Asymmetric permanent magnet auxiliary synchronous reluctance motor rotor structure for new energy vehicle

Abstract

The invention discloses an asymmetric permanent magnet auxiliary synchronous reluctance motor rotor structure for a new energy vehicle, and relates to the technical field of motor rotor structures, the asymmetric permanent magnet auxiliary synchronous reluctance motor rotor structure comprises an asymmetric rotor, the right side of the front part of the asymmetric rotor is connected with a first outer side air slot A, and the left side of the first outer side air slot A is provided with a second outer side air slot A; and the bottom side of the second outer side air slot A is connected with a second outer side air slot B. The rotor has the advantages that by constructing a phase coordination mechanism of an asymmetric magnetic circuit topology, optimization of current phase angle difference of permanent magnet torque and reluctance torque is realized, the comprehensive performance of the motor is further improved, the rotor adopts a composite configuration of a double-layer U-shaped magnetic barrier and a spoke type magnetic barrier, and the rotor is more compact in structure and more compact in structure. Differentiation configuration is carried out on permanent magnet space distribution based on the axis asymmetry principle, so that phase cooperation of the maximum value of the reluctance torque and the maximum value of the permanent magnet torque is achieved, and the dual optimization objectives of torque density improvement and pulsation suppression are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor rotor structures, and specifically to an asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles. Background Technique

[0002] The permanent magnet assisted synchronous reluctance motor inherits the excellent characteristics of the permanent magnet synchronous motor and the synchronous reluctance motor, and has advantages such as high torque and power density, wide speed regulation range, and high cost performance, and has broad application prospects in the field of new energy vehicles;

[0003] However, due to the design of its symmetric rotor structure in the conventional permanent magnet assisted synchronous reluctance motor, the current phase angles when the permanent magnet torque and the reluctance torque reach the maximum values are significantly different, which results in the inability to make full use of both at the same time, thereby restricting the improvement of the motor torque density. More critically, the torque ripple during the operation of the motor under the traditional structure is relatively large, which not only reduces the efficiency, but also causes vibration and abnormal noise when the vehicle is accelerating or running at low speed, affecting the driving smoothness and comfort, and thus restricting its further popularization and application in new energy vehicles. Therefore, optimizing the rotor structure to improve the torque density, reduce the torque ripple and improve the operation efficiency has become the key path to improving the comprehensive performance of the motor and meeting the high-performance requirements of new energy vehicles. For this reason, we propose an asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles. Summary of the Invention

[0004] The purpose of the present invention is to provide an asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles.

[0005] To achieve the above object, the present invention provides the following technical solution: An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles, including an asymmetric rotor. A first outer air groove A is connected to the right side of the front part of the asymmetric rotor. A second outer air groove A is arranged on the left side of the first outer air groove A. A second outer air groove B is connected to the bottom side of the second outer air groove A. The second outer air groove B is located on the left side of the front part of the asymmetric rotor. The second outer air groove A and the second outer air groove B are integrally arranged in a U shape. A second permanent magnet is connected to the intersection of the second outer air groove A and the second outer air groove B. A third outer air groove A is arranged on the left side of the second outer air groove A. A third outer air groove B is connected to the bottom side of the third outer air groove A. The third outer air groove B is located on the left side of the front part of the asymmetric rotor. The third outer air groove A and the third outer air groove B are integrally arranged in a U shape. A first permanent magnet is connected to the intersection of the third outer air groove A and the third outer air groove B. The third outer air groove B is located on the right side of the second outer air groove B. A first outer air groove B is arranged on the left side of the second outer air groove B. The first outer air groove B is connected to the left side of the front part of the asymmetric rotor. A first inner air groove A is connected to the bottom end of the first outer air groove B. A third permanent magnet is connected to the intersection of the first outer air groove B and the first inner air groove A. A first inner air groove B is connected to the bottom end of the first outer air groove A. A fourth permanent magnet is connected to the intersection of the first inner air groove B and the first outer air groove A.

