Oriented silicon steel magnetic field intensity prediction method and system considering skin effect under direct current magnetic bias high-frequency excitation

Abstract

The invention provides an oriented silicon steel magnetic field intensity prediction method and system considering a skin effect under direct current magnetic bias high-frequency excitation, and belongs to the technical field of soft magnetic material high-frequency hysteresis performance analysis. The method comprises the following steps: determining magnetic field intensity corresponding to static hysteresis loss of oriented silicon steel under direct current magnetic bias excitation; determining the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel; determining the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel; and according to the magnetic field intensity corresponding to the static magnetic hysteresis loss, the eddy current loss and the abnormal loss, constructing a dynamic magnetic hysteresis model of the oriented silicon steel under direct current magnetic bias high-frequency excitation so as to predict the magnetic field intensity of the oriented silicon steel. In the process of determining the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel, the direct-current component of magnetic flux density excitation and the non-uniform characteristic of magnetic field distribution under high-frequency excitation are considered, and accurate characterization of hysteresis and loss under direct-current magnetic bias high-frequency excitation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-frequency hysteresis performance analysis of soft magnetic materials, and in particular relates to a method and system for predicting the magnetic field intensity of oriented silicon steel taking skin effect into consideration under direct current bias high-frequency excitation. Background Art

[0002] Soft magnetic materials are widely used in the cores of electrical and electronic equipment due to their high magnetic resistance and low magnetic loss. As power electronic equipment is increasingly integrated into power systems, the DC bias current is increasing, which may affect the performance of electrical equipment. At the same time, in order to improve power density, the operating frequency is also increasing, which produces a significant skin effect in the core. Therefore, it is crucial to study the dynamic hysteresis characteristics of oriented silicon steel under high-frequency DC bias excitation for the design of electrical equipment.

[0003] At present, the research on the dynamic hysteresis and loss characteristics of oriented silicon steel mainly adopts the Steinmetz formula method and Bertotti loss separation method based on empirical parameters. The Steinmetz formula method uses a large number of experimental measurement results to fit parameters, especially under complex excitation conditions, the accuracy is relatively low. In contrast, the Bertotti loss separation method is more meaningful from a physical point of view, and can fit the hysteresis loop, which is more in line with engineering requirements and more applicable under complex excitation. A method for predicting magnetic field intensity under multi-harmonic high-frequency excitation is proposed in the related technology. This method establishes a dynamic hysteresis model based on the Bertotti loss separation theory, calculates the magnetic field intensity corresponding to the static hysteresis loss, eddy current loss and abnormal loss respectively, and uses the Preisach model to realize the calculation of the static hysteresis loop. However, the existing related hysteresis models that consider the uneven distribution of the magnetic field ignore the DC bias component, or ignore the uneven characteristics of the magnetic field distribution under high-frequency excitation, resulting in the inability to accurately characterize the hysteresis and loss under DC bias high-frequency excitation. Summary of the invention

[0004] The present invention provides a method and system for predicting the magnetic field intensity of oriented silicon steel under DC bias high-frequency excitation taking into account the skin effect, taking into account the DC bias component and the uneven characteristics of the magnetic field distribution under high-frequency excitation, and realizing accurate characterization of hysteresis and loss under DC bias high-frequency excitation.

[0005] In a first aspect, the present invention provides a method for predicting the magnetic field intensity of oriented silicon steel under DC bias high frequency excitation taking into account the skin effect, comprising:

[0006] Determine the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under DC bias excitation;

[0007] Determine the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel;

[0008] Determine the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel;

[0009] According to the magnetic field strength corresponding to static hysteresis loss, eddy current loss and abnormal loss, a dynamic hysteresis model of oriented silicon steel under DC bias high frequency excitation is constructed to predict the magnetic field strength of oriented silicon steel.

