Method for determining magnetic property parameters of annular permanent magnet based on molecular current theory, and electronic equipment

Abstract

The present invention belongs to the technical field of magnetic property testing and numerical calculation, and particularly relates to a method for determining magnetic property parameters of a toroidal permanent magnet steel based on the molecular current theory and an electronic device, including: measuring the actual size data of the toroidal permanent magnet steel; measuring the magnetic field distribution f 实测 (z) at the central axis of the toroidal permanent magnet steel; determining the surface magnetization current density value K 实测 ; establishing a finite element model of the permanent magnet steel; extracting the magnetic field distribution f 仿真 (z) of the central axis of the magnet steel; determining the surface magnetization current density value K 仿真 ; comparing K 仿真 with K 实测 for differences, and adjusting the magnetic property parameters of the material in the finite element model of the magnet steel. The present invention comprehensively applies the molecular current theory and the finite element method to solve the problem of determining the magnetic property parameters of the toroidal magnet steel, reduces the difficulty of in-hospital acceptance of the magnet steel performance and evaluation of the attenuation degree after long-term operation, helps to improve the detection efficiency, economy and operation reliability of the magnet steel, and has important significance for the magnetic property research of the toroidal magnet steel.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic property testing and numerical calculation, and in particular relates to a method for determining magnetic property parameters of annular permanent magnet steel based on molecular current theory and electronic equipment. Background Art

[0002] Active magnetic bearings are an electromechanical system that uses electromagnetic force to achieve rotor suspension. This type of magnetic bearing can be divided into two categories: pure electrically excited magnetic bearings and permanent magnetic biased magnetic bearings. Permanent magnetic biased magnetic bearings use permanent magnets to generate a bias magnetic field, while electromagnets redistribute the magnetic field to provide the required combined force. Due to its advantages such as non-contact, low loss, controllable stiffness and damping, permanent magnetic biased magnetic bearings have broad application prospects in the fields of new energy power, aerospace, nuclear industry and military support.

[0003] During the design and operation of magnetic bearings, some structures of electromagnetic magnetic circuits pass through annular magnets, which are repeatedly charged and demagnetized. The magnetic performance parameters of annular magnets change during long-term operation. Accurately measuring the magnetic performance parameters of magnets is of great research significance for reducing operating risks and improving the reliability of magnetic bearings. In addition, after the annular magnets are magnetized, the production inspection department also urgently needs a test method to verify the magnetization effect and evaluate the degree of magnetization.

[0004] After searching, the patent application document of Chinese patent application No. 201310607163.1 discloses a method for testing the magnetic properties of tile-shaped ferrite. This method uses a serpentine scanning trajectory corresponding to the inner arc surface of the tile-shaped magnet to draw the magnetic intensity distribution curves of the ferrite in the arc length direction and the axial direction respectively, so as to determine the magnetic distribution and material uniformity of the whole tile-shaped ferrite. Although this method can give the surface magnetic distribution and magnetic field uniformity of the magnet, due to the lack of a numerical relationship between the surface magnetic distribution and the magnetic properties of the magnet, this method is actually unable to give the magnetic property parameters of the ferrite material. In addition, during the test process, the evaluation results of the magnetic field uniformity will also be significantly affected by factors such as scanning position accuracy and measurement accuracy. The patent application document of Chinese patent application No. 201410406412.5 discloses a non-destructive test method and device for the average magnetic field strength of a permanent magnet. The device and method obtain the average magnetic field strength of the permanent magnet according to the relationship between the magnetic field strength and the induced current by collecting the current value of the induction coil. The average magnetic field strength determined by this method is related to the shape and size of the induction coil, and cannot quantitatively give the magnetic performance parameters of the permanent magnet material. It is more suitable for characterizing the time stability and temperature stability of the permanent magnet within a certain spatial range. At present, the characterization method of the magnetic performance parameters of magnetic steel still has certain limitations and needs further research. Summary of the invention

[0005] In order to solve the above problems in the prior art, the present invention provides a method for determining magnetic property parameters of annular permanent magnet steel based on molecular current theory.

