JP2005164365A - Magnetostriction analysis apparatus and method, magnetostriction measurement apparatus and method, computer program, and computer-readable recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine magnetostriction occurring in an iron core excited by AC by calculations to estimate noise occurring in an apparatus using the iron core at the designing stage of the apparatus. <P>SOLUTION: Predetermined elliptic magnetic flux is applied to a sample 31, to which strain gauges 32 to 34 are attached, to measure a strain ratio. Using the measured strain ratio, a strain tensor E is calculated. A maximum strain ratio λ<SB>MAX</SB>is determined from eigenvalues eig1 and eig2 of the calculated strain tensor E. The determined maximum strain ratio λ<SB>MAX</SB>and the elliptic magnetic flux producing the maximum strain ratio λ<SB>MAX</SB>are related with each other to be stored in a magnetostriction characteristics database 4a. Magnetic characteristics obtained by magnetic characteristics analysis and the maximum strain ratio λ<SB>MAX</SB>, an indicator for estimating noise, are thereby related with each other to determine the maximum strain ratio λ<SB>MAX</SB>occurring in the iron core, an object to be analyzed, on the basis of analysis results by the magnetic characteristics analysis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnetostriction analysis device, a magnetostriction measurement device, a magnetostriction analysis method, a magnetostriction measurement method, a computer program, and a computer-readable recording medium, and in particular, an iron core configured by laminating a plurality of thin steel plates. It is suitable for use in analyzing the magnetostriction that occurs.

  In a device such as a transformer formed by winding a coil around a plurality of laminated thin steel plates (iron cores), there is a problem that noise is generated due to magnetostriction generated in the iron core when AC excitation is performed. there were.

  Therefore, conventionally, a transformer was prototyped and the prototyped transformer was AC-excited to evaluate the noise generated in the transformer. Hereinafter, AC excitation is referred to as excitation.

Naoya Soda, Masato Gion, “Hysteresis modeling of two-dimensional magnetic properties by E & S model”, Journal of Japan Society of Applied Magnetics, Japan Society of Applied Magnetics, 2000, Vol. 24, p. 827-830 Masato Gion, Yasuhiro Suzuki, Johannes Sievert, “Measurement of Dynamic Magnetostriction under Rotating Magnetic Field”, IEEE Transactions on Magnetics, American Electric, Electronics Engineers Association (The Institute of Electrical and Electronics Engineers, Inc), 1990, Vol. 26, No. 5, p. 2067-2069 Masato Gion, Takataka Totaka, Shinichi Kaneo, “Two-dimensional magnetostriction characteristics of silicon steel sheet I. Magnetostriction in arbitrary direction under alternating magnetic flux”, Journal of Japan Society of Applied Magnetics, Japan Society of Applied Magnetics, 1995, No. Volume 19, p. 293-296 Masato Gion, Takataka Totaka, Shinichi Kaneo, “Two-dimensional magnetostriction characteristics of silicon steel sheet II. Magnetostriction in arbitrary direction under rotating magnetic flux”, Journal of Japan Society of Applied Magnetics, Japan Society of Applied Magnetics, 1995, No. Volume 19, p. 293-296

  However, with the above-described conventional technology, the noise generated in the transformer could not be evaluated unless a prototype of the transformer was made. Therefore, in order to provide a transformer with low noise to the user, the prototype of the transformer has to be repeated many times, and there has been a problem that a great amount of labor and cost are consumed.

  The present invention has been made in view of the above-described problems, and it is possible to determine the magnetostriction generated in the iron core by calculation, and to reduce the noise generated in the equipment using the iron core in the design stage of the equipment. The purpose is to be able to evaluate with.

  The magnetostriction analyzer of the present invention is a magnetostriction analyzer for analyzing magnetostriction generated in an excited iron core, the magnetic flux density calculating means for calculating the magnetization characteristics of the excited iron core, and the magnetic flux density calculating means. And a magnetostriction analyzing means for reading out the magnetostriction characteristic recorded on the recording medium in association with the magnetization characteristic calculated by the above, and analyzing the magnetostriction generated in the excited iron core.

  The magnetostriction measuring apparatus according to the present invention includes a magnetostriction that occurs in a plate surface direction of the thin steel plate due to a change in the plurality of strain gauges that occurs when an elliptical magnetic flux is applied to the thin steel plate having a plurality of strain gauges attached to the surface. The plurality of strain gauges are attached to the surface of the thin steel plate so as to face different directions.

  The magnetostriction analysis method of the present invention is a magnetostriction analysis method for analyzing magnetostriction generated in an excited iron core, the magnetic flux density calculating step for calculating the magnetization characteristics of the excited iron core, and the magnetic flux density calculating step. A magnetostriction analysis step of reading out the magnetostriction characteristic recorded on the recording medium in association with the magnetization characteristic calculated by the above, and analyzing the magnetostriction generated in the excited iron core.

