A harmonic-guided design method for electromagnetic vibration suppression of V-type magnetic field modulation permanent magnet motor in electric vehicles

Abstract

The present invention discloses a method for designing electromagnetic vibration suppression of a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance, comprising: establishing an initial finite element model of the motor, determining structural parameters to be optimized, and determining the selection range of the structural parameters through stress analysis and mechanical strength verification; analytically deriving the radial electromagnetic force of the motor to obtain the order distribution of the radial electromagnetic force harmonics; analyzing the source of the air gap magnetic flux harmonics of the radial electromagnetic force harmonics that dominate the electromagnetic vibration, performing sensitivity analysis of the structural parameters to the key magnetic flux harmonics, prioritizing low-order radial electromagnetic forces according to the degree of influence on the electromagnetic vibration, and performing hierarchical multi-objective optimization on their amplitudes and motor torque performance; simulating the electromagnetic performance and vibration performance of the motor optimization scheme through finite element analysis, carrying out prototype processing and relevant tests according to the design scheme, and further verifying the effectiveness and reliability of the motor optimization design.

Description

Technical Field

[0001] The present invention belongs to the field of motor design, and in particular relates to a method for designing electromagnetic vibration suppression of a motor driven by a magnetic field modulation of an electric vehicle under harmonic guidance. Background Art

[0002] As a new type of motor, the field-modulated motor (FMPM) boasts high torque at low speed, making it a potential candidate for in-wheel motor applications. The introduction of the field-modulated principle in this type of motor breaks the design rule that the number of armature field pole pairs must be equal to the number of permanent magnet pole pairs. This allows full utilization of the motor's air gap field harmonics, enabling high-performance applications in direct-drive electric vehicles.

[0003] To achieve ride comfort in electric vehicles, the noise and vibration of electric vehicle drive motor systems have become a significant issue. Within the research field of electric vehicle drive motors, implementing vibration and noise reduction technology for drive motors has become a key topic in electric vehicle motor design. For example, Chinese Patent Publication No. CN111193337B discloses an electric vehicle built-in permanent magnet drive motor and its electromagnetic vibration reduction method. This method reduces the cogging torque, tooth harmonic electromotive force, and torque ripple of the built-in permanent magnet motor by segmenting the rotor magnetic poles, thereby reducing the electromagnetic vibration of the built-in permanent magnet motor. However, the skewed pole or slot method increases the difficulty and cost of industrial manufacturing, making it difficult to implement when the motor has a short axial length. Chinese Patent Publication No. CN111697903B discloses a control method for simultaneously suppressing torque ripple and vibration in a switched reluctance motor. The system implementing this control method includes a speed controller, a torque-radial force estimator, a reference generator, and a current controller. The torque-radial force estimator uses a rotor position slicing function fitting method. However, since dual-objective control is difficult to achieve, this method has not been widely used. It can be seen that the current research on drive motor noise suppression methods is mainly considered from the perspective of structural optimization and control strategy.

[0004] Clearly, current motor vibration reduction optimization designs fail to fully address the low-vibration, high-reliability design requirements for automotive drive motors. Therefore, suppressing the electromagnetic vibration of magnetic field modulation drive motors while maintaining basic electromagnetic performance remains a pressing challenge in the development of automotive magnetic field modulation drive motors. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of existing motor vibration suppression designs and propose a new electromagnetic vibration suppression method for a V-shaped magnetic field modulated permanent magnet motor of an electric vehicle under harmonic guidance. The magnetic field harmonics are used as the key intermediate quantity. While ensuring the basic electromagnetic characteristics of the motor, its electromagnetic vibration is directly and efficiently reduced. Multi-objective hierarchical optimization is adopted in the process to improve the practicality and universality of the method.

