Modeling method for dynamical model of permanent magnet motor rotor

Abstract

The invention discloses a modeling method for a dynamical model of a permanent magnet motor rotor, and provides an integral modeling method and a unified modeling process for a permanent magnet motor rotor system with a complex topological structure. The problem that the rigidity of a complex multi-component assembly is difficult to accurately characterize is effectively solved, and the prediction reliability of the model on the modal characteristics of the rotor is improved. Besides, a finite element and analysis combined mode is adopted, the bending deflection and the shearing deflection are considered at the same time under the four-point bending boundary condition, a bending rigidity parameter finally used for modeling is reconstructed through an equivalent mass diameter method, the reinforcing effect of the iron core laminated assembly on the rigidity of the rotating shaft is represented, and the modeling accuracy is improved. The problem that a full-size entity contact finite element model is difficult to calculate is avoided, and the method has the advantages of being small in calculation amount and high in accuracy.

Description

Technical Field

[0001] This invention belongs to the field of motor rotor dynamics analysis technology, specifically relating to a modeling method for permanent magnet motor rotor dynamics. Background Technology

[0002] High-speed permanent magnet motors occupy an important position in high-end equipment due to their high power density, high efficiency, and compact structure. To ensure their safe and stable operation under high-speed conditions, establishing an accurate dynamic model to precisely predict the rotor's critical speed and modal characteristics is particularly necessary. However, the unique silicon steel lamination structure of the rotor core presents significant challenges for accurate modeling. Due to the nonlinear micro-contact and friction effects between the laminations, the rotor exhibits complex mechanical characteristics. Its actual bending stiffness is significantly lower than the theoretical value calculated based on solid materials, and it shows a nonlinear decay characteristic that varies with the number of layers.

[0003] Existing technologies often struggle to accurately characterize the actual deformation mechanism of stacked structures under load when establishing rotor dynamics models. The literature [Wang Dongxiong, Cao Kanglei, Yu Zewen. Modal characteristics of rotor systems of high-speed built-in permanent magnet motors. Bearings, 2024(7):62-71] proposes an algorithm for the rotor's equivalent elastic modulus based on a cantilever beam model, considering the different material properties of multiple components. However, this method is primarily based on idealized analytical assumptions and does not consider the effects of silicon steel sheet stacking and interference fit. The literature [Huang Jinping, Zhang Zhengyue, Huang Daoqiong. Research on rotor dynamics characteristics of high-speed permanent magnet motors. Rocket Propulsion, 2019, 45(3):20-25] proposes a method to calculate the actual stiffness by recalculating the stiffness of models with different numbers of laminations and then using curve fitting. However, this method involves applying forced displacement at the axial center position to obtain the reaction force and then performing back-calculation, incorporating shear deformation, and the support reaction force is mixed with shear force, thus failing to obtain an equivalent elastic modulus that can be directly used for calculation.

[0004] If such parameters are directly applied to the rotor dynamics equations, it is difficult to truly reflect the mechanical behavior of the rotor under full-size and high-speed conditions, which leads to deviations in the prediction results of key indicators such as critical speed. Summary of the Invention

[0005] In view of the above, the present invention provides a modeling method for the rotor dynamics model of a permanent magnet motor. This method aims to construct a complete modeling process that is clear in physical meaning and high in accuracy, from component equivalence to system integration, in order to solve the problem of rotor dynamics model prediction deviation caused by inaccurate equivalence of complex components such as stacked structures. It is faster than the finite element method and has the advantages of high speed and high accuracy.