  The magnetostriction measuring method of the present invention is a magnetic strain generated in the in-plane direction of the thin steel plate due to a change in the plurality of strain gauges generated when an elliptical magnetic flux is applied to the thin steel plate having a plurality of strain gauges attached to the surface. A magnetostriction measuring method for measuring strain, wherein the plurality of strain gauges are attached to the surface of the thin steel plate so as to face different directions.

  A computer program of the present invention is a computer program for causing a computer to analyze magnetostriction generated in an excited iron core, the magnetic flux density calculating step for calculating the magnetization characteristics of the excited iron core, Read the magnetostriction characteristics recorded in the recording medium in association with the magnetization characteristics calculated in the magnetic flux density calculation step, and execute the magnetostriction analysis step for analyzing the magnetostriction generated in the magnetized iron core. It is characterized by making it.

  A computer-readable recording medium according to the present invention records the above-described computer program.

  According to the present invention, since the magnetostriction characteristic recorded in the recording medium in association with the calculated magnetization characteristic is read and the magnetostriction generated in the excited iron core is analyzed, the noise is evaluated. Can be obtained based on the magnetic characteristics analyzed by the magnetic characteristic analysis. Thereby, the noise which generate | occur | produces in the apparatus using the said iron core can be correctly evaluated in the stage of the said apparatus design.

  According to another aspect of the present invention, the magnetic strain generated in the in-plane direction of the thin steel plate is measured by changing a plurality of strain gauges attached to the surface of the thin steel plate so as to face different directions. Since it did in this way, no matter how the said thin steel plate is distorted in the plate | board surface direction, the distortion can be measured correctly.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of the configuration of the magnetostriction analyzer according to the present embodiment.
In FIG. 1, the magnetostriction analyzer 1 has an operation unit 2, a display unit 3, and a processing unit 4.
The operation unit 2 is a device configured by a keyboard, a mouse, and the like, and is a device for transmitting the contents executed by the user (analyzer) to the processing unit 4.

  The display unit 3 is a device configured with a display or the like, and is a device for displaying a processing result or the like executed by the processing unit 4. The user (analyzer) inputs desired content by operating the operation unit 2 while viewing the content displayed on the display unit 3.

  The processing unit 4 is a computer that includes a CPU, a ROM, a RAM, and the like. The processing unit 4 performs a processing operation in the magnetostriction analyzer 1 by executing a program recorded in the ROM.

  Specifically, the processing unit 4 includes a magnetostriction characteristic database 4a, a magnetostriction characteristic calculation unit 4b, a magnetic flux density distribution calculation unit 4c, a magnetostriction characteristic search unit 4d, and a noise evaluation unit 4e.

The magnetostrictive property database 4a is a database that stores the maximum strain rate λ _MAX of a thin steel plate and the elliptical magnetic flux that gives the maximum strain rate λ _MAX in association with each other.
Here, the elliptical magnetic flux is a magnetic flux in which the magnetic flux density vector when excited is temporally changed and the locus drawn is an ellipse.
In the present embodiment, the elliptical magnetic flux is specified from the major axis B _{MAX of the} ellipse, the axial ratio α, and the inclination inc of the major axis B _MAX (see FIG. 2).
The maximum strain rate λ _MAX is calculated by the magnetostrictive characteristic calculation unit 4b based on the strain rate measured for the thin steel plate constituting the iron core to be analyzed.

(Measurement method of strain rate)
Here, the measuring method of the distortion rate of a thin steel plate is demonstrated.
In the present embodiment, as shown in FIG. 3A, three strain gauges 32 to 34 that are not parallel to each other are attached to the surface of the sample (thin steel plate) 31.
Specifically, as shown in FIG. 3B, the angle formed between the strain gauge 32 and the strain gauge 33 and the angle formed between the strain gauge 33 and the strain gauge 34 are set to 60 [°]. The strain gauges 32 to 34 are affixed radially from the center of the sample 31.

The sample (thin steel plate) 31 to which the strain gauges 32 to 34 are attached in this way is attached to a two-dimensional magnetic measurement apparatus 40 as shown in FIG. 4 and the direction in which the strain gauges 32 to 34 are attached. The strain rates λ ₃₀ , λ ₉₀ and λ ₁₅₀ in the (strain measurement direction) are measured simultaneously.

In FIG. 4, the two-dimensional magnetic measurement apparatus 40 includes excitation yokes 41 a to 41 d, excitation coils 42 a to 42 d, a B coil 43, and an H coil 44.
The exciting yoke 41a and the exciting yoke 41c are arranged so as to face each other with the sample (thin steel plate) 31 in the x-axis direction. Further, the excitation yoke 41b and the excitation yoke 41d are arranged to face each other with the sample 31 in the y-axis direction.