[0006] The technical solution adopted by the present invention to solve this problem is:

[0007] The method for determining the magnetic performance parameters of annular permanent magnet steel based on molecular current theory comprises the following steps:

[0008] Step 1, measuring the outer dimensions of the annular permanent magnetic steel to obtain the measured dimension data of the annular permanent magnetic steel;

[0009] Step 2: Measure the magnetic field distribution f of the annular permanent magnet at the central axis 实测 (z);

[0010] Step 3: Distribute the magnetic field of the annular permanent magnet steel 实测 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K 实测 ;

[0011] Step 4, establishing a finite element model of the permanent magnetic steel according to the measured size data of the annular permanent magnetic steel;

[0012] Step 5: Input the estimated performance parameters of the annular magnetic steel material, complete the finite element simulation of the magnetic field in the magnetic steel space, and extract the magnetic field distribution f of the central axis of the magnetic steel. 仿真 (z);

[0013] Step 6: Distribute the magnetic field of the magnetic steel 仿真 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K 仿真 ;

[0014] Step 7, compare K 仿真 With K 实测 By adjusting the magnetic parameters of the material in the magnetic steel finite element model, repeat steps 4-6 until K 仿真 With K 实测 Equivalently, the input parameters of the material in the finite element model are the magnetic properties parameters of the annular permanent magnet steel.

[0015] In the above technical solution, the magnetization direction of the annular permanent magnet steel is axial.

[0016] In the above technical solution, the measured dimensional data of the annular permanent magnet steel in step 1 includes the outer diameter, inner diameter and height of the annular permanent magnet steel.

[0017] In the above technical solution, the magnetic field distribution f of the annular permanent magnet steel in step 2 is 实测(z) includes axial magnetic induction intensity B 实测 (z) or axial magnetic field strength H 实测 (z).

[0018] In the above technical solution, the analytical expression based on molecular current theory in step 3 is:

[0019]

[0020] Where: When the magnetic field distribution f(z) is the axial magnetic induction intensity B(z), m is equal to μ 0 , when the magnetic field distribution f(z) is the axial magnetic field intensity H(z), m is equal to 1 / μ r , μ 0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability, K is the surface magnetizing current density value, z is the axial distance from the measured position to the magnetic steel surface, h is the height of the magnetic steel, a is the outer diameter of the magnetic steel, and b is the inner diameter of the magnetic steel.

[0021] In the above technical solution, the magnetic field distribution f of the magnetic steel in step 5 is 仿真 (z) includes axial magnetic induction intensity B 仿真 (z) or axial magnetic field strength H 仿真 (z).

[0022] In the above technical solution, the magnetic field distribution f of the annular permanent magnet steel at the central axis is 实测 (z) The test position origin and the calculated value of the magnetic field distribution f 仿真 The extraction position origin of (z) is the same and is located at the center of the upper or lower surface of the annular magnetic steel.

[0023] In the above technical solution, the magnetic field distribution f of the annular permanent magnet steel at the central axis is 实测 The number of test positions for (z) is not less than 4, and the calculated value of magnetic field distribution f 仿真 The number of extraction positions of (z) is not less than 4.

[0024] In the above technical solution, the magnetic performance parameters of the permanent magnet steel include relative magnetic permeability and magnetic coercivity.

[0025] In the above technical solution, the method for optimizing the material magnetic property parameters in the magnetic steel finite element model is an annealing algorithm, a genetic algorithm, a neural network algorithm or a combination of several of them.

[0026] The second inventive object of the present invention is to provide an electronic device, comprising: at least one processor, at least one memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the method for determining the magnetic properties parameters of annular permanent magnet steel based on molecular current theory is implemented.

[0027] The advantages and positive effects of the present invention are:

[0028] 1. The present invention comprehensively applies molecular current theory and finite element method to solve the problem of determining the magnetic performance parameters of annular magnetic steel, reduces the difficulty of hospital acceptance of magnetic steel performance and evaluation of attenuation degree after long-term operation, helps to improve the detection efficiency, economy and operation reliability of magnetic steel, and has important engineering significance for the research and numerical calculation of the magnetic properties of annular magnetic steel.