[0006] A method for modeling the rotor dynamics of a permanent magnet motor includes the following steps: (1) Discretize the permanent magnet motor rotor along the axial direction into multiple nodes and shaft segments located between adjacent nodes, and establish a Riccati transfer matrix model; based on the natural frequency of the free mode of the finite element model of the shaft entity, calibrate and optimize the shear correction coefficient of each shaft segment in the Riccati transfer matrix model to obtain the optimal shear correction coefficient. (2) Construct multiple discrete local finite element models for rotor core stacked components with different lamination numbers. Apply four-point bending loading boundary conditions to each discrete local finite element model and extract the total mid-span deflection of the model in the pure bending segment. Use Timoshenko beam theory to divide the total mid-span deflection into bending deformation components and shear deformation components, establish the deflection-stiffness inverse calculation relationship, and calculate the equivalent bending stiffness under the corresponding lamination number. (3) Establish the power function decay relationship of the equivalent bending stiffness with the number of laminations, and determine the equivalent elastic modulus of the rotor core stacked assembly under the actual number of laminations by fitting extrapolation; assign the equivalent elastic modulus to the shaft segment corresponding to the rotor core to characterize the stiffness strengthening effect on the shaft segment, and combine the optimal shear correction coefficient to construct a complete rotor system Riccati transfer matrix model containing the stiffness characteristics of the stacked core, and solve the modal characteristics of the rotor system.

[0007] Furthermore, in step (1), the shear correction coefficients of each shaft segment in the Riccati transfer matrix model are calibrated and optimized. Specifically, the following method is used: First, a solid finite element model of the rotating shaft is established, and modal analysis is performed under free boundary conditions to extract the natural frequencies of the free modes. As a benchmark, the shear correction coefficients of each shaft segment of the rotor are defined as the design vector variables to be optimized. x Construct an optimization objective function that minimizes the relative error between the reference frequency and the theoretically calculated frequency: in: f i ( x To optimize the objective function, ω i ( x ) to pass the matrix model to Riccati in the current variable x The calculated first shaft i First natural frequency; The above optimization objective function is solved using a multi-objective genetic algorithm to select the optimal shearing correction coefficient, and the optimized shearing correction coefficient is then introduced into the Riccati transfer matrix model.

[0008] Furthermore, the calculation method for the equivalent bending stiffness in step (2) is as follows: First, simply supported constraints are set at both ends of the discrete local finite element model, and then at the distance from each support point... a Loading points are set at each location, with an applied size of [value missing]. P A load of / 2 was applied to the discrete local finite element models of different stack numbers for each group of stacks, and the total mid-span deflection was extracted. w The four-point bending loading boundary conditions are uniformly applied to the loading method of each set of discrete local finite element models. The equivalent shear stiffness is calculated based on the shear modulus and volume fraction of each material layer in the laminated assembly. ; Utilizing equivalent shear stiffness Calculate the theoretical shear deflection at the mid-span position for each group of discrete local finite element models under four-point bending loading; extract the total mid-span deflection from the simulation. w Subtracting the theoretical shear deflection, the bending deformation component contributed solely by the bending effect is analytically separated, and the equivalent bending stiffness is obtained by inverse solution based on this. EI ) eq The calculation formula is as follows: in: P The total radial load applied to the discrete local finite element model. a The distance from the loading point to the pivot point. L denoted as the span length between the two supports of the discrete local finite element model.

[0009] Furthermore, the fitting formula for the power function decay relationship in step (3) is as follows: in:( EI ) eq ( n The number of stacked pieces is n Equivalent bending stiffness at time, λ 1 and λ 2 is the fitting coefficient. λ 1>0, λ 2 < 0.

[0010] Furthermore, in step (3), the equivalent bending stiffness of the actual rotor core stacked assembly is calculated by using the fitting formula of the power function attenuation relationship and inputting the actual number of laminations, and combined with the actual geometric cross-sectional moment of inertia of the rotor core. I real This allows the attenuation stiffness characteristics of the laminated structure to be characterized as the equivalent elastic modulus at the material property level. E eq The fitting extrapolation is used to obtain equivalent parameters based on the actual number of laminations on a limited sample basis, so that the equivalent parameters of the lamination structure can serve full-size rotor dynamics modeling.

[0011] Furthermore, in step (3), during the process of constructing the Riccati transfer matrix model of the complete rotor system, the equivalent cross-sectional moment of inertia of the rotor core nodes is calculated using the equivalent mass diameter method. I eq The specific formula is as follows: in: d eq For the equivalent outer diameter, d s The outer diameter of the shaft. m a For the quality of auxiliary components, ρ Density of the shaft material l The length of the shaft segment; The equivalent elastic modulus E eq With equivalent cross section moment of inertia I eq The product of the two is used as the bending stiffness parameter in the Riccati transfer matrix model of the complete rotor system to characterize the strengthening effect of the rotor core stacked assembly on the shaft stiffness. Then, combined with the mass and moment of inertia parameters of each component except the shaft, the complete transfer matrix of each shaft segment and the transfer matrix of the nodal rigid disk are established. The recursive relationship of the state vector of the overall rotor system is derived through Riccati transformation, the frequency characteristic equation of the rotor system is established, and the natural frequency, critical speed and mode shape of the rotor system are solved.

