Method, device, computer equipment, readable storage medium and program product for determining loss under DC bias conditions

Abstract

The present application relates to a method, device, computer equipment, computer-readable storage medium and computer program product for determining loss under DC bias conditions, and relates to the field of electromagnetic equipment technology, which can improve the accuracy of calculating the loss of magnetic materials under DC bias conditions. The method includes: determining the energy distribution of different magnetic domains of the magnetic material of the electrical steel sheet under DC bias and their distribution ratio; calculating the magnetization intensity of the single crystal material according to the magnetic domain distribution ratio; spatially averaging the magnetization intensity of the single crystal material, and obtaining the hysteresis-free magnetization intensity of the polycrystalline material according to the effective magnetic field intensity; when the total magnetization intensity includes reversible and irreversible magnetization intensity, determining the reversible magnetization intensity according to the hysteresis-free magnetization intensity, and determining the irreversible magnetization intensity according to the total magnetization intensity and the reversible magnetization intensity; determining the hysteresis loss according to the irreversible magnetization intensity; calculating the eddy current loss and abnormal loss through the change of magnetic induction intensity; and finally determining the total loss.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic equipment, and in particular to a method, device, computer equipment, computer-readable storage medium and computer program product for determining loss under a DC bias condition. Background Art

[0002] With the increasing demand for high efficiency and low energy loss in modern electromagnetic equipment, the performance optimization of magnetic materials has become a key link in power transmission and conversion systems. Under the DC bias state, the winding current of the power transformer will be severely distorted, and the transformer will be in an abnormal working state. The saturation of the magnetic flux density of the core inside the transformer is aggravated, and a large amount of magnetic flux is closed outside the oversaturated core, resulting in aggravated transformer vibration, increased noise, increased losses, local overheating, and even insulation damage. Among them, the overheating problem that may occur in the transformer core under the influence of DC bias current is one of the research focuses. Therefore, studying the hysteresis characteristics and loss characteristics of ferromagnetic materials under DC bias conditions is the basis and key to correctly evaluate the possible overheating problem of the transformer core.

[0003] In traditional technology, although the magnetization of ferromagnetic materials can be determined based on one or more theories such as micro-magnetization theory and macro-magnetization theory, the inventors have found in practice that the above theories are relatively rarely used under DC bias conditions, and it is difficult to accurately identify the loss of electrical steel sheets under DC bias conditions. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device, computer equipment, computer-readable storage medium and computer program product for determining losses under DC bias conditions in order to address the above technical problems.

[0005] In a first aspect, the present application provides a method for determining loss under a DC bias magnetic condition, comprising:

[0006] Determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0007] Calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0008] By performing spatial homogenization processing on the magnetization intensity of the single crystal material, and according to the effective magnetic field intensity, the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material is obtained;

[0009] In the case where the total magnetization includes a reversible magnetization and an irreversible magnetization, the reversible magnetization is determined according to the hysteresis-free magnetization, and the irreversible magnetization is determined according to the total magnetization and the reversible magnetization;

[0010] Determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity;

[0011] In the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0012] In the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material;

[0013] The sum of the hysteresis loss, the eddy current loss and the abnormal loss is determined as the total loss of the electrical steel sheet under the DC bias condition.

[0014] In one embodiment, determining the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions and obtaining the distribution ratio of each magnetic domain under the energy distribution includes:

[0015] Calculating the anisotropy energy of each magnetic domain according to the directions of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC biasing condition and the directional parameters corresponding to each direction;

[0016] Calculating the magnetostatic energy of the magnetic domain according to the magnetic field strength and magnetization strength of the magnetic domain;

[0017] calculating magnetoelastic energy of the magnetic domain according to the applied stress and elastic parameters of the magnetic domain;

[0018] Summing the anisotropic energy, the magnetostatic energy and the magnetoelastic energy to obtain the free energy of the magnetic domain;

[0019] Based on the Boltzmann distribution function and according to the free energy of the magnetic domains, the distribution ratio of each magnetic domain is obtained.

[0020] In one embodiment, the spatially homogenizing the magnetization intensity of the single crystal material comprises:

[0021] Projecting the magnetization intensity of the single crystal material into a spatial coordinate system of a polycrystalline material according to the orientation distribution of the single crystal material and the magnetization intensity corresponding to the orientation distribution;

[0022] In the spatial coordinate system, the magnetization intensities in different dimensions are homogenized by a nonlinear function.

[0023] In one embodiment, determining the reversible magnetization according to the hysteresis-free magnetization, and determining the irreversible magnetization according to the total magnetization and the reversible magnetization, comprises:

[0024] Obtaining a reversible coefficient, and determining the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization according to the reversible coefficient;

[0025] Determining the reversible magnetization represented by the hysteresis-free magnetization according to the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization;

[0026] The irreversible magnetization is determined based on the total magnetization and the reversible magnetization represented by the hysteresis-free magnetization.

[0027] In one embodiment, determining the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes includes:

[0028] Obtaining irreversible loss coefficient and coupling coefficient between magnetic domains;

[0029] Determining the hysteresis-free magnetization intensity in the effective magnetic field according to the coupling coefficient;

[0030] Based on the law of conservation of energy, the irreversible loss coefficient is adjusted to determine the rate of change of the irreversible magnetization intensity;

[0031] The accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes is determined according to the change rate of the irreversible magnetization intensity, thereby obtaining the hysteresis loss.

[0032] In one embodiment, determining the abnormal loss according to the energy loss caused by overcoming the obstacle caused by the material properties of the magnetic domains during the movement of the magnetic domains caused by the change of the magnetic induction intensity over time comprises:

[0033] In the process of the movement of the magnetic domain caused by the change of the magnetic induction intensity over time, a loss statistical distribution coefficient is obtained; the loss statistical distribution coefficient is determined by the DC magnetic field intensity of the magnetic domain;

[0034] According to the loss statistical distribution coefficient, the energy loss of the magnetic domain at different obstacles when the magnetic induction intensity changes is determined, and the energy loss at the different obstacles is accumulated to obtain the abnormal loss.

[0035] In a second aspect, the present application also provides a loss determination device under a DC bias magnetic condition, comprising:

[0036] A magnetic domain energy distribution calculation module is used to determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0037] A single crystal material magnetization intensity calculation module, used to calculate the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0038] A polycrystalline material hysteresis-free magnetization intensity calculation module is used to obtain the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material by performing spatial homogenization processing on the magnetization intensity of the single crystal material and according to the effective magnetic field intensity;

[0039] a reversible and irreversible magnetization determination module, configured to determine the reversible magnetization according to the hysteresis-free magnetization when the total magnetization includes the reversible magnetization and the irreversible magnetization, and to determine the irreversible magnetization according to the total magnetization and the reversible magnetization;

[0040] A hysteresis loss calculation module, used to determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes a DC magnetic field intensity, an AC magnetic field intensity and a hysteresis-free magnetic field intensity;

[0041] An eddy current loss calculation module is used to determine the eddy current loss in the induced electric field formed by the change of magnetic induction intensity according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0042] an abnormal loss calculation module, for determining abnormal loss according to energy loss caused by overcoming obstacles caused by the properties of magnetic domain materials during the movement of magnetic domains caused by the change of magnetic induction intensity over time;

[0043] The total loss determination module is used to determine the sum of the hysteresis loss, the eddy current loss and the abnormal loss as the total loss of the electrical steel sheet under the DC bias condition.

