Analysis method and program
By defining magnetic circuits for two-particle systems in a composite magnetic member model, the method addresses the long calculation times associated with thin insulating layers in SMC models, achieving efficient and accurate analysis.
Patent Information
- Application Number
- JP2024039354
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-13
- Publication Date
- 2025-09-29
AI Technical Summary
Calculating the insulating layer between multiple metal powder particles in a soft magnetic composite (SMC) model with a thickness of less than several hundred nanometers requires a huge number of elements, leading to non-convergence or excessively long calculation times in finite element analysis.
An analysis method that defines a magnetic circuit for each two-particle system in a composite magnetic member model using a discrete particle method, calculating the magnetic resistance between the centers of adjacent particles to reduce calculation time.
Reduces calculation time significantly compared to traditional finite element methods while maintaining analysis accuracy, especially for thin insulating layers.
Smart Images
Figure 2025140157000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure generally relates to an analysis method and a program, and more particularly to an analysis method for a composite magnetic member and a program for executing the analysis method. [Background technology]
[0002] Non-Patent Document 1 discloses an analysis method for soft magnetic composites (SMCs). In this analysis method, the metal magnetic powder that constitutes the composite magnetic member is modeled using the discrete element method (DEM), the obtained SMC model is converted into a finite element mesh, and various properties are calculated by analyzing it using the finite element method (FEM). [Prior art documents] [Patent documents]
[0003] [Non-Patent Document 1] A. Maruo and H. Igarashi, “Analysis of Magnetic Properties of Soft Magnetic Composite Using Discrete Element Method,” IEEE Trans. Magn., vol. 55, no. 6, pp.1-5, Art no. 2002205 (2019) Summary of the Invention [Problem to be solved by the invention]
[0004] However, when calculating the insulating layer between multiple metal powder particles (between multiple particles) in an SMC model with a thickness of less than several hundred nanometers, a huge number of elements are required for finite element analysis, which can result in problems such as the calculation not converging or taking a long time to calculate.
[0005] The present disclosure has been made in view of the above circumstances, and aims to provide an analysis method and program that can shorten calculation time. [Means for solving the problem]
[0006] An analysis method according to one aspect of the present disclosure is a method for analyzing a composite magnetic member. The composite magnetic member contains a plurality of soft magnetic particles. The analysis method includes a defining step and a calculating step. In the defining step, a magnetic circuit is defined for each two-particle system including any two adjacent particle models among the plurality of particle models based on the arrangement of the plurality of particle models corresponding to the plurality of soft magnetic particles in a composite magnetic member model obtained by modeling the composite magnetic member using a discrete particle method. In the calculating step, the magnetic resistance between the centers of the two particle models is calculated using the magnetic circuit defined in the defining step.
[0007] A program according to one aspect of the present disclosure is a program for causing one or more processors to execute the analysis method. [Effects of the Invention]
[0008] According to the present disclosure, it is possible to reduce the calculation time. [Brief explanation of the drawings]
[0009] [Figure 1] FIG. 1 is a schematic diagram of an SMC model in an analysis method according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of magnetic flux in a multi-particle system in the above analysis method. [Figure 3] FIG. 3 is an explanatory diagram of a magnetic circuit of a two-particle system in the above analysis method. [Figure 4] FIG. 4 is another explanatory diagram of the magnetic circuit of the two-particle system in the above analysis method. [Figure 5] FIG. 5 is an explanatory diagram of the entire magnetic circuit in the above analysis method. [Figure 6]FIG. 6 is an explanatory diagram of the relationship between the thickness of the insulating layer model and the macroscopic relative permeability in the above analysis method. [Figure 7] FIG. 7 is a flowchart showing the process of the above analysis method. [Figure 8] FIG. 8 is an explanatory diagram of a magnetic circuit of a two-particle system in the analysis method according to the first modification. [Figure 9] FIG. 9 is an explanatory diagram of a magnetic circuit of a two-particle system in an analysis method according to the second modification. DETAILED DESCRIPTION OF THE INVENTION
[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Common elements in the embodiments described below are designated by the same reference numerals, and redundant descriptions of the common elements may be omitted. The following embodiments and modifications are merely a portion of the various embodiments of the present disclosure. Various modifications of the following embodiments and modifications can be made depending on the design, etc., as long as the object of the present disclosure can be achieved. The configurations of the modifications can also be combined as appropriate.
