Working condition-based order electromagnetic force calculation method

Abstract

The invention discloses a working condition-based order electromagnetic force calculation method. The method comprises the following steps of receiving a motor operation working condition point obtained based on vehicle road spectrum and vehicle model parameter conversion; judging whether the working condition is a single working condition, and if so, calculating and classifying electromagnetic force of a specified space order; if the working condition is not the single working condition, working condition conversion is carried out, the vehicle speed history is converted into the motor rotating speed and torque, and then whether single or multi-scheme analysis is executed or not is judged; in single scheme analysis, electromagnetic force of each working condition point is calculated and classified, and the electromagnetic force distribution of the order under all working conditions is visually displayed by adopting a Colormap; in multi-scheme analysis, electromagnetic forces of different schemes are calculated in parallel, and after a difference value is obtained, the difference is displayed by a Colormap. According to the method, all-condition evaluation and multi-scheme comparison of the NVH performance of the motor are realized, and the design perspectiveness and optimization efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of order electromagnetic force calculation method, and more particularly to an order electromagnetic force calculation method based on working conditions. BACKGROUND

[0002] With the development of industry and the progress of technology, the requirements for torque density and NVH related performance indicators are becoming higher and higher. NVH is noise, unevenness. The motor, as the core component of the power system, is the main excitation source of NVH. The NVH characteristics mainly depend on two aspects. The first aspect is the inherent parameters of the system itself, such as the inertia and damping of the system. The second aspect is the exciting force, under the action of which the system produces forced vibration. There are many exciting forces during the operation of the motor, in addition to mechanical factors such as machining precision, the electromagnetic force caused by the air gap magnetic field is the main factor. The electromagnetic force includes radial electromagnetic force and tangential electromagnetic force. The radial electromagnetic force causes periodic deformation vibration of the iron core, and the tangential force wave mainly causes torque fluctuation, causing bending deformation of the tooth part. The tangential electromagnetic force is the main source of electromagnetic vibration noise. There are a series of magnetic field harmonics with different pole numbers, different sizes and different speeds in the air gap magnetic field of the motor. This series of harmonic magnetic fields produce a series of radial force waves with different spatial distributions, different sizes and time-varying on the surface of the stator and rotor. From the spatial point of view, the radial electromagnetic force has various distributions along the air gap circumferential surface, and in time, the radial electromagnetic force also changes with time. This is the time-space characteristic of electromagnetic force, which makes the analysis and calculation of electromagnetic force extremely complex. Since the dynamic deformation amplitude of the iron core is inversely proportional to the 4th power of the spatial order r, the lower the force wave order, the greater the vibration and noise caused. The spatial 0-order electromagnetic force is the main analysis object.

[0003] The traditional electromagnetic force calculation method of permanent magnet motor is basically only for single speed / torque working condition, and the calculation time is long, the analysis is one-sided, and the whole speed / torque working condition of the motor is not covered.

[0004] The traditional calculation method does not calculate the electromagnetic force for different application scenarios and different road spectrum working conditions, and cannot comprehensively diagnose vibration and noise in the early design stage.

[0005] In the early design stage, comparative analysis is very important, and the traditional calculation method cannot perform quantitative and intuitive comparative analysis of different schemes under full working conditions. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an order electromagnetic force calculation method based on working conditions to solve the above technical problems.

[0007] To achieve the above purpose, the present application provides the following technical scheme: A method for calculating order electromagnetic force based on working condition, comprising the following steps: S1, working condition input: receiving the motor operating working condition points converted based on the target vehicle road spectrum and vehicle model parameters, the working condition points including motor speed and torque; S2, working condition judgment: whether it is a single working condition; S3, if it is judged as a single working condition, the following steps are executed in turn: S31, calculating the air gap electromagnetic force according to the working condition points by finite element simulation and Maxwell stress tensor method, and performing Fourier decomposition on the time domain electromagnetic force waveform to extract the electromagnetic force amplitude of the specified spatial order; S32, order electromagnetic force classification: classifying the electromagnetic force amplitudes of the same spatial order under the working condition points into the same data set; S4, if it is judged as a non-single working condition, the working condition conversion is performed, and then it is judged whether it is a single scheme; S5, if it is judged to execute single scheme analysis, the following steps are executed in turn: S51, order electromagnetic force calculation: for each working condition point obtained in step S4, calculating the air gap electromagnetic force by finite element simulation and Maxwell stress tensor method, and performing Fourier decomposition on the time domain electromagnetic force waveform to extract the electromagnetic force amplitude of the specified spatial order; S52, order electromagnetic force classification: classifying the electromagnetic force amplitudes of the same spatial order under different working condition points into the same data set; S53, first visualization display: visualizing the classified specified order electromagnetic force data set with motor speed and torque as coordinate axes by Colormap diagram to represent the distribution of the order electromagnetic force under the whole working condition; S6, if it is judged to execute multi-scheme comparative analysis, the following steps are executed in turn: S61, parallel calculation and classification: for at least a first motor design scheme and a second motor design scheme, respectively executing the steps of S51 and S52 in parallel to obtain the classified order electromagnetic force data set corresponding to each scheme; S62, difference calculation: performing difference operation on the same order electromagnetic force amplitudes of the first scheme and the second scheme under the same working condition points to obtain the whole working condition order electromagnetic force difference data set; S63, second visualization display: visualizing the difference data set with motor speed and torque as coordinate axes by Colormap diagram to intuitively compare the differences of the order electromagnetic force of different schemes under the whole working condition.