[0044] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0045] Determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0046] Calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0047] By performing spatial homogenization processing on the magnetization intensity of the single crystal material, and according to the effective magnetic field intensity, the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material is obtained;

[0048] In the case where the total magnetization includes a reversible magnetization and an irreversible magnetization, the reversible magnetization is determined according to the hysteresis-free magnetization, and the irreversible magnetization is determined according to the total magnetization and the reversible magnetization;

[0049] Determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity;

[0050] In the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0051] In the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material;

[0052] The sum of the hysteresis loss, the eddy current loss and the abnormal loss is determined as the total loss of the electrical steel sheet under the DC bias condition.

[0053] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0054] Determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0055] Calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0056] By performing spatial homogenization processing on the magnetization intensity of the single crystal material, and according to the effective magnetic field intensity, the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material is obtained;

[0057] In the case where the total magnetization includes a reversible magnetization and an irreversible magnetization, the reversible magnetization is determined according to the hysteresis-free magnetization, and the irreversible magnetization is determined according to the total magnetization and the reversible magnetization;

[0058] Determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity;

[0059] In the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0060] In the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material;

[0061] The sum of the hysteresis loss, the eddy current loss and the abnormal loss is determined as the total loss of the electrical steel sheet under the DC bias condition.

[0062] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0063] Determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0064] Calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0065] By performing spatial homogenization processing on the magnetization intensity of the single crystal material, and according to the effective magnetic field intensity, the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material is obtained;

[0066] In the case where the total magnetization includes a reversible magnetization and an irreversible magnetization, the reversible magnetization is determined according to the hysteresis-free magnetization, and the irreversible magnetization is determined according to the total magnetization and the reversible magnetization;

[0067] Determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity;

[0068] In the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0069] In the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material;

[0070] The sum of the hysteresis loss, the eddy current loss and the abnormal loss is determined as the total loss of the electrical steel sheet under the DC bias condition.

[0071] The above-mentioned method, device, computer equipment, computer-readable storage medium and computer program product for determining loss under a DC bias condition determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias condition in their respective directions to obtain the distribution ratio of each magnetic domain under the energy distribution; calculate the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains; obtain the hysteresis-free magnetization intensity of the polycrystalline material composed of the single crystal material by spatially averaging the magnetization intensity of the single crystal material and obtaining the reversible magnetization intensity of the polycrystalline material composed of the single crystal material according to the effective magnetic field intensity; when the total magnetization intensity includes the reversible magnetization intensity and the irreversible magnetization intensity, determine the reversible magnetization intensity according to the hysteresis-free magnetization intensity and obtain the reversible magnetization intensity according to the total magnetization intensity. Intensity and reversible magnetization intensity, determine the irreversible magnetization intensity; determine the hysteresis loss according to the accumulated loss of irreversible magnetization intensity with the change of effective magnetic field intensity; effective magnetic field includes DC magnetic field intensity, AC magnetic field intensity and hysteresis-free magnetic field intensity; in the induced electric field formed by the change of magnetic induction intensity, determine the eddy current loss according to the accumulated loss of magnetic induction intensity with time; magnetic induction intensity includes DC magnetic induction intensity and AC magnetic induction intensity; in the process of magnetic domain movement caused by the change of magnetic induction intensity with time, determine the abnormal loss according to the energy loss caused by overcoming the obstacles caused by the properties of magnetic materials; determine the sum of hysteresis loss, eddy current loss and abnormal loss as the total loss of electrical steel sheet under DC bias working condition. In this application, by determining the energy distribution of different magnetic domains in their respective directions, and calculating the distribution ratio of magnetic domains in different energy states according to these energy distributions, the magnetization characteristics of magnetic materials under DC magnetic field conditions are accurately described. By microscopic magnetic domains to mesoscopic single crystal materials, and finally to macroscopic polycrystalline materials, the error problem caused by the complexity of polycrystalline materials is solved, the accuracy of the description of local magnetic properties is improved, and the magnetization characteristics of magnetic materials are described more accurately. The total magnetization intensity is divided into reversible and irreversible, and the hysteresis loss caused by irreversibility is separated by the hysteresis-free magnetic field intensity under polycrystalline materials. It can accurately capture the dissipation behavior of magnetic domains under different magnetic field combinations, and the hysteresis loss under DC conditions is further accurate. Considering the combined effect of DC magnetic induction intensity and AC magnetic induction intensity, the eddy current loss can be calculated more accurately; by taking the abnormal loss under DC bias conditions as part of the loss calculation, and taking into account the nonlinear energy loss caused by the microstructure of the magnetic material, the dynamic behavior of the magnetic domain in a complex magnetic field can be reflected, and the loss under DC bias conditions can be measured more accurately. It realizes an accurate description of the abnormal phenomena in the energy distribution, magnetization intensity and magnetic domain movement of the magnetic domain, and a comprehensive calculation of the hysteresis loss, eddy current loss and abnormal loss, which significantly improves the calculation accuracy of the loss under complex magnetic field conditions, and achieves an accurate prediction of the loss of electrical steel sheets under DC bias conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0073] Figure 1 It is a schematic flow chart of a method for determining loss under a DC bias magnetic working condition in one embodiment;

[0074] Figure 2 A structural block diagram of a method for determining loss under a DC bias magnetic condition in one embodiment;

[0075] Figure 3 A schematic diagram of a model for calculating hysteresis loss in one embodiment;

[0076] Figure 4 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0078] In order to enable those skilled in the art to better understand the present application, the relevant technology is first introduced below.

[0079] At present, the research theories of the magnetization phenomenon of ferromagnetic materials are mainly divided into three categories: the first is the microscopic magnetization theory, which is based on the hysteresis theory derived from micromagnetism. Although it has a rigorous physical basis, it is complex and time-consuming and is not suitable for macroscopic application scenarios; the second is the macroscopic magnetization theory, which is based on phenomenological principles or experimental data for curve fitting. However, this method is overly dependent on experimental data and has limited applicability; the third is the semi-macroscopic magnetization theory, which combines the microscopic structural parameters and macroscopic performance of ferromagnetic materials, reflects the magnetization mechanism of the material, and does not completely rely on experimental data, and has a good balance. The Jiles-Atherton model is one of the representative classical models in the semi-macroscopic magnetization theory. The model has been widely used in the calculation of magnetic properties of electromagnetic equipment and has achieved good accuracy under various working conditions. However, the application of the Jiles-Atherton model under DC bias conditions is relatively limited, and its description of the magnetic domain energy mechanism in the magnetization process is incomplete, and the model has not yet been applied to the calculation of magnetic properties under DC bias conditions.

[0080] In one embodiment, Figure 1As shown, a method for determining loss under DC bias magnetic working conditions is provided. This embodiment uses the method applied to a server as an example for illustration. It can be understood that the method can also be applied to a terminal, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0081] Step S101, determining the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet in respective directions under a DC bias condition, and obtaining the distribution ratio of each magnetic domain under the energy distribution.