  Moreover, in order to concentrate magnetic flux in the sample (thin steel plate) 31, the tips of the exciting yokes 41a to 41d have a tapered shape. Furthermore, in order to make the magnetic flux in the sample (thin steel plate) 31 uniform, a gap of about 0.1 [mm] is provided between the sample (thin steel plate) 31 and the excitation yokes 41a to 41d. ing.

The exciting coils 42a to 42d are wound around the exciting yokes 41a to 41d, respectively.
The B coil 43 includes a B _x coil 43a wound through two holes provided so as to face each other in the x-axis direction through the center point of the sample (thin steel plate) 31, and the center of the sample (iron core) 31. and a wound B _y coil 43b through two holes provided so as to face in advance y-axis direction via the.
The H coil 44 includes a H _y coil 44a wound in the y-axis direction above or below the sample 31, and a H _x coil 44b wound in the x-axis direction on the H _y coil 44a. Yes.

The strain rate of the sample (thin steel plate) 31 is measured using the two-dimensional magnetometer 40 configured as described above. That is, an exciting current is passed through the exciting coils 42a to 42d so that the magnetic flux inside the sample (thin steel plate) 31 becomes a predetermined elliptical magnetic flux. Then, the strain rates λ ₃₀ , λ ₉₀ , and λ ₁₅₀ in each strain measuring direction generated in the sample (thin steel plate) 31 when the exciting current is passed are measured.

Next, the content calculated by the magnetostriction characteristic calculation unit 4b will be described.
(Strain tensor calculation method)
The magnetostrictive characteristic calculation unit 4b inputs the distortion rates λ ₃₀ , λ ₉₀ , and λ ₁₅₀ measured as described above based on the operation of the operation unit 2 by the user.
The distortion factor lambda ₃₀ were entered, lambda _90, the lambda _0.99, calculates each component e _11, e _12, e ₂₂ strain tensor E which is represented as the following expression (1).

More specifically, the components e ₁₁ , e ₁₂ , and e ₂₂ of the strain tensor E are expressed by the following (3) because the unit vector βθ in each strain measurement direction is expressed as the following (Expression 2). It is expressed as That is, the components e ₁₁ , e ₁₂ , and e ₂₂ of the strain tensor E are calculated based on the following (Equation 3). In the present specification and drawings, vectors are represented in bold.

(Distortion rate calculation method)
Then, the strain rate λ is calculated by a strain tensor model using the strain tensor E as described above.
As shown in FIG. 5, the strain tensor model is such that when the vector r ₀ representing the positional relationship between the reference point and an arbitrary point inside the thin steel plate becomes a vector r due to the strain of the thin steel plate, the vector r This is a model that expresses the difference between the vector r ₀ and the vector r ₀ as shown in the following (formula 4).
r−r ₀ : = Er ₀ (Expression 4)
In the above (Expression 4), E is a strain tensor represented by the above (Expression 1).

The above (Equation 4) can be rewritten as the following (Equation 5), considering the conversion from the vector r ₀ to the vector r.
r = (I + E) r ₀ (Expression 5)

Therefore, it can be seen that the strain tensor model is a model that can be linearly transformed and that deforms the disk into an ellipse as shown in FIG.
Here, the length of the vector r ₀ is r ₀ , the length of the vector r is r, and the unit matrix is I. A unit vector representing the direction of the vector r ₀ is β. These can be expressed in the following formulas (6) to (8).

Generally, since the strain rate of a thin steel plate used as an iron core is about 10 ⁻⁶ to 10 ⁻⁵ , each component e ₁₁ , e ₁₂ , e _{22 of} the strain tensor E and the eigenvalue are sufficiently larger than 1. Can be considered small. Therefore, the length r ₀ of the vector r _0, the relationship between the length r of the vectors r, can be expressed as the following (9 type).

  When the above (formula 9) is modified, the distortion rate λ can be expressed as the following formula (10).

  In the present embodiment, the strain rate λ in the direction in which the strain gauges 32 to 34 are attached is calculated by the above (Equation 10), and the maximum value and the minimum value of the calculated strain rate are obtained.

  Here, the maximum value and the minimum value of the distortion rate are expressed by eigenvalues eig1 and eig2 (eig1> eig2) of the distortion tensor E. In addition, the direction in which the distortion rate λ is maximized and the direction in which the distortion rate λ is minimized are represented by the eigenvectors of the distortion tensor E. These are shown below.

The eigenvectors of length 1 corresponding to the eigenvalues eig1 and eig2 of the strain tensor E are denoted by ν ₁ and ν ₂ , respectively. At this time, if the eigenvectors ν ₁ and ν ₂ are set as in the following (formula 11), the following formula (12) is established from the definition of the eigenvalue / eigenvector.

As described above, since the eigenvectors ν ₁ and ν ₂ have a length of 1 and have directions orthogonal to each other, the following (Expression 13) and (Expression 14) hold.