[0012] A computer device includes a memory and a processor, wherein the memory stores a computer program and the processor executes the computer program to implement the above-described modeling method for the rotor dynamics of a permanent magnet motor.

[0013] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described modeling method for the rotor dynamics model of a permanent magnet motor.

[0014] Based on the above technical solution, the present invention has the following beneficial technical effects: 1. This invention provides a holistic modeling method and unified modeling process for permanent magnet motor rotor systems with complex topologies. By calibrating shaft parameters and obtaining equivalent core parameters, it effectively solves the problem of difficulty in accurately characterizing the stiffness of complex multi-component assemblies and improves the reliability of the model in predicting rotor modal characteristics.

[0015] 2. This invention adopts a combination of finite element and analytical methods, simultaneously considering bending deflection and shear deflection under four-point bending boundary conditions, and reconstructs the bending stiffness parameters used for modeling by the equivalent mass diameter method, characterizing the strengthening effect of the core stacked assembly on the shaft stiffness, avoiding the problem of difficulty in calculating full-size solid contact finite element models, and has the advantages of low computational load and high accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of the modeling method for the rotor dynamics model of the permanent magnet motor of the present invention.

[0017] Figure 2 This is a schematic diagram of the rotor core stacked assembly of a permanent magnet motor. In the diagram, 1 is the silicon steel sheet stacked assembly, 2 is the permanent magnet, 3 is the shaft, and 4 is a single-layer silicon steel sheet.

[0018] Figure 3 This is a schematic diagram of four-point bending loading.

[0019] Figure 4 This is a schematic diagram of the rotor lumped mass model.

[0020] Figure 5 This is a graph showing the relationship between the equivalent bending stiffness of the laminated assembly and the number of silicon steel sheets.

[0021] Figure 6 This is a graph showing the frequency response function of the rotor system during modal testing.

[0022] Figure 7 The figures show the first-order (top) and second-order (bottom) bending mode shapes of the rotor system obtained from finite element simulation.

[0023] Figure 8 The first-order (top) and second-order (bottom) bending mode shapes of the rotor system calculated using the dynamic model established in this invention. Detailed Implementation

[0024] To describe the present invention in more detail, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown in the figure, this embodiment provides a method for modeling the rotor dynamics of a permanent magnet motor. The specific implementation steps are as follows: (1) Discretize the permanent magnet motor rotor along the axial direction into multiple nodes and shaft segments located between adjacent nodes, and establish the Riccati transfer matrix model; based on the free modal frequency of the solid finite element model of the shaft, calibrate and optimize the shear correction coefficient of each shaft segment in the Riccati transfer matrix model to obtain the optimal shear correction coefficient.

[0026] The permanent magnet motor rotor is discretized along the axial direction into individual units.N Node (rigid thin disk) and N -1 lumped mass model of a massless elastic shaft segment, the first i The state vector of each unit is: in: y For linear displacement, θ For the corner, M For bending moment, Q This refers to shear force.

[0027] Based on d'Alembert's principle and the equilibrium and deformation conditions of forces, for the first... i The rigid disk and the first i The transmission relationships of the massless elastic shaft segments are as follows: in: , These are the left and right state vectors of the disk element, respectively. For the first i The transfer matrix of each unit disk element. M , J p and J d These are the concentrated mass, polar moment of inertia, and diametrical moment of inertia of the disk, respectively. ω For the frequency of the rotor system, K j For support stiffness; for The derivative of For the first i Transfer matrix of each shaft segment unit l The length of the shaft segment element. E, I These are the equivalent elastic modulus and equivalent moment of inertia of the shaft segment, respectively; where the coefficient characterizing the effect of shear deformation is... ,in A, G These are the shear correction factor, cross-sectional area, and shear modulus of the shaft segment, respectively.