[0082] Among them, magnetic domains are microscopic areas in ferromagnetic materials, where the internal magnetic moments are neatly arranged and tend to be in the same direction. Under the action of an external magnetic field, different magnetic domains will be magnetized or demagnetized according to their respective directions and energy states. Energy distribution refers to the energy state of different magnetic domains inside a magnetic material under conditions such as external magnetic fields and stresses. The distribution ratio is determined by statistical or computational methods to determine the proportion of magnetic domains in a material that are in a specific energy state among all magnetic domains. It reflects how the magnetic domains inside the material are distributed in different directions according to the energy state. The ratio can be a calculation result based on a probability model, statistical theory, or a physical energy model.

[0083] Exemplarily, the server obtains the crystal structure, magnetization intensity, direction and intensity of the external magnetic field of the magnetic material. In the process of calculating the energy distribution, the server calculates the energy of each magnetic domain based on the acquired external magnetic field and material properties to obtain the energy distribution of the magnetic domain. The distribution ratio of each magnetic domain is determined by a probability distribution model or energy accumulation method.

[0084] Alternatively, for the calculation of the distribution ratio, a statistical mechanics model Monte Carlo method can be used to simulate the distribution of magnetic domains under different energy states. A numerical calculation method based on random sampling is used to simulate the arrangement of magnetic domains under different energy states in a large number of samples to generate the distribution ratio of magnetic domains in the material.

[0085] Step S102, calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains.

[0086] Among them, single crystal material refers to a material in which all atoms are arranged in the same way to form a complete crystal structure. In the present invention, the single crystal material is composed of magnetic domains, and the magnetization intensity is determined by the magnetization contribution of each magnetic domain.

[0087] Specifically, the server gradually accumulates the magnetization intensity of each magnetic domain based on the magnetization contribution of each magnetic domain according to the magnetic domain distribution ratio determined in the previous step to obtain the total magnetization value of the entire single crystal material.

[0088] Optionally, the server can simulate the magnetic field distribution inside the material according to the magnetic domain distribution ratio, and then divide the single crystal material into multiple small units by gridding the magnetic field distribution, and then calculate the magnetization intensity in each unit, accumulate the obtained magnetization intensity, and obtain the total magnetization value of the entire single crystal material.

[0089] Step S103, spatially averaging the magnetization intensity of the single crystal material, and obtaining the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material according to the effective magnetic field intensity.

[0090] Among them, spatial averaging refers to processing the local magnetization intensity values ​​within the spatial range so that these local magnetization values ​​can show the overall magnetization intensity of the material on a macro scale. The effective magnetic field intensity refers to the net magnetic field that acts inside the magnetic material and can affect the magnetization state of the magnetic domain. It not only includes the external magnetic field, but also takes into account the influence of other factors such as the interaction between internal magnetic domains and stress effects. It is used to reflect the magnetic response of magnetic materials in practical applications.

[0091] Exemplarily, the server first receives the magnetization data of the single crystal material, which represents the local magnetic response characteristics of each single crystal material. When constructing a polycrystalline material, the single crystal material with different magnetization intensities in different directions is spatially homogenized and integrated into a unified polycrystalline material response. Finally, combined with the applied effective magnetic field strength, the magnetization intensity of the polycrystalline material after homogenization is corrected to obtain the hysteresis-free magnetization intensity of the polycrystalline material under the magnetic field condition.

[0092] Step S104, when the total magnetization includes reversible magnetization and irreversible magnetization, determining the reversible magnetization according to the hysteresis-free magnetization, and determining the irreversible magnetization according to the total magnetization and the reversible magnetization;

[0093] Among them, reversible magnetization refers to the part of the magnetic domain inside the material that can change and recover its magnetization direction and magnetization intensity when the external magnetic field intensity changes. In other words, when the magnetic field is withdrawn, the magnetization state of the material can return to its original state without permanent changes. Irreversible magnetization refers to the part of the magnetic domain arrangement inside the material that undergoes irreversible changes when the magnetic field intensity increases. Even if the magnetic field is withdrawn, the magnetization direction of some magnetic domains remains in a changed state and will not recover. Hysteresis-free magnetization refers to the magnetization of the material under ideal conditions without hysteresis. Under this condition, the magnetization intensity of the material is linear with the change of the magnetic field, which is related to the reversible magnetization.

[0094] Exemplarily, the server first divides the total magnetization into reversible magnetization and irreversible magnetization, processes the hysteresis-free magnetization data based on the linear response model of the hysteresis-free magnetization, and obtains the reversible magnetization of the material. The linear response model is a proportional function of the hysteresis-free magnetization and the reversible magnetization. The server determines the irreversible magnetization based on the difference between the total magnetization and the reversible magnetization.

[0095] Optionally, when the total magnetization intensity is divided into reversible magnetization intensity and irreversible magnetization intensity, the server records the momentum relaxation time during the magnetization process. The reversible magnetization intensity is obtained by responding in a faster momentum relaxation time, and the irreversible magnetization intensity corresponds to the response in a slower momentum relaxation time. The irreversible magnetization intensity is separated through different momentum relaxation time scales, and the irreversible magnetization intensity based on the hysteresis-free magnetization intensity is verified.

[0096] Step S105, determining the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity.

[0097] Among them, the effective magnetic field strength is the result of the combined effect of various magnetic fields inside and outside the material. The effective magnetic field includes not only the external DC and AC magnetic fields, but also the hysteresis-free magnetic field formed inside the material due to the interaction of magnetic domains or other factors.

[0098] DC magnetic field intensity refers to the constant magnetic field continuously applied in the material, which is generated by DC current. The DC magnetic field will cause the steady-state magnetization of the magnetic domains inside the material, forming hysteresis and triggering irreversible magnetization behavior.

[0099] AC magnetic field intensity refers to a changing magnetic field, usually a periodically changing magnetic field. The AC magnetic field has a more complex effect on the magnetization and demagnetization of materials, which can cause the recurrence of hysteresis.

[0100] Exemplarily, the server obtains a relationship curve of irreversible magnetization intensity with effective magnetic field according to the finite magnetic field strength composed of DC magnetic field strength, AC magnetic field strength and hysteresis-free magnetic field strength. According to the relationship curve, the relationship between magnetic field strength and magnetization strength is processed cyclically, and the energy loss generated in each magnetization and demagnetization cycle is calculated. In the process of effective magnetic field strength change, the DC, AC components and hysteresis-free magnetic field in the magnetic field work together. The server can separate the influence of each magnetic field component, calculate the sum of the accumulated loss values ​​of all magnetic field conditions, and output the overall hysteresis loss.

[0101] Step S106, determining eddy current loss in the induced electric field formed by the change of magnetic induction intensity according to the accumulated loss of the change of magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity.

[0102] Among them, the induced electric field is the electric field generated inside the material due to electromagnetic induction when the magnetic induction intensity changes. According to Faraday's law of electromagnetic induction, the change of magnetic induction intensity will cause electromotive force, which will then generate induced current in the conductor. In the process of electromagnetic induction, an induced electric field will be generated.

[0103] Eddy current loss refers to the energy loss caused by the circulation of induced current (eddy current) inside the material. When eddy current circulates in the material, it encounters resistance, resulting in heat loss. This energy loss is related to factors such as the speed of change of magnetic induction intensity, the conductivity and thickness of the material.