[0006] To achieve the above objectives, the present invention adopts a technical solution: a method for designing electromagnetic vibration suppression of a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance, comprising the following steps:

[0007] Step 1) Establishing an initial finite element model of the motor, determining the structural parameters to be optimized, and determining the selection range of the structural parameters through stress analysis and mechanical strength verification;

[0008] Step 2) Analytically derive the radial electromagnetic force of the motor to obtain the harmonic order distribution of the radial electromagnetic force and identify the low-order radial electromagnetic force that dominates the electromagnetic vibration;

[0009] Step 3) Analyze the source of the air gap magnetic flux harmonics that dominate the radial electromagnetic force harmonics of the electromagnetic vibration, and consider the impact of each air gap magnetic flux harmonic on the torque and torque ripple to select the key air gap magnetic flux harmonics;

[0010] Step 4) performing sensitivity analysis of structural parameters to key magnetic density harmonics and selecting sensitive structural parameters;

[0011] Step 5) Prioritize the low-order radial electromagnetic forces according to their impact on electromagnetic vibration and optimize their amplitudes in a hierarchical manner, while taking other electromagnetic properties into consideration during the optimization process: the first-level optimization target is the first-order radial electromagnetic force amplitude, and the second-level optimization target is the second-order radial electromagnetic force amplitude, torque, and torque ripple;

[0012] Step 6) Using finite element simulation to simulate the electromagnetic performance and vibration performance of the motor optimization solution, preliminarily determine the effectiveness and reliability of the optimization results;

[0013] Step 7) After simulating and evaluating the performance of the optimization scheme through finite element simulation, prototype processing is carried out according to the design scheme and relevant tests are performed to further verify the effectiveness and reliability of the motor optimization design.

[0014] Furthermore, in the step 1), the specific process is as follows: establishing a 3D structural model of the rotor, performing stress analysis on the rotor, applying a rotational inertia load at different speeds using the finite element method, and obtaining the stress distribution of the rotor. The values ​​of the structural parameters must ensure that the maximum stress σ generated by the rotor under different rotation states is max Less than the yield strength of its material, that is, the initial range of each design variable is determined while meeting the mechanical strength requirements of different operating conditions of the motor.

[0015] Furthermore, in step 3), during the selection of key magnetic flux harmonics, the Maxwell stress tensor method is used to consider the contribution of harmonics to torque and torque ripple, thereby improving the accuracy of subsequent multi-objective optimization.

[0016] Furthermore, in step 5), first-order radial electromagnetic force optimization is performed by response surface optimization.

[0017] Furthermore, in step 5), the second-order radial electromagnetic force, torque, and torque ripple are optimized by using a MOGA multi-objective genetic algorithm.

[0018] Furthermore, in step 5), the second-order radial electromagnetic force amplitude F r , torque T and torque ripple T r As a variable target, construct the second-order radial electromagnetic force amplitude F r is minimum, torque T is maximum, torque ripple T r is the smallest optimized model.

[0019] Furthermore, in step 2), the radial electromagnetic force Among them, B r (θ,t) is the radial air gap flux density, B t (θ,t) is the tangential air gap flux density, the tangential air gap flux density with a smaller amplitude B t (θ, t) is usually ignored in the calculation of radial electromagnetic force. θ is the mechanical angle, t is the time, and the vacuum permeability μ0 = 4π×10 -7 .

[0020] Furthermore, the radial air gap magnetic flux density B r The expansion of (θ, t) is:

[0021]

[0022] in, are the permanent magnet magnetomotive force and the armature magnetomotive force, i is an odd number with positive polarity, m is an integer other than a multiple of three, i and m are the harmonic order of the permanent magnet magnetomotive force and the armature magnetomotive force, respectively, F i and F m are the i-th harmonic amplitude of the permanent magnet magnetic field and the m-th harmonic amplitude of the armature field magnetomotive force, respectively. ω is the current angular frequency, ω=ω r P r , P r is the number of permanent magnet pole pairs of the motor, ω r is the mechanical speed of the motor rotor, are the stator permeability and rotor permeability considering the slotting effect, P j is the amplitude of the jth order function of the stator permeability function, P k is the amplitude of the kth harmonic of the rotor permeability function, j and k are both natural numbers, N s is the number of modulated teeth on the motor stator.

