Magnetic steel structure, motor rotor, motor, and vehicle

Abstract

Embodiments of the present disclosure provide a magnetic steel structure, a motor rotor, a motor, and a vehicle. The magnetic steel structure is arranged on a motor rotor; the magnetic steel structure comprises a first magnetic steel and a second magnetic steel which are arranged in a V-shaped structure; in a direction moving away from the tip of the included angle of the V-shaped structure, the first magnetic steel and / or the second magnetic steel are / is formed by assembling four relatively insulated magnetic steel segments; and the materials of adjacent magnetic steel segments are different. In the present application, on the basis of the solution, the first magnetic steel and the second magnetic steel that are arranged in the V-shaped structure are each configured to be formed by assembling four magnetic steel segments, thereby reducing eddy current loss; and in addition, the materials of the segments are set to be different, thereby achieving improving the remanence and reducing costs.

Description

Magnetic steel structure, motor rotor, motor and vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202420601163.4 and application date March 26, 2024, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present disclosure relates to the field of vehicle technology, and in particular to a magnetic steel structure, a motor rotor, a motor, and a vehicle. Background Art

[0004] With the rapid development of the electric vehicle market and technology, electric drive systems are gradually replacing engine systems and gaining widespread application. As the power source for vehicles, the development of motor technology is not only reflected in power density, NVH, and efficiency indicators, but also in increasingly stringent technical requirements for reliability. Magnets, as key components of motors, generate permanent magnet torque to drive rotor rotation. Their demagnetization performance is particularly stringent and is one of the most important indicators in motor electromagnetic design.

[0005] Currently, the main means to improve the motor's anti-demagnetization ability include: improving the motor's cooling capacity, reducing the operating temperature of the magnet, increasing the magnet's coercive force, and changing the rotor topology through electromagnetic design. The above methods have relatively limited effects and greatly increase the cost and time cycle. How to further improve and optimize the motor's anti-demagnetization ability has become an urgent problem to be solved. Summary of the Invention

[0006] In order to solve the above technical problems, the embodiments of the present disclosure provide a magnetic steel structure, a motor rotor, a motor and a vehicle.

[0007] In a first aspect, an embodiment of the present disclosure provides a magnetic steel structure, wherein the magnetic steel structure is arranged on a motor rotor; the magnetic steel structure includes a first magnetic steel and a second magnetic steel arranged in a V-shaped structure;

[0008] Along a direction away from the tip of the angle of the V-shaped structure, the first magnetic steel and / or the second magnetic steel is formed by splicing four relatively insulated magnetic steel segments, and adjacent magnetic steel segments are made of different materials.

[0009] Optionally, along a direction away from a tip of the angle of the V-shaped structure, the widths of each magnetic steel segment are equal.

[0010] Optionally, along a direction away from a tip of the angle of the V-shaped structure, the widths of each magnetic steel segment are different.

[0011] Optionally, along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure, the width corresponding to each magnetic steel segment decreases successively.

[0012] Optionally, along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure, the coercive force corresponding to each magnetic steel segment decreases successively.

[0013] Optionally, along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure, the residual magnetism corresponding to each magnetic steel segment increases successively.

[0014] Optionally, along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure, the magnetic energy product corresponding to each magnetic steel segment decreases successively.

[0015] In a second aspect, the present application further provides a motor rotor, comprising the magnetic steel structure as described in any one of the first aspects.

[0016] In a third aspect, the present application further provides a motor, comprising the motor rotor as described in the second aspect.

[0017] In a fourth aspect, the present application also provides a vehicle, comprising the motor as described in the third aspect.

[0018] The present application provides a magnetic steel structure, a motor rotor, a motor, and a vehicle. The magnetic steel structure is disposed on the motor rotor; the magnetic steel structure includes a first magnetic steel and a second magnetic steel arranged in a V-shaped structure; in a direction away from the tip of the angle of the V-shaped structure, the first magnetic steel and / or the second magnetic steel are composed of four relatively insulated magnetic steel segments, with adjacent magnetic steel segments being made of different materials. Based on the above scheme, the present application reduces eddy current losses by configuring the first and second magnetic steels of the V-shaped structure to be composed of four magnetic steel segments. Furthermore, by configuring each segment to be made of a different material, the purpose of both increasing residual magnetism and reducing costs can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0020] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without inventive work, including:

[0021] FIG1 is a schematic diagram of a magnetic steel structure provided in an embodiment of the present application;

[0022] FIG2 is a schematic diagram of another magnetic steel structure provided in an embodiment of the present application;

[0023] FIG3 is a schematic diagram of another magnetic steel structure provided in an embodiment of the present application;

[0024] FIG4 is a graph showing eddy current loss of a magnetic steel with different numbers of segments provided by an embodiment of the present application;

[0025] FIG5 is a graph showing a change in demagnetization area versus coercive force of a magnetic steel according to an embodiment of the present application;

[0026] FIG6 is a demagnetization cloud diagram provided in an embodiment of the present application;

[0027] FIG7 is a schematic diagram of another magnetic steel structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0029] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc. mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0030] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, they should be understood as "one or more".