Substituting the above (14) into the above (10), the distortion rate λ can be expressed as the following (15). Then, by using (Equation 15), it can be shown that (Equation 16) holds as follows.

Here, since the following (Expression 17) holds, the above (Expression 16) can be expressed as the following (Expression 18).

Therefore, it can be seen that the maximum value and the minimum value of the distortion rate λ become eigenvalues eig1 and eig2 of the distortion tensor E, respectively.
Further, the fact that the direction in which the distortion rate λ becomes the maximum and the direction in which the distortion rate λ becomes the minimum is the eigenvector of the distortion tensor E, for example, using the following (19) and the above (15), It can be seen from the fact that (formula) holds.

In the above (Equation 19), the unit vector β representing the direction of the vector r ₀ is the eigenvector ν ₁ of the eigenvalue eig1 of the distortion tensor E (β = ν ₁ ).
Moreover, it is proved as follows that said (Formula 16) is materialized.
First, the following (Expression 21) holds from the above (Expression 15).

  For example, if the component is displayed as shown in the following (Expression 22), the following (Expression 23) is established.

The second formula of the above (16 formula) is shown by the above (23 formula). The same applies to the first formula (16 formula). (End of proof)
FIG. 6 shows an example of a waveform 61 for one period of the maximum value of the distortion rate λ and a waveform 62 for one period of the minimum value.

(Maximum strain rate calculation method)
Then, the absolute value of the eigenvalue eig1 calculated as described above is selected with the largest value, and the absolute value of the eigenvalue eig2 is selected with the largest value. Then, the absolute value of the eigenvalue eig1 having the largest value and the absolute value of the eigenvalue eig2 having the largest value are further selected, and the absolute value of the selected eigenvalue is set as the maximum distortion rate λ _MAX . . This can be expressed by the following equation (24).

The maximum distortion rate λ _MAX selected according to this (Equation 24) and the elliptical magnetic flux that gives the maximum distortion rate λ _MAX are associated with each other and stored in the magnetostriction characteristic database 4a.
Then, the calculation of the strain tensor E and the maximum strain rate λ _MAX as described above is performed by changing the elliptical magnetic flux (ellipse major axis B _MAX , axial ratio α, and slope inc of major axis B _MAX ).

(Calculation example)
Next, the result of calculating the strain rate λ using the non-oriented steel plate (NO material) and the directional steel plate (GO material) as the sample 31 is shown.
Here, the magnetic flux inside the sample 31 is an elliptical magnetic flux in which the major axis B _MAX of the ellipse is 1 [T], the axial ratio α is 0.6, and the inclination inc of the major axis B _MAX is 0 [°]. As described above, an exciting current is applied to the exciting coils 42 a to 42 d of the two-dimensional magnetic measurement apparatus 40.

In FIG. 7, the calculation result about a non-oriented steel plate is shown.
From the results of FIG. 7, it was found that the following magnetostriction characteristics were obtained for the non-oriented steel sheet.
(1) As shown in FIG. 7B, the characteristic 73 indicating the direction of the eigenvector corresponding to the eigenvalue eig1 of the strain tensor E is substantially the same as the characteristic 74 indicating the magnetic flux density B. This indicates that the sample 31 expands in substantially the same direction as the magnetic flux density B.
(2) As shown in FIG. 7A, the characteristics 71 and 72 indicating the eigenvalues eig1 and eig2 of the strain tensor E are substantially constant with respect to time, but the difference may be temporarily reduced ( ωt = 135 [°], near 315 [°]). Then, when the characteristic 73 indicating the direction of the eigenvector corresponding to the eigenvalue eig1 of the strain tensor E at this time is compared with the characteristic 74 indicating the direction of the magnetic flux density vector, it can be seen that the eigenvector overtakes the magnetic flux density vector at this time. You can see (Fig. 7 (b)).

In FIG. 8, the calculation result about a grain-oriented steel plate is shown.
From the results of FIG. 8, it was found that the following magnetostriction characteristics can be obtained for the grain-oriented steel plate.
(1) As shown in FIG. 8B, the characteristic 83 indicating the direction of the eigenvector corresponding to the eigenvalue eig1 of the strain tensor E does not depend on the characteristic 84 indicating the magnetic flux density B, and is substantially constant indicating the transverse direction. It becomes a characteristic. This indicates that the sample 31 is distorted (shrinks) in the transverse direction regardless of the direction of the magnetic flux density B.
(2) As shown in FIG. 8A, the characteristics 81 and 82 indicating the eigenvalues eig1 and eig2 of the strain tensor E have a small difference when the magnetic flux density B faces the rolling direction (ωt = 90 [°]). 270 [°]]) and increases in the transverse direction (ωt = 0 [°], 180 [°], 360 [°]). Moreover, the magnitude | size becomes 10 times at maximum compared with a non-oriented steel plate (NO).

