Surface-mounted permanent magnet motor pole optimization design method

Abstract

The application discloses a surface-mounted permanent magnet motor magnetic pole optimization design method, and steps are finite element preliminary scanning calculation of permanent magnet magnetic pole design variables, determination of design variable refinement range based on target variables, finite element refinement scanning calculation of permanent magnet magnetic pole design variables and determination of final optimization scheme based on target variables; the design method scans and calculates the design variables twice and screens the scheme manually, thus improving design capability and calculation efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromagnetic design of electric machines, and particularly relates to a surface-mounted permanent magnet motor magnetic pole optimization design method. BACKGROUND

[0002] Permanent magnet motors have various structural forms, and the surface-mounted rotor structure has the advantages of simple structure, small leakage magnetic flux and small armature reaction, and has become one of the typical structures of permanent magnet motors.

[0003] With the continuous development of permanent magnet motor technology, higher requirements are put forward for the performance thereof, and it is necessary to design the magnetic pole of the surface-mounted permanent magnet motor according to the structural characteristics thereof, pay attention to the key parameters such as electromagnetic torque, torque ripple and air gap magnetic flux of the motor which affect the performance of the permanent magnet motor, and meet the needs of high performance. SUMMARY

[0004] The application provides a surface-mounted permanent magnet motor magnetic pole optimization design method, which aims to weaken the vibration caused by the tangential electromagnetic force of the motor, reduce the torque fluctuation caused by the stator slotting and armature reaction, and thus reduce the tangential electromagnetic vibration of the motor and improve the operating performance of the permanent magnet motor.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the application to solve the technical problems is as follows: a surface-mounted permanent magnet motor magnetic pole optimization design method, comprising the following steps:

[0006] S1, finite element preliminary scanning calculation of permanent magnet pole design variables:

[0007] S1.1, finite element-based parameterized modeling of a permanent magnet motor: taking the magnetic pole arc coefficient, the magnetic pole eccentricity and the permanent magnet thickness in the form of parameters as the permanent magnet pole design variables, the permanent magnet motor stator-rotor geometric model is parameterized modeled;

[0008] S1.2, within the range of geometric dimensions, the optimization interval of the design variables is determined, that is, the maximum value and the minimum value of the permanent magnet pole design variables which meet the geometric dimension requirements, which should ensure that the permanent magnet motor magnetic pole model does not have problems such as intersection and out-of-bounds; the maximum value and the minimum value of the permanent magnet pole design variables should be brought into the permanent magnet motor stator-rotor geometric model for checking to ensure the correctness of the geometric model;

[0009] S1.3, parameterized scanning calculation for permanent magnet pole design variables: the range of permanent magnet pole design variables determined in S1.2 is scanned and calculated according to equal intervals by using transient electromagnetic field and static electromagnetic field respectively, so as to obtain the corresponding target variables, i.e. the values of electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap magnetic density, in order to improve the calculation efficiency, the design variables are designed to have a relatively wide interval range according to design experience;

[0010] S2, determining the refinement range of design variables based on target variables: a comparison table of design variables and target variables is established, and the designer preliminarily determines the refinement range of design variables according to the size of electromagnetic torque, the size of electromagnetic torque pulsation rate, the requirement of power factor, and the size of no-load air gap magnetic density.

[0011] S3, finite element refinement scanning calculation of permanent magnet pole design variables: according to the refinement range of design variables determined in S2, the pole arc coefficient, pole eccentricity and permanent magnet thickness of permanent magnet pole design variables are scanned and calculated according to equal intervals by using transient electromagnetic field and static electromagnetic field again, so as to obtain the corresponding target variables, i.e. the values of electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap magnetic density.

[0012] S4, determining the final optimization scheme based on target variables: according to the finite element refinement scanning calculation results of permanent magnet pole design variables, a comparison table of design variables and target variables is established, and the designer selects the final optimization scheme based on the principle that the electromagnetic torque, no-load air gap magnetic density, electromagnetic torque pulsation rate and power factor meet the design requirement range while taking into account the need for reasonable permanent magnet motor structure design.