[0031] The present invention provides a magnetic steel structure, which is arranged on a motor rotor. Figure 1 is a schematic diagram of a magnetic steel structure provided in an embodiment of the present invention. The magnetic steel structure includes a first magnetic steel 100 and a second magnetic steel 200 arranged in a V-shaped structure.

[0032] Along the direction away from the tip of the angle of the V-shaped structure, the first magnetic steel 100 and / or the second magnetic steel 200 is composed of four relatively insulated magnetic steel segments 101 , and adjacent magnetic steel segments 101 are made of different materials.

[0033] First of all, it should be noted that although the embodiment of the present application protects a magnetic steel structure, it is understandable that the magnetic steel structure is arranged on the motor rotor, and corresponding technical problems arise when the motor is working. Therefore, in the process of describing the technical solution and technical effects, the embodiment of the present application is inevitably described as a motor..., but this does not affect the fact that the protected subject of this embodiment is a magnetic steel structure. In the embodiment of the present application, except for possible special instructions, the first magnetic steel 100 or the second magnetic steel 200 is not deliberately limited. Therefore, for the sake of simplicity of description, the embodiment of the present application directly replaces the first magnetic steel 100 and the second magnetic steel 200 with magnetic steel, that is, the magnetic steel described in the embodiment of the present application can refer to at least one of the first magnetic steel 100 and the second magnetic steel 200.

[0034] Specifically, eddy current loss Pe∝t 2- ×V, where the heat loss generated by the magnet is eddy current loss, which means that when the magnet is in an alternating magnetic field, a rotating current is generated inside the magnet. This current is eddy current, and when it passes through the magnet, it will inevitably encounter resistance (the magnet is a conductor), thereby generating heat, and thus energy is converted into heat energy. This part of energy constitutes eddy current loss.

[0035] The calculation formula of eddy current loss Pe is: Pe=Ke×f 2 ×B 2 ×t 2 ×V.

[0036] Where Ke is a constant related to material properties, including material resistivity and eddy current distribution factors, f is the frequency of the alternating magnetic field, B is the peak value of the magnetic flux density, and t is the lamination width of the magnetic material perpendicular to the magnetic field. This formula shows that eddy current loss is proportional to the square of the frequency, the square of the magnetic flux density, the square of the material width, and the material volume. Dividing the structure into four sections along the direction away from the tip of the V-shaped angle (hereinafter referred to as the direction along the width of the magnetic steel) advantageously reduces the lamination width, thereby reducing eddy current losses.

[0037] On the other hand, in the embodiments of the present application, different magnetic steel segments 101 can be made of different materials. For example, a material with a higher remanence can be used in locations with a stronger demagnetization effect, while a material with a lower remanence can be used in locations with a weaker demagnetization effect. Since materials with higher remanence are more expensive, the embodiments of the present application can reduce costs while ensuring anti-demagnetization performance.

[0038] In summary, the embodiments of the present application can improve the anti-demagnetization capability of the motor and reduce costs through the above-mentioned solution.

[0039] Continuing to refer to FIG. 1 , in some embodiments, along a direction away from the tip of the angle of the V-shaped structure, the width of each magnetic steel segment 101 is equal.

[0040] As shown in FIG1 , the width of each magnetic steel segment 101 can be W0. According to the above eddy current loss calculation formula, when the magnetic steel segment 101 is divided into four equal sections along the magnetic steel width direction, t becomes 1 / 16 of the original, that is, the eddy current loss of the magnetic steel is reduced to 1 / 16 of the original. When divided into two equal sections, the eddy current loss is 1 / 4 of the original; when divided into three equal sections, the eddy current loss is 1 / 9 of the original; when divided into N equal sections, the eddy current loss is 1 / N of the original. 2 .