[0023] Furthermore, the radial electromagnetic force F rThe expansion of (θ, t) is:

[0024]

[0025] Among them, is the difference between some items, such as F i Expand after multiplying the squares, where i is i1 and i2 (μ1≠μ2), j1 and j2, k1 and k2, m1 and m2. Similarly, j is j1 and j2, k is k1 and k2, and m is m1 and m2.

[0026] Furthermore, in step 3), during the selection of key magnetic flux harmonics, the Maxwell stress tensor method is used to consider the influence of each air gap harmonic component on the torque and torque ripple:

[0027]

[0028]

[0029] Among them, T outq is the electromagnetic torque generated by the qth air gap harmonic, R is the radius of the motor air gap, l ef is the motor shaft length, B rq With B tq are the radial and tangential air gap flux densities of the qth harmonic, θ rq and θ tq are the initial phases of the qth harmonic in radial and tangential directions, T qrip is the torque ripple generated by the qth harmonic, T qMax is the maximum output torque generated by the qth harmonic, T qMin is the minimum output torque generated by the qth harmonic, T qavg is the average output torque generated by the qth harmonic

[0030] The beneficial effects of the present invention are:

[0031] 1. Before optimization, the present invention uses the yield strength of the rotor material as a constraint condition, applies rotational inertia loads at different speeds to the rotor, obtains stress distribution under different rotational states, and determines the selection range of design variables based on the requirement that the maximum stress is less than the yield strength of its material. Within this range, the high mechanical strength of the rotor is guaranteed, ensuring the high reliability of the motor under different driving requirements of electric vehicles, and avoiding the problem of mechanical strength failure and repeated work after optimization in traditional vibration reduction design optimization methods.

[0032] 2. The present invention conducts a detailed analytical derivation of the radial electromagnetic force of the motor. After obtaining the harmonic distribution of the radial electromagnetic force and clarifying the low-order radial electromagnetic force that dominates the vibration, it optimizes the priority according to the degree of its influence on the electromagnetic vibration, and then optimizes its amplitude in layers. During the optimization process, other electromagnetic properties are taken into account: the target of the first-level optimization is the amplitude of the first-order radial electromagnetic force, and the target of the second-level optimization is the amplitude, torque, and torque pulsation of the second-order radial electromagnetic force. The low-order radial electromagnetic force that dominates the electromagnetic vibration is accurately and effectively reduced, while taking into account the basic performance of the motor, ensuring that the motor can meet the high comfort and high reliability driving requirements of electric vehicles, and avoiding the problem of single optimization target and neglect of other motor performance in traditional vibration reduction design optimization methods.

[0033] 3. Based on the characteristics of magnetic field modulation motors, the present invention optimizes the amplitude of the dominant radial electromagnetic force harmonics as a means of optimizing electromagnetic vibration, derives and analyzes the relationship between the radial electromagnetic force and the air gap magnetic density harmonics, and then uses the key radial air gap magnetic density harmonics as the intermediate target for optimizing electromagnetic vibration. It directly and effectively reduces the electromagnetic vibration of the motor from the root of the electromagnetic vibration, solves the shortcomings of repeated trial and error and time-consuming traditional vibration reduction design optimization methods, and has strong engineering application value.

[0034] 4. This invention implements multi-objective optimization of torque, torque ripple, and radial force amplitude. While maintaining good torque characteristics, it achieves smoother motor output torque and significantly reduces torque ripple, ensuring smoother and more efficient operation within the electric drive system. Simultaneously, it effectively reduces the electromagnetic vibration of the magnetic field modulation motor, significantly minimizing the vibration noise it generates, addressing the low reliability and versatility of traditional vibration reduction design optimization methods.