[0013] The permanent magnet motor pole optimization design method mainly uses maxwell, ansysEM, magnet and other software to perform parameterized modeling on the permanent magnet motor.

[0014] The permanent magnet motor pole optimization design method, the comparison table of design variables and target variables involved in steps S2 and S4 is realized by using python, Matlab and other software programming to load and establish data, and the scheme range is clear by using a scroll bar to view the scheme.

[0015] The permanent magnet motor pole optimization design method, the comparison table is a comparison table of electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap magnetic density.

[0016] The beneficial effects of the present application are: the method designed by the present application scans and calculates the design variables twice and screens the schemes by artificial selection, on the one hand, the designer can understand the change trend of the target variable in the optimization process of the design variable, and then master the relationship and rules between the change of the design variable and the target variable, so as to accumulate design experience and improve design ability for the technical personnel; on the other hand, wide range scanning calculation can quickly grasp the approximate range of the design variable, so that the design process is not blind, and the small range of scanning calculation can quickly and accurately locate the value of the design variable, the whole process effectively improves the calculation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The flow chart of the optimization design method of the present application;

[0018] Figure 2 The optimization result list of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Referring to Figure 1 The surface-mounted permanent magnet motor pole optimization design method disclosed by the present application mainly includes four steps of S1, S2, S3 and S4.

[0021] The step S1 is specifically as follows.

[0022] S1.1, finite element parameterized modeling of permanent magnet motor: taking the pole arc coefficient, pole eccentricity and permanent magnet thickness in the form of parameters as the permanent magnet pole design variable, the permanent magnet motor stator and rotor geometric model is parameterized modeled.

[0023] S1.2, within the range of geometric dimensions, determine the optimization interval of the design variable, i.e. the maximum and minimum values of the permanent magnet pole design variable that meet the geometric size requirements, which should ensure that there is no cross, out-of-boundary, etc. problem in the permanent magnet motor pole model, the maximum and minimum values of the permanent magnet pole design variable need to be brought into the permanent magnet motor stator-rotor geometric model to check the correctness of the geometric model; if the model has no cross, no out-of-boundary, etc. situation, the maximum and minimum values are appropriate, otherwise the maximum and minimum values need to be redefined.

[0024] S1.3, parameterized scanning calculation of permanent magnet pole design variables: respectively using transient electromagnetic field and static electromagnetic field, the permanent magnet pole design variables are scanned and calculated according to equal interval, so as to obtain the corresponding target variables, i.e. electromagnetic torque, electromagnetic torque ripple, power factor and no-load air gap flux density. In order to improve the calculation efficiency, the design variable is taken in a relatively wide interval range according to the design experience.

[0025] The finite element preliminary scanning calculation of permanent magnet pole design variables mainly uses maxwell, ansysEM, magnet and other software to parameterize the modeling of permanent magnet motor, sets the maximum, minimum range and calculation interval of the design variables (pole arc coefficient, pole eccentricity and permanent magnet thickness), and respectively uses transient finite element and static finite element to complete the calculation of load electromagnetic torque, load electromagnetic torque ripple, power factor and no-load air gap flux density.

[0026] S2, according to the results of the finite element preliminary scanning calculation of permanent magnet pole design variables, a comparison table of design variables and target variables is established, and the designer preliminarily determines the range of design variables according to the size of target variables, i.e. electromagnetic torque, electromagnetic torque ripple, power factor and no-load air gap flux density.

[0027] S3, finite element refined scanning calculation of permanent magnet pole design variables: according to the refined range of design variables, the pole arc coefficient, pole eccentricity and permanent magnet thickness of permanent magnet pole design variables are again scanned and calculated according to equal interval, so as to obtain the values of the corresponding target variables, i.e. electromagnetic torque, electromagnetic torque ripple, power factor and no-load air gap flux density.

[0028] Step S3 is to refine the parameterized scanning calculation of the design variables according to the range of the design variables in step S2, so as to obtain the corresponding target variables, i.e. electromagnetic torque, electromagnetic torque ripple, power factor and no-load air gap flux density.