[0008] Further, the working condition conversion in step S4 comprises: Based on the vehicle's longitudinal dynamics equations, the vehicle's driving resistance is calculated from the vehicle speed history. The resistance includes rolling resistance, air resistance, and gradient resistance. The required motor drive torque is calculated based on the driving resistance. The motor speed is calculated based on the vehicle's speed and transmission system parameters.

[0009] Furthermore, the specific calculation process for the working condition conversion in step S4 includes: deriving the corresponding motor speed and torque based on different application scenarios, different standard road spectra, and vehicle parameters, and converting different working conditions to the corresponding motor output; Force analysis of the longitudinal motion of the car: In the formula Total resistance: , respectively rolling resistance air resistance and gravity The detailed calculations are as follows: Note: gravity, Rolling friction coefficient, drag coefficient, Windward area, speed, slope.

[0010] Therefore, the driving force for the car to move forward is: The corresponding motor torque is: The corresponding motor speed is: in For transmission efficiency, The transmission ratio is... Let be the tire radius, and m be the vehicle mass.

[0011] Furthermore, the vehicle parameters mentioned include at least one of the following: vehicle weight, rolling resistance coefficient, drag coefficient, frontal area, tire radius, transmission ratio, and transmission efficiency.

[0012] The further steps S31 and S51, specifically the calculation of the order electromagnetic force, include: According to Maxwell's stress tensor theory, the radial electromagnetic force density is: Radial magnetic flux density, Tangential magnetic flux density, =4π×10^(−7)H / m is the vacuum permeability.

[0013] By performing line integration of the electromagnetic force density along the circumference of the air gap using finite element method software, the radial electromagnetic force of any circle within the air gap can be obtained as follows: The electromagnetic force waveform obtained is then divided by the length of the circumference to obtain the time-domain electromagnetic force density curve.

[0014] Finally, a one-dimensional Fourier decomposition of the electromagnetic force density curve in this time domain is performed to obtain the electromagnetic force of the corresponding order.

[0015] Furthermore, the Colormap used in the first visualization in step S53 and the second visualization in step S63 uses color depth or hue variations to characterize the magnitude of electromagnetic force amplitude or electromagnetic force difference.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Achieved a forward-looking assessment of motor NVH performance across the entire operating range: This invention establishes an analytical framework covering all typical operating ranges of the motor in the entire application scenario by converting the road spectrum and vehicle model parameters of the target vehicle into the motor's operating point. This enables comprehensive and systematic prediction of the electromagnetic force excitation of the motor under real and complex driving conditions in the early design stage, thereby achieving early identification and proactive optimization of potential vibration and noise problems, greatly improving the completeness and reliability of the design, and effectively reducing the risks and costs of later development.

[0017] 2. Provides precise and efficient "operating condition-order" correlation diagnostic capabilities: By combining full-condition calculation with spatial order decomposition, this invention can accurately reveal the distribution pattern of electromagnetic forces of a specific spatial order (such as low-order force waves that contribute the most to vibration and noise) throughout the entire motor operating range. This method can clearly locate the key excitation sources of electromagnetic forces under different driving conditions (such as acceleration, cruising, and hill climbing), enabling NVH optimization measures to be targeted at specific problem conditions and specific order force waves, significantly improving the pertinence and efficiency of design optimization.

