CN-121996900-A - Permanent magnet synchronous motor statistical energy analysis and noise prediction method based on stator orthotropic

CN121996900ACN 121996900 ACN121996900 ACN 121996900ACN-121996900-A

Abstract

The invention belongs to the technical field of motor noise prediction, and particularly provides a stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method. The method comprises the steps of dividing a subsystem of a motor structure, taking the orthotropic characteristics of a stator and a winding into consideration, establishing an anisotropic cylindrical shell model, deducing an analytical expression of coupling loss factors among the subsystems based on a first-order shear deformation theory, taking electromagnetic force as input power, constructing a statistical energy analysis model by combining internal loss factors, solving and obtaining average vibration energy of each subsystem, calculating radiated sound power and sound pressure level by combining an acoustic radiation efficiency model, and realizing quick and accurate prediction of medium-high frequency vibration noise of the motor under constant rotating speed and variable speed working conditions. The invention can realize the effective prediction of the high-frequency noise of the motor in the design stage, and solves the problems that the traditional numerical method has large calculated amount and the analytic method is not suitable for the high-frequency statistical characteristic.

Inventors

DENG WENZHE
JIANG YUJIE
WANG QUNJING
WU LIJIAN
QIAN ZHE
CHEN QIXU
DIAO KAIKAI
SUN ZEHUI

Assignees

安徽大学

Dates

Publication Date: 20260508
Application Date: 20260128

Claims (10)

1. The method for analyzing the statistical energy and predicting the noise of the permanent magnet synchronous motor based on the orthotropic stator is characterized by comprising the following steps: Dividing subsystems based on structural characteristics of a permanent magnet synchronous motor to obtain a plurality of structural subsystems, wherein the structural subsystems comprise a first subsystem formed by combining a stator yoke and a shell, a second subsystem formed by combining stator teeth, and a third subsystem and a fourth subsystem which are respectively provided with shells at two ends; constructing a coupling loss factor matrix for representing vibration energy transfer among subsystems based on the subsystem division; acquiring electromagnetic force of the motor under a specific working condition, and calculating and inputting excitation power to a corresponding subsystem based on a surface mobility functional relation between the electromagnetic force and a stator structure; the excitation power and the coupling loss factor matrix are combined with preset internal loss factors of all subsystems to jointly establish a statistical energy analysis energy balance equation of the permanent magnet synchronous motor; solving the energy balance equation to obtain the average vibration energy of each subsystem in time and space; And calculating the total radiated sound power and sound pressure level of the motor based on the average vibration energy in combination with a sound radiation efficiency model of the corresponding subsystem so as to predict high-frequency vibration noise.
2. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the constructing a coupling loss factor matrix for representing vibration energy transfer between subsystems specifically comprises: equivalent at least one structural subsystem to an orthotropic cylindrical shell model; Based on a first-order shear deformation theory and an orthotropic constitutive relation, establishing a vibration differential equation of the cylindrical shell model; solving the vibration differential equation to obtain a dispersion curve representing wave propagation characteristics; based on the dispersion curve, a coupling loss factor between subsystems is calculated.
3. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 2, wherein the calculation of the coupling loss factor between subsystems is achieved by the following formula: ; Wherein, the In order to couple the loss factor(s), For the group velocity to be the velocity of the group, In order to be of an angular frequency, For the area of the subsystem i, Is the energy transfer coefficient.
4. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 3, wherein the energy transfer coefficient Based on the geometric connection structure between subsystems, the following steps are determined: For a "T" like connection between the stator teeth and the stator yoke, the energy transfer coefficient is constant; For a wire connection between collinear housing components contacted by a ring, the energy transfer coefficient is calculated by: ; Wherein, the Respectively subsystem And Is used for the density of the (c) in the (c), Respectively subsystem And Is a longitudinal wave velocity of (c).
5. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the calculating the excitation power based on the surface mobility function relation between the electromagnetic force and the stator structure specifically comprises: for the stator structure of the permanent magnet synchronous motor, based on the high-frequency vibration response characteristic under the excitation of radial electromagnetic force, establishing an equivalent surface mobility function of the stator structure, wherein the real part of the equivalent surface mobility is Approximated according to the following equation: ; Wherein, the For the total mass of the stator, Is the excitation angular frequency; Acquiring a total radial electromagnetic force spectrum F of the motor under a target working condition, and taking the total radial electromagnetic force spectrum F as excitation force input; combining the total radial electromagnetic force spectrum F with the real part of the equivalent surface mobility Substituting the power input model shown in the following formula, and calculating to obtain the excitation power P2 input to the second subsystem: 。
6. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the statistical energy analysis energy balance equation is expressed in a matrix form, and the average vibration energy vector E of each subsystem is solved by the following formula: ; wherein P is the input power vector, As a loss factor matrix, the loss factor matrix Diagonal elements of (a) Off-diagonal elements , Is the internal loss factor of each subsystem.
7. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the calculating the total radiated sound power of the motor based on the average vibration energy in combination with a sound radiation efficiency model of a corresponding subsystem specifically comprises: determining the average acoustic radiation efficiency of each of said structural subsystems separately ; Average vibration energy based on subsystems Subsystem quality According to Calculate the average vibration velocity ; Calculating the total radiated sound power of the motor according to : ; Wherein, the In order to achieve an air density of the air, Is the speed of sound, Is subsystem Is provided for the radiation surface area of the substrate.
8. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 7, wherein the determining of the average acoustic radiation efficiency of each of the structural subsystems The method specifically comprises the following steps: for a subsystem equivalent to a flat plate structure, the acoustic radiation efficiency is based on the area And the wavelength of sound wave Determining; for a subsystem equivalent to a cylindrical shell structure, the acoustic radiation efficiency is calculated by the following formula And carrying out modal averaging to obtain: ; Wherein, the As the number of circumferential modes, Is the number of sound waves, and the number of sound waves, Is the radius of the cylindrical shell, and the diameter of the cylindrical shell is the same as the radius of the cylindrical shell, And Respectively of a first type and a second type Order Bessel function.
9. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the internal loss factors of the respective subsystems are preset From friction loss factor in structural material Damping loss factor of acoustic radiation And boundary connection damping loss factor The constitution, it satisfies the relation: in predicting the middle-high frequency vibration noise, the friction loss factor in the structural material is used Is the basis for value taking.
10. The stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method according to claim 1, wherein the method is applied in a motor design stage and is used for predicting medium-high frequency electromagnetic vibration noise of a permanent magnet synchronous motor for a vehicle under a constant rotation speed or variable speed working condition.