[0104] For example, the server can calculate the induced electric field generated by the magnetic induction change according to the change of magnetic induction intensity over time, and further calculate the eddy current loss through the current distribution in the induced electric field. During the calculation process, the server will distinguish the influence of DC magnetic induction intensity and AC magnetic induction intensity. The eddy current loss caused by DC magnetic induction intensity is small and continuous and stable, while the eddy current loss caused by AC magnetic induction intensity is more complex, and the loss changes with the frequency and amplitude of the magnetic induction intensity. The server will accumulate the energy loss within the time period to obtain the eddy current loss.

[0105] Step S107, in the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material.

[0106] Among them, obstacles are various factors that exist inside the material that hinder the rearrangement of magnetic domains during the movement of magnetic domains. The obstacle factors are related to the properties of the material itself and can come from material crystal defects, impurities, grain boundaries, etc.

[0107] Exemplarily, as the magnetic induction intensity changes, the magnetic domains will gradually rearrange or flip to adapt to the changes in the external magnetic field. The server simulates the movement of magnetic domains inside the material based on the input magnetic induction intensity data. During the movement of the magnetic domains, obstacles inside the material will hinder the free movement of the magnetic domains. By modeling these obstacles, the additional energy required by the magnetic domains to overcome these obstacles is calculated, and the abnormal losses generated during the entire magnetic induction intensity change process are obtained. In one embodiment, the server calculates the instantaneous resistance encountered by the magnetic domains during the movement based on the instantaneous speed of the magnetic domain movement, calculates the energy dissipation rate of the internal obstacles of the material based on the instantaneous resistance, and dynamically estimates the abnormal losses.

[0108] Step S108, determining the sum of the hysteresis loss, eddy current loss and abnormal loss as the total loss of the electrical steel sheet under the DC bias condition.

[0109] Optionally, the server obtains independent calculation results of hysteresis loss, eddy current loss and abnormal loss, and accumulates them according to their manifestation and proportion in the material. Through the numerical accumulation method, the various loss items are combined to obtain the total energy loss.

[0110] Optionally, the server corresponds hysteresis loss, eddy current loss and abnormal loss to different frequencies respectively, separates different loss items in the frequency domain, and then accumulates them to obtain the total loss.

[0111] In the above-mentioned method for determining the loss under the DC bias working condition, the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition is determined in their respective directions to obtain the distribution ratio of each magnetic domain under the energy distribution; the magnetization intensity of the single crystal material composed of the magnetic domains is calculated according to the distribution ratio of the magnetic domains; the magnetization intensity of the single crystal material is spatially homogenized, and the hysteresis-free magnetization intensity of the polycrystalline material composed of the single crystal material is obtained according to the effective magnetic field intensity; in the case where the total magnetization intensity includes the reversible magnetization intensity and the irreversible magnetization intensity, the reversible magnetization intensity is determined according to the hysteresis-free magnetization intensity, and the irreversible magnetization intensity is determined according to the total magnetization intensity and the reversible magnetization intensity. Reversed magnetization intensity; according to the accumulated loss of irreversible magnetization intensity with the change of effective magnetic field intensity, the hysteresis loss is determined; the effective magnetic field includes DC magnetic field intensity, AC magnetic field intensity and hysteresis-free magnetic field intensity; in the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of magnetic induction intensity with time; magnetic induction intensity includes DC magnetic induction intensity and AC magnetic induction intensity; in the process of magnetic domain movement caused by the change of magnetic induction intensity with time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacles caused by the properties of magnetic materials; the sum of hysteresis loss, eddy current loss and abnormal loss is determined as the total loss of electrical steel sheets under DC bias conditions. In this embodiment, by determining the energy distribution of different magnetic domains in their respective directions, and calculating the distribution ratio of magnetic domains under different energy states based on these energy distributions, the magnetization characteristics of magnetic materials under DC magnetic field conditions are accurately described. By microscopic magnetic domains to mesoscopic single crystal materials, and finally to macroscopic polycrystalline materials, the error problem caused by the complexity of polycrystalline materials is solved, the accuracy of the description of local magnetic properties is improved, and the magnetization characteristics of magnetic materials are described more accurately. The total magnetization intensity is divided into reversible and irreversible, and the hysteresis loss caused by irreversibility is separated by the hysteresis-free magnetic field intensity under polycrystalline materials. It can accurately capture the dissipation behavior of magnetic domains under different magnetic field combinations, and the hysteresis loss under DC conditions is further accurate. Considering the combined effect of DC magnetic induction intensity and AC magnetic induction intensity, the eddy current loss can be calculated more accurately; by taking the abnormal loss under DC bias conditions as part of the loss calculation, and taking into account the nonlinear energy loss caused by the microstructure of the magnetic material, the dynamic behavior of the magnetic domain in a complex magnetic field can be reflected, and the loss under DC bias conditions can be measured more accurately. It realizes an accurate description of the abnormal phenomena in the energy distribution, magnetization intensity and magnetic domain movement of the magnetic domain, and a comprehensive calculation of the hysteresis loss, eddy current loss and abnormal loss, which significantly improves the calculation accuracy of the loss under complex magnetic field conditions, and achieves an accurate prediction of the loss of electrical steel sheets under DC bias conditions.

[0112] In an exemplary embodiment, the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias condition in their respective directions is determined, and the distribution ratio of each magnetic domain under the energy distribution is obtained, including: calculating the anisotropy energy of each magnetic domain according to the directions of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias condition and the directional parameters corresponding to each direction; calculating the static magnetic energy of the magnetic domain according to the magnetic field strength and magnetization intensity of the magnetic domain; calculating the magnetoelastic energy of the magnetic domain according to the applied stress and elastic parameters of the magnetic domain; summing the anisotropy energy, static magnetic energy and magnetoelastic energy to obtain the free energy of the magnetic domain; and obtaining the distribution ratio of each magnetic domain according to the free energy of the magnetic domain based on the Boltzmann distribution function.

[0113] Among them, anisotropy energy is the difference in the ease of magnetization of magnetic materials in different crystal directions. It is closely related to the crystal structure of the material and reflects the response characteristics of the magnetic domain to the external magnetic field in a specific direction. The direction with high anisotropy energy is more difficult to magnetize, and the magnetic domain tends to be magnetized in the same direction as the high anisotropy energy.

[0114] Static magnetoenergy refers to the energy generated by the interaction between the magnetization intensity of the magnetic domains inside the material and the external magnetic field. It reflects the energy state of the magnetic domains under the external magnetic field, and the magnetic domains will minimize the static magnetoenergy by adjusting their direction. A lower static magnetoenergy state means a higher stability of the system.

[0115] Magnetoelastic energy refers to the energy change of magnetic domains under external stress. The magnetostrictive effect causes magnetic materials to deform under stress. This deformation is related to the magnetization direction, so the external stress will affect the movement and arrangement of magnetic domains. Magnetoelastic energy reflects the magnetization state of the material under the combined action of stress and magnetic field.

[0116] Specifically, the server obtains the directional parameters of each magnetic domain k from the crystal structure data of the magnetic material. The directional parameters may include: the magnetization direction of the magnetic domain, the crystal axis, and the direction of the external magnetic field. According to the directional parameters, the anisotropy energy It can be obtained by formula (1).

[0117]

[0118] in, is the magnetization direction in the domain, is the easy magnetization direction of the crystal.