[0018] It possesses powerful multi-scheme quantitative comparison and decision support capabilities: This invention supports parallel calculation and full-condition comparison of multiple motor design schemes. By calculating the difference in electromagnetic force of the same order at the same operating point and visualizing it using a colormap, it can generate intuitive and quantitative global comparison results. This function provides precise data guidance for design iteration, helping engineers quickly understand the performance differences and optimization effects between different schemes, thereby rapidly selecting the optimal design scheme and significantly accelerating the product optimization process.

[0019] 4. A standardized and automated high-efficiency analysis process has been established: This invention integrates a series of steps, including road spectrum conversion, finite element calculation, order decomposition, data integration, and visualization, into a clear and standardized closed-loop process. This process has high repeatability and scalability, and can be applied to the NVH analysis needs of different projects and vehicle models. It is conducive to the accumulation of enterprise R&D knowledge, the construction of a standardized system, and the overall improvement of analysis efficiency.

[0020] 5. Enhanced technical insight and team collaboration efficiency through intuitive visualization: Colormap diagrams are used to transform massive amounts of "speed-torque-electromagnetic force" three-dimensional data into clear images, making the complex electromagnetic force distribution patterns and differences between solutions readily apparent. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the overall process of a working condition-based method for calculating order electromagnetic force. Figure 2 This is a flowchart illustrating the process of changing operating conditions. Figure 3 This is a distribution map of the set of operating point points after the operating condition transformation; Figure 4 Colormap of the order electromagnetic force distribution; Figure 5 This is a colormap showing the distribution of the order electromagnetic force difference. Detailed Implementation

[0022] In the description of this invention, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0024] A method for calculating order electromagnetic force based on operating conditions includes the following steps: S1. Operating condition input: Receive motor operating condition points obtained based on the conversion of target vehicle road spectrum and vehicle model parameters, wherein the operating condition points include motor speed and torque; S2. Working condition judgment: Is it a single working condition? S3. If it is determined to be a single operating condition, then perform the following steps in sequence: S31. Calculate the air gap electromagnetic force based on the working point using finite element simulation and Maxwell stress tensor method, and perform Fourier decomposition on the time-domain electromagnetic force waveform to extract the electromagnetic force amplitude of the specified spatial order. S32, Classification of Electromagnetic Force by Order: Classify the amplitudes of electromagnetic forces of the same spatial order at the operating point into the same dataset; S4. If it is determined that it is not a single working condition, then the working condition is changed, and then it is determined whether it is a single solution. S5. If the analysis is determined to be a single-solution analysis, then the following steps are executed sequentially: S51, Calculation of electromagnetic force of order: For each working point obtained in step S4, the air gap electromagnetic force is calculated by finite element simulation and Maxwell stress tensor method, and the time-domain electromagnetic force waveform is Fourier decomposed to extract the electromagnetic force amplitude of the specified spatial order. S52, Classification of Electromagnetic Force by Order: Classify the amplitudes of electromagnetic forces of the same spatial order under different operating conditions into the same dataset; S53. First visualization display: The classified electromagnetic force dataset of the specified order is visualized using a Colormap with motor speed and torque as coordinate axes to represent the distribution of the electromagnetic force of that order under all working conditions. S6. If it is determined that a multi-scheme comparison analysis is to be performed, then the following steps are executed in sequence: S61, Parallel Computation and Classification: For at least the first motor design scheme and the second motor design scheme, execute the steps of S51 and S52 in parallel to obtain the classified order electromagnetic force datasets corresponding to each scheme. S62. Difference Calculation: The difference between the electromagnetic force amplitudes of the first and second schemes at the same working point is calculated to obtain the electromagnetic force difference dataset for all working conditions. S63. Second visualization display: The difference dataset is visualized using a Colormap with motor speed and torque as coordinate axes to intuitively compare the differences in electromagnetic force of this order under all working conditions.

[0025] Preferably, the operating condition transition in step S4 includes: Based on the vehicle's longitudinal dynamics equations, the vehicle's driving resistance is calculated from the vehicle speed history. The resistance includes rolling resistance, air resistance, and gradient resistance. The required motor drive torque is calculated based on the driving resistance. The motor speed is calculated based on the vehicle's speed and transmission system parameters.

[0026] Preferably, the specific calculation process for the working condition conversion in step S4 includes: deriving the corresponding motor speed and torque based on different application scenarios, different standard road spectra, and vehicle parameters, and converting different working conditions to the corresponding motor output; Force analysis of the longitudinal motion of the car: In the formula Total resistance: , respectively rolling resistance air resistance and gravity The detailed calculations are as follows: Note: gravity, Rolling friction coefficient, drag coefficient, Windward area, speed, slope.