Description

Permanent magnet synchronous motor statistical energy analysis and noise prediction method based on stator orthotropic Technical Field The invention belongs to the technical field of machine life prediction, and particularly relates to a stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method. Background The Permanent Magnet Synchronous Motor (PMSM) has the advantages of simple structure, reliable operation, low manufacturing cost, good regulation performance and the like, and is widely applied to the fields of new energy automobiles and the like, however, the noise problem, particularly the electromagnetic noise problem, limits the application of the PMSM. When the permanent magnet synchronous motor is designed, vibration noise is a key for designing a low-noise motor, so that research on the vibration noise prediction of the motor has important theoretical significance and great practical value. The numerical method is mainly based on finite element and boundary methods, and electromagnetic noise of the motor under different working conditions is simulated and predicted. The analysis method is based on a plate-shell theory or an energy method, and numerical prediction of modal and electromagnetic vibration noise is performed on the basis of moderately simplifying a stator model. The prior art has the following problems 1. Because the motor is driven by SVPWM, the high-frequency noise prediction around the switching frequency is limited by computational resources, and the numerical method is difficult to be qualified. 2. The analysis rule is insufficient in structural uncertainty and statistic characteristic adaptability of a high-frequency dense mode because complex geometric structures are difficult to process. 3. The method is limited by the fact that the loss factors of the complicated irregular structure and the design stage of the motor are unknown, and the high-frequency vibration noise prediction is difficult to realize efficiently by the existing method. In addition, the existing SEA method ignores the anisotropic material properties of the stator. Disclosure of Invention The invention aims to provide a stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method to solve the problem of how to efficiently and accurately predict electromagnetic vibration noise of a Permanent Magnet Synchronous Motor (PMSM) for a vehicle in a middle-high frequency band (especially near a switching frequency) in a motor design stage without relying on a prototype experiment. The invention realizes the above purpose through the following technical scheme: the invention provides a stator orthotropic permanent magnet synchronous motor statistical energy analysis and noise prediction method, which comprises the following steps: Dividing subsystems based on structural characteristics of a permanent magnet synchronous motor to obtain a plurality of structural subsystems, wherein the structural subsystems comprise a first subsystem formed by combining a stator yoke and a shell, a second subsystem formed by combining stator teeth, and a third subsystem and a fourth subsystem which are respectively provided with shells at two ends; constructing a coupling loss factor matrix for representing vibration energy transfer among subsystems based on the subsystem division; acquiring electromagnetic force of the motor under a specific working condition, and calculating and inputting excitation power to a corresponding subsystem based on a surface mobility functional relation between the electromagnetic force and a stator structure; the excitation power and the coupling loss factor matrix are combined with preset internal loss factors of all subsystems to jointly establish a statistical energy analysis energy balance equation of the permanent magnet synchronous motor; solving the energy balance equation to obtain the average vibration energy of each subsystem in time and space; And calculating the total radiated sound power and sound pressure level of the motor based on the average vibration energy in combination with a sound radiation efficiency model of the corresponding subsystem so as to predict high-frequency vibration noise. Preferably, the constructing a coupling loss factor matrix for representing vibration energy transfer among subsystems specifically comprises: equivalent at least one structural subsystem to an orthotropic cylindrical shell model; Based on a first-order shear deformation theory and an orthotropic constitutive relation, establishing a vibration differential equation of the cylindrical shell model; solving the vibration differential equation to obtain a dispersion curve representing wave propagation characteristics; based on the dispersion curve, a coupling loss factor between subsystems is calculated. As a preferred scheme, the coupling loss factor between the computing subsystems is realized by the following