[0029] 2. The present invention fits the measured magnetic field results by using an analytical formula for the magnetic field distribution on the central axis of the annular permanent magnet based on the molecular current theory, thereby effectively reducing the influence of the test position accuracy and measurement accuracy on the accuracy of the magnetic field distribution on the central axis of the magnet.

[0030] 3. The present invention uses the finite element method to complete the spatial magnetic field simulation of the annular magnetic steel under certain size and specified performance parameters, and gives the magnetic field simulation distribution at the specified position, providing a comparative basis for determining the magnetic performance parameters of the magnetic steel.

[0031] 4. The present invention takes the surface magnetization current density value as the optimization target, further reducing the influence of the test position accuracy and measurement accuracy on the determination results of the magnetic properties of the annular magnetic steel, and improving the accuracy of the magnetic property parameter results.

[0032] 5. In the present invention, the magnetic steel performance parameters are determined by surface magnetism measurement method, thus avoiding the influence of repeated charging and demagnetization process on the magnetic steel performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0034] Figure 1 is a flow chart of the method of the present invention;

[0035] Figure 2 is the axial magnetic induction intensity B of the ferrite magnet at the center axis in Application Example 1 of the present invention 实测 (z) distribution;

[0036] Figure 3is the finite element model of the ferrite magnetic steel in Application Example 1 of the present invention;

[0037] Figure 4 The axial magnetic induction intensity distribution B of the ferrite magnet at the central axis in Application Example 1 of the present invention is 仿真 (z) and B 实测 (z) comparison;

[0038] Figure 5 The axial magnetic field intensity H of the NdFeB magnet at the center axis in Application Example 2 of the present invention is 实测 (z) distribution;

[0039] Figure 6 is the finite element model of the NdFeB magnet in Application Example 2 of the present invention;

[0040] Figure 7 The axial magnetic field intensity distribution H of the NdFeB magnet at the central axis in Application Example 2 of the present invention is 仿真 (z) and H 实测 (z) comparison. DETAILED DESCRIPTION

[0041] First of all, it should be noted that the specific structure, characteristics and advantages of the present invention will be specifically described below by way of example, but all descriptions are only used for illustration and should not be understood as forming any limitation on the present invention. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted arbitrarily between these technical features (or their equivalents), so as to obtain more other embodiments of the present invention that may not be directly mentioned in this article. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing. The present invention will be specifically described below in conjunction with the drawings.

[0042] Embodiment 1:

[0043] The method for determining the magnetic performance parameters of annular permanent magnet steel based on molecular current theory comprises the following steps:

[0044] Step 1, measuring the external dimensions of the annular permanent magnet steel to obtain the measured dimension data of the magnetic steel;

[0045] Wherein: the measured dimension data of the magnetic steel are the outer diameter, inner diameter and height of the annular permanent magnetic steel;

[0046] Step 2: Measure the magnetic field distribution f of the annular permanent magnet at the central axis 实测 (z);

[0047] Where: the magnetic field distribution f of the magnetic steel 实测(z) is the axial magnetic induction intensity B 实测 (z) or axial magnetic field strength H 实测 (z);

[0048] Step 3: Distribute the magnetic field of the magnetic steel 实测 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K 实测 ;

[0049] Step 4, establishing a finite element model of the permanent magnet steel according to the measured dimensions of the annular magnet steel;

[0050] Step 5: Input the estimated performance parameters of the annular magnetic steel material, complete the finite element simulation of the magnetic field in the magnetic steel space, and extract the magnetic field distribution f of the central axis of the magnetic steel. 仿真 (z);

[0051] Where: the magnetic field distribution f of the magnetic steel 仿真 (z) is the axial magnetic induction intensity B 仿真 (z) or axial magnetic field strength H 仿真 (z);

[0052] Step 6: Distribute the magnetic field of the magnetic steel 仿真 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K 仿真 ;

[0053] Step 7, compare K 仿真 With K 实测 By adjusting the magnetic parameters of the material in the magnetic steel finite element model, repeat steps 4-6 until K 仿真 With K 实测 Equivalently, the input parameters of the material in the finite element model are the magnetic properties parameters of the annular permanent magnet steel.