[0041] The more segments the magnet has, the more difficult it is to assemble the magnet. Moreover, the more segments the magnet segment 101 has, the worse the gain effect of improving the eddy current loss it brings. For example, in the case of bisection, the eddy current loss is 1 / 4 of that in the case of no segmentation, that is, a reduction of 75%. In the case of trisection, the eddy current loss is 1 / 9 of that in the case of no segmentation, that is, a reduction of about 89%. In the case of quadsection, the eddy current loss is 1 / 16 of that in the case of no segmentation, that is, a reduction of 93.75%. In the case of quintuple section, the eddy current loss is 1 / 25, that is, a reduction of 96%. From the above comparison, it can be seen that when the number of segments is gradually increased, the trend of improving the eddy current loss slows down, but in fact, as the number of segments increases, the difficulty of assembly increases. In addition, the direction of the magnetic field in which the actual magnetic steel is located changes and is non-uniformly distributed, and the reduction in eddy current loss is lower than the theoretical effect. Combined with finite element simulation, dividing it into 4 sections can meet the design scenario requirements of automotive permanent magnet motors (current fundamental frequency is less than 1500hz) to improve efficiency, achieve a balance between cost optimization and ease of mass production.

[0042] Figure 2 is a schematic diagram of another magnetic steel structure provided by an embodiment of the present application. In some embodiments, along a direction away from the tip of the angle of the V-shaped structure, the width of each magnetic steel segment 101 is different.

[0043] Specifically, Figure 2 illustrates only a portion of the magnetic steel structure, which may be the first magnetic steel 100 or the second magnetic steel 200. In the embodiment of the present application, the first magnetic steel 100 and the second magnetic steel 200 may also be configured as unequally divided magnetic steel segments 101. Thus, in the embodiment of the present application, the width of each magnetic steel segment 101 can also be reduced, thereby reducing eddy current losses.

[0044] 2 , in some embodiments, the width of each magnetic steel segment 101 decreases in sequence along a direction from the center of the magnetic steel segment 101 toward the tip of the angle of the V-shaped structure, and / or along a direction from the center of the magnetic steel segment 101 away from the tip of the angle of the V-shaped structure.

[0045] As shown in FIG. 2 , the width of the outermost magnetic steel segment 101 may be W1 , and the width of the inner magnetic steel segment 101 may be W2 , where W1 < W2 .

[0046] In some embodiments, the coercive force corresponding to each magnetic steel segment 101 decreases successively along the direction from the center of the magnetic steel segment 101 toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment 101 away from the tip of the angle of the V-shaped structure.

[0047] In some embodiments, the residual magnetism corresponding to each magnetic steel segment 101 increases sequentially along the direction from the center of the magnetic steel segment 101 toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment 101 away from the tip of the angle of the V-shaped structure.

[0048] In some embodiments, the magnetic energy product corresponding to each magnetic steel segment 101 decreases successively along the direction from the center of the magnetic steel segment 101 toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment 101 away from the tip of the angle of the V-shaped structure.

[0049] The embodiment of this application verifies the structure of the magnetic steel under equal segmentation. Take the electromagnetic design scheme of an 8-pole 48-slot motor as an example. By dividing the magnetic steel into 4 equal segments along the width direction of the magnetic steel using a double V rotor topology, insulating it, and then bonding it together, the general rules are summarized and the effects of segmentation and non-segmentation on the eddy current loss of the magnetic steel are compared. Figure 3 is a schematic diagram of another magnetic steel structure provided in the embodiment of this application.

[0050] Figure a (Scheme 1) in Figure 3 is not segmented. In Figure b (Scheme 2), c (Scheme 3) and d (Scheme 4) in Figure 3, the large and small magnets of the double V-rotor topology are respectively divided into 2 segments, 3 segments and 4 segments along the width direction of the magnets; the eddy current losses of the magnets of the three segmentation methods under a certain characteristic working condition of the motor are calculated respectively through finite element simulation. The calculation results are shown in Table 1 and Figure 4. Figure 4 is a graph of the eddy current loss of the magnets of different sizes with different numbers of segments provided in an embodiment of the present application.

[0051] Table 1 - Eddy current loss improvement trend corresponding to different magnetic steel segmentation methods

[0052] As can be seen from Table 1 and Figure 4, the simulated eddy current loss of the magnetic steel decreases with the increase of the number of magnetic steel segments, and the four-segment equal distribution has obvious benefits, exceeding 60% for large magnetic steel and 80% for small magnetic steel. Moreover, the slope becomes slower and the benefits decrease with the increase of the number of segments. At the same time, considering that the size of the magnetic steel of the automotive permanent magnet synchronous motor is generally 10 to 30 mm in width and 2 to 6 mm in thickness, considering the influence of the bonding gap and the manufacturing process, the size of the block magnetic steel in the width direction is not easy to be smaller than the thickness of the magnetic steel, so this case chooses to divide the magnetic steel into 4 sections in the width direction.