[0010] Optionally, the determining of the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation includes:

[0011] The magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under DC bias excitation is calculated according to the following formula:

[0012]

[0013] Among them, H hy (B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

[0014] Optionally, determining the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel includes:

[0015] The magnetic field intensity corresponding to the eddy current loss of oriented silicon steel in the descending branch of the hysteresis loop is calculated according to the following formula:

[0016]

[0017] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0018] Optionally, determining the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel includes:

[0019] The magnetic field intensity corresponding to the eddy current loss of oriented silicon steel in the rising branch of the hysteresis loop is calculated according to the following formula:

[0020]

[0021] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0022] Optionally, determining the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel includes:

[0023] The magnetic field intensity corresponding to the abnormal loss of oriented silicon steel is calculated according to the following formula:

[0024]

[0025] Among them, H ex (t, B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

[0026] In a second aspect, the present invention provides a magnetic field intensity prediction system for oriented silicon steel taking into account the skin effect under DC bias high frequency excitation, comprising:

[0027] The first determination module is used to determine the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation;

[0028] A second determination module is used to determine the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel;

[0029] A third determination module is used to determine the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel;

[0030] The magnetic field strength prediction module is used to construct a dynamic hysteresis model of oriented silicon steel under DC bias high-frequency excitation according to the magnetic field strength corresponding to static hysteresis loss, eddy current loss and abnormal loss, so as to predict the magnetic field strength of oriented silicon steel.

[0031] Optionally, the first determining module includes:

[0032] The first calculation unit is used to calculate the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation according to the following formula:

[0033]

[0034] Among them, H hy (B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

[0035] Optionally, the second determining module includes:

[0036] The second calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel at the descending branch of the hysteresis loop according to the following formula:

[0037]

[0038] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0039] Optionally, the second determining module includes:

[0040] The third calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel in the ascending branch of the hysteresis loop according to the following formula:

[0041]

[0042] Among them, H cl(t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0043] Optionally, the third determining module includes:

[0044] The fourth calculation unit is used to calculate the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel according to the following formula:

[0045]

[0046] Among them, H ex (t, B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

[0047] The present invention provides a method and system for predicting the magnetic field strength of oriented silicon steel under direct current bias high frequency excitation taking into account the skin effect, wherein the method includes determining the magnetic field strength corresponding to the static hysteresis loss of the oriented silicon steel under direct current bias high frequency excitation; determining the magnetic field strength corresponding to the eddy current loss of the oriented silicon steel; determining the magnetic field strength corresponding to the abnormal loss of the oriented silicon steel; constructing a dynamic hysteresis model of the oriented silicon steel under direct current bias high frequency excitation according to the magnetic field strength corresponding to the static hysteresis loss, eddy current loss and abnormal loss, so as to predict the magnetic field strength of the oriented silicon steel. In determining the magnetic field strength corresponding to the eddy current loss of the oriented silicon steel, the present invention takes into account the DC component of the magnetic flux density excitation and the non-uniform characteristics of the magnetic field distribution under high frequency excitation, so as to achieve accurate characterization of hysteresis and loss under direct current bias high frequency excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 A schematic flow chart of a method for predicting magnetic field strength of oriented silicon steel taking skin effect into consideration under direct current bias high frequency excitation provided by an embodiment of the present invention;

[0050] Figure 2 A schematic diagram of the structure of the oriented silicon steel provided in an embodiment of the present invention;

[0051] Figure 3 A schematic diagram of a piecewise linearization principle of a nonlinear BH curve provided by an embodiment of the present invention;

[0052] Figure 4 Another schematic diagram of the principle of piecewise linearization of a nonlinear BH curve provided by an embodiment of the present invention;

[0053] Figure 5 A first comparison diagram of simulated values ​​and measured values ​​of a hysteresis loop provided in an embodiment of the present invention;

[0054] Figure 6 A second comparison diagram of simulated values ​​and measured values ​​of a hysteresis loop provided in an embodiment of the present invention;

[0055] Figure 7 A third comparison diagram of simulated values ​​and measured values ​​of a hysteresis loop provided in an embodiment of the present invention;

[0056] Figure 8 A schematic structural diagram of a magnetic field intensity prediction system for oriented silicon steel taking skin effect into consideration under DC bias high frequency excitation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] like Figure 1 As shown, an embodiment of the present invention provides a method for predicting the magnetic field strength of oriented silicon steel considering the skin effect under DC bias high frequency excitation, comprising:

[0060] Step 101, determining the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation.