[0006] As a further solution of the present invention: The second outer air groove A and the second outer air groove B are integrally provided with a U-shaped magnetic barrier. The U-shaped magnetic barrier formed by the second outer air groove A and the second outer air groove B is axially symmetrically arranged. The third outer air groove A and the third outer air groove B are integrally provided with a U-shaped magnetic barrier.

[0007] As a further solution of the present invention: The third outer air groove A and the third outer air groove B are axially asymmetrically arranged. The circumferential ratio of the third outer air groove A is greater than the circumferential ratio of the third outer air groove B.

[0008] As a further solution of the present invention: The first permanent magnet is axially offset. The effective magnetization length of the first permanent magnet in contact with the third outer air groove A is less than the effective magnetization length of the first permanent magnet in contact with the third outer air groove B. The magnetic barrier opening angle formed axially by the third outer air groove A is greater than the magnetic barrier opening angle formed axially by the third outer air groove B.

[0009] As a further solution of the present invention: the width of the first outer air groove A is smaller than the width of the first outer air groove B, the width of the first inner air groove B is larger than the width of the first inner air groove A, and the length of the first outer air groove B is larger than the length of the first inner air groove A.

[0010] As a further solution of the present invention: the overall proportion of the fourth permanent magnet is larger than the overall proportion of the third permanent magnet, and the length of the first outer air groove A is larger than the length of the first inner air groove B.

[0011] As a further solution of the present invention: the first outer air groove A and the first outer air groove B are mirror-asymmetrically arranged, and the first inner air groove A and the first inner air groove B are mirror-asymmetrically arranged.

[0012] As a further solution of the present invention: the first outer air groove A and the first inner air groove B are integrally provided with a spoke-type magnetic barrier, and the first outer air groove B and the first inner air groove A are integrally provided with a spoke-type magnetic barrier.

[0013] Adopting the above technical solutions, compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] 1. The present invention realizes the optimization of the phase angle difference between the permanent magnet torque and the reluctance torque current by constructing a phase coordination mechanism for an asymmetric magnetic circuit topology, thereby improving the comprehensive performance of the motor. The rotor adopts a composite configuration of a double-layer U-shaped magnetic barrier and a spoke-type magnetic barrier, and differentially configures the spatial distribution of the permanent magnets based on the principle of axis asymmetry, thereby realizing the phase coordination of the maximum values of the reluctance torque and the permanent magnet torque, and achieving the dual optimization goals of torque density improvement and ripple suppression;

[0015] 2. The present invention adjusts the distribution of the permanent magnets and the air grooves, prompting the magnetic flux path to redistribute. The implementation of this series of asymmetric design strategies brings significant performance improvement. On the one hand, it increases the maximum values of both the permanent magnet torque and the reluctance torque, which means that the motor can generate a larger output torque under the same conditions. On the other hand, by optimizing the magnetic field distribution and the main magnetic flux path, the utilization rates of the reluctance torque and the permanent magnet torque are also significantly improved. Therefore, without increasing the amount of permanent magnets, this asymmetric design significantly improves the torque density of the motor, reduces the torque ripple, increases the efficiency, and improves the comprehensiveness of the motor;

[0016] 3. The present invention adopts an asymmetric rotor structure design of a permanent magnet assisted synchronous reluctance motor, asymmetrically arranges the magnetic barrier opening angle, air grooves and permanent magnets in space, and by reconstructing the d-q axis magnetic field coupling relationship, makes the d-axis equivalent magnetic circuit deviate directionally, thereby converging the peak current phase difference between the permanent magnet torque and the reluctance torque within a smaller interval and realizing the improvement of their utilization rates.

[0017] Other advantages, objects and features of the present invention will be set forth in part in the following description, and in part will be obvious to those skilled in the art upon examination of the following, or may be learned from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the local structure of the asymmetric rotor in the embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the main asymmetric parameter dimensions in the embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the local structure of the symmetric rotor in the embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the torque characteristics of the asymmetry in the embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of the torque characteristics of the symmetric motor in the embodiment of the present invention;

[0023] Figure 6 It is the magnetic cloud diagram of the motor load in the embodiment of the present invention;

[0024] Figure 7 It is a schematic diagram of the output torque of the symmetric rotor structure motor and the asymmetric rotor structure motor in the embodiment of the present invention; [[ID=3②]]

[0025] Figure 8 It is a schematic diagram of the efficiency MAP of the asymmetric rotor structure motor in the embodiment of the present invention.