[0054] The present invention uses the finite element method to complete the spatial magnetic field simulation of the annular magnetic steel under the conditions of a certain size and specified performance parameters, and gives the magnetic field simulation distribution at the specified position, which provides a comparative basis for determining the magnetic performance parameters of the magnetic steel; and takes the surface magnetization current density value as the optimization target, further reducing the influence of the test position accuracy and measurement accuracy on the determination results of the magnetic performance of the annular magnetic steel, and improving the accuracy of the magnetic performance parameter results. The magnetic steel performance parameters are determined by the surface magnetic measurement method, avoiding the influence of repeated charging and demagnetization processes on the magnetic steel performance.

[0055] Furthermore, in this embodiment, it can also be considered that the magnetizing direction of the annular permanent magnet steel is axial.

[0056] Furthermore, in this embodiment, it can also be considered that the magnetic performance parameters of the permanent magnet steel are relative magnetic permeability and magnetic coercivity.

[0057] Furthermore, in this embodiment, it can also be considered that the analytical expression based on the molecular current theory is:

[0058]

[0059] Where: When the magnetic field distribution f(z) is the axial magnetic induction intensity B(z), m is equal to μ 0 , when the magnetic field distribution f(z) is the axial magnetic field intensity H(z), m is equal to 1 / μ r , μ 0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability, K is the surface magnetizing current density value, z is the axial distance from the measured position to the magnetic steel surface, h is the height of the magnetic steel, a is the outer diameter of the magnetic steel, and b is the inner diameter of the magnetic steel.

[0060] The present invention fits the measured magnetic field results by using an analytical formula for the magnetic field distribution on the central axis of the annular permanent magnet based on the molecular current theory, thereby effectively reducing the influence of the test position accuracy and measurement accuracy on the accuracy of the magnetic field distribution on the central axis of the magnet.

[0061] Furthermore, in this embodiment, it can also be considered that the magnetic field distribution f of the annular permanent magnet steel at the central axis is 实测 (z) The test position origin and the calculated value of the magnetic field distribution f 仿真 The extraction position origin of (z) is the same and is located at the center of the upper or lower surface of the annular magnetic steel.

[0062] Furthermore, in this embodiment, it can also be considered that the magnetic field distribution f of the annular permanent magnet steel at the central axis is 实测 The number of test positions for (z) is not less than 4, and the calculated value of magnetic field distribution f 仿真 The number of extraction positions of (z) is not less than 4.

[0063] In the above technical solution, the optimization method of the material magnetic property parameters in the magnetic steel finite element model is an annealing algorithm, a genetic algorithm, a neural network algorithm or a combination of several of them.

[0064] The present invention comprehensively applies molecular current theory and finite element method to solve the problem of determining the magnetic property parameters of annular magnetic steel, reduces the difficulty of hospital acceptance of magnetic steel performance and evaluation of attenuation degree after long-term operation, helps to improve the detection efficiency, economy and operation reliability of magnetic steel, and has important engineering significance for the research and numerical calculation of the magnetic properties of annular magnetic steel.

[0065] Embodiment 2:

[0066] An electronic device that uses the method for determining the magnetic property parameters of annular permanent magnet steel based on the molecular current theory in Example 1 to determine the magnetic property parameters of annular permanent magnet steel, taking a general computing device as an example, includes but is not limited to: at least one processor, at least one memory, a computer program stored in the memory and executable on the processor, and a bus, display, network adapter, etc. that connect different system components. The present invention implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The processor can be, but is not limited to, a central processing unit (CPU), a digital signal processor (DSP), other general-purpose processors, etc. Computer readable media may include at least: any entity or device capable of carrying computer program codes to a camera / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electric carrier signal, a telecommunication signal, and a software distribution medium, such as a USB flash drive, a mobile hard disk, a magnetic disk, or an optical disk.

[0067] When the computer program is executed by the processor, the method for determining the magnetic property parameters of the annular permanent magnet steel described above can be implemented according to the steps of the implementation method in Example 1.