[0011] The drawings described in this disclosure are schematic drawings, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.
[0012] (1) Overview First, an overview of the analysis method according to this embodiment will be described with reference to FIGS.
[0013] The analysis method of this embodiment is a method for analyzing a composite magnetic member containing a plurality of soft magnetic particles. In this embodiment, the composite magnetic member is a powder magnetic core used in, for example, an inductor (for example, a power choke coil).
[0014] The soft magnetic particles have soft magnetic properties. In this embodiment, the soft magnetic particles are soft magnetic alloy particles. However, the soft magnetic particles may be soft magnetic iron powder particles. The soft magnetic alloy particles are, for example, iron-based soft magnetic alloy particles. Specific examples of iron-based soft magnetic alloys include soft magnetic iron-silicon (Fe-Si) alloys, soft magnetic iron-aluminum (Fe-Al) alloys, soft magnetic iron-aluminum-silicon (Fe-Al-Si) alloys, soft magnetic iron-silicon-chromium (Fe-Si-Cr) alloys, soft magnetic iron-chromium (Fe-Cr) alloys, soft magnetic iron-nickel (Fe-Ni) alloys, soft magnetic iron-silicon-boron (Fe-Si-B) alloys, soft magnetic iron-nitrogen (Fe-N) alloys, soft magnetic iron-carbon (Fe-C) alloys, soft magnetic iron-boron (Fe-B) alloys, soft magnetic iron-phosphorus (Fe-P) alloys, permendur (Fe-Co), soft magnetic iron-cobalt-vanadium (Fe-Co-V) alloys, Fe-based amorphous alloys, and Fe-based nanocrystalline alloys.
[0015] Furthermore, the composite magnetic member may contain, in addition to the plurality of soft magnetic particles, for example, a plurality of inorganic insulating particles and a thermosetting resin.
[0016] Such a composite magnetic member has excellent relative magnetic permeability and withstand voltage, and can therefore be suitably used to produce powder magnetic cores and powder magnetic cores for power choke coils and the like.
[0017] The analysis method includes a defining step and a calculating step.
[0018] In the definition step, a magnetic circuit is defined for each two-particle system including any two adjacent particle models 2 out of the plurality of particle models 2 based on the arrangement state of the plurality of particle models 2 corresponding to the plurality of soft magnetic particles in the composite magnetic member model 1, which is a composite magnetic member modeled using the discrete particle method.
[0019] In the calculation step, the magnetic resistance between the centers 21 of the two particle models 2 is calculated using the magnetic circuit defined in the definition step.
[0020] In the following description, the composite magnetic member model 1 may be referred to as the "SMC model 1."
[0021] According to the analysis method of this embodiment, by defining (constructing) a magnetic circuit based on the internal structure of the composite magnetic material model 1 modeled using the discrete particle method, it is possible to take into account the particle distribution and local magnetic flux distribution of the composite magnetic material, while reducing the calculation time compared to analysis methods using the finite element method.
[0022] (2)Details The analysis method according to this embodiment will be described in detail below with reference to Figures 1 to 7. The analysis method according to this embodiment includes a modeling step (modeling processing: step S1 in Figure 7), a defining step (defining processing: step S2 in Figure 7), a first calculation step (first calculation processing: step S3 in Figure 7), and a second calculation step (second calculation processing: step S4 in Figure 7).
[0023] (2.1) Modeling process In the modeling step of the analysis method of this embodiment, a composite magnetic member is modeled using a discrete particle method to generate an SMC model 1. The SMC model 1 is a three-dimensional model. The SMC model 1 includes a plurality of particle models 2 corresponding to a plurality of soft magnetic particles in the composite magnetic member. The discrete particle method calculates the motion of the plurality of particle models 2 by solving the equations of motion shown in the following equations (1) and (2) in small time steps. In the following description, the particle models 2 may be simply referred to as "particles 2."
[0024]
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[0025]
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[0026] "m" in Equation (1) and Equation (2) i "," "u i "," "Ii "," θ i " and "g" are the mass, displacement vector, moment of inertia, rotational displacement vector, and gravitational acceleration of the i-th particle 2, respectively. "¨" indicates the second derivative of time. "f ij " and "T ij " are the interaction force and rotation moment between particle model i and particle model j, respectively. In the analysis method of this embodiment, for particle model j that is in contact with particle model i, "f ij " and "T ij In the analysis method of this embodiment, the contact determination is performed using the following equations (3) and (4).