[0119] The server calculates the static magnetoenergy of each magnetic domain based on the magnetization intensity of each magnetic domain and the external magnetic field strength. It can be obtained by formula (2).

[0120]

[0121] in, is the vacuum permeability, is the magnetic field strength in the domain, is the magnetization intensity in the magnetic domain.

[0122] The server calculates the magnetoelastic energy of the magnetic domain based on the elastic parameters of the material and the direction and magnitude of the applied stress. It can be obtained by formula (3).

[0123]

[0124] in, is the applied stress tensor, is the magnetostrictive strain in the magnetic domain.

[0125] The server obtains the free energy of the magnetic domain by summing up the anisotropic energy, static magnetoenergy and magnetoelastic energy. The free energy can be obtained by formula (4).

[0126]

[0127] After determining the free energy of each magnetic domain, the volume fraction of each magnetic domain at different energy states can be calculated by the Boltzmann distribution function. Boltzmann distribution is an important tool in physical statistics, used to describe the probability distribution of energy states. According to the principle that magnetic domains with lower energy occupy a higher volume fraction, magnetic domains with lower free energy are more likely to have a larger volume fraction. Its formula (5) is:

[0128]

[0129] Among them, the parameters is a material-specific parameter that is related to the initial magnetic susceptibility and saturation magnetization related, It can be obtained by formula (6).

[0130]

[0131] In this embodiment, the distribution ratio of magnetic domains is calculated based on the microstructure of the material (anisotropy, static magnetic energy and magnetoelasticity) and the Boltzmann distribution. Compared with the traditional magnetic domain distribution estimation method, this scheme has higher accuracy, especially in the face of DC bias and external stress, and can capture subtle changes in magnetic domains.

[0132] In an exemplary embodiment, the magnetization intensity of a single crystal material is spatially homogenized, including: projecting the magnetization intensity of the single crystal material into a spatial coordinate system of a polycrystalline material according to the orientation distribution of the single crystal material and the magnetization intensity corresponding to the orientation distribution; and homogenizing the magnetization intensity of different dimensions in the spatial coordinate system through a nonlinear function.

[0133] Optionally, the server determines the magnetization intensity of the single crystal material according to the orientation distribution of the single crystal material and the magnetization intensity data corresponding to the orientation distribution. It can be obtained by formula (7).

[0134]

[0135] in, represents the saturation magnetization of a single magnetic domain, It is a magnetic domain The magnetization direction, It is a magnetic domain From formula (7), we can know how the magnetization intensity of a single crystal material is synthesized from the directions and proportions of different magnetic domains. The contribution of each magnetic domain is reflected according to the weight of its magnetization intensity and direction in the magnetization of the single crystal material.

[0136] The server uses the rotation matrix to perform corresponding projection processing on the magnetization intensity in different directions according to the orientation information of the single crystal material, and converts the magnetization intensity of each single crystal material from its original coordinate system to the global spatial coordinate system of the polycrystalline material. Since the magnetization intensity of each single crystal material is unevenly distributed in space, and there may be a nonlinear relationship between the magnetization intensity in different directions, after projecting the magnetization intensity of the single crystal material to a unified spatial coordinate system, the server then uses a nonlinear function to average the magnetization intensity in different directions to obtain the magnetization intensity of the polycrystalline material. , as shown in formula (8).

[0137]

[0138] in, They represent quantities related to material stress, ,here is the vacuum permeability, is the material parameter, is the saturation magnetization. is the external magnetic field intensity. This formula describes the distribution of the magnetization intensity of polycrystalline materials under anisotropic conditions. It describes the nonlinear response of the magnetization intensity under external magnetic fields and stresses through the transcendental functions of hyperbolic sine and cosine functions.

[0139] In some specific embodiments, the magnetization intensity of the polycrystalline material can be obtained without hysteresis of the magnetic domains, and the hysteresis phenomenon is ignored, thereby obtaining the hysteresis-free magnetization intensity of the polycrystalline material, as shown in formula (9).

[0140]

[0141] Among them, the magnetization intensity Completely dependent on external magnetic field and the internal parameters of the material , without additional hysteresis losses.

[0142] In this embodiment, by projecting the magnetization intensity of each single crystal material into a unified spatial coordinate system, the system can handle complex crystal orientation distributions and ensure that the magnetization characteristics of different orientations can be effectively combined in polycrystalline materials. Secondly, the magnetization intensity of different dimensions is homogenized using a nonlinear function, which can more accurately capture the true magnetization behavior of magnetic materials in the presence of nonlinear interactions or anisotropic characteristics. This process not only improves the prediction accuracy of the overall magnetization performance of polycrystalline materials, but also provides more accurate input data for subsequent hysteresis loss, eddy current loss and other analyses, ultimately improving the accuracy of material loss assessment and the reliability of application.

[0143] In an exemplary embodiment, the reversible magnetization is determined according to the hysteresis-free magnetization, and the irreversible magnetization is determined according to the total magnetization and the reversible magnetization, including: obtaining a reversible coefficient, determining the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization according to the reversible coefficient; determining the reversible magnetization represented by the hysteresis-free magnetization according to the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization; determining the irreversible magnetization according to the total magnetization and the reversible magnetization represented by the hysteresis-free magnetization.

[0144] Specifically, the server first obtains the reversibility coefficient, which is a parameter describing the relationship between the reversible magnetization intensity, the irreversible magnetization intensity and the hysteresis-free magnetization intensity. The relationship can be expressed by formula (10).

[0145]

[0146] in, is the reversible magnetization, Irreversible magnetization, The reversibility coefficient reflects the ability of a material's partial magnetic domains to respond quickly and return to their initial state during the application and removal of an external magnetic field.

[0147] According to this reversible magnetization, and as shown in formula (11) based on the total magnetization On the basis of the reversible magnetization and the irreversible magnetization, the irreversible magnetization is derived.

[0148]

[0149] In this embodiment, by obtaining and calculating the reversible coefficient and the irreversible coefficient, the system can accurately model the hysteresis behavior of the material, especially under DC bias conditions, effectively distinguishing the reversible and irreversible changes of the material. This not only lays the foundation for the calculation of hysteresis loss, but also provides key support for the overall magnetic performance evaluation of the material.

[0150] In an exemplary embodiment, the hysteresis loss is determined based on the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes, including: obtaining the irreversible loss coefficient and the coupling coefficient between the magnetic domains; determining the hysteresis-free magnetic field intensity in the effective magnetic field based on the coupling coefficient; adjusting the irreversible loss coefficient based on the law of conservation of energy to determine the rate of change of the irreversible magnetization intensity; determining the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes based on the rate of change of the irreversible magnetization intensity to obtain the hysteresis loss.

[0151] Specifically, the server obtains the irreversible loss coefficient and the inter-domain coupling coefficient , irreversible loss coefficient It is used to reflect the energy loss caused by domain wall pinning or domain wall movement during irreversible magnetization, and the coupling coefficient between magnetic domains It is used to reflect the influence of the interaction between magnetic domains on the effective magnetic field.

[0152] According to the coupling coefficient between magnetic domains , effective magnetic field strength It can be determined by formula (12):

[0153]

[0154] in, Contains DC magnetic field and AC magnetic field , which can be expressed as .