[0026] In the figure: 1, the first outer air groove A; 2, the second outer air groove A; 3, the third outer air groove A; 4, the first permanent magnet; 5, the third outer air groove B; 6, the second outer air groove B; 7, the first outer air groove B; 8, the second permanent magnet; 9, the third permanent magnet; 10, the first inner air groove A; 11, the first inner air groove B; 12, the fourth permanent magnet; 13, the asymmetric rotor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following further describes the specific embodiments of the present invention with reference to the drawings. It should be noted here that the description of these embodiments is for helping to understand the present invention, but does not constitute a limitation to the present invention.

[0028] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Please refer to the attached Figure 1-Appendix Figure 8 For a novel energy vehicle's asymmetric permanent magnet assisted synchronous reluctance motor rotor structure of the present invention, it includes an asymmetric rotor 13. On the right side of the front part of the asymmetric rotor 13, there is a first outer air groove A1. On the left side of the first outer air groove A1, there is a second outer air groove A2. At the bottom side of the second outer air groove A2, there is a second outer air groove B6 which is located on the left side of the front part of the asymmetric rotor 13. The second outer air groove A2 and the second outer air groove B6 are integrally arranged in a U shape. At the intersection of the second outer air groove A2 and the second outer air groove B6, there is a second permanent magnet 8. On the left side of the second outer air groove A2, there is a third outer air groove A3. At the bottom side of the third outer air groove A3, there is a third outer air groove B5 which is located on the left side of the front part of the asymmetric rotor 13. The third outer air groove A3 and the third outer air groove B5 are integrally arranged in a U shape. At the intersection of the third outer air groove A3 and the third outer air groove B5, there is a first permanent magnet 4. The third outer air groove B5 is located on the right side of the second outer air groove B6. On the left side of the second outer air groove B6, there is a first outer air groove B7 which is connected to the left side of the front part of the asymmetric rotor 13. At the bottom end of the first outer air groove B7, there is a first inner air groove A10. At the intersection of the first outer air groove B7 and the first inner air groove A10, there is a third permanent magnet 9. At the bottom end of the first outer air groove A1, there is a first inner air groove B11. At the intersection of the first inner air groove B11 and the first outer air groove A1, there is a fourth permanent magnet 12.

[0030] In the first embodiment, the second outer air groove A2 and the second outer air groove B6 are integrally formed with a U-shaped magnetic barrier. The U-shaped magnetic barrier formed by the second outer air groove A2 and the second outer air groove B6 is axially symmetrically arranged. The third outer air groove A3 and the third outer air groove B5 are integrally formed with a U-shaped magnetic barrier. The third outer air groove A3 and the third outer air groove B5 are axially asymmetrically arranged. The circumferential ratio of the third outer air groove A3 is greater than that of the third outer air groove B5. The first permanent magnet 4 is axially offset. The effective magnetization length of the first permanent magnet 4 in contact with the third outer air groove A3 is less than the effective magnetization length of the first permanent magnet 4 in contact with the third outer air groove B5. The magnetic barrier opening angle formed axially by the third outer air groove A3 is greater than the magnetic barrier opening angle formed axially by the third outer air groove B5.

[0031] Specifically, by adjusting the distribution of permanent magnets and air slots, the magnetic flux path is redistributed. The implementation of this series of asymmetric design strategies has brought significant performance improvements. On the one hand, it increases the maximum values of both the permanent magnet torque and the reluctance torque, which means that the motor can generate a larger output torque under the same conditions. On the other hand, by optimizing the magnetic field distribution and the main magnetic flux path, the utilization rates of the reluctance torque and the permanent magnet torque are also significantly improved. Therefore, without increasing the amount of permanent magnets, this asymmetric design significantly improves the torque density of the motor, reduces the torque ripple, increases the efficiency, and enhances the comprehensiveness of the motor.