[0027]
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[0028]
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[0029] "r" in Equation (3) and Equation (4) i ", "r j " are the particle radii of particle model i and particle model j, respectively, and "x i ", "x j " are the center coordinate vectors of particle model i and particle model j, respectively.
[0030] In the analysis method of this embodiment, each particle model 2 of the particle model group (plurality of particle models 2) is initially placed at a random position within the area A1 (see FIG. 1), and equations (1) and (2) are solved at every minute time step (every 1.0 ms in this embodiment) to calculate the motion of the particle model group.
[0031] Furthermore, in the analysis method of this embodiment, in order to simulate the compression of particles in the manufacturing process of the composite magnetic member, a mass plate is dropped from above the particle model group, and the movement of the particle model group is calculated in the same manner.
[0032] Figure 1 shows an SMC model 1 of a composite magnetic member obtained by the discrete particle method. In this embodiment, the number of particles is set to 300, and a three-dimensional model is obtained from a Gaussian distribution with an average particle radius of 5.0 μm and a standard deviation of 1.8 μm.
[0033] Although overlapping may occur between particle models 2 due to numerical errors, this overlapping allows contact between particles due to compression to be naturally considered. In the analysis method of this embodiment, the overlapping portion of two particle models 2 is analyzed as a cylindrical insulating layer model 3. The insulating layer model 3 includes an insulating layer model 3i on the particle i side and an insulating layer model 3j on the particle j side. In the present disclosure, when two particle models 2 partially overlap, the two particle models 2 are said to be in contact. In the present disclosure, in two contacting particle models 2, a portion of the surface of one of the two particle models 2 (first particle model) and a portion of the surface of the other of the two particle models 2 (second particle model) are in contact via the insulating layer model 3. In an actual composite magnetic member, an insulating layer is formed using a resin, oxide film, or the like that covers the surface of the soft magnetic particles.
[0034] As shown in FIG. 2, in the SMC model 1 obtained by the discrete particle method, multiple particles 2 are arranged around one particle 2. In the example of FIG. 2, one particle model 2 (particle model i) is in contact with all of the multiple particle models 2 (particle models j) adjacent to particle model i (four particle models 2 (particle models j) in the example of FIG. 2). However, in the SMC model 1 obtained by the discrete particle method, there may be a particle model j that is separated from particle model i without contacting it. In the following description, when there is no need to distinguish between particle model i and particle model j, particle model i and particle model j may each be referred to as a "particle model 2 (or particle 2)." In the following description, particle model i may be simply referred to as a "particle i," and particle model j may be simply referred to as a "particle j." In FIG. 2, insulating layer model 3i and insulating layer model 3j are collectively referred to as insulating layer model 3.
[0035] (2.2) Prescribed Processing As described above, in the definition step of the analysis method of this embodiment, a magnetic circuit is defined for each two-particle system including any two adjacent particles 2 among the plurality of particles 2 based on the arrangement state of the plurality of particles 2 in the SMC model 1 modeled using the discrete particle method.
[0036] In the defining step, a magnetic circuit of a two-particle system is defined between one particle i and each of a plurality of particles 2 (particles j) adjacent to the particle i (four particles in the example of FIG. 2).
[0037] As shown in Figure 3, a magnetic scalar potential φ is applied to the center 21i of particle i. i and apply a magnetic scalar potential φ to the center 21j of particle j. j is given, the magnetic flux Φ flowing between particles i and j ij is expressed by equation (5).
[0038]
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[0039] "R" in equation (5) ij ” is the magnetic resistance between the centers 21i and 21j of particles i and j. As shown in Figure 3, the magnetic circuit of the two-particle system is pij ,R pji and the magnetoresistance R of the insulating layer model 3 sij ,R sji Includes: R pij ,R sij and represent the magnetic resistance inside particle i when particle j is seen from particle i, and the magnetic resistance inside particle j when particle j is seen from particle i, respectively. As shown in equation (6), R ij is the magnetoresistance R inside particle 2 pij ,R pji and the magnetoresistance R of the insulating layer model 3i on the particle i side sij and the magnetoresistance R of the insulating layer model 3j on the particle j side sji That is, in the defining step of this embodiment, the magnetoresistance R inside the particle 2 is pij ,R pji and the magnetoresistance R of the insulating layer model 3 sij ,Rsji The magnetic circuit in which the two particles are connected in series is defined as the magnetic circuit of a two-particle system in contact.