[0068] Application Example 1:

[0069] The 4240 type ferrite ring magnet is selected as the research object. Its factory performance range is: remanence 0.41T-0.43T; magnetic coercive force 298.1kA / m-309.8kA / m. The magnetic performance parameters of the magnet are determined according to the following steps:

[0070] (1) Measure the external dimensions of the ferrite ring magnet and obtain the actual dimensions of the magnet: outer diameter φ60 mm, inner diameter φ30 mm, height 30 mm;

[0071] (2) Measure the axial magnetic induction intensity distribution B of the ferrite magnet at the center axis 实测 (z), the specific test results are as follows Figure 2 As shown;

[0072] (3) The axial magnetic induction intensity distribution B of the magnetic steel 实测 (z) and the measured size data are substituted into the analytical expression based on the molecular current theory to determine the surface magnetization current density value K of the ferrite magnet in this magnetization state.实测 325.76 kA / m;

[0073] (4) According to the measured dimensions of the annular magnetic steel, a finite element model of the ferrite magnetic steel is established. The specific model is as follows: Figure 3 As shown;

[0074] (5) Input the magnetic properties parameters of the magnetic steel material in the finite element model, complete the finite element simulation of the magnetic field in the space of the magnetic steel, and extract the axial magnetic induction intensity distribution B of the central axis of the magnetic steel. 仿真 (z), fitting the surface magnetization current density value K 仿真 , with the help of genetic algorithm, the relative magnetic permeability and magnetic coercivity of the magnetic steel material are adjusted until K 仿真 Equal to 325.76kA / m, the specific comparison between the simulation results and the measured data is as follows Figure 4 As shown. The relative magnetic permeability and magnetic coercivity at this time are the magnetic performance parameters of 4240 type ferrite ring magnet;

[0075] (6) Output the magnetic performance parameters of the ferrite ring magnet: relative magnetic permeability 1.12, magnetic coercivity 303.95kA / m. According to the above data, the remanence of the ferrite magnet is 0.43T. Compared with the factory performance range, it can be seen that the magnetic performance parameters of the magnet are qualified.

[0076] Application Example 2:

[0077] A domestic brand of NdFeB ring magnet is selected as the research object. Its factory performance range is: remanence 0.62T-0.65T; magnetic coercivity 420kA / m-440kA / m. The magnetic performance parameters of the magnet are determined according to the following steps:

[0078] (1) Measure the external dimensions of the NdFeB ring magnet and obtain the actual dimensions of the magnet: outer diameter φ100 mm, inner diameter φ10 mm, height 50 mm;

[0079] (2) Measure the axial magnetic field intensity distribution H of the NdFeB magnet at the center axis 实测 (z), the specific test results are as follows Figure 5 As shown;

[0080] (3) The axial magnetic induction intensity distribution H of the magnetic steel 实测 (z) and the measured size data are substituted into the analytical expression based on the molecular current theory to determine the surface magnetization current density value K of the NdFeB magnet in this magnetization state. 实测 454.36 kA / m;

[0081] (4) According to the measured dimensions of the annular magnetic steel, a finite element model of the NdFeB magnetic steel is established. The specific model is as follows: Figure 6 As shown;

[0082] (5) Input the magnetic properties parameters of the magnetic steel material in the finite element model, complete the finite element simulation of the magnetic field in the space of the magnetic steel, and extract the axial magnetic induction intensity distribution H of the central axis of the magnetic steel. 仿真 (z), fitting the surface magnetization current density value K 仿真 , with the help of neural network algorithm, the relative magnetic permeability and magnetic coercivity of magnetic steel materials are adjusted until K 仿真 Equal to 454.36kA / m, the relative magnetic permeability and magnetic coercivity at this time are the magnetic performance parameters of domestic NdFeB ring magnets;

[0083] (6) Output the magnetic performance parameters of the NdFeB ring magnet: relative magnetic permeability 1.16, magnetic coercivity 432.2kA / m. According to the above data, the remanence of the NdFeB magnet is 0.63T. Compared with the factory performance range, it can be seen that the magnetic performance parameters of the magnet are qualified.