[0032] Embodiment 2: The width of the first outer air slot A1 is less than the width of the first outer air slot B7, the width of the first inner air slot B11 is greater than the width of the first inner air slot A10, the length of the first outer air slot B7 is greater than the length of the first inner air slot A10, the overall proportion of the fourth permanent magnet 12 is greater than the overall proportion of the third permanent magnet 9, the length of the first outer air slot A1 is greater than the length of the first inner air slot B11, the first outer air slot A1 and the first outer air slot B7 are mirror-asymmetrically arranged, the first inner air slot A10 and the first inner air slot B11 are mirror-asymmetrically arranged, the first outer air slot A1 and the first inner air slot B11 as a whole adopt a spoke-type magnetic barrier, and the first outer air slot B7 and the first inner air slot A10 as a whole adopt a spoke-type magnetic barrier;

[0033] Specifically, by adopting the asymmetric rotor 13 structure design of a permanent magnet assisted synchronous reluctance motor, the magnetic barrier opening angle, air slots, and permanent magnets are arranged asymmetrically in space. By reconstructing the d-q axis magnetic field coupling relationship, the d-axis equivalent magnetic circuit is directionally offset, so as to converge the peak current phase difference between the permanent magnet torque and the reluctance torque within a smaller interval, and improve the utilization rates of both. The composite configuration of a double-layer U-shaped magnetic barrier and a spoke-type magnetic barrier is adopted, and the spatial distribution of permanent magnets is differentially configured based on the axis asymmetry principle, thereby realizing the phase coordination of the maximum values of the reluctance torque and the permanent magnet torque, and achieving the dual optimization goals of torque density improvement and ripple suppression.

[0034] Comparative example: Based on the above embodiments, the present invention provides a rotor structure of an asymmetric permanent magnet assisted synchronous reluctance motor for new energy vehicles:

[0035]

[0036] Working principle:

[0037] By offsetting the d-axis, the air-gap magnetic field of the motor is enhanced, thereby improving the output torque of the motor. The asymmetric rotor structure design effectively reduces the current angle difference between the permanent magnet torque and the reluctance torque, and significantly improves the utilization rates of the permanent magnet torque and the reluctance torque, as Figure 4 andFigure 5 As shown in Figure 2, by comparing the torque characteristics of the asymmetric rotor structure motor and the symmetric rotor structure motor, it can be seen that the current angle difference between the permanent magnet torque and the reluctance torque of the motor under the asymmetric design is significantly smaller than that of the symmetric design. Figure 7 As shown in the figure, the output torque characteristics of the motor with a symmetrical rotor structure and the motor with an asymmetrical rotor structure are compared. The output torque of the motor with a symmetrical rotor structure is stably maintained at 328N·m, while the output torque of the motor with an asymmetrical rotor structure fluctuates around 344N·m. The asymmetrical rotor structure design also increases the proportion of high efficiency of the motor. Figure 8 As shown in the figure, the efficiency of the motor exceeds 96%, which is quite significant. This high-efficiency operating area occupies a considerable part of the working point range. Through the composite configuration of double-layer U-shaped magnetic barriers and spoke-type magnetic barriers, the spatial distribution of permanent magnets is differentiated based on the principle of axis asymmetry. Specifically, the geometric parameters of the U-shaped magnetic barrier are asymmetrically distributed along the circumference, and the filling ratio and position of the permanent magnets in the magnetic barrier are mirror-image asymmetrically distributed along the d-axis, thereby achieving phase coordination between the reluctance torque and the maximum value of the permanent magnet torque. The overall process is: the improvement of the utilization of permanent magnet torque and reluctance torque significantly increases the output torque of the motor. Secondly, through the adjustment of the rotor structure, the torque pulsation during operation is effectively reduced, and the running stability of the motor is enhanced. Finally, the asymmetric magnetic field distribution optimizes the internal magnetic field environment of the motor, expands the high-efficiency operating area, and thus improves the overall efficiency of the motor. At this point, the entire workflow ends.

[0038] The above-mentioned front, back, left, right, up and down are all based on the Figure 1 As a benchmark.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are 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, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0040] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments.