[0040]
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[0041] (2.3) First calculation process As described above, in the calculation step (first calculation step) of the analysis method of this embodiment, the magnetic circuit defined in the definition step is used to calculate the magnetic resistance between the centers 21 of the two particles 2. In the calculation step of the analysis method of this embodiment, the magnetic resistance R of the insulating layer model 3 interposed between the surfaces of the two particles 2 is calculated. sij ,R sji In addition, in the calculation step of the analysis method of this embodiment, the magnetic resistance R pij ,R pji This includes the calculation of the above, which can improve the accuracy of the analysis.
[0042] 3 and 4 show the state where two particles 2 (particle i and particle j) are in contact with each other. In this case, the shapes of particles i and j are hemispherical, cut off at the contact surface. Therefore, the magnetic resistance R inside particle 2 is pij ,R pji can be regarded as the resistance of a hemisphere cut off at the contact surface. The shape of the insulating layer model 3 is a cylinder with a contact surface (first bottom surface) on the particle i side and a contact surface (second bottom surface) on the particle j side. Here, if the thickness of the insulating layer model 3 in the direction in which the two particles 2 contact is l, the magnetic resistance R of the insulating layer model 3i on the particle i side is sij and the magnetoresistance R of the insulating layer model 3j on the particle j side sji can be modeled as a cylindrical resistor with height l / 2.
[0043] The magnetic path is along the direction in which the two particles 2 are aligned. ij ", "d´ ji" are the length (magnetic path length) between the center 21i of particle i and the insulating layer model 3 in the alignment direction of the two particles 2, and the length (magnetic path length) between the center 21j of particle j and the insulating layer model 3, respectively. The length (magnetic path length) between the center 21i of particle i and the center of the insulating layer model 3 in the alignment direction of the two particles 2 is defined as d ij The length between the center 21j of the particle j and the center of the insulating layer model 3 (magnetic path length) is d ji The length between the centers 21 of particles i and j (magnetic path length) is D ij Then, D ij is expressed by equation (7).
[0044]
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[0045] Furthermore, equation (8) can be obtained from the Pythagorean theorem.
[0046]
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[0047] Equations (9) and (10) are obtained from equations (7) and (8).
[0048]
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[0049]
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[0050] d´ ij and d´ ji is expressed by equations (11) and (12).
[0051]
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[0052]
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[0053] Using the magnetic path length obtained from equations (7) to (12), R pij ,R pji is expressed by equations (13) and (14).
[0054]
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[0055]
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[0056] "μ" in equations (13) and (14) is the magnetic permeability of particles i and j. i (x) is the cross-sectional area of particle i at distance x from the center 21i of particle i. j (y)” is the cross-sectional area of particle j at a distance y from the center 21j of particle j.
[0057] In addition, the magnetic path length obtained from equations (7) to (12) is used to calculate the magnetic resistance R of the insulating layer model 3i on the particle i side. sij is expressed by equation (15), and the magnetoresistance R of the insulating layer model 3j on the particle j side is sji is expressed by equation (16).
[0058]
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[0059]
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[0060] "μ0" in equations (15) and (16) is the magnetic permeability of a vacuum.
[0061] (2.4) Second calculation process The second calculation step of the analysis method of this embodiment calculates the macroscopic magnetic permeability of the SMC model 1. In this disclosure, the term "macroscopic magnetic permeability" refers to the equivalent magnetic permeability when the entire material is considered to be homogeneous.
[0062] By applying Kirchhoff's law in the magnetic circuit to the node (central node) at the center 21i of particle i (see Fig. 2), we obtain Equation (17), which is the relational expression for the magnetic scalar potential centered on particle i.
[0063]
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[0064] By calculating equation (17) for all particles 2 inside the SMC model 1, the simultaneous equations to be solved are obtained.
[0065] Figure 5 is a schematic diagram showing the entire magnetic circuit. It is assumed that a uniform magnetic flux density B0 is applied to the SMC model 1 in the upward direction in Figure 5, and this is represented by a constant magnetic flux source Φ0 = B0S SMC It is expressed by S SMC is the area of the upper (or lower) surface of the SMC model 1, that is, the area of the upper (or lower) surface of the region A1.