[0061] In this step, the quasi-static hysteresis loop under the action of DC bias is experimentally measured to obtain the inverse Everette function required for identifying the Preisach model and obtain a static hysteresis model. For example, the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under DC bias excitation is calculated according to the following formula:

[0062]

[0063] Among them, H hy(B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

[0064] According to the characteristics of the Preisach model, if the hysteresis loop containing DC bias characteristics is used as an input parameter in the process of identifying its inverse Everett function, the static field calculation results of arbitrary excitation under the same bias degree can also be accurately obtained.

[0065] Step 102, determining the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel.

[0066] like Figure 2 For the oriented silicon steel strip shown in the figure, in the non-saturated magnetization state, the basic magnetization curve can be linearly segmented into n segments by using the piecewise linear method, such as Figure 3 As shown. The value of n can be determined by the accuracy requirement. The larger the value of n, the more accurate the magnetic permeability μ selected on the magnetization curve. In general, n of 40 can meet higher accuracy requirements. The y-axis direction is the thickness direction of the oriented silicon steel strip. The constructed DC bias magnetic component B dc The eddy current field expression is as follows:

[0067]

[0068] Among them, H a,i (t) is the average magnetic field intensity on the surface of the oriented silicon steel with respect to the i-th segment permeability at time t; H i (t) is the average magnetic field intensity inside the oriented silicon steel at the time with respect to the i-th segment permeability; B m is the peak value of the AC component excited by the magnetic flux density; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; μ i is the slope corresponding to the i-th segment on the magnetization curve; B 0,iis the magnetic flux density corresponding to the i-th segment on the basic magnetization curve; F i and are the amplitude parameter and phase angle parameter corresponding to the i-th segment permeability, and satisfy:

[0069]

[0070] Among them, γ i is a physical quantity related to skin depth, and its value is D is the thickness of the oriented silicon steel sheet, σ is the electrical conductivity of the oriented silicon steel, and π is the circumference of the circle. The expression of the eddy current field is:

[0071] H cl (t) = Re[H a (t)]-Re[H(t)].

[0072] Among them, H a (t) is the magnetic field intensity on the surface of oriented silicon steel at time t; H(t) is the average magnetic field intensity inside oriented silicon steel at time t; H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t, and satisfies:

[0073]

[0074] Where d / dt represents the derivative operation; B a (t) is the magnetic flux density on the surface of oriented silicon steel at time t; j is an imaginary unit; H i (y, t) represents the magnetic field intensity related to the y-axis position and time t of the i-th segment permeability; B i (y, t) represents the magnetic flux density related to the y-axis position and time with respect to the i-th segment permeability.

[0075] For H a (t) and the nonlinear permeability μ in H(t) i That is, the permeability μ is extracted from the basic magnetization curve using a piecewise linear method. i When the DC component B in the excitation is considered dc The value of H a (t) is combined with H(t), otherwise the DC component B in the excitation dc will be eliminated, making it impossible to consider the influence of the DC component on the eddy current field.

[0076] Based on oriented silicon steel Figure 4 The BH relationship under the saturated magnetization state is shown, and the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel in the descending branch of the hysteresis loop is calculated according to the following formula:

[0077]

[0078] Or, the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel on the rising branch of the hysteresis loop can be calculated according to the following formula:

[0079]

[0080] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0081] Step 103, determining the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel.

[0082] In this step, illustratively, the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel is calculated according to the following formula:

[0083]

[0084] Among them, H ex (t,B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss, which is related to B m It is related to the excitation frequency f; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

[0085] Step 104, constructing a dynamic hysteresis model of the oriented silicon steel under DC bias high frequency excitation according to the magnetic field strength corresponding to the static hysteresis loss, eddy current loss and abnormal loss, so as to predict the magnetic field strength of the oriented silicon steel.

[0086] According to the principle of field superposition, the magnetic field intensities corresponding to static hysteresis loss, eddy current loss and abnormal loss are superimposed, and a dynamic hysteresis model of oriented silicon steel under DC bias high-frequency excitation is established to realize the prediction of the magnetic field intensity of oriented silicon steel.

[0087] like Figure 5 , Figure 6 and Figure 7 As shown in the figure, the comparison between the simulation result of the hysteresis loop obtained by the method of this embodiment and the measurement result is given. The method provided in this embodiment takes into account the inhomogeneity of the magnetic field distribution along the thickness direction inside the sample. Under the condition of high fundamental frequency (greater than 500Hz), the calculated classical eddy current loss part is compared with the traditional formula Has higher accuracy.