[0053] Secondly, with the rapid development of electric vehicle technology, the coercive force of the four magnetic steel segments 101 in the width direction is adjusted based on the above magnetic steel segmentation scheme, and the effects of different coercive force combinations on the anti-demagnetization performance of the rotor are compared.

[0054] As shown in Figure 3-a and Table 2, in Scheme 1's double-V rotor topology, the large and small magnets are not segmented along the magnet width, similar to conventional rotor designs, where both large and small magnets have the same coercivity. Using 45UH (a type of magnet material) as an example, finite element simulations performed on demagnetization revealed that the demagnetization area of ​​the small magnets, approximately 15%, exceeded 10% of the assessment criteria, and the total torque drop rate, 1.26%, exceeded 1%, failing the standard.

[0055] Table 2 - Demagnetization simulation data of rotor hard-cut active short-circuit protection with different magnetic steel segment coercivity

[0056] If demagnetization fails, as shown in Figure 3-a and Table 2, traditional solution 2 is adopted to increase the overall coercive force of large and small magnets. Here, taking the increase from 45UH to 45EH as an example, after demagnetization verification through finite element simulation, it is found that the demagnetization area of ​​the small magnet is 10% qualified and the total torque reduction rate is 0.06% qualified.

[0057] Solution 3, shown in Table 2, better addresses this problem. This approach improves the coercivity of the segments at both ends of the magnet—here, from 45UH to 45EH—and replaces the material of the central, non-demagnetizing area of ​​the magnet with 45SH. Finite element simulation and demagnetization verification revealed that the demagnetization area of ​​the small magnets qualified at 10%, and the overall torque reduction rate qualified at 0.08%. Solution 3 utilizes lower material performance to meet the same demagnetization requirements, enhancing product competitiveness.

[0058] In Table 2, the coercive force Hcb of the grade 45 magnetic steel at 150°C is -843.8kA / m, which is close to N45EH, -731.1kA / m is close to N45UH, and -678.5A / m is close to N45SH.

[0059] Finally, by adjusting the remanence of the four segments of magnetic steel in the width direction of the magnetic steel (the higher the remanence, the greater the torque and power, the higher the remanence, the lower the coercive force, the product of the two is the magnetic energy product as the limit, and on the basis of the coercive force that meets the anti-demagnetization requirements, the material with the highest remanence can be selected to improve the performance of the motor), the performance limit of the magnetic material is fully utilized to pursue higher power density and torque density. Taking the second scheme in Table 3 as an example, based on the scheme one in Table 3, the remanence of the magnetic material in the middle segment of the large and small magnetic steel is adjusted from 45SH to 53SH. While ensuring the anti-demagnetization performance, the torque is increased by 1.8% and the power is increased by 2.2%. Through this embodiment, magnetic materials with high remanence performance can also be used in rotor design scenarios with high demagnetization pressure to obtain higher motor performance.

[0060] Table 3 - True data of different residual magnetism of magnetic steel segments

[0061] In Table 3, the remanent magnetism Br of the 45EH magnetic material used at both ends of the large and small magnets in Scheme 1 at 150°C is 1.157T, and the remanent magnetism Br of the 45SH magnetic material used in the middle is 1.157T. In Table 3, the remanent magnetism Br of the 45EH magnetic material used at both ends of Scheme 2 and the 53SH magnetic material used in the middle is 1.234T.

[0062] In summary, traditional magnet segmentation can reduce the eddy current loss of the magnet, appropriately reduce the temperature of the motor, improve efficiency and improve the anti-demagnetization ability to a certain extent, but the effect is limited; at the same time, the traditional overall improvement of the coercive force of the magnet, although it can greatly improve the anti-demagnetization ability of the motor, but the increase in coercive force will reduce the remanence of the magnetic material, which will reduce the power and torque density of the motor, in other words, reduce the utilization rate of the magnet.

[0063] This case combines two traditional methods, and improves the structure and materials through finite element simulation design optimization. It reduces eddy current loss by evenly dividing the large and small magnets into four sections, improves motor efficiency and appropriately enhances anti-demagnetization ability. On the basis of the segmented process, high coercivity and low remanence materials (maximum magnetic energy product) are used at the ends of the magnet corners where demagnetization is strictly required to pursue high anti-demagnetization ability. At the same time, low coercivity and high remanence materials (minimum magnetic energy product) are used in the middle area where demagnetization is relatively small to pursue maximum torque and power density. It fully utilizes the limits of magnetic material performance and achieves effects that traditional solutions cannot achieve.