[0066] To connect the SMC model 1 and the constant magnetic flux source, node 0 is introduced on the top surface of the SMC model 1 and node N+1 is introduced on the bottom surface. N is the number of nodes (i.e., the number of particles) in the SMC model 1. Kirchhoff's law centered on these two nodes is given by equations (18) and (19).
[0067]
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[0068]
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[0069] "j" in equations (18) and (19) represents the central node of particle 2 that is in contact with the top or bottom surface of the SMC model 1. When the equations for all nodes are combined into a matrix form, equation (20) is obtained.
[0070]
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[0071] "R" in equation (20) ∈ real number R (N+2)×(N+2) is a matrix whose elements are magnetic resistance values. I} T ∈ real number R N+2 is the external magnetic flux flowing into each node (Φ I = 0). Also, "φ"∈R N+2 is the unknown magnetic scalar potential. By solving the simultaneous equations expressed by this matrix, the unknown φ is obtained.
[0072] Macroscopic permeability of SMC model 1 <μ r > is the magnetomotive force F=φ0-φ applied to the entire circuit N+1 and the magnetic path length L (= length of SMC model 1 in the B0 direction), we obtain equation (21).
[0073]
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[0074] (3) Effects Next, the effects of the analysis method of this embodiment will be described with reference to Tables 1 and 2 and FIG.
[0075] The calculation results (analysis results) of the macroscopic relative magnetic permeability of the SMC model 1 of the composite magnetic member using the analysis method of this embodiment are compared with the calculation results (analysis results) of the macroscopic relative magnetic permeability of the composite magnetic member using an analysis method using FEM. Here, the analysis method using FEM uses a hexahedral volume lookup mesh divided into tetrahedrons, and performs calculations by reflecting the particle distribution shown in Figure 1 in the mesh material information. Table 1 shows the analysis settings. The "insulating layer thickness" in Table 1 is the thickness of the insulating layer model 3.
[0076] [Table 1]
[0077] For comparison with the analysis method of this embodiment, we use the calculation results of the Ohlendorff equation corresponding to the filling factor η calculated for each insulating layer thickness. The Ohlendorff equation is expressed as Equation (22) using the demagnetizing factor N (N=1 / 3 for a sphere).
[0078]
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[0079] Graph G1 in Fig. 6 shows the calculation results using the analysis method of this embodiment, graph G2 shows the calculation results using the analysis method using FEM, and graph G3 shows the calculation results using the Ohlendorf equation. As shown in Fig. 6, the analysis method of this embodiment can obtain calculation results that are close to those obtained using the analysis method using FEM.
[0080] Table 2 shows the results of a comparison between the calculation time in the analysis method of this embodiment and the calculation time in the analysis method using FEM.
[0081] [Table 2]
[0082] In Table 2, the calculation time for each insulating layer thickness using the analysis method of this embodiment is normalized as 1. As shown in Table 2, the analysis method of this embodiment can significantly reduce calculation time compared to the analysis method using FEM. Furthermore, with the analysis method of this embodiment, the calculation time remains roughly the same even when the insulating layer thickness changes. On the other hand, with the analysis method using FEM, the calculation time becomes significantly longer as the insulating layer thickness becomes thinner. In other words, with the analysis method of this embodiment, the calculation time can be reduced as the insulating layer thickness becomes thinner compared to the analysis method using FEM.
[0083] Note that the calculation time for an FEM-based analysis method is estimated because the calculation time is enormous when the insulation layer thickness is 0.1 μm. When using the FEM-based analysis method, the number of elements required for modeling when the insulation layer thickness is 0.1 μm is 27 times (= 3 × 3 × 3) times greater than when the insulation layer thickness is 0.3 μm. Furthermore, assuming that the calculation volume using a sparse matrix solver using the conjugate gradient method (CG method) accounts for the majority of the total calculation volume, the total calculation volume is considered to be proportional to the square of the number of elements required for modeling. Therefore, when using the FEM-based analysis method, the calculation time for an insulation layer thickness of 0.1 μm is estimated to be approximately 729 times (27 squared) the calculation time for an insulation layer thickness of 0.3 μm.
[0084] The analysis method of this embodiment and the effects of the analysis method are also described in the reference (Sato Shunsuke, Igarashi Hajime. On speeding up the analysis of soft magnetic composite models using the discrete element method. Materials from the Institute of Electrical Engineers of Japan (Joint Study Group on Stationary Machines / Rotating Machines), 2023, SA23063 / RM23062, pp. 29-34).