[0028] Based on the above relationships, the first i The unit and the first i The transitive relationship between +1 units is as follows: The state vector is decomposed into displacement components. Sum of forces And introduce the Riccati transform: The Riccati recursive formula is obtained by combining the results: Combining the initial and final free-free boundary conditions of the rotor system, the interval of the natural frequency zero point is determined by the final residual equation, which is written as: A solid finite element model of the rotating shaft is established; modal analysis is performed under free boundary conditions to extract the free modal frequencies of the rotating shaft. As the reference frequency, the shaft segments are grouped according to their inner and outer diameter ratios, with the same shear correction coefficient applied to segments within each group, forming a vector of variables to be optimized. The range of variables was estimated based on Cowper's empirical formula for the shear correction coefficient, and the following optimization model was established: The optimal shear correction coefficient vector is selected by solving the problem using a multi-objective genetic algorithm and then substituted back into the corresponding shaft segment shear term to obtain the calibrated Riccati transfer matrix model.

[0029] (2) Establish multiple discrete local finite element models with different lamination numbers for rotor core stacked assemblies. The assembly in the rotor system, consisting of the shaft, silicon steel laminated core, and permanent magnets, is considered as the stacked assembly. Figure 2 As shown.

[0030] A three-dimensional solid element model of the laminated assembly is established in the finite element software. The silicon steel sheets are modeled as discrete layers, and surface-to-surface contact pairs are set between the laminated layers. The contact relationships between the components of the model are set: the silicon steel sheets, end plates and rotating shafts are set as interference fit contacts, and the interference amount is set according to the actual assembly process; the silicon steel sheet layers are set as friction contacts, and the corresponding friction coefficient is set (generally 0.2). The augmented Lagrange contact algorithm is used for contact solution.

[0031] Four-point bending loading of the local model of the stacked component, as shown Figure 3 As shown, simply supported constraints are set at both ends of the model to limit radial displacement and release axial displacement and rotation. The distance from the two end supports is... a Loading points are set at symmetrical positions. The solution process is set as three load steps: applying interference to simulate the assembly state, applying axial preload, and applying a force of magnitude of [value missing] at the loading points. PA radial concentrated load of 2 / 2 was applied. Each model was solved separately under the same boundary conditions and loading procedure. After solving, the total deflection at the mid-span section of the shaft model was extracted. w .

[0032] The equivalent sectional moment of inertia of each node of the laminated assembly is determined using the equivalent mass diameter method: in: d eq For the equivalent outer diameter, d s The outer diameter of the shaft. m a For the quality of auxiliary components, ρ Density of the shaft material l This is the length of the shaft segment.

[0033] The equivalent moment of inertia of the cross section used for dynamic analysis is calculated from the equivalent outer diameter: In the calculation of the equivalent bending stiffness of laminated components, the total mid-span deflection is calculated based on Timoshenko beam theory. w Divided into bending deflection w b With shear deflection w s Two parts; based on the four-point bending simply supported beam relationship, the mid-span bending deflection is written as: Using the Reussian isostress assumption, the volume fraction weighted average of the shear modulus is applied to obtain the equivalent shear stiffness of the laminated assembly as follows: in: t This represents the number of components contained in the stacked component. V i For the volume fraction of each component, G i This refers to the shear modulus of the materials used in each component.

[0034] Combined with four-point bending loading, the left half span (0≤ x ≤ L / 2) shear force Q ( x The shear deflection at the mid-span position is obtained by the distribution: The total deflection at mid-span is written as: Establish the inverse relationship between deflection and stiffness: For multiple sets of discrete number of pieces n Calculated one by one ( EI ) eq Then, a functional relationship between the number of stacked pieces and the relationship was established and fitted using a power function: in: λ 1 and λ 2 is the fitting coefficient. λ 1>0, λ 2 < 0.