Returning to FIG. 1, the magnetic flux density distribution calculation unit 4 c performs a magnetic characteristic analysis on the specified iron core based on the operation of the operation unit 2 by the user, and calculates the magnetic flux density B for all the regions of the specified iron core. calculate. Then, based on the calculated magnetic flux density B, and calculating the long axis B _MAX of the ellipse, and the axial ratio alpha, and inclination inc long axis B _MAX. The magnetic characteristic analysis may be performed using, for example, E & S (Enokizono and Soda) modeling (two-dimensional vector method) defined by the following (Equation 25) (for example, Non-Patent Documents 1 to 3). 4).

In the above (Equation 25), H _x and _Hy are magnetic field strengths. B _x, B _y is the magnetic flux density. ν _xr and ν _yr are magnetic resistivity. ν _xi and ν _yi are magnetic hysteresis coefficients.

The magnetostriction characteristic search unit 4d reads the maximum distortion rate λ _MAX associated with the elliptical magnetic flux calculated by the magnetic flux density distribution calculation unit 4c from the magnetostriction characteristic database 4a. This reading operation is performed for all areas of the iron core designated based on the operation of the operation unit 2 by the user.

The noise evaluation unit 4e displays how the maximum distortion rate λ _MAX read by the magnetostriction characteristic search unit 4d is distributed in the iron core specified based on the operation of the operation unit 2 by the user. 3 is displayed.
The noise evaluation unit 4e calculates the average value of the maximum distortion rate λ _MAX read by the magnetostriction characteristic search unit 4d, and displays the calculated result on the display unit 3.
That is, the noise generated in the iron core increases in proportion to the distortion rate of the iron core. In this embodiment, the maximum distortion rate λ _MAX is employed as an index for evaluating the noise generated in the iron core.
The

Next, the operation of the magnetostriction characteristic calculation unit 4b when the elliptical magnetic flux and the maximum distortion rate λ _MAX are associated with each other and stored in the magnetostriction characteristic database 4a will be described with reference to the flowchart of FIG.

First, in the first step S1, the elliptical magnetic flux is set to an initial value.
In this embodiment, the major axis B _{MAX of the} ellipse is changed from 0 [T] to 2 [T]. Further, the axial ratio α is changed from 0 to 1. Further, the inclination inc of the long axis B _MAX is changed from 0 [°] to 180 [°].
For example, an elliptical magnetic flux in which the long axis B _MAX is 0.1 [T], the axial ratio α is 0.1, and the inclination inc of the long axis B _MAX is 0 [°] is set as an initial value.

Next, in step S2, the phase ωt of the elliptical magnetic flux is set to an initial value.
In the present embodiment, the phase ωt is changed from 0 [rad] to 2π [rad].
Therefore, for example, 0 [rad] is set as the initial value of the phase ωt.

Next, in step S3, a distortion tensor E (ωt) at the set phase ωt is calculated. As described above, the strain tensor E (ωt) is calculated by substituting the strain rates λ ₃₀ , λ ₉₀ , and λ ₁₅₀ measured by applying an elliptical magnetic flux to the sample 31 into the above (Equation 3).

  Next, in step S4, eigenvalues eig1 and eig2 of the distortion tensor E calculated in step S3 are calculated. That is, the maximum value and the minimum value of the distortion rate λ (ωt) at the set phase ωt are calculated.

  Next, in step S5, it is determined whether or not the calculation for one cycle is completed. As a result of the determination, if not completed, the process proceeds to step S6, the next phase ωt is set, the process returns to step S3, and the processes of steps S3 to S6 are completed until the calculation for one cycle is completed. repeat.

On the other hand, when the calculation for one period is completed, the process proceeds to step S7, and the maximum distortion rate λ _MAX in one period of the set elliptical magnetic flux is calculated. This calculation is performed according to the above (Equation 24).

Next, in step S8, the elliptical magnetic flux set in step S1 (or step S10 described later) and the maximum distortion rate λ _MAX calculated in step S7 are associated with each other and stored in the magnetostriction characteristic database 4a. .

Next, in step S9, it is determined whether or not the calculation for the predetermined number of elliptical magnetic fluxes has been completed. If the calculation has been completed, the process is terminated. On the other hand, if the calculation is not completed, the process proceeds to step S10, the next elliptical magnetic flux is set, the process returns to step S2, and the calculation of the predetermined number of elliptical magnetic fluxes is completed until the calculation of steps S2 to S10 is completed. Repeat the process.
Needless to say, the operation in the flowchart shown in FIG. 9 is performed for each type of thin steel plate to be analyzed.

Next, the operation of the magnetostriction analyzer 1 when analyzing magnetostriction generated in the iron core will be described with reference to the flowchart of FIG.
First, in the first step S21, the magnetic flux density calculator 4c sets the magnetic resistivity ν _xr , ν _yr and the magnetic hysteresis coefficients ν _xi , ν _yi to initial values.
Next, in step S22, the magnetic flux density calculator 4c sets the phase ωt to an initial value.
In the present embodiment, the phase ωt is changed from 0 [°] to 360 [°]. Therefore, here, 0 [°] is set as the initial value.