[0085] (4) Variations Modifications of the above embodiment are listed below.
[0086] (4.1) Variation 1 In the defining step of the analysis method of the first modification, when two particle models 2 are not in contact with each other and are separated as shown in FIG. 8, a magnetic circuit of a two-particle system in a non-contact state is defined. Note that the "non-contact state" in this disclosure includes the two particle models 2 not overlapping each other. The magnetic resistance R inside the particle 2 is defined as pij ,R pji The resistance value of is the magnetic resistance R between the surfaces of particles i and j. inj Since the resistance between the centers 21 of particles i and j in a non-contact state is negligibly small compared to the resistance value of ij is the magnetic resistance R between the surfaces of particles i and j inj As a result, the magnetic circuit of a two-particle system in a non-contact state can be expressed by equation (23).
[0087]
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[0088] In the calculation step of the analysis method of the first modification, the magnetic resistance R between the centers 21 of the two particles 2 in a non-contact state is calculated using the magnetic circuit defined in the definition step. ij Calculate the magnetic resistance R between the surfaces of particles i and j. inj is the radius of particle 2, which is the smaller of particles i and j (in the example of Figure 8, particle i has radius r i ), and thus equation (24) can be obtained from equation (23).
[0089]
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[0090] Considering that the particles are spherical, the magnetic flux actually passes through the part where the distance between the surfaces of the particles is short. Therefore, the radius of the area through which the magnetic flux can pass is the radius r of particle i. i Therefore, using the effective radius ratio α (≦1), we can obtain equation (25) from equation (24).
[0091]
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[0092] In the calculation step of the first modification, when two particle models 2 are not in contact with each other and are separated from each other, the effective radius αr i is used to calculate the magnetic resistance between the centers 21. This makes it possible to improve the accuracy of the analysis.
[0093] (4.2) Variation 2 In the defining step of the analysis method of the modified example 2, when two particle models 2 are in contact with each other as shown in Fig. 9, a magnetic circuit of a two-particle system in contact is defined. In the defining step of the modified example 2, the magnetic resistance R between the insulating layer model 3 of the two particle models 2 and the surfaces that are not in contact with each other is defined. eij In the defining step of the analysis method of the second modification, the magnetic circuit is defined by taking into consideration the magnetic resistance R sij ,R sji and the magnetic resistance R between the insulating layer model 3 of particle i, j and the surface that is not in contact with it. eij The magnetic circuit defined in the defining step of Modification 2 can be expressed by Equation (26).
[0094]
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[0095] In the calculation step of the analysis method of the second modification, the magnetic resistance R between the centers 21 of the two particles 2 in contact with each other is calculated using the magnetic circuit defined in the definition step. ij Here, "R eij " can be expressed by equation (27).
[0096]
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[0097] In the second modification, the radius of the inner periphery is the radius of the insulating layer model 3 (i.e., the radius of the contact surface), and the radius of the outer periphery is r j and the height is D ij The magnetic resistance of the cylindrical region A3 is expressed as the magnetic resistance R between the insulating layer model 3 of the particle i, j and the surface that is not in contact with the particle i, j. eij The magnetic permeability of the entire area of the area A3 is μ0. The area A3 is an area corresponding to the magnetic path of the non-contact part of the particles i and j. The area A2 has a radius equal to the radius of the insulating layer model 3 and a height D ij Region A2 is a cylindrical region where A2 corresponds to the magnetic path at the contact point between particles i and j, that is, the magnetic path including the insulating layer model 3. Regions A2 and A3 are concentric regions, and region A3 exists around region A2.
[0098] In the calculation step of the analysis method of the second modification, the magnetic resistance R sij ,R sji and the magnetic resistance R between the insulating layer model 3 and the surface that is not in contact with the two particle model 2. eij The combined magnetic resistance of the parallel connected coils is calculated, which improves the accuracy of the analysis.
[0099] (4.3) Other variations Functions equivalent to the analysis methods according to the above-described embodiment, modification 1, and modification 2 may be embodied as a (computer) program, a non-transitory recording medium on which a program is recorded, etc. A program according to one aspect is a program for causing one or more processors to execute the analysis methods according to the above-described embodiment, modification 1, and modification 2.