[0035] Substituting the actual number of laminated sheets into the equation yields the equivalent bending stiffness of the actual laminated assembly. The actual moment of inertia of the laminated assembly's geometric cross-section is denoted as... I real It is calculated based on the actual cross-sectional geometry of the laminated components, and then the equivalent bending stiffness is converted into the equivalent elastic modulus: (3) Assign the equivalent elastic modulus to the shaft segment corresponding to the rotor core, and compare it with the equivalent section moment of inertia. I eq The bending stiffness parameters that together constitute this shaft segment E eq I eq Substitute the optimal shear correction coefficient of the shaft obtained in step (1) back into the shear term in the shaft segment transfer matrix, and load the mass and moment of inertia of the bearing, nut and end plate into the corresponding nodes in the form of lumped parameters to complete the input of shaft segment parameters and disk parameters for the transfer matrix model of the complete rotor system; establish the transfer relationship of each unit, and solve the problem using the Riccati transfer matrix recursive formula and residual equation in combination with the actual boundary conditions of the rotor system to obtain the modal characteristic data of the complete rotor system.

[0036] In a specific embodiment, we take a 20,000 r / min high-speed built-in permanent magnet synchronous motor rotor as an example for modeling and testing. The rotor adopts an 8-pole double V-type topology, and the material parameters are shown in Table 1. The lumped mass model of the rotor system based on equivalent parameters is established as follows: Figure 4 As shown.

[0037] Table 1 In this embodiment, the comparison results of the first two natural frequencies and the first two critical speeds after calibration and optimization of the shear correction coefficients for each shaft segment are shown in Table 2; simulation and calculation are performed using the equivalent bending stiffness calculation method of this invention, and power function fitting is performed, as shown in Table 2. Figure 5 As shown. The attenuation coefficients obtained through fitting in this embodiment are respectively... λ 1 = 1.43×10 6 , λ 2 =- 0.298, goodness of fit R 2 The value is 0.992. The equivalent bending stiffness under the actual number of laminations is calculated using this fitting formula. Combined with the equivalent section moment of inertia calculated by the equivalent mass diameter method, the equivalent elastic modulus of the core segment used for modeling is determined. The above parameters are introduced into the Riccati transfer matrix to construct a complete rotor system dynamic model and calculate the rotor's natural frequency and mode shape.

[0038] Table 2 The calculated values ​​of the model in the embodiment of the present invention are compared with the measured values ​​of the modal test (e.g., Figure 6 A comparison was made (as shown in the figure), and the results are shown in Table 3. It can be seen that the first and second order bending modes are consistent with the results of the finite element simulation. Figure 7 and Figure 8 As shown, this demonstrates that the equivalent modeling method proposed in this invention has good prediction accuracy.

[0039] Table 3 The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be made to the above embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure thereof should be within the scope of protection of the present invention.

Claims

1. A method for modeling the rotor dynamics of a permanent magnet motor, characterized in that, Includes the following steps: (1) Discretize the permanent magnet motor rotor along the axial direction into multiple nodes and shaft segments located between adjacent nodes, and establish a Riccati transfer matrix model; based on the natural frequency of the free mode of the finite element model of the shaft entity, calibrate and optimize the shear correction coefficient of each shaft segment in the Riccati transfer matrix model to obtain the optimal shear correction coefficient. (2) Construct multiple discrete local finite element models for rotor core stacked components with different lamination numbers, apply four-point bending loading boundary conditions to each discrete local finite element model, and extract the total mid-span deflection of the model in the pure bending segment; use Timoshenko beam theory to divide the total mid-span deflection into bending deformation component and shear deformation component, establish deflection-stiffness inverse calculation relationship, and calculate the equivalent bending stiffness under the corresponding lamination number. (3) Establish the power function decay relationship of the equivalent bending stiffness with the number of laminations, and determine the equivalent elastic modulus of the rotor core stacked assembly under the actual number of laminations by fitting extrapolation; assign the equivalent elastic modulus to the shaft segment corresponding to the rotor core to characterize the stiffness strengthening effect on the shaft segment, and combine the optimal shear correction coefficient to construct a complete rotor system Riccati transfer matrix model containing the stiffness characteristics of the stacked core, and solve the modal characteristics of the rotor system.