[0035] 5. The present invention introduces the MOGA genetic algorithm to realize the multi-objective optimization process. While achieving low vibration and high reliability of the motor, it also ensures the motor torque output capacity. The whole process improves the overall design optimization efficiency of the motor and solves the problems of insufficient parameter optimization accuracy and insufficient real-time performance that may be caused by traditional vibration reduction design optimization methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the process of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of an example motor with V-type magnetic field modulation;

[0038] Figure 3 for Figure 2 The local structure and the enlarged schematic diagram of the design variables to be optimized;

[0039] In the figure: 1. Stator; 2. Rotor; 3. Permanent magnet; 4. Internal magnetic barrier; 5. External magnetic barrier.

[0040] Figure 4 for Figure 2 The radial air gap flux density and radial electromagnetic force waveforms and harmonic distribution of the motor; (a) is the radial air gap flux density and radial electromagnetic force waveforms; (b) is a schematic diagram of the radial air gap flux density and radial electromagnetic force harmonic distribution;

[0041] Figure 5 The results of the sensitivity analysis are shown in Figure 2. (a) shows the sensitivity index of the design variable to the tenth-order air gap harmonic; (b) shows the sensitivity index of the design variable to the fifth-order air gap harmonic.

[0042] Figure 6 Result graph for response surface optimization;

[0043] Figure 7 This is the multi-objective optimization result diagram of the MOGA genetic algorithm;

[0044] Figure 8 This is a comparison chart of torque performance before and after optimization;

[0045] Figure 9 Comparison of vibration and noise performance before and after optimization; (a) Comparison of motor core vibration acceleration before and after optimization; (b) Comparison of motor sound pressure level before and after optimization; DETAILED DESCRIPTION

[0046] See also Figure 1 , Figure 1 This is a flow chart of a method for suppressing electromagnetic vibration of a built-in magnetic field modulation drive motor of an electric vehicle provided by an embodiment of the present invention.

[0047] Figure 2 The V-shaped magnetic field modulation hub V-FMPM-IW motor shown is an embodiment of the present invention. The motor includes an inner stator 1 and an outer rotor 2. The outer rotor 2 has V-shaped permanent magnets 3 embedded in it. External magnetic barriers 4 and internal magnetic barriers 5 are provided on both sides of the permanent magnets 3 in the length direction. The internal magnetic barrier 5 is close to the inner stator 1, and the external magnetic barrier 4 is opposite. The inner stator 1 adopts a slotted structure, and each stator tooth acts as a magnetic modulation block to achieve a magnetic field modulation effect. Virtual slots equal to the number of permanent magnets are used on the inner side of the outer rotor 2 to reduce torque pulsation and short-circuiting of the magnetic circuit at the opening of the V-shaped permanent magnet. The permanent magnet 3 adopts a V-shaped topology and has a magnetic concentration effect. The purpose is to improve the utilization rate of the permanent magnets of the motor and avoid magnetic leakage, thereby improving the utilization rate of the permanent magnets and achieving high output torque.

[0048] by Figure 2 The electromagnetic vibration suppression method of the V-FMPM-IW motor shown as an embodiment includes the following steps:

[0049] S1. Establishment of motor model and determination of initial range of structural parameters:

[0050] For the structural parameters x1, x2, x3, ... x i The ultimate yield strength of the rotor silicon steel sheet is used as a constraint to determine the initial range of the parameters. Combined with the requirements of the electric vehicle drive motor for multi-operation, different driving conditions require different speeds. Among them, the motor rotor has the potential risk of deformation and fracture when it is in a high-speed rotation state. In order to improve the reliability of the motor structure, a 3D model of the motor is constructed and simulated using the Workbench static structure module. Rotational inertia loads at different speeds are applied to the rotor to obtain the stress distribution under different operating conditions. The maximum stress σ is used as the maximum stress. max The value range of the structural parameters to be optimized is determined to be [l1, h1], [l2, h2], … [li, hi], which is less than the yield strength of the material. This not only ensures that the mechanical strength of the motor structure meets the requirements, but also reasonably narrows the value range of the structural parameters to be optimized, saving computing time and cost for subsequent vibration reduction optimization.