[0100] The executing entity of the analysis method of the present disclosure includes a computer system. The computer system is primarily composed of a processor and memory as hardware. The processor executes a program stored in the memory of the computer system to realize the function of the executing entity of the analysis method of the present disclosure. The program may be pre-stored in the memory of the computer system, provided via a telecommunications line, or provided in a non-transitory recording medium readable by the computer system, such as a memory card, optical disk, or hard disk drive. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits, such as ICs and LSIs, are referred to by different names depending on the degree of integration, and include integrated circuits called system LSIs, very large-scale integrations (VLSIs), or ultra-large-scale integrations (ULSIs). Furthermore, field-programmable gate arrays (FPGAs), which are programmed after the LSI is manufactured, or logic devices capable of reconfiguring the connections within the LSI or the circuit partitions within the LSI, can also be used as processors. The electronic circuits may be integrated into one chip or distributed across multiple chips. The chips may be integrated into one device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.
[0101] (summary) As is clear from the above-described embodiments and modifications, the analysis method according to the first aspect is a method for analyzing a composite magnetic member. The composite magnetic member contains a plurality of soft magnetic particles. The analysis method includes a defining step and a calculating step. In the defining step, a magnetic circuit is defined for each two-particle system including any two adjacent particle models (2) among the plurality of particle models (2) based on the arrangement of the plurality of particle models (2) corresponding to the plurality of soft magnetic particles in a composite magnetic member model (1) obtained by modeling the composite magnetic member using a discrete particle method. In the calculating step, the magnetic resistance between the centers (21) of the two particle models (2) is calculated using the magnetic circuit defined in the defining step.
[0102] According to this aspect, it is possible to reduce the calculation time compared to an analysis method using FEM.
[0103] In the analysis method according to the second aspect, when the two particle models (2) are not in contact with each other but are separated from each other in the calculation step of the first aspect, the magnetic resistance between the centers (21) is calculated using an effective radius that is equal to or smaller than the radius of the particle model (2) having the smaller radius of the two particle models (2).
[0104] According to this aspect, the accuracy of the analysis can be improved.
[0105] In the analysis method according to the third aspect, in the calculation step of the first or second aspect, when two particle models (2) are in contact with each other via an insulating layer model (3), the magnetic resistance of the insulating layer model (3) is calculated.
[0106] According to this aspect, the accuracy of the analysis can be improved.
[0107] The analysis method according to the fourth aspect further calculates a combined magnetic resistance by connecting in parallel the magnetic resistance of the insulating layer model (3) and the magnetic resistance between the surfaces of the two particle models (2) that are not in contact with the insulating layer model (3) in the calculation step of the third aspect.
[0108] According to this aspect, the accuracy of the analysis can be further improved.
[0109] The configurations other than those of the first aspect are not essential for the analysis method and can be omitted as appropriate.
[0110] A program according to a fifth aspect is a program for causing one or more processors to execute the analysis method according to any one of the first to fourth aspects.
[0111] According to this aspect, it is possible to reduce the calculation time compared to the conventional program and analysis method. [Explanation of symbols]
[0112] 1 Composite magnetic component model 2,i,j particle model 21,21i,21j center 3. Insulation layer model
Claims
1. A method for analyzing a composite magnetic member containing a plurality of soft magnetic particles, comprising: a defining step of defining a magnetic circuit for each two particle systems including any two adjacent particle models among the plurality of particle models based on an arrangement state of a plurality of particle models corresponding to the plurality of soft magnetic particles in a composite magnetic member model obtained by modeling the composite magnetic member using a discrete particle method; a calculation step of calculating a magnetic resistance between the centers of the two particle models using the magnetic circuit defined in the definition step; having Analysis method.
2. In the calculation step, when the two particle models are not in contact with each other and are separated from each other, the magnetic resistance between the centers is calculated using an effective radius that is equal to or smaller than the radius of the particle model having a smaller radius of the two particle models. The analysis method according to claim 1 .
3. In the calculation step, when the two particle models are in contact with each other via an insulating layer model, a magnetic resistance of the insulating layer model is calculated. The analysis method according to claim 1 .
4. The calculation step further includes calculating a combined magnetic resistance by connecting in parallel the magnetic resistance of the insulating layer model and the magnetic resistance between surfaces of the two particle models that are not in contact with the insulating layer model. The analysis method according to claim 3 .
5. In order to cause one or more processors to execute the analysis method according to any one of claims 1 to 4, program.