[0088] In summary, the magnetic field strength prediction method for oriented silicon steel considering the skin effect under DC bias high-frequency excitation provided in this embodiment takes into account the DC component of the flux density excitation and the uneven characteristics of the magnetic field distribution under high-frequency excitation in determining the magnetic field strength corresponding to the eddy current loss of the oriented silicon steel, thereby achieving accurate characterization of hysteresis and loss under DC bias high-frequency excitation.

[0089] Example 2

[0090] Based on the same inventive concept as Example 1, this embodiment provides a magnetic field strength prediction system for oriented silicon steel considering the skin effect under DC bias high frequency excitation. Since the principle of solving the problem by this system is similar to the aforementioned magnetic field strength prediction method for oriented silicon steel considering the skin effect under DC bias high frequency excitation, the implementation of this system can refer to the implementation of the magnetic field strength prediction method for oriented silicon steel considering the skin effect under DC bias high frequency excitation.

[0091] like Figure 8 As shown, the magnetic field intensity prediction system of oriented silicon steel considering skin effect under DC bias high frequency excitation includes:

[0092] The first determination module 10 is used to determine the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation.

[0093] The second determination module 20 is used to determine the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel.

[0094] The third determination module 30 is used to determine the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel.

[0095] The magnetic field strength prediction module 40 is used to construct a dynamic hysteresis model of oriented silicon steel under DC bias high frequency excitation according to the magnetic field strength corresponding to the static hysteresis loss, eddy current loss and abnormal loss, so as to predict the magnetic field strength of the oriented silicon steel.

[0096] Exemplarily, the first determining module includes:

[0097] The first calculation unit is used to calculate the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation according to the following formula:

[0098]

[0099] Among them, H hy(B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

[0100] Exemplarily, the second determining module includes:

[0101] The second calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel at the descending branch of the hysteresis loop according to the following formula:

[0102]

[0103] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0104] Exemplarily, the second determining module includes:

[0105] The third calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel in the ascending branch of the hysteresis loop according to the following formula:

[0106]

[0107] Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

[0108] Exemplarily, the third determining module includes:

[0109] The fourth calculation unit is used to calculate the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel according to the following formula:

[0110]

[0111] Among them, H ex (t, B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

[0112] For more specific working processes of the above modules, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here.

[0113] Example 3

[0114] This embodiment provides a computer device, including a processor and a memory; wherein the processor implements the steps of the method for predicting the magnetic field intensity of oriented silicon steel described in Example 1 when executing a computer program stored in the memory.

[0115] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here.

[0116] Example 4

[0117] This embodiment provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the method for predicting the magnetic field intensity of oriented silicon steel described in Embodiment 1 are implemented.

[0118] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here.

[0119] Example 5

[0120] This embodiment provides a computer program product, including computer executable instructions or a computer program. When the computer executable instructions or the computer program are executed by a processor, the steps of the method for predicting the magnetic field intensity of oriented silicon steel described in Example 1 are implemented.

[0121] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here.

[0122] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the systems, devices, storage media, and computer program products disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0123] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention or some parts of the embodiments.

[0124] In some embodiments, computer executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0125] As an example, computer-executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions).

[0126] As an example, computer executable instructions may be deployed to be executed on one electronic device, or on multiple electronic devices located at one site, or on multiple electronic devices distributed at multiple sites and interconnected by a communication network.

[0127] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for predicting the magnetic field intensity of oriented silicon steel under DC bias high frequency excitation considering the skin effect, characterized in that: include: Determine the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under DC bias excitation; Determine the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel; Determine the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel; According to the magnetic field strength corresponding to static hysteresis loss, eddy current loss and abnormal loss, a dynamic hysteresis model of oriented silicon steel under DC bias high frequency excitation is constructed to predict the magnetic field strength of oriented silicon steel.