[0051] S2. Analytical derivation of radial electromagnetic force:

[0052] Considering the double salient effect caused by the slots in the stator and rotor, the radial electromagnetic force of the V-FMPM-IW motor with V-type magnetic field modulation is analytically derived, and the radial electromagnetic force F is obtained. r The expansion of (θ,t):

[0053]

[0054] Among them, B r (θ, t) is the radial air gap flux density, θ is the mechanical angle, t is the time, and the vacuum permeability μ0 = 4π×10 -7 , are the permanent magnet magnetomotive force and the armature magnetomotive force, i is an odd number with positive polarity, m is an integer other than a multiple of three, i and m are the harmonic order of the permanent magnet magnetomotive force and the armature magnetomotive force, respectively, F i and F m are the amplitude of the i-th harmonic of the permanent magnet magnetic field and the m-th harmonic of the armature field, ω is the angular frequency of the current, ω = Ω r P r , P r is the number of permanent magnet pole pairs of the motor, ω r is the mechanical speed of the motor's rotor, are the stator permeance and rotor permeance considering the slotting effect, P j is the amplitude of the jth order function of the stator permeability function, P k is the amplitude of the kth harmonic of the rotor permeability function, j and k are both natural numbers, N sis the number of modulated teeth of the motor stator, is the distinguishing partial term, where i is i1 and i2 (μ1≠μ2), j1 and j2, k1 and k2, m1 and m2. Similarly, j is j1 and j2, k is k1 and k2, and m is m1 and m2.

[0055] Then the radial electromagnetic force harmonics that dominate the electromagnetic vibration are analyzed, and the source of the air gap magnetic density harmonics is analyzed;

[0056] S3. Select critical air gap harmonics:

[0057] According to formula (2) and formula (3), the contribution of each harmonic to the output torque and torque ripple is calculated using the Maxwell stress tensor method;

[0058]

[0059]

[0060] Among them, T outq is the electromagnetic torque generated by the qth air gap harmonic, R is the radius of the motor air gap, l ef is the motor shaft length, B rq With B tq are the radial and tangential air gap flux densities of the qth harmonic, θ rq and θ tq are the initial phases of the qth harmonic in radial and tangential directions, T qrip is the torque ripple generated by the qth harmonic, T qMax is the maximum output torque generated by the qth harmonic, T qMin is the minimum output torque generated by the qth harmonic, T qavg is the average output torque generated by the qth harmonic.

[0061] Combining the radial electromagnetic force harmonics of the dominant vibration obtained in S2. and the sources of its air gap magnetic density harmonics, the influence of each harmonic on the torque and torque ripple is merged to select the key air gap magnetic density harmonics.

[0062] S4. Sensitivity analysis:

[0063] Calculate the sensitivity index of the structural parameters to be optimized to the selected key air gap magnetic density harmonics, select the highly sensitive structural parameters of the key air gap harmonics, and the sensitivity S(x) of a single parameter to a single optimization target is calculated by formula (4);

[0064]

[0065] Where X is the structural parameter to be optimized, X0 is the initial value. ΔX is the change range of the structural parameter X. F is the optimization target. F(x) is the target value of the motor when the value of the structural parameter is x. Avg[S(Xi )] is S(X i )’s average value.

[0066] S5. Optimize target stratification:

[0067] The low-order radial electromagnetic force harmonics that dominate vibration are optimized in layers based on their degree of influence. The displacement amplitude of the electromagnetic vibration caused by the radial electromagnetic force is inversely proportional to the fourth power of the radial electromagnetic force harmonic order and directly proportional to the amplitude of the radial electromagnetic force harmonic. Therefore, the lower the order of the radial electromagnetic force harmonic, the higher the amplitude, and the greater the impact on the electromagnetic vibration. Therefore, the first layer of optimization is to optimize the amplitude of the first-order radial electromagnetic force harmonics, and the second layer is to optimize the amplitude of the second-order radial electromagnetic force harmonics and other basic electromagnetic properties.