[0027] Therefore, the driving force for the car to move forward is: The corresponding motor torque is: The corresponding motor speed is: in For transmission efficiency, The transmission ratio is... Let be the tire radius, and m be the vehicle mass.

[0028] Preferably, the vehicle parameters include at least one of the following: vehicle weight, rolling resistance coefficient, drag coefficient, frontal area, tire radius, transmission ratio, and transmission efficiency.

[0029] Preferably, the order electromagnetic force calculation in steps S31 and S51 specifically includes: According to Maxwell's stress tensor theory, the radial electromagnetic force density is: Radial magnetic flux density, Tangential magnetic flux density, =4π×10^(−7)H / m is the vacuum permeability.

[0030] By performing line integration of the electromagnetic force density along the circumference of the air gap using finite element method software, the radial electromagnetic force of any circle within the air gap can be obtained as follows: The electromagnetic force waveform obtained is then divided by the length of the circumference to obtain the time-domain electromagnetic force density curve.

[0031] Finally, a one-dimensional Fourier decomposition of the electromagnetic force density curve in this time domain is performed to obtain the electromagnetic force of the corresponding order.

[0032] Preferably, the Colormap used in the first visualization in step S53 and the second visualization in step S63 uses color depth or hue variations to characterize the magnitude of electromagnetic force amplitude or electromagnetic force difference.

[0033] Invention principle: The core principle of this invention lies in constructing a closed-loop analysis system that integrates "actual vehicle driving scenarios" with "motor electromagnetic force characteristics." Through the fusion of multidisciplinary technologies, it systematically solves the industry problem of the difficulty in predicting and comparing motor electromagnetic vibration and noise (NVH) under all operating conditions. Its basic principles can be divided into the following four levels: 1. Vehicle dynamics and operating condition mapping principle: The motor does not operate independently; its operating point (speed and torque) is entirely determined by the vehicle's driving state. This invention first establishes an accurate mapping model based on the vehicle's longitudinal dynamics.

[0034] Using vehicle speed-time history data from standard road profiles (such as NEDC and WLTC) or custom road profiles as input, the total driving resistance (including rolling resistance, air resistance, and gradient resistance) overcome by the vehicle is calculated through force analysis. Then, based on the parameters of the transmission system (transmission ratio, efficiency, tire radius), the required motor torque and motor speed to drive the vehicle are derived in reverse.

[0035] This step transforms the macroscopic and complex vehicle operating conditions into a discrete set of operating point values ​​that can be directly used by motor simulation software. This ensures that all subsequent electromagnetic analyses are based on real and representative operating conditions, fundamentally guaranteeing the engineering practical value of the analysis results.

[0036] 2. The principle of electromagnetic field and force wave decomposition: The main excitation source of motor vibration and noise is the electromagnetic force generated by the interaction of the air gap magnetic field. These electromagnetic forces are distributed in a complex manner in both space and time.

[0037] For each operating point obtained from the above steps, transient electromagnetic field simulation is performed using the finite element method to accurately solve for the radial and tangential magnetic flux densities in the stator and rotor air gap.

[0038] Based on Maxwell's stress tensor method, the magnetic flux density is converted into the radial electromagnetic force density acting on the iron core. This method is based on the fundamental theory of electromagnetic fields, has clear physical meaning, and offers high computational accuracy.

[0039] The calculated time-domain electromagnetic force waveform is subjected to one-dimensional spatial Fourier decomposition. This step is crucial, as it decomposes the complex force wave distributed along the circumference of the air gap into a superposition of a series of simple harmonic force waves with fixed spatial orders (such as 0th, 2nd, 4th, etc.) and amplitudes.

[0040] Spatial order serves as a bridge connecting electromagnetic forces and structural vibrations. Low-order force waves (especially the 0th order) are more likely to induce structural resonances, which is the "main contradiction" in NVH (Noise, Vibration, and Harshness) problems. By decomposing these forces, we can shift our analytical focus from the complex spatiotemporal force field to a few key order components that contribute the most to vibration, greatly simplifying the problem's complexity.

[0041] 3. Principles of Data Integration and Global Representation: Analysis of a single operating point is one-sided; it is necessary to examine the performance of electromagnetic force across the entire operating range.

[0042] The electromagnetic force amplitudes calculated at all operating points and of the same spatial order are extracted and categorized according to their corresponding speed and torque coordinates to form an "electromagnetic force amplitude-operating condition matrix" specific to that order.