[0029] The steps S1 and S3 can be realized by using Maxwell, AnsysEM and Magnet finite element software.

[0030] S4, determining the final optimization scheme based on the target variable: according to the finite element refinement scanning calculation results of the permanent magnet pole design variable, a comparison table of the design variable and the target variable is established, that is, a comparison table of the electromagnetic torque, the electromagnetic torque ripple, the power factor and the no-load air gap magnetic flux density, and the designer selects the final optimization scheme based on the principle that the electromagnetic torque, the no-load air gap magnetic flux density, the electromagnetic torque ripple and the power factor meet the design requirement range while taking into account the need for reasonable permanent magnet motor structure design.

[0031] The comparison table of the design variable and the target variable involved in steps S2 and S4 is established by using software such as python or Matlab after data loading, and the scheme range is determined by viewing the scheme through a scroll bar. The determination of the design variable refinement range based on the target variable is mainly aimed at the finite element preliminary scanning calculation results of the permanent magnet pole design variable, and the calculation results are loaded into software such as python and matlab to form an optimization result list as shown in Figure 2 The designer determines the permanent magnet pole design variable refinement range by comparison. The designer determines the final optimization scheme according to the target value of the target variable (load electromagnetic torque, load electromagnetic torque ripple, power factor and no-load air gap magnetic flux density) and the feasibility of the structure design.

[0032] The above examples only exemplarily illustrate the principles and effects of the present application, and part of the applied examples, and those skilled in the art can make several modifications and improvements without departing from the concept of the present application, which all belong to the protection scope of the present application.

Claims

1. A method for optimizing the design of magnetic poles of a surface-mounted permanent magnet motor, characterized in that: Includes the following steps S1, preliminary finite element scanning calculation of permanent magnet pole design variables: first, the pole arc coefficient, pole eccentricity and permanent magnet thickness, which exist in the form of parameters, are used as permanent magnet pole design variables to perform parameterized modeling of the permanent magnet motor stator and rotor geometric model; Secondly, the maximum and minimum values ​​of the permanent magnet pole design variables that meet the geometric size requirements are determined, and the maximum and minimum values ​​of the permanent magnet pole design variables are brought into the permanent magnet motor stator and rotor geometric model to check and ensure the model is correct; Then, based on the transient electromagnetic field and the static electromagnetic field, the permanent magnet pole design variables are scanned and calculated at equal intervals to obtain the corresponding electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap flux density. S2, determine the refinement range of design variables based on target variables: establish a comparison table of design variables and target variables, and preliminarily determine the refinement range of design variables based on the requirements of target variables; S3, finite element refinement scanning calculation of permanent magnet pole design variables: again using transient electromagnetic fields and static electromagnetic fields, within the range of the permanent magnet pole design variables determined in S2, including the pole arc coefficient, pole eccentricity, and permanent magnet thickness, refinement scanning calculations are performed at equal intervals to obtain the corresponding electromagnetic torque, electromagnetic torque ripple rate, power factor, and no-load air gap flux density. S4, determine the final optimization scheme based on the target variables: According to the finite element refinement scanning calculation results of the permanent magnet pole design variables, establish a comparison table of design variables and target variables, and select the final optimization scheme based on the design requirements of electromagnetic torque, no-load air gap flux density, electromagnetic torque pulsation rate, and power factor.

2. The method for optimizing the magnetic pole design of a surface-mounted permanent magnet motor according to claim 1, wherein: The parametric modeling is completed in Maxwell, AnsysEM or Magnet software, and the calculation of load electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap magnetic flux density is completed using transient finite element and static finite element respectively.

3. The method for optimizing the magnetic pole design of a surface-mounted permanent magnet motor according to claim 2, wherein: The comparison table of the design variables and the target variables is established by using Python or Matlab software to load data.

4. The method for optimizing the magnetic pole design of a surface-mounted permanent magnet motor according to claim 3, wherein: The comparison table is a comparison table of electromagnetic torque, electromagnetic torque pulsation rate, power factor and no-load air gap magnetic flux density.

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