[0155] In one embodiment, in order to comply with the principle of energy conservation, the energy of the irreversible loss part in the magnetization process is deducted from the total energy. Specifically, the energy balance is shown in formula (13).

[0156]

[0157] in, is the vacuum permeability; is the actual magnetization; is the hysteresis-free magnetization; is the irreversible magnetization; is the irreversible loss coefficient, which is adjusted by , which can correct the rate of change of irreversible magnetization , in order to comply with the law of conservation of energy; Is the sign function, used to distinguish the change in magnetization direction during the magnetization process. According to the time rate of change The sign of hour, ;when hour, .

[0158] By comparing the irreversible magnetization intensity with the effective magnetic field By calculating the rate of change of the change, the cumulative loss in the entire magnetization process can be obtained, and thus the hysteresis loss can be obtained. The hysteresis loss can be expressed by formula (14).

[0159]

[0160] In this embodiment, by obtaining the irreversible loss coefficient and the magnetic domain coupling coefficient, the irreversible magnetization process of the magnetic material under the external magnetic field can be accurately modeled. The determination of the hysteresis-free magnetic field strength and the calculation of the irreversible magnetization intensity change rate ensure that the system can accurately describe the hysteresis behavior of the material under the framework of energy conservation. Finally, by integrating the cumulative loss of irreversible magnetization intensity, the system can accurately calculate the hysteresis loss.

[0161] In an exemplary embodiment, during the movement of magnetic domains caused by the change of magnetic induction intensity over time, abnormal loss is determined based on the energy loss caused by overcoming obstacles caused by the properties of the magnetic domain material, including: obtaining a loss statistical distribution coefficient during the movement of magnetic domains caused by the change of magnetic induction intensity over time; the loss statistical distribution coefficient is determined by the DC magnetic field strength of the magnetic domains; based on the loss statistical distribution coefficient, the energy loss of the magnetic domains at different obstacles when the magnetic induction intensity changes is determined, and the energy loss at different obstacles is accumulated to obtain abnormal loss.

[0162] Among them, the loss statistical distribution coefficient is a parameter used to describe the distribution of energy loss of magnetic domains under different obstacles. It reflects the degree of resistance of different obstacles inside the material to the movement of magnetic domains. It can be determined by the physical properties of the material and the magnetic field conditions. It can be expressed by formula (15).

[0163]

[0164] in, Describes the statistical distribution of losses, defined as the DC magnetic field strength Function of is the conductor resistivity; is a dimensionless coefficient; is the cross-sectional area of ​​the steel sheet.

[0165] Based on the loss statistical distribution coefficient, the energy loss of the magnetic domain when overcoming different obstacles is calculated. The energy loss at each obstacle is determined by the microstructure of the material and the rate of change of the magnetic induction intensity. By accumulating the energy loss of the magnetic domain at different obstacles, the abnormal loss is determined. The abnormal loss is the sum of the energy consumed by the magnetic domain when overcoming all obstacles inside the material, which can be expressed by formula (16).

[0166]

[0167] In this embodiment, by introducing the loss statistical distribution coefficient, the system can quantify the obstacle effect inside the magnetic material according to the DC magnetic field strength, so as to accurately calculate the abnormal loss after accumulating the energy loss caused by different obstacles, thereby significantly improving the accuracy of the magnetic material loss calculation.

[0168] In an exemplary embodiment, in step S106, eddy current loss It can be determined by formula (17).

[0169]

[0170] in, is the thickness of the material; is the electrical conductivity of the material; is the rate of change of magnetic induction intensity over time. The term reflects the effect of material thickness on eddy current loss. The greater the thickness, the longer the eddy current path, the greater the thermal effect generated by the current, and the increase in eddy current loss. On the other hand, the conductivity of the material It reflects the freedom and flow resistance of electrons inside the material. The higher the conductivity, the easier it is for electrons to flow, and the greater the eddy current loss. Since the magnetic induction intensity is not constant, but changes with time. During the calculation of eddy current loss, the server will integrate and accumulate each time period of the change in magnetic induction intensity to reflect the contribution of the change in magnetic induction intensity of the material in different time periods to the eddy current loss.

[0171] In this embodiment, the eddy current loss inside the material is accurately calculated based on the accumulated loss due to the change of magnetic induction intensity over time and considering the different effects of material thickness and conductivity on eddy current, thereby further improving the accuracy and efficiency of loss analysis.

[0172] In an exemplary embodiment, in step S108, the total loss is determined based on Bertotti's loss separation theory. Bertotti's loss separation theory is applied in the present invention and can be expressed by formula (18).

[0173]

[0174] Formula (18) expresses the total loss , is the hysteresis loss , turbine losses and abnormal loss Based on common results.

[0175] Based on the law of conservation of energy, turbine loss and abnormal loss are introduced to control the energy balance, as shown in formula (19).

[0176]

[0177] In one embodiment, the server excites the material at a specific frequency and magnetic field strength and records its magnetization intensity. With the strength of the external magnetic field The relationship between the magnetic field and the magnetic field is plotted as a hysteresis loop. The hysteresis loop can reflect the hysteresis characteristics of the material, including hysteresis loss, irreversible magnetization, and saturation magnetization.

[0178] Furthermore, the server will adjust the parameters in formula (19) according to the measured hysteresis loop. The adjustment parameters may include , determine the total loss W, as shown in formula (20).

[0179]

[0180] Optionally, the server uses a particle swarm algorithm (PSO) to optimize and adjust the parameters. Through PSO, the parameter combination that best fits the loss determination to the measured data can be found based on the measured hysteresis loop data. The specific steps are as follows:

[0181] For each parameter to be identified ( ), generate random initial solutions within a reasonable range. A particle represents a candidate solution for a parameter combination, and there are multiple particles in the group, each with its own speed and position.

[0182] Define the objective function, which can be the mean square error (MSE) between the experimental data and the model output, as shown in formula (21). The objective function is used to evaluate the quality of each particle (i.e., each parameter combination). The simulated hysteresis loop can be compared with the experimental loop to minimize the error between them.

[0183]

[0184] in, is the loss experimental data obtained under an external magnetic field. is the loss value calculated by the model.

[0185] Update each particle in the particle swarm based on its current velocity, its best historical position (personal best solution, ) and the global best position (the group best solution, ) to update its velocity and position. The update formulas (22) and (23) are as follows:

[0186]

[0187]

[0188] in, is the velocity of particle i in generation t; is the parameter position of particle i in the tth generation; is the inertia weight, which controls how much the particle depends on its current velocity; is a learning factor, which controls the degree to which particles approach the individual optimal position and the group optimal position; is a random number.

[0189] For each particle's new position, calculate the corresponding objective function value (MSE). Then update the personal best solution and the group best solution This process will be repeated until the maximum number of iterations is reached or the objective function value meets the preset convergence condition. After multiple iterations, the optimal solution of the group is confirmed. , that is, the parameter combination that best fits the experimental data ( ).

[0190] In this embodiment, by recording the relationship between the magnetization intensity and the external magnetic field intensity, a hysteresis curve is drawn, and the parameter values ​​of the hysteresis loss, eddy current loss and abnormal loss are further adjusted according to the hysteresis curve, so that the measurement accuracy of the loss is significantly improved.

[0191] In order to enable those skilled in the art to better understand the above steps, the embodiment of the present application is illustrated below by using an example, but it should be understood that the embodiment of the present application is not limited to this.