[0043] This classification method constructs a complete three-dimensional dataset of "operating condition-order-amplitude". It allows us to examine the distribution pattern of electromagnetic force of a specific order within the entire motor operating envelope from a global perspective, and identify which operating condition areas are "high-risk areas" or "resonance risk points" of electromagnetic force of that order.

[0044] 4. Principles of Visualization and Difference Quantification Comparison: Massive amounts of data need to be presented in an intuitive way to support engineering decisions.

[0045] Visualization of a single scenario: The above "electromagnetic force amplitude-operating condition matrix" is presented in the form of a colormap (i.e., a heatmap). The graph uses rotational speed and torque as the X and Y axes, and the magnitude of the electromagnetic force amplitude is mapped by changes in color intensity or hue.

[0046] Multi-scheme comparison and quantification: For multiple design schemes, firstly, the full-condition order electromagnetic force datasets of each scheme are efficiently obtained through parallel computing. Then, at the same condition grid points, the difference of the same order electromagnetic force amplitude of the two schemes is calculated to generate an "electromagnetic force difference matrix", which is also visualized using a Colormap.

[0047] Colormaps transform abstract data into images that engineers can understand at a glance, making high-risk areas and optimization effects immediately apparent. Difference calculations transform qualitative statements like "Solution A is better than Solution B" into quantitative, full-range statements about "where it's better and by how much," providing precise guidance for design iterations.

[0048] The principle chain can be summarized as follows: road spectrum input → vehicle dynamics conversion → motor operating point → finite element electromagnetic simulation → Maxwell stress calculation → spatial Fourier decomposition → order electromagnetic force extraction → full operating condition data integration → colormap visualization / difference comparison. This is a complete technology chain from system to component, from macro to micro, from complexity to decomposition, and from data to insight.

[0049] advantage: 1. Achieved a forward-looking assessment of motor NVH performance across the entire operating range: This invention establishes an analytical framework covering all typical operating ranges of the motor in the entire application scenario by converting the road spectrum and vehicle model parameters of the target vehicle into the motor's operating point. This enables comprehensive and systematic prediction of the electromagnetic force excitation of the motor under real and complex driving conditions in the early design stage, thereby achieving early identification and proactive optimization of potential vibration and noise problems, greatly improving the completeness and reliability of the design, and effectively reducing the risks and costs of later development.

[0050] 2. Provides precise and efficient "operating condition-order" correlation diagnostic capabilities: By combining full-condition calculation with spatial order decomposition, this invention can accurately reveal the distribution pattern of electromagnetic forces of a specific spatial order (such as low-order force waves that contribute the most to vibration and noise) throughout the entire motor operating range. This method can clearly locate the key excitation sources of electromagnetic forces under different driving conditions (such as acceleration, cruising, and hill climbing), enabling NVH optimization measures to be targeted at specific problem conditions and specific order force waves, significantly improving the pertinence and efficiency of design optimization.

[0051] It possesses powerful multi-scheme quantitative comparison and decision support capabilities: This invention supports parallel calculation and full-condition comparison of multiple motor design schemes. By calculating the difference in electromagnetic force of the same order at the same operating point and visualizing it using a colormap, it can generate intuitive and quantitative global comparison results. This function provides precise data guidance for design iteration, helping engineers quickly understand the performance differences and optimization effects between different schemes, thereby rapidly selecting the optimal design scheme and significantly accelerating the product optimization process.

[0052] 4. A standardized and automated high-efficiency analysis process has been established: This invention integrates a series of steps, including road spectrum conversion, finite element calculation, order decomposition, data integration, and visualization, into a clear and standardized closed-loop process. This process has high repeatability and scalability, and can be applied to the NVH analysis needs of different projects and vehicle models. It is conducive to the accumulation of enterprise R&D knowledge, the construction of a standardized system, and the overall improvement of analysis efficiency.

[0053] 5. Enhanced technical insight and team collaboration efficiency through intuitive visualization: Colormap diagrams are used to transform massive amounts of "speed-torque-electromagnetic force" three-dimensional data into clear images, making the complex electromagnetic force distribution patterns and differences between solutions readily apparent.