  Next, in step S23, the magnetic flux density calculation unit 4c applies the finite element method (FEM) to the iron core to be analyzed, and uses the above (Equation 25) to calculate the vector potential A (ωt). calculate.

  Next, in step S24, the magnetic flux density calculator 4c calculates the magnetic flux density B generated in the iron core to be analyzed using the vector potential A (ωt) calculated in step S23.

  Next, in step S25, the magnetic flux density calculation unit 4c determines whether or not the calculation for one cycle is completed. As a result of the determination, if not completed, the process proceeds to step S26, the next phase ωt is set, the process returns to step S23, and the processes of steps S23 to S26 are completed until the calculation for one cycle is completed. repeat.

Meanwhile, 1 when the period of the calculation is finished, the process proceeds to step S27, the magnetic flux density calculation section 4c based on the magnetic flux density B for one period calculated by the step S23-S26, ellipse major axis B _MAX And the axial ratio α and the inclination inc of the long axis B _MAX are calculated.

Next, in step S28, it is determined whether or not the major axis B _{MAX of the} ellipse, the axial ratio α, and the inclination inc of the major axis B _MAX have converged as a result of the calculation in step S27. If the result of this determination is that there is no convergence, the process proceeds to step S29, where the magnetic resistivity ν _xr , ν _yr and the magnetic hysteresis coefficients ν _xi , ν _yi are changed, and the procedure returns to step 22 and the major axis B of the ellipse Steps S22 to S29 are repeated until _MAX , the axial ratio α, and the inclination inc of the long axis B _MAX converge.

On the other hand, when the major axis B _{MAX of the} ellipse, the axial ratio α, and the slope inc of the major axis B _MAX converge, the process proceeds to step S30, and the major axis B _{MAX of the} ellipse calculated in step S27 and the axial ratio and alpha, reads the maximum strain rate lambda _MAX stored in association with the inclination inc long axis B _MAX magnetostriction characteristic database 4a. In step S30, the maximum distortion rate λ _MAX in all the regions divided by the finite element method (all regions in the iron core to be analyzed) is read out.

Next, in step S31, the noise evaluation unit 4e calculates the distribution of the maximum distortion rate λ _MAX in the analysis target iron core based on the maximum distortion rate λ _MAX read in step S30, and displays the calculated result. Part 3 is displayed.

Next, in step S32, the noise evaluation unit 4e calculates the average value of the maximum distortion rate λ _MAX read out in step S30, and displays the calculated result on the display unit 3.

As described above, in this embodiment, since the strain rate generated in the sample (thin steel plate) 31 to which the strain gauges 32 to 34 are attached is measured using the two-dimensional magnetometer 40, the sample ( Even when the thin steel plate 31 is distorted elliptically by excitation, the major axis B _{MAX of the} ellipse, the axial ratio α, and the inclination inc of the major axis B _MAX can be obtained. Therefore, no matter how the sample (thin steel plate) 31 is distorted in the plate surface direction, the distortion can be accurately measured.

In addition, since the magnetostriction characteristic database 4a is used to associate the magnetic characteristics obtained by E & S modeling with the maximum distortion rate λ _MAX that is an index for evaluating noise, a device using an iron core such as a transformer. Noise can be accurately evaluated at the design stage of the equipment.

In the present embodiment, the maximum distortion rate λ _MAX is used as an index for evaluating the noise generated in the iron core. However, as long as it represents the magnitude of the distortion rate, the index for evaluating the magnetostriction is: It is not limited to the maximum distortion rate λ _MAX . For example, an expansion rate variation width λ _p as shown in FIG. 11A or a distortion rate variation width λ _2p as shown in FIG. 11B may be used as an index for evaluating the magnetostriction.

Here, the expansion rate variation width λ _p is the amplitude of the waveform 1101 representing the eigenvalue eig1 of the strain tensor E. The distortion rate fluctuation range λ _2p is a width determined from the maximum value of the waveform 1102 representing the eigenvalue eig1 of the distortion tensor E and the minimum value of the waveform 1103 representing the eigenvalue eig1 of the distortion tensor E. These are expressed by the following equations (26) and (27), respectively.

  In addition, if the magnetic characteristics are analyzed by the above E & S modeling (two-dimensional vector method) as in the present embodiment, it is possible to analyze the magnetic characteristics with higher accuracy, but it is preferable to analyze the magnetic characteristics. The method is not limited to the E & S modeling (two-dimensional vector method).