[0084] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for determining the magnetic properties parameters of annular permanent magnets based on molecular current theory. Features: The following steps are involved: Step 1, measuring the outer dimensions of the annular permanent magnetic steel to obtain the measured dimension data of the annular permanent magnetic steel; Step 2: Measure the magnetic field distribution f of the annular permanent magnet at the central axis 实测 (z); Step 3: Distribute the magnetic field of the annular permanent magnet steel 实测 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K by fitting. 实测 , the analytical expression based on molecular current theory is: ; Where: When the magnetic field distribution f(z) is the axial magnetic induction intensity B(z), m is equal to μ 0 , when the magnetic field distribution f(z) is the axial magnetic field intensity H(z), m is equal to 1 / μ r , μ 0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability, K is the surface magnetization current density value, z is the axial distance from the measured position to the magnetic steel surface, h is the height of the magnetic steel, a is the outer diameter of the magnetic steel, and b is the inner diameter of the magnetic steel; Step 4, establishing a finite element model of the permanent magnetic steel according to the measured size data of the annular permanent magnetic steel; Step 5: Input the estimated performance parameters of the annular magnetic steel material, complete the finite element simulation of the magnetic field in the magnetic steel space, and extract the magnetic field distribution f of the central axis of the magnetic steel. 仿真 (z); Step 6: Distribute the magnetic field of the magnetic steel 仿真 (z) and the measured size data are substituted into the analytical expression based on molecular current theory to determine the surface magnetization current density value K by fitting. 仿真 ; Step 7, compare K 仿真 With K 实测 By adjusting the magnetic parameters of the material in the magnetic steel finite element model, repeat steps 4-6 until K 仿真 With K 实测 Equivalently, the input parameters of the material in the finite element model are the magnetic properties parameters of the annular permanent magnet steel.

2. The method for determining magnetic properties parameters of annular permanent magnet steel based on molecular current theory according to claim 1, Features: The magnetization direction of the annular permanent magnet steel is axial.

3. The method for determining magnetic properties parameters of annular permanent magnet steel based on molecular current theory according to claim 2, Features: The measured dimensional data of the annular permanent magnet steel in step 1 include the outer diameter, inner diameter and height of the annular permanent magnet steel.

4. The method for determining magnetic properties parameters of annular permanent magnet steel based on molecular current theory according to claim 3, Features: The magnetic field distribution f of the annular permanent magnet steel in step 2 实测 (z) includes axial magnetic induction intensity B 实测 (z) or axial magnetic field strength H 实测 (z).

5. The method for determining magnetic performance parameters of annular permanent magnet steel based on molecular current theory according to claim 2, Features: The magnetic field distribution f of the magnetic steel in step 5 仿真 (z) includes axial magnetic induction intensity B 仿真 (z) or axial magnetic field strength H 仿真 (z).

6. The method for determining magnetic performance parameters of annular permanent magnet steel based on molecular current theory according to claim 5, Features: The magnetic field distribution of the annular permanent magnet steel at the central axis is f 实测 (z) The test position origin and the calculated value of the magnetic field distribution f 仿真 The extraction position origin of (z) is the same and is located at the center of the upper or lower surface of the annular magnetic steel.

7. The method for determining magnetic performance parameters of annular permanent magnet steel based on molecular current theory according to claim 6, Features: The magnetic field distribution of the annular permanent magnet steel at the central axis is f 实测 The number of test positions of (z) is not less than 4, and the calculated value of magnetic field distribution f 仿真 The number of extraction positions of (z) is not less than 4.

8. The method for determining magnetic performance parameters of annular permanent magnet steel based on molecular current theory according to claim 1, Features: The magnetic performance parameters of the permanent magnet steel include relative magnetic permeability and magnetic coercivity.

9. An electronic device, Features: include: At least one processor, at least one memory, and a computer program stored in the memory and executable on the processor, which, when executed by the processor, implements the method for determining magnetic property parameters of annular permanent magnet steel based on molecular current theory as described in any one of claims 1 to 8.

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