[0041] It is obvious to those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these changes still fall within the scope of protection of the present invention.

Claims

1. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles, comprising an asymmetric rotor (13), characterized in that: The front right side of the asymmetric rotor (13) is connected with a first outer air groove A (1). A second outer air groove A (2) is arranged on the left side of the first outer air groove A (1). The bottom side of the second outer air groove A (2) is connected with a second outer air groove B (6). The second outer air groove B (6) is located on the front left side of the asymmetric rotor (13). The second outer air groove A (2) and the second outer air groove B (6) are integrally arranged in a U shape. A second permanent magnet (8) is connected at the intersection of the second outer air groove A (2) and the second outer air groove B (6). A third outer air groove A (3) is arranged on the left side of the second outer air groove A (2). The bottom side of the third outer air groove A (3) is connected with a third outer air groove B (5). The third outer air groove B (5) is located on the front left side of the asymmetric rotor (13). The third outer air groove A (3) and the third outer air groove B (5) are integrally arranged in a U shape. A first permanent magnet (4) is connected at the intersection of the third outer air groove A (3) and the third outer air groove B (5). The third outer air groove B (5) is located on the right side of the second outer air groove B (6). A first outer air groove B (7) is arranged on the left side of the second outer air groove B (6). The first outer air groove B (7) is connected to the front left side of the asymmetric rotor (13). The bottom end of the first outer air groove B (7) is connected with a first inner air groove A (10). A third permanent magnet (9) is connected at the intersection of the first outer air groove B (7) and the first inner air groove A (10). The bottom end of the first outer air groove A (1) is connected with a first inner air groove B (11). A fourth permanent magnet (12) is connected at the intersection of the first inner air groove B (11) and the first outer air groove A (1).

2. The rotor structure of an asymmetric permanent magnet assisted synchronous reluctance motor for new energy vehicles according to claim 1, characterized in that: The second outer air groove A (2) and the second outer air groove B (6) integrally adopt a U-shaped magnetic barrier. The U-shaped magnetic barrier formed by the second outer air groove A (2) and the second outer air groove B (6) is axially symmetrically arranged. The third outer air groove A (3) and the third outer air groove B (5) integrally adopt a U-shaped magnetic barrier.

3. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles according to claim 1, characterized in that: The third outer air groove A (3) and the third outer air groove B (5) are axially asymmetrically arranged. The circumferential proportion of the third outer air groove A (3) is greater than the circumferential proportion of the third outer air groove B (5).

4. The rotor structure of an asymmetric permanent magnet assisted synchronous reluctance motor for new energy vehicles according to claim 1, characterized in that: The first permanent magnet (4) is axially offset. The effective magnetization length of the first permanent magnet (4) in contact with the third outer air groove A (3) is less than the effective magnetization length of the first permanent magnet (4) in contact with the third outer air groove B (5). The magnetic barrier opening angle formed axially by the third outer air groove A (3) is greater than the magnetic barrier opening angle formed axially by the third outer air groove B (5).

5. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles according to claim 1, characterized in that: The width of the first outer air groove A (1) is less than the width of the first outer air groove B (7), the width of the first inner air groove B (11) is greater than the width of the first inner air groove A (10), and the length of the first outer air groove B (7) is greater than the length of the first inner air groove A (10).

6. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles according to claim 1, characterized in that: The overall proportion of the fourth permanent magnet (12) is greater than the overall proportion of the third permanent magnet (9), and the length of the first outer air groove A (1) is greater than the length of the first inner air groove B (11).

7. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles according to claim 1, characterized in that: The first outer air groove A (1) and the first outer air groove B (7) are mirror asymmetrically arranged, and the first inner air groove A (10) and the first inner air groove B (11) are mirror asymmetrically arranged.

8. An asymmetric permanent magnet assisted synchronous reluctance motor rotor structure for new energy vehicles according to claim 1, characterized in that: The first outer air groove A (1) and the first inner air groove B (11) are integrally provided with a spoke-type magnetic barrier, and the first outer air groove B (7) and the first inner air groove A (10) are integrally provided with a spoke-type magnetic barrier.

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