[0054] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for calculating order electromagnetic force based on operating conditions, characterized in that, Includes the following steps: S1. Operating condition input: Receive motor operating condition points obtained based on the conversion of target vehicle road spectrum and vehicle model parameters, wherein the operating condition points include motor speed and torque; S2. Working condition judgment: Is it a single working condition? S3. If it is determined to be a single operating condition, then perform the following steps in sequence: S31. Calculate the air gap electromagnetic force based on the working point using finite element simulation and Maxwell stress tensor method, and perform Fourier decomposition on the time-domain electromagnetic force waveform to extract the electromagnetic force amplitude of the specified spatial order. S32, Classification of Electromagnetic Force by Order: Classify the amplitudes of electromagnetic forces of the same spatial order at the operating point into the same dataset; S4. If it is determined that it is not a single working condition, then the working condition is changed, and then it is determined whether it is a single solution. S5. If the analysis is determined to be a single-solution analysis, then the following steps are executed sequentially: S51, Calculation of electromagnetic force of order: For each working point obtained in step S4, the air gap electromagnetic force is calculated by finite element simulation and Maxwell stress tensor method, and the time-domain electromagnetic force waveform is Fourier decomposed to extract the electromagnetic force amplitude of the specified spatial order. S52, Classification of Electromagnetic Force by Order: Classify the amplitudes of electromagnetic forces of the same spatial order under different operating conditions into the same dataset; S53. First visualization display: The classified electromagnetic force dataset of the specified order is visualized using a Colormap with motor speed and torque as coordinate axes to represent the distribution of the electromagnetic force of that order under all working conditions. S6. If it is determined that a multi-scheme comparison analysis is to be performed, then the following steps are executed in sequence: S61, Parallel Computation and Classification: For at least the first motor design scheme and the second motor design scheme, execute the steps of S51 and S52 in parallel to obtain the classified order electromagnetic force datasets corresponding to each scheme. S62. Difference Calculation: The difference between the electromagnetic force amplitudes of the first and second schemes at the same working point is calculated to obtain the electromagnetic force difference dataset for all working conditions. S63. Second visualization display: The difference dataset is visualized using a Colormap with motor speed and torque as coordinate axes to intuitively compare the differences in electromagnetic force of this order under all working conditions.

2. The method for calculating order electromagnetic force based on operating conditions according to claim 1, characterized in that, The operating condition transition in step S4 includes: Based on the vehicle's longitudinal dynamics equations, the vehicle's driving resistance is calculated from the vehicle speed history. The resistance includes rolling resistance, air resistance, and gradient resistance. The required motor drive torque is calculated based on the driving resistance. The motor speed is calculated based on the vehicle's speed and transmission system parameters.

3. The method for calculating order electromagnetic force based on operating conditions according to claim 2, characterized in that, The specific calculation process for the working condition conversion in step S4 includes: deriving the corresponding motor speed and torque based on different application scenarios, different standard road spectra, and vehicle parameters, and converting different working conditions to the corresponding motor output; Force analysis of the longitudinal motion of the car: In the formula Total resistance: , respectively rolling resistance air resistance and gravity The detailed calculations are as follows: Note: gravity, Rolling friction coefficient, drag coefficient, Windward area, speed, slope.

4. Therefore, the driving force for the car's forward motion is: The corresponding motor torque is: The corresponding motor speed is: in For transmission efficiency, The transmission ratio is... Where is the tire radius and m is the vehicle mass.

5. The method for calculating order electromagnetic force based on operating conditions according to claim 3, characterized in that: The vehicle parameters include at least one of the following: vehicle weight, rolling resistance coefficient, drag coefficient, frontal area, tire radius, transmission ratio, and transmission efficiency.

6. The method for calculating order electromagnetic force based on operating conditions according to claim 1, characterized in that, The order electromagnetic force calculations in steps S31 and S51 specifically include: According to Maxwell's stress tensor theory, the radial electromagnetic force density is: Radial magnetic flux density, Tangential magnetic flux density, =4π×10^(−7) H / m is the vacuum permeability.

7. By performing line integration of the electromagnetic force density along the air gap circumference using finite element software, the radial electromagnetic force on any circle within the air gap circumference can be obtained as follows: The electromagnetic force waveform obtained is then divided by the length of the circumference to obtain the time-domain electromagnetic force density curve.

8. Finally, a one-dimensional Fourier decomposition of the electromagnetic force density curve in this time domain is performed to obtain the electromagnetic force of the corresponding order.

9. The method for calculating order electromagnetic force based on operating conditions according to claim 2, characterized in that: The Colormap used in the first visualization in step S53 and the second visualization in step S63 uses color depth or hue variations to characterize the magnitude of electromagnetic force amplitude or electromagnetic force difference.

Images