnet usage as the original symmetric structure, it achieves an output torque performance equivalent to it, while increasing the peak efficiency by 0.73%, significantly reducing the torque ripple and cogging torque, thereby optimizing the magnetic field distribution, improving the magnetic energy utilization rate, and effectively improving the operation stability and overall stability of the motor, and further enhancing the performance of the motor under complex working conditions.

[0038] And the second layer is close to both sides of the second layer No. 4 permanent magnet 6, and the spacing between adjacent permanent magnets is smaller than the spacing between other permanent magnets, that is, the corresponding magnetic isolation groove length is reduced, which helps to concentrate the magnetic field in the middle area, thereby forming a magnetic concentration effect, and further enhancing the magnetic field strength in this area; in addition, in the comparison of the tooth slot torque of the Halbach array rotor structure and the original structure, the tooth slot torque amplitude of the Halbach array rotor structure is significantly lower than the original structure, the former is 0.1Nm, and the latter is 0.14Nm. In traditional permanent magnet motors, the magnetic field on the rotor is usually symmetrically distributed, which causes the relative position change between the stator teeth and the rotor poles to induce tooth slot torque. Through the design of the Halbach array, the distribution of the magnetic field becomes more uniform, especially at the junction of the stator and the rotor, the uneven magnetic field area is greatly reduced, thereby reducing the pulsating force generated when the stator teeth contact the rotor poles, and by enhancing the field strength in a specific area, the magnetic force between the rotor and the stator becomes smoother and more stable, and the tooth slot torque is effectively suppressed.

[0039] Working principle:

[0040] First, the double-layer structure can increase the number of effective magnetic poles of the rotor, reduce the leakage of magnetic field in the air gap, and improve the efficiency of the motor. The permanent magnets are arranged in segments in the rotor core to improve the utilization rate of the permanent magnets and make the motor structure more compact. The Halbach array permanent magnet distribution is adopted, and the permanent magnets are radially magnetized, and the magnetization angles of each permanent magnet are different. Through the design of unequal width poles, the magnetic field is more concentrated in the required area, further improving the uniformity of the magnetic field and effectively reducing the magnetic field fluctuations during motor operation. In terms of torque characteristics, the stability of the torque output is maintained, and the It significantly reduces torque pulsation and the vibration and noise problems caused by torque pulsation. In terms of energy efficiency, it can operate at higher efficiency in a wider range of operating points, thereby reducing energy consumption, reducing heat generation, improving motor performance, and enhancing system stability and market competitiveness. It then effectively solves the problems of traditional permanent magnet synchronous motors in torque pulsation, cogging torque and material usage, while improving the efficiency and operating stability of the motor, meeting the requirements of modern motor design for high efficiency, low noise and low vibration, and has significant technical advantages and application prospects. At this point, the entire workflow is completed.

[0041] The above-mentioned front, back, left, right, up and down are all based on the Figure 1 As a benchmark.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention.

[0043] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments.

[0044] For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations made to these embodiments still fall within the protection scope of the present invention.

Claims

1. Rotor structure of a Halbach array type permanent magnet motor for new energy vehicles, including rotor silicon steel sheets (1), characterized in that: On the inner side walls of the rotor silicon steel sheet (1), a second-layer No. 1 permanent magnet (2), a second-layer No. 2 permanent magnet (4), a second-layer No. 3 permanent magnet (5), a second-layer No. 4 permanent magnet (6), a second-layer No. 5 permanent magnet (7), a second-layer No. 6 permanent magnet (8), and a second-layer No. 7 permanent magnet (9) are respectively fixedly installed.

2. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 1, characterized in that: The rotor silicon steel sheet (1) is provided with a plurality of outer magnetic isolation grooves (14) on each layer.

3. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 2, characterized in that: The rotor silicon steel sheet (1) is provided with four magnetic isolation grooves (3) between adjacent permanent magnets in the second layer.

4. The rotor structure of the Halbach array permanent magnet motor for new energy vehicles according to claim 1, characterized in that: On the inner side walls of the rotor silicon steel sheet (1), a first-layer No. 1 permanent magnet (10), a first-layer No. 2 permanent magnet (12), and a first-layer No. 3 permanent magnet (13) are also respectively fixedly installed.

5. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 4, characterized in that: The rotor silicon steel sheet (1) is provided with two magnetic isolation grooves (11) between adjacent permanent magnets in the first layer.

6. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 4, wherein: The first-layer No. 1 permanent magnet (10), the first-layer No. 2 permanent magnet (12), and the first-layer No. 3 permanent magnet (13) have the same size value of w3, where w3 = 4.7 mm.

7. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 1, characterized in that: The second-layer No. 2 permanent magnet (4), the second-layer No. 4 permanent magnet (6), and the second-layer No. 6 permanent magnet (8) have the same size value of w2, and the second-layer No. 1 permanent magnet (2), the second-layer No. 3 permanent magnet (5), the second-layer No. 5 permanent magnet (7), and the second-layer No. 7 permanent magnet (9) have the same size value of w1, where w2 = 6.4 mm and w1 = 3.95 mm.

8. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 4, characterized in that: The radial magnetization angles of the first-layer No. 2 permanent magnet (12) with the first-layer No. 1 permanent magnet (10) and the first-layer No. 3 permanent magnet (13) on the left and right sides are both 25°.

9. The rotor structure of the Halbach array type permanent magnet motor for new energy vehicles according to claim 1, wherein: The arrangement angles of the second-layer No. 1 permanent magnet (2), the second-layer No. 2 permanent magnet (4), the second-layer No. 3 permanent magnet (5), the second-layer No. 4 permanent magnet (6), the second-layer No. 5 permanent magnet (7), the second-layer No. 6 permanent magnet (8), and the second-layer No. 7 permanent magnet (9) from left to right are 25°, 25°, 20°, 20°, 25°, 25° in sequence.

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