[0192] like Figure 2As shown in Figure 1, the total loss of electrical steel sheets consists of three parts: hysteresis loss, eddy current loss and abnormal loss. By calculating each loss separately, we can have a clearer understanding of the performance of materials under different magnetic field conditions and optimize the material selection and use strategy.

[0193] For the calculation of hysteresis loss, a simplified multi-scale model is applied, first describing the behavior of magnetic domains from the microscopic scale, and then gradually expanding to the mesoscopic single crystal and macroscopic polycrystalline scales. The movement of microscopic magnetic domains is affected by the lattice structure of the material, and their arrangement and magnetization behavior determine the magnetization intensity at the single crystal scale. As the scale increases, the local characteristics of the magnetic domains gradually accumulate and affect the overall magnetization characteristics of the material. In polycrystalline materials, the magnetization behavior of each single crystal is converted into the performance of the entire polycrystalline material through spatial averaging.

[0194] Through the calculation of the multi-scale model, the hysteresis-free magnetization intensity of the material under lossless conditions can be obtained. It represents the magnetization state of the magnetic material under ideal conditions, that is, the reversible magnetization part of the material.

[0195] Based on the simplified multi-scale model, the Jiles-Atherton hysteresis model is combined to decompose the total magnetization into reversible magnetization and irreversible magnetization. The energy balance equation is used to explain how the total magnetization is related to the hysteresis-free magnetization and the irreversible magnetization. The reversible magnetization represents the part that the material can recover after the external magnetic field is removed, while the irreversible magnetization is the loss caused by irreversible processes such as magnetic domain reversal and domain wall pinning.

[0196] The Jiles-Atherton hysteresis model can effectively describe hysteresis loss by calculating the response of materials under DC and AC magnetic fields. In this model, the magnetic induction intensity and magnetic field intensity can be divided into DC and AC parts. Under the combined action of DC and AC magnetic fields, the reversal and dynamic loss of magnetic domains are affected. By separating the reversible and irreversible magnetization processes, the specific value of hysteresis loss can be calculated.

[0197] Since eddy current loss is caused by the induced electric field generated by the change of magnetic induction intensity over time. When eddy current flows in conductive materials, heat is generated due to the resistance effect, thereby causing energy loss. The magnitude of eddy current loss is directly related to the thickness, conductivity and rate of change of magnetic induction intensity of the material. In this embodiment, eddy current loss is calculated by integrating the change of magnetic induction intensity. Specifically, eddy current loss is accumulated over time, and the greater the rate of change of magnetic induction intensity, the more obvious the eddy current effect inside the material.

[0198] Abnormal loss is the energy loss generated when the magnetic domain overcomes the internal obstacles of the material during movement. Unlike hysteresis loss and eddy current loss, abnormal loss is mainly caused by the interaction between the microscopic movement of magnetic domains and obstacles.

[0199] The loss statistical distribution coefficient, which is a function of the applied magnetic field strength, describes the loss distribution of the magnetic domains when overcoming different obstacles in the material. By statistically analyzing the energy consumption caused by these obstacles, the specific value of the abnormal loss can be calculated.

[0200] The calculation of abnormal loss also takes into account the change of magnetic induction intensity over time. When the magnetic domain passes through different microscopic obstacles, the accumulated loss will grow over time. By integrating the loss over time, the total abnormal loss of the material is finally obtained.

[0201] In this embodiment, the hysteresis-free magnetization intensity in the Jiles-Atherton hysteresis model is calculated using a simplified multi-scale model, and the DC magnetic flux density and DC magnetic field intensity are introduced to accurately simulate the offset of the hysteresis loop under DC bias. Then, through the iron loss separation theory, a Jiles-Atherton dynamic hysteresis model considering eddy current loss and abnormal loss is established to accurately calculate the abnormal loss under DC bias.

[0202] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0203] Based on the same inventive concept, the embodiment of the present application also provides a device for determining loss under a DC bias magnetic working condition for implementing the method for determining loss under the DC bias magnetic working condition involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the device for determining loss under a DC bias magnetic working condition provided below can refer to the limitations of the method for determining loss under a DC bias magnetic working condition above, and will not be repeated here.

[0204] In an exemplary embodiment, Figure 3As shown, a loss determination device under a DC bias working condition is provided, comprising: a magnetic domain energy distribution calculation module 310, a single crystal material magnetization intensity calculation module 320, a polycrystalline material hysteresis-free magnetization intensity calculation module 330, a reversible and irreversible magnetization intensity determination module 340, a hysteresis loss calculation module 350, an eddy current loss calculation module 360, an abnormal loss calculation module 370 and a total loss determination module 380, wherein:

[0205] A magnetic domain energy distribution calculation module 310 is used to determine the energy distribution of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition in respective directions, and obtain the distribution ratio of each magnetic domain under the energy distribution;

[0206] A single crystal material magnetization intensity calculation module 320, used to calculate the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains;

[0207] A polycrystalline material hysteresis-free magnetization intensity calculation module 330 is used to obtain the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material by performing spatial homogenization processing on the magnetization intensity of the single crystal material and according to the effective magnetic field intensity;

[0208] A reversible and irreversible magnetization determination module 340, configured to determine the reversible magnetization according to the hysteresis-free magnetization when the total magnetization includes the reversible magnetization and the irreversible magnetization, and to determine the irreversible magnetization according to the total magnetization and the reversible magnetization;

[0209] A hysteresis loss calculation module 350 is used to determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes a DC magnetic field intensity, an AC magnetic field intensity and a hysteresis-free magnetic field intensity;

[0210] The eddy current loss calculation module 360 ​​is used to determine the eddy current loss in the induced electric field formed by the change of magnetic induction intensity according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity;

[0211] The abnormal loss calculation module 370 is used to determine the abnormal loss according to the energy loss caused by overcoming the obstacles caused by the properties of the magnetic domain materials during the magnetic domain movement caused by the change of the magnetic induction intensity over time;

[0212] The total loss determination module 380 is used to determine the sum of the hysteresis loss, the eddy current loss and the abnormal loss as the total loss of the electrical steel sheet under the DC bias condition.

[0213] In one embodiment, the magnetic domain energy distribution calculation module 310 is used to: calculate the anisotropy energy of each magnetic domain according to the directions of different magnetic domains of the magnetic material used for the electrical steel sheet under the DC bias condition and the directional parameters corresponding to each direction; calculate the static magnetic energy of the magnetic domain according to the magnetic field strength and magnetization intensity of the magnetic domain; calculate the magnetoelastic energy of the magnetic domain according to the applied stress and elastic parameters of the magnetic domain; sum the anisotropy energy, the static magnetic energy and the magnetoelastic energy to obtain the free energy of the magnetic domain; and obtain the distribution ratio of each magnetic domain according to the free energy of the magnetic domain based on the Boltzmann distribution function.

[0214] In one embodiment, the polycrystalline material hysteresis-free magnetization intensity calculation module 330 is used to: project the magnetization intensity of the single crystal material into the spatial coordinate system of the polycrystalline material according to the orientation distribution of the single crystal material and the magnetization intensity corresponding to the orientation distribution; in the spatial coordinate system, homogenize the magnetization intensity of different dimensions through a nonlinear function.