[0068] S6. Optimization of the first-order radial electromagnetic force harmonic amplitude:

[0069] After clarifying the optimization objectives and the highly sensitive structural parameters to be optimized, a two-factor response surface algorithm was used to perform the first-level optimization. The response surface model used is shown below:

[0070]

[0071] Among them, f(z) is the optimization target, that is, the first-order radial electromagnetic force harmonic amplitude, z is the structural parameter to be optimized, z is z1 and z2, σ is the residual; β0, β i , β ii , β ij The coefficient in the algorithm. k is the number of design variables.

[0072] S7. Establish a multi-objective optimization model:

[0073] A multi-objective genetic algorithm (MOGA) is used to find the optimal design scheme for motor vibration reduction. The mathematical model of multi-objective optimization design consists of three parts: design variables, objective function and constraint conditions. r , torque T and torque ripple T r As the objective function, the structural variables to be optimized and their value ranges are the design variables and constraints, and the second-order radial electromagnetic force harmonic amplitude F is constructed. r is minimum, torque T is maximum, torque ripple T r is the minimum optimization model. The optimization model and constraints are as follows:

[0074] Function:[max(T),(Tr),Min(Fr)] (5)

[0075]

[0076] S8. Optimization solution:

[0077] After the settings are completed, the optimization model is optimized and calculated. After a finite number of iterations, the Pareto front optimal solution set is obtained. If convergence is achieved, the optimization ends and the final motor design solution is selected. Otherwise, the process returns to step S7 and the optimization model is redesigned.

[0078] S9. Performance evaluation of optimization results:

[0079] Compare the basic electromagnetic performance and electromagnetic vibration performance of the V-FMPM-IW motor before and after optimization. If the performance is significantly improved after optimization, the analysis is completed. If the expected vibration reduction effect is not achieved after optimization, return to step S5 and perform the optimization analysis again.

[0080] S10. Determine the motor processing plan:

[0081] Prototype processing and related tests are carried out according to the optimized design plan to further verify the optimized structure of the motor;

[0082] The above is based on Figure 2 The motor in the figure is used as an example to illustrate the optimization design method of the present invention. Those skilled in the art should understand that the present invention is not limited to the above specific embodiment. The above specific embodiment and description in the specification are only for further illustrating the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the invention claimed. The scope of the invention claimed is defined by the claims and their equivalents.

Claims

1. A method for designing electromagnetic vibration suppression of a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance, characterized in that: The following steps are involved: Step 1) Establishing an initial finite element model of the motor, determining the structural parameters to be optimized, and determining the selection range of the structural parameters through stress analysis and mechanical strength verification; Step 2) Analytically derive the radial electromagnetic force of the motor to obtain the harmonic order distribution of the radial electromagnetic force and identify the low-order radial electromagnetic force that dominates the electromagnetic vibration; Step 3) Analyze the source of the air gap magnetic flux harmonics that dominate the radial electromagnetic force harmonics of the electromagnetic vibration, and consider the impact of each air gap magnetic flux harmonic on the torque and torque ripple to select the key air gap magnetic flux harmonics; Step 4) performing sensitivity analysis of structural parameters to key magnetic density harmonics and selecting sensitive structural parameters; Step 5) Prioritize the low-order radial electromagnetic forces according to their impact on electromagnetic vibration and optimize their amplitudes in a hierarchical manner, while taking other electromagnetic properties into consideration during the optimization process: the first-level optimization target is the first-order radial electromagnetic force amplitude, and the second-level optimization target is the second-order radial electromagnetic force amplitude, torque, and torque ripple; Step 6) Using finite element simulation to simulate the electromagnetic performance and vibration performance of the motor optimization solution, preliminarily determine the effectiveness and reliability of the optimization results; Step 7) After simulating and evaluating the performance of the optimized solution through finite element simulation, a prototype is manufactured according to the design solution and relevant tests are performed to further verify the effectiveness and reliability of the motor optimization design; In step 2), the radial electromagnetic force Among them, B r (θ,t) is the radial air gap flux density, B t (θ,t) is the tangential air gap flux density, the tangential air gap flux density with a smaller amplitude B t (θ, t) is usually ignored in the calculation of radial electromagnetic force. θ is the mechanical angle, t is the time, and the vacuum permeability μ0 = 4π×10 -7 ; The radial air gap magnetic flux density B r The expansion of (θ, t) is: in, are the permanent magnet magnetomotive force and the armature magnetomotive force, i is an odd number with positive polarity, m is an integer other than a multiple of three, i and m are the harmonic order of the permanent magnet magnetomotive force and the armature magnetomotive force, respectively, F i and F m are the i-th harmonic amplitude of the permanent magnet magnetic field and the m-th harmonic amplitude of the armature field magnetomotive force, respectively. ω is the current angular frequency, ω=ω r P r , P r is the number of permanent magnet pole pairs of the motor, ω r is the mechanical speed of the motor rotor, are the stator permeability and rotor permeability considering the slotting effect, P j is the amplitude of the jth order function of the stator permeability function, P k is the amplitude of the kth harmonic of the rotor permeability function, j and k are both natural numbers, N s is the number of modulated teeth on the motor stator.

2. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: The specific process of step 1) is as follows: establish a 3D structural model of the rotor, perform stress analysis on the rotor, apply rotational inertia loads at different speeds to it using the finite element method, and obtain the stress distribution of the rotor. The values ​​of the structural parameters must ensure that the maximum stress σ generated by the rotor under different rotation states is max Less than the yield strength of its material, that is, the initial range of each design variable is determined while meeting the mechanical strength requirements of different operating conditions of the motor.

3. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: In step 3), during the selection of key magnetic flux harmonics, the Maxwell stress tensor method is used to consider the contribution of harmonics to torque and torque ripple, thereby improving the accuracy of subsequent multi-objective optimization.

4. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: In step 5), the first-order radial electromagnetic force is optimized by response surface optimization.

5. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: In step 5), the second-order radial electromagnetic force, torque, and torque ripple are optimized by using a MOGA multi-objective genetic algorithm.

6. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: In step 5), the second-order radial electromagnetic force amplitude F r , torque T and torque ripple T r As a variable target, construct the second-order radial electromagnetic force amplitude F r is minimum, torque T is maximum, torque ripple T r is the smallest optimized model.

7. The method for designing electromagnetic vibration suppression of a V-shaped magnetic field modulation permanent magnet motor for an electric vehicle under harmonic guidance according to claim 1 is characterized by: Radial electromagnetic force F r The expansion of (θ, t) is: Among them, subscripts are used to distinguish the source of the expanded terms, such as F i The cross product terms that appear after expanding the square multiplication, where i is i1 and i2 (μ1≠μ2), j1 and j2, k1 and k2, m1 and m2, similarly, j is j1 and j2, k is k1 and k2, and m is m1 and m2.

8. The electromagnetic vibration suppression design method for a V-shaped magnetic field modulation permanent magnet motor of an electric vehicle under harmonic guidance according to claim 1 is characterized in that: In step 3), during the selection of key magnetic flux harmonics, the Maxwell stress tensor method is used to consider the influence of each air gap harmonic component on the torque and torque ripple: Among them, T outq is the electromagnetic torque generated by the qth air gap harmonic, R is the radius of the motor air gap, l ef is the motor shaft length, B rq With B tq are the radial and tangential air gap flux densities of the qth harmonic, θ rq and θ tq are the initial phases of the qth harmonic in radial and tangential directions, T qrip is the torque ripple generated by the qth harmonic, T qMax is the maximum output torque generated by the qth harmonic, T qMin is the minimum output torque generated by the qth harmonic, T qavg is the average output torque generated by the qth harmonic.

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