2. The modeling method for the rotor dynamics of a permanent magnet motor according to claim 1, characterized in that: In step (1), the shear correction coefficients of each shaft segment in the Riccati transfer matrix model are calibrated and optimized. The specific implementation method is as follows: First, a solid finite element model of the rotating shaft is established, and modal analysis is performed under free boundary conditions to extract the natural frequencies of the free modes. As a benchmark, the shear correction coefficients of each shaft segment of the rotor are defined as the design vector variables to be optimized. x Construct an optimization objective function that minimizes the relative error between the reference frequency and the theoretically calculated frequency: in: f i ( x To optimize the objective function, ω i ( x ) to pass the matrix model to Riccati in the current variable x The calculated first shaft i First natural frequency; The above optimization objective function is solved using a multi-objective genetic algorithm to select the optimal shearing correction coefficient, and the optimized shearing correction coefficient is then introduced into the Riccati transfer matrix model.

3. The modeling method for the rotor dynamics of a permanent magnet motor according to claim 1, characterized in that, The calculation method for the equivalent bending stiffness in step (2) is as follows: First, simply supported constraints are set at both ends of the discrete local finite element model, and then at the distance from each support point... a Loading points are set at each location, with an applied size of [value missing]. P A load of / 2 was applied to the discrete local finite element models of different stack numbers for each group of stacks, and the total mid-span deflection was extracted. w The four-point bending loading boundary conditions are uniformly applied to the loading method of each set of discrete local finite element models. The equivalent shear stiffness is calculated based on the shear modulus and volume fraction of each material layer in the laminated assembly. ; Utilizing equivalent shear stiffness Calculate the theoretical shear deflection at the mid-span position for each discrete local finite element model under four-point bending loading; extract the total mid-span deflection from the simulation. w Subtracting the theoretical shear deflection, the bending deformation component contributed solely by the bending effect is analytically separated, and the equivalent bending stiffness is obtained by inverse solution based on this. EI ) eq The calculation formula is as follows: in: P The total radial load applied to the discrete local finite element model. a The distance from the loading point to the pivot point. L denoted as the span length between the two supports of the discrete local finite element model.

4. The modeling method for the rotor dynamics of a permanent magnet motor according to claim 1, characterized in that, The fitting formula for the power function decay relationship in step (3) is as follows: in:( EI ) eq ( n The number of stacked pieces is n Equivalent bending stiffness at time, λ 1 and λ 2 is the fitting coefficient. λ 1>0, λ 2 < 0.

5. The modeling method for the rotor dynamics of a permanent magnet motor according to claim 4, characterized in that: In step (3), the equivalent bending stiffness of the actual rotor core stacked assembly is calculated by using the fitting formula of the power function attenuation relationship and inputting the actual number of laminations, and combined with the actual geometric cross-section moment of inertia of the rotor core. I real This allows the attenuation stiffness characteristics of the laminated structure to be characterized as the equivalent elastic modulus at the material property level. E eq ; The fitting extrapolation is used to obtain equivalent parameters based on the actual number of laminations on a limited sample basis, so that the equivalent parameters of the lamination structure can serve full-size rotor dynamics modeling.

6. The modeling method for the rotor dynamics of a permanent magnet motor according to claim 1, characterized in that: In step (3), during the construction of the Riccati transfer matrix model of the complete rotor system, the equivalent mass diameter method is used to calculate the equivalent cross-sectional moment of inertia of the rotor core nodes. I eq The specific formula is as follows: in: d eq For the equivalent outer diameter, d s The outer diameter of the shaft. m a For the quality of auxiliary components, ρ The density of the shaft material, l This refers to the length of the shaft segment; The equivalent elastic modulus E eq With equivalent cross section moment of inertia I eq The product of the two is used as the bending stiffness parameter in the Riccati transfer matrix model of the complete rotor system to characterize the strengthening effect of the rotor core stacked assembly on the shaft stiffness. Then, combined with the mass and moment of inertia parameters of each component except the shaft, the complete transfer matrix of each shaft segment and the transfer matrix of the nodal rigid disk are established. The recursive relationship of the state vector of the overall rotor system is derived through Riccati transformation, the frequency characteristic equation of the rotor system is established, and the natural frequency, critical speed and mode shape of the rotor system are solved.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: The processor is used to execute the computer program to implement the modeling method for the rotor dynamics model of the permanent magnet motor as described in any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, it implements the modeling method for the rotor dynamics model of the permanent magnet motor as described in any one of claims 1 to 6.

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