[0215] In one embodiment, the reversible and irreversible magnetization determination module 340 is used to: when the total magnetization includes the reversible magnetization and the irreversible magnetization, determine the reversible magnetization according to the hysteresis-free magnetization, and determine the irreversible magnetization according to the total magnetization and the reversible magnetization.

[0216] In one embodiment, the hysteresis loss calculation module 350 is used to: obtain the irreversible loss coefficient and the coupling coefficient between magnetic domains; determine the hysteresis-free magnetic field strength in the effective magnetic field based on the coupling coefficient; adjust the irreversible loss coefficient based on the law of conservation of energy to determine the rate of change of the irreversible magnetization intensity; determine the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes based on the rate of change of the irreversible magnetization intensity to obtain the hysteresis loss.

[0217] In one embodiment, the abnormal loss calculation module 370 is used to: obtain a loss statistical distribution coefficient during the movement of the magnetic domain caused by the change of the magnetic induction intensity over time; the loss statistical distribution coefficient is determined by the DC magnetic field intensity of the magnetic domain; according to the loss statistical distribution coefficient, determine the energy loss of the magnetic domain at different obstacles when the magnetic induction intensity changes, accumulate the energy loss at the different obstacles, and obtain the abnormal loss.

[0218] Each module in the above loss determination device under DC bias magnetic working condition can be implemented in whole or in part by software, hardware and their combination. Each module can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0219] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 4 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a method for determining loss under a DC bias magnetic condition is implemented.

[0220] Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0221] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0222] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0223] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0224] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0225] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0226] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0227] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining loss under DC bias conditions, characterized in that: The method comprises: Calculating the anisotropy energy of each magnetic domain according to the directions of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC biasing condition and the directional parameters corresponding to each direction; Calculating the magnetostatic energy of the magnetic domain according to the magnetic field strength and magnetization strength of the magnetic domain; calculating magnetoelastic energy of the magnetic domain according to the applied stress and elastic parameters of the magnetic domain; Summing the anisotropic energy, the magnetostatic energy and the magnetoelastic energy to obtain the free energy of the magnetic domain; Based on the Boltzmann distribution function, according to the free energy of the magnetic domains, obtaining the distribution ratio of each of the magnetic domains; Calculating the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains; By performing spatial homogenization processing on the magnetization intensity of the single crystal material, and according to the effective magnetic field intensity, the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material is obtained; In the case where the total magnetization includes reversible magnetization and irreversible magnetization, obtaining a reversibility coefficient, and determining a relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization according to the reversibility coefficient; Determining the reversible magnetization represented by the hysteresis-free magnetization according to the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization; Determining the irreversible magnetization according to the total magnetization and the reversible magnetization represented by the hysteresis-free magnetization; Determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes the DC magnetic field intensity, the AC magnetic field intensity and the hysteresis-free magnetic field intensity; In the induced electric field formed by the change of magnetic induction intensity, the eddy current loss is determined according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity; In the process of magnetic domain movement caused by the change of magnetic induction intensity over time, the abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the properties of the magnetic material; The sum of the hysteresis loss, the eddy current loss and the abnormal loss is determined as the total loss of the electrical steel sheet under the DC bias condition.

2. The method according to claim 1, characterized in that The spatially homogenizing the magnetization intensity of the single crystal material comprises: Projecting the magnetization intensity of the single crystal material into a spatial coordinate system of a polycrystalline material according to the orientation distribution of the single crystal material and the magnetization intensity corresponding to the orientation distribution; In the spatial coordinate system, the magnetization intensities in different dimensions are homogenized by a nonlinear function.

3. The method according to claim 1, characterized in that The determining of the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes includes: Obtaining irreversible loss coefficient and coupling coefficient between magnetic domains; Determining the hysteresis-free magnetic field intensity in the effective magnetic field according to the coupling coefficient; Based on the law of conservation of energy, the irreversible loss coefficient is adjusted to determine the rate of change of the irreversible magnetization intensity; The accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes is determined according to the change rate of the irreversible magnetization intensity, thereby obtaining the hysteresis loss.

4. The method according to claim 1, characterized in that: The abnormal loss is determined according to the energy loss caused by overcoming the obstacle caused by the material properties of the magnetic domains during the movement of the magnetic domains caused by the change of the magnetic induction intensity over time, including: In the process of the movement of the magnetic domain caused by the change of the magnetic induction intensity over time, a loss statistical distribution coefficient is obtained; the loss statistical distribution coefficient is determined by the DC magnetic field intensity of the magnetic domain; According to the loss statistical distribution coefficient, the energy loss of the magnetic domain at different obstacles when the magnetic induction intensity changes is determined, and the energy loss at the different obstacles is accumulated to obtain the abnormal loss.

5. A loss determination device under DC bias conditions, characterized in that: The device comprises: A magnetic domain energy distribution calculation module is used to calculate the anisotropy energy of each magnetic domain according to the directions of different magnetic domains of the magnetic material used in the electrical steel sheet under the DC bias working condition and the directional parameters corresponding to each direction; calculate the static magnetic energy of the magnetic domain according to the magnetic field intensity and magnetization intensity of the magnetic domain; calculate the magnetoelastic energy of the magnetic domain according to the applied stress and elastic parameters of the magnetic domain; sum the anisotropy energy, the static magnetic energy and the magnetoelastic energy to obtain the free energy of the magnetic domain; based on the Boltzmann distribution function, obtain the distribution ratio of each magnetic domain according to the free energy of the magnetic domain; A single crystal material magnetization intensity calculation module, used to calculate the magnetization intensity of the single crystal material composed of the magnetic domains according to the distribution ratio of the magnetic domains; A polycrystalline material hysteresis-free magnetization intensity calculation module is used to obtain the hysteresis-free magnetization intensity of the entire polycrystalline material composed of the single crystal material by performing spatial homogenization processing on the magnetization intensity of the single crystal material and according to the effective magnetic field intensity; A reversible and irreversible magnetization determination module, for obtaining a reversible coefficient when the total magnetization includes a reversible magnetization and an irreversible magnetization, and determining the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization according to the reversible coefficient; determining the reversible magnetization represented by the hysteresis-free magnetization according to the relationship between the reversible magnetization, the irreversible magnetization and the hysteresis-free magnetization; and determining the irreversible magnetization according to the total magnetization and the reversible magnetization represented by the hysteresis-free magnetization; A hysteresis loss calculation module, used to determine the hysteresis loss according to the accumulated loss of the irreversible magnetization intensity as the effective magnetic field intensity changes; the effective magnetic field includes a DC magnetic field intensity, an AC magnetic field intensity and a hysteresis-free magnetic field intensity; An eddy current loss calculation module is used to determine the eddy current loss in the induced electric field formed by the change of magnetic induction intensity according to the accumulated loss of the change of the magnetic induction intensity over time; the magnetic induction intensity includes direct current magnetic induction intensity and alternating current magnetic induction intensity; an abnormal loss calculation module, for determining abnormal loss according to energy loss caused by overcoming obstacles caused by the properties of magnetic domain materials during the movement of magnetic domains caused by the change of magnetic induction intensity over time; The total loss determination module is used to determine the sum of the hysteresis loss, the eddy current loss and the abnormal loss as the total loss of the electrical steel sheet under the DC bias condition.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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