  Further, the magnetic field strength H generated in the sample (thin steel plate) 31 is measured using the two-dimensional magnetic measuring device 40, and the measured magnetic field strength H and the elliptical magnetic flux that gives the magnetic field strength H are stored in the database in association with each other. Then, the magnetic field strength H stored in association with the result calculated in step S27 of FIG. 10 is read from the database, and the distribution of the magnetic field strength H generated in the iron core to be analyzed is displayed on the display unit 3. It may be. Furthermore, the distribution of the iron loss W of the iron core to be analyzed may be obtained in the same manner as the magnetic field strength H and displayed on the display unit 3.

(Another embodiment of the present invention)
The control operation by the magnetostriction analyzer in each of the embodiments described above can be realized by using a computer system as shown in FIG.
FIG. 12 is a block diagram showing an example of the configuration of a computer system arranged in the magnetostriction analysis apparatus 1.
In FIG. 12, a computer system 120 includes a CPU 121, a ROM 122, a RAM 123, a keyboard controller (KBC) 125 of a keyboard (KB) 124, a CRT controller (CRTC) 127 of a CRT display (CRT) 126 as a display unit, The disk controller (DKC) 130 of the hard disk (HD) 128 and flexible disk (FD) 129 and the network interface controller (NIC) 132 for connecting to the network 131 can communicate with each other via the system bus 133. Connected configuration.

The CPU 121 generally controls each component connected to the system bus 123 by executing software stored in the ROM 122 or the HD 128 or software supplied from the FD 129.
That is, the CPU 121 performs a control for realizing an operation to be described later by reading a processing program according to a predetermined processing sequence from the ROM 122, the HD 128, or the FD 129 and executing it.

The RAM 123 functions as a main memory or work area for the CPU 121.
The KBC 125 controls an instruction input from the KB 124 or a pointing device (not shown).

The CRTC 127 controls display on the CRT 126.
The DKC 130 controls access to the HD 128 and the FD 129 that store a boot program, various applications, an edit file, a user file, a network management program, a predetermined processing program in the present embodiment, and the like.
The NIC 132 exchanges data bidirectionally with devices or systems on the network 131.

  In addition, software for realizing the functions of the above-described embodiments for an apparatus or a computer in the system connected to the various devices so that the various devices are operated to realize the functions of the above-described embodiments. The program implemented by supplying the program code and operating the various devices according to the program stored in the computer (CPU or MPU) of the system or apparatus is also included in the scope of the present invention.

  Further, in this case, the program code of the software itself realizes the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, for example, the program code The stored recording medium constitutes the present invention. As a recording medium for storing the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code supplied by the computer, not only the functions of the above-described embodiments are realized, but also the OS (operating system) or other application software in which the program code is running on the computer. The program code is also included in the embodiment of the present invention even when the functions of the above-described embodiment are realized in cooperation with the above.

  Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the CPU provided in the function expansion board or function expansion unit based on the instruction of the program code The present invention also includes a case where the functions of the above-described embodiment are realized by performing part or all of the actual processing.

It is the block diagram which showed embodiment of this invention and showed an example of the structure of the magnetostriction analyzer. It is the figure which showed embodiment of this invention and showed an example of the concept of elliptical magnetic flux. It is the figure which showed embodiment of this invention and showed an example of the sample in which the strain gauge was affixed. It is the figure which showed embodiment of this invention and showed an example of the structure of a two-dimensional magnetic measuring apparatus. It is the figure which showed embodiment of this invention and showed the vector showing the positional relationship of the reference point and arbitrary points in an iron core. It is a figure which shows embodiment of this invention and demonstrates the concept of the maximum distortion rate. It is a figure which showed embodiment of this invention and showed an example of the waveform of the eigenvalue of the distortion tensor in a non-oriented steel plate, and the waveform of the eigenvector of a distortion tensor. It is a figure which showed embodiment of this invention and showed an example of the waveform of the eigenvalue of the distortion tensor in a grain-oriented steel plate, and the waveform of the eigenvector of a distortion tensor. It is a flowchart which shows embodiment of this invention and demonstrates an example of operation | movement of the magnetostriction characteristic calculating part at the time of matching and storing an elliptical magnetic flux and a maximum distortion rate in a magnetostriction characteristic database. It is a flowchart which shows embodiment of this invention and demonstrates an example of the operation | movement of the magnetostriction analyzer at the time of analyzing the magnetostriction which arises in an iron core. It is a figure which shows embodiment of this invention and demonstrates the concept of an expansion rate fluctuation range and a distortion rate fluctuation range. It is the block diagram which showed other embodiment of this invention and showed an example of the structure of the computer system arrange | positioned at the magnetostriction analyzer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetostriction analyzer 2 Operation part 3 Display part 4 Processing part 4a Magnetostriction characteristic database 4b Magnetostriction characteristic calculation part 4c Magnetic flux density distribution calculation part 4d Magnetostriction characteristic search part 4e Noise evaluation part 31 Sample (thin steel plate)
32 to 34 Strain gauge 40 Two-dimensional magnetometer

Claims (16)