2. The method for predicting magnetic field intensity of oriented silicon steel according to claim 1, characterized in that: The method of determining the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation includes: The magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under DC bias excitation is calculated according to the following formula: Among them, H hy (B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

3. The method for predicting magnetic field intensity of oriented silicon steel according to claim 2, characterized in that: The method of determining the magnetic field strength corresponding to the eddy current loss of the oriented silicon steel comprises: The magnetic field intensity corresponding to the eddy current loss of oriented silicon steel in the descending branch of the hysteresis loop is calculated according to the following formula: Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

4. The method for predicting magnetic field intensity of oriented silicon steel according to claim 2, characterized in that: The method of determining the magnetic field strength corresponding to the eddy current loss of the oriented silicon steel comprises: The magnetic field intensity corresponding to the eddy current loss of oriented silicon steel in the rising branch of the hysteresis loop is calculated according to the following formula: Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

5. The method for predicting magnetic field intensity of oriented silicon steel according to claim 1, characterized in that: The determining of the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel comprises: The magnetic field intensity corresponding to the abnormal loss of oriented silicon steel is calculated according to the following formula: Among them, H ex (t, B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

6. A magnetic field intensity prediction system for oriented silicon steel under DC bias high frequency excitation taking into account skin effect, characterized in that: include: The first determination module is used to determine the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation; A second determination module is used to determine the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel; A third determination module is used to determine the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel; The magnetic field strength prediction module is used to construct a dynamic hysteresis model of oriented silicon steel under DC bias high-frequency excitation according to the magnetic field strength corresponding to static hysteresis loss, eddy current loss and abnormal loss, so as to predict the magnetic field strength of oriented silicon steel.

7. The magnetic field intensity prediction system for oriented silicon steel according to claim 6, characterized in that: The first determining module comprises: The first calculation unit is used to calculate the magnetic field intensity corresponding to the static hysteresis loss of the oriented silicon steel under DC bias excitation according to the following formula: Among them, H hy (B) is the magnetic field intensity corresponding to the static hysteresis loss of oriented silicon steel under magnetic flux density B; B0 is the extreme value of magnetic flux density corresponding to the rising branch of the hysteresis loop; b0 is the extreme value of magnetic flux density corresponding to the falling branch of the hysteresis loop; E(B0, b0) is the value of the inverse Everett function at positive saturation; N is the maximum value of the sampling point sequence of the rising branch or the falling branch corresponding to the magnetic field intensity; B k is the magnetic flux density of the kth sampling point in the rising branch of the hysteresis loop; b k is the magnetic flux density of the kth sampling point in the descending branch of the hysteresis loop; E(B k ,b k ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the ascending and descending branches of the hysteresis loop; E(B k ,b k-1 ) is the value of the inverse Everett function corresponding to the extreme value of the kth sampling point in the rising branch of the hysteresis loop and the extreme value of the k-1th sampling point in the falling branch.

8. The magnetic field intensity prediction system for oriented silicon steel according to claim 7, characterized in that: The second determining module comprises: The second calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel at the descending branch of the hysteresis loop according to the following formula: Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

9. The magnetic field intensity prediction system for oriented silicon steel according to claim 7, characterized in that: The second determining module comprises: The third calculation unit is used to calculate the magnetic field intensity corresponding to the eddy current loss of the oriented silicon steel in the ascending branch of the hysteresis loop according to the following formula: Among them, H cl (t) is the magnetic field intensity corresponding to the eddy current loss of oriented silicon steel at time t; σ is the electrical conductivity of oriented silicon steel; D is the thickness of oriented silicon steel sheet; ω is the angular frequency; B dc is the DC component of the magnetic flux density excitation; B m is the peak value of the AC component excited by the magnetic flux density; e is a natural constant.

10. The magnetic field intensity prediction system for oriented silicon steel according to claim 6, characterized in that: The third determination module comprises: The fourth calculation unit is used to calculate the magnetic field intensity corresponding to the abnormal loss of the oriented silicon steel according to the following formula: Among them, H ex (t, B) is the magnetic field intensity corresponding to the abnormal loss of oriented silicon steel under magnetic flux density B at time t; σ is the electrical conductivity of oriented silicon steel; S is the cross-sectional area of ​​oriented silicon steel; V0 is the statistical parameter of abnormal loss; G is a dimensionless coefficient; d / dt represents the derivative operation; when dB / dt is a positive value, δ=1, and when dB / dt is a negative value, δ=-1; |·| represents taking the absolute value.

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