[0064] Regarding the unequal segmentation method, the embodiment of the present application also makes improvements that are not limited to dividing the magnetic steel into four segments. Specifically, under the condition that other parameters of the motor are fixed, a DOE experiment of simulating demagnetization of the coercive force of the magnetic steel is performed to obtain the demagnetization area under different coercive force conditions.

[0065] FIG5 is a graph showing a change in the demagnetization area along with the coercive force of the magnet provided in an embodiment of the present application. As shown in FIG5 , as the coercive force decreases, the demagnetization area increases. FIG6 is a demagnetization cloud diagram provided in an embodiment of the present application. As can be seen from FIG6 , as the coercive force decreases, the demagnetization area increases from the two ends to the middle along the width direction of the magnet. When the coercive force approaches the critical point of -640Ka / m, the demagnetization area increases sharply. From this trend, it can be derived that an unequal segmentation method of the magnet is shown in FIG7 , which is another schematic diagram of the magnet structure provided in an embodiment of the present application. In FIG7 , the width of the magnet segment 101 gradually increases from the edge of the magnet to the center of the magnet, that is, W3<W4<W5<W6<W7. From the center of the magnet to the two ends, the coercive force of the magnet is increased in steps. The closer to the two ends of the magnet, the larger the coercive force value required to ensure that the magnet in each section does not demagnetize. This segmentation scheme requires the use of a DOE experiment of simulated demagnetization to calculate the demagnetization range of magnets with different coercive forces and the distance between the demagnetization boundary and the two ends of the magnet. The calculation results of unequal segmented magnets are shown in Scheme 7 in Figure 6. The demagnetization area is the same as that of Scheme 1 in Figure 6 using high coercive force magnets. The same anti-demagnetization ability of high coercive force magnets is achieved at the lowest magnet material cost. In the actual production process, process manufacturability must also be considered. At the same time, reducing the number of materials can reduce the number of segments and select a more appropriate number of segments.

[0066] An embodiment of the present application further provides a motor rotor, which includes a magnetic steel structure as described in any one of the above-mentioned magnetic steel structure embodiments.

[0067] The motor rotor provided in the embodiment of the present application has at least some of the same technical features as the above-mentioned magnetic steel structure embodiment, and therefore can also solve the same technical problems as the above-mentioned magnetic steel structure and achieve the same technical effects, which will not be repeated here.

[0068] An embodiment of the present application further provides a motor, which includes the motor rotor in the above-mentioned motor rotor embodiment.

[0069] The motor provided in the embodiment of the present application has at least some of the same technical features as the above-mentioned motor rotor embodiment, and therefore can also solve the same technical problems as the above-mentioned motor rotor embodiment and achieve the same technical effects, which will not be repeated here.

[0070] An embodiment of the present application also provides a vehicle, which includes the motor in the above motor embodiment.

[0071] The vehicle provided in the embodiment of the present application has at least some of the same technical features as the above-mentioned motor embodiment, and therefore can also solve the same technical problems as the above-mentioned motor embodiment and achieve the same technical effects, which will not be repeated here.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0073] The foregoing are merely specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not to be limited to the embodiments described herein, but is to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A magnetic steel structure, the magnetic steel structure being disposed on a motor rotor; the magnetic steel structure comprising a first magnetic steel and a second magnetic steel arranged in a V-shaped structure; Along a direction away from the tip of the angle of the V-shaped structure, the first magnetic steel and / or the second magnetic steel is formed by splicing four relatively insulated magnetic steel segments, and adjacent magnetic steel segments are made of different materials.

2. The magnetic steel structure according to claim 1, wherein the width of each magnetic steel segment is equal along a direction away from the tip of the angle of the V-shaped structure.

3. The magnetic steel structure according to claim 1, wherein the width of each magnetic steel segment is different along a direction away from the tip of the angle of the V-shaped structure.

4. The magnetic steel structure according to claim 3, wherein the width of each magnetic steel segment decreases successively along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure.

5. The magnetic steel structure according to claim 2 or 4, wherein the coercive force corresponding to each magnetic steel segment decreases successively along a direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along a direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure.

6. The magnetic steel structure according to claim 2 or 4, wherein the residual magnetism corresponding to each magnetic steel segment increases successively along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure.

7. The magnetic steel structure according to claim 2 or 4, wherein the magnetic energy product corresponding to each magnetic steel segment decreases successively along the direction from the center of the magnetic steel segment toward the tip of the angle of the V-shaped structure, and / or along the direction from the center of the magnetic steel segment away from the tip of the angle of the V-shaped structure.

8. A motor rotor, comprising the magnetic steel structure according to any one of claims 1 to 7. 9 . An electric motor comprising the motor rotor according to claim 8 .

10. A vehicle comprising the electric machine according to claim 9.

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