A magnetostriction analyzer for analyzing magnetostriction generated in an excited iron core,
Magnetic flux density calculating means for calculating the magnetization characteristics of the excited iron core;
Magnetostriction analysis means for reading out magnetostriction characteristics recorded on the recording medium in association with the magnetization characteristics calculated by the magnetic flux density calculation means and analyzing magnetostriction generated in the excited iron core. A magnetostriction analyzer characterized by. The magnetization characteristics include the major axis of the ellipse in the elliptical magnetic flux, the axial ratio, and the tilt angle of the major axis,
2. The magnetostriction analysis apparatus according to claim 1, wherein the magnetostriction characteristic includes a distortion rate of the iron core or a thin steel plate constituting the iron core.   3. The magnetostriction analysis apparatus according to claim 2, wherein the magnetostriction analysis means obtains a position distribution of the distortion rate read from the recording medium and displays it on a display device.   4. The magnetostriction analysis apparatus according to claim 2, wherein the magnetostriction analysis means obtains an average value regarding the position of the distortion rate read from the recording medium and displays the average value on a display device.   The magnetostriction analyzer according to any one of claims 1 to 4, wherein the magnetization characteristics and the magnetostrictive characteristics are characteristics in an in-plane direction of the iron core or the thin steel plate. The strain tensor is calculated from the measurement result of the strain rate of the thin steel plate that constitutes the iron core, the magnetostriction characteristic is obtained based on the eigenvalue of the calculated strain tensor, the obtained magnetostriction characteristic, and the magnetization characteristic that gives the magnetostriction characteristic A magnetostriction characteristic calculating means for recording on the recording medium in association with
The magnetostriction analysis apparatus according to claim 1, wherein the magnetostriction analysis unit reads the magnetostriction characteristic recorded by the magnetostriction characteristic calculation unit. A magnetostriction measuring apparatus that measures the magnetostriction generated in the plate surface direction of the thin steel plate due to a change in the plurality of strain gauges that occurs when an elliptical magnetic flux is applied to the thin steel plate having a plurality of strain gauges attached to the surface. And
The magnetostriction measuring apparatus, wherein the plurality of strain gauges are attached to the surface of the thin steel plate so as to face different directions. A magnetostriction analysis method for analyzing magnetostriction generated in an excited iron core,
A magnetic flux density calculating step for calculating the magnetization characteristics of the excited iron core;
A magnetostriction analysis step of reading out magnetostriction characteristics recorded on a recording medium in association with the magnetization characteristics calculated in the magnetic flux density calculation step and analyzing magnetostriction generated in the excited iron core. A magnetostriction analysis method characterized by the above. The magnetization characteristics include the major axis of the ellipse in the elliptical magnetic flux, the axial ratio, and the tilt angle of the major axis,
The magnetostriction analysis method according to claim 8, wherein the magnetostriction characteristic includes a strain rate of a thin steel plate constituting the iron core.   10. The magnetostriction analysis method according to claim 9, wherein in the magnetostriction analysis step, a position distribution of a distortion rate read from the recording medium is obtained and displayed on a display method.   The magnetostriction analysis method according to claim 9 or 10, wherein in the magnetostriction analysis step, an average value regarding a position of a distortion rate read from the recording medium is obtained and displayed on a display method.   The magnetostriction analysis method according to any one of claims 8 to 11, wherein the magnetization characteristics and the magnetostriction characteristics are characteristics in an in-plane direction of the iron core or the thin steel plate. The strain tensor is calculated from the measurement result of the strain rate of the thin steel plate that constitutes the iron core, the magnetostriction characteristic is obtained based on the eigenvalue of the calculated strain tensor, the obtained magnetostriction characteristic, and the magnetization characteristic that gives the magnetostriction characteristic A magnetostriction characteristic calculation step for recording on the recording medium in association with
The magnetostriction analysis method according to any one of claims 8 to 12, wherein the magnetostriction analysis step reads out the magnetostriction characteristic recorded by the magnetostriction characteristic calculation step. A magnetostriction measuring method for measuring magnetostriction generated in the plate surface direction of the thin steel plate due to a change in the plurality of strain gauges caused when an elliptical magnetic flux is applied to the thin steel plate having a plurality of strain gauges attached to the surface. And
The magnetostriction measurement method, wherein the plurality of strain gauges are attached to the surface of the thin steel plate so as to face different directions. A computer program for causing a computer to analyze magnetostriction generated in an excited iron core,
A magnetic flux density calculating step for calculating the magnetization characteristics of the excited iron core;
A magnetostriction analysis step for reading out the magnetostriction characteristics recorded in the recording medium in association with the magnetization characteristics calculated in the magnetic flux density calculation step and analyzing the magnetostriction generated in the excited iron core, on a computer A computer program that is executed.   A computer-readable recording medium on which the computer program according to claim 15 is recorded.

Images