JP2000206164A - Method and device for analyzing electromagnetic field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time and labor necessary for preparing input data by analyzing the electromagnetic field of whole object region of analysis through the use of the distribution of forced current density vectors obtained for element groups constituting conductors. SOLUTION: The distribution of forced current density vectors is obtained for element groups constituting conductors. The electromagnetic field of whole object region of analysis is analyzed through the use of the vector distribution. The distribution of forced current density vectors is data for specifying the directions of flow of forced current through conductors, and directional vectors in which an angle θ formed with any of the direction of flow of forced current, the direction of a magnetic field generated by the forced current, or the direction of the forced current from its inflow surface to outflow surface on the surfaces of the conductors is an acute angle (0 deg.<=θ<=90 deg.) are used. By this constitution, as a small number of pieces of input data on the forced current flowing through the conductors is sufficient, it is possible to perform efficient analysis on a magnetic field which occurs in apparatus with a complicated conductor structure using electromagnetic phenomena.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric / electric device utilizing electromagnetic phenomena such as a transformer, a reactor, a motor and a generator.
The present invention relates to an electromagnetic field analysis method and apparatus useful for designing electronic equipment.

[0002]

2. Description of the Related Art When an electromagnetic field analysis is performed on a region including a conductor through which a forced current flows, a forced current density vector in the conductor is expressed by:
This is the amount that must be entered directly as an initial condition for the analysis or calculated and calculated at the initial stage of the analysis. It is very difficult to directly input all of the forced current density vectors of the elements constituting the conductor of an arbitrary shape as initial conditions.

[0003] Conventionally, therefore, the current vector potential (for example, “Practical analysis of electric and electronic equipment by the latest three-dimensional finite element method”, written by Junyo Kawase and Shokichi Ito) Morikita Publishing 199
7) and simultaneous potential equations (JP-A-6-123752) are used as unknown variables to solve simultaneous equations, and the resulting equations are used to obtain a forced current density vector distribution.

[0004]

However, in the prior art, a predetermined conductor surface (an inflow surface or an outflow surface of a forced current or another side surface) is determined as an initial condition for calculating a forced current density vector distribution. ) Must be specified by element data such as position coordinates, node numbers and surface numbers. The above process is a very laborious operation when the number of elements constituting the conductor is large or when the shape of the conductor is complicated.

As described above, according to the conventional technique, it is very complicated to create input data necessary for performing an electromagnetic field analysis of an analysis target area including a conducting wire through which a forced current flows, and it performs a large-scale electromagnetic field analysis. Was one of the obstacles above.

Accordingly, an object of the present invention is to provide an electromagnetic field analysis of an analysis target area including a conductor having an arbitrary shape, by inputting a small number of data which can be given relatively easily, and forcing a forced current density vector distribution necessary for the analysis. To provide an electromagnetic field analysis method and an electromagnetic field analysis apparatus for performing the method.

[0007]

According to the present invention, there is provided a method and apparatus for analyzing an electromagnetic field in a region to be analyzed including a conductor through which a forced current flows using a computer. Means for obtaining a forced current density vector distribution in the group, and means for analyzing the electromagnetic field of the entire analysis target area using the obtained forced current density vector distribution, wherein the forced current density vector distribution is An input of data for specifying a direction in which a current flows through the conductor is received, and calculation is performed using a direction of the flow of the forced current specified by the received data.

Here, the data for specifying the direction in which the forced current flows in the conductor is, for example, data for selecting one of a plurality of directions in which the forced current can flow.

The data for specifying the direction in which the forcible current flows through the conductive wire include the direction in which the forcible current flows, the direction of the magnetic field generated by the forcible current, and the force on the surface of the conductive wire. It is also possible to use a direction vector in which the angle θ between the current inflow surface and the outflow surface is an acute angle (0 ° ≦ θ <90 °).

[0010] The absolute value of the forced current may be input as a norm of a direction vector for designating a direction in which the forced current flows in the conductor.

In the case where a direction vector for designating a direction of a magnetic field generated by the forced current is input as data for specifying a direction in which the forcible current flows through the conductor, It is preferable to input a direction vector corresponding to the direction of the magnetic field generated substantially at the position of the center of gravity.

Further, in the above invention, a configuration may be adopted in which a forced current density vector distribution is displayed on a display device before starting the electromagnetic field analysis of the entire analysis target area. Also,
An arbitrary conductor may be designated for the displayed forced current density vector distribution, the direction of the vector is inverted only in the designated conductor, and the electromagnetic field analysis of the entire analysis target area may be performed using the designated conductor. Furthermore, if the direction of the forced current flow is not specified before obtaining the forced current density vector distribution, the forced current density vector distribution is obtained by assuming the direction of the flow according to a preset procedure,
It may be configured to display on a display device.

According to another aspect of the present invention, there is provided a method and apparatus for analyzing an electromagnetic field in a region to be analyzed including a conductor through which a forced current flows using a computer. Means for determining a current density vector distribution, and means for analyzing the electromagnetic field of the entire analysis target area using the determined forced current density vector distribution, wherein the means for determining the forced current density vector distribution comprises: , And one of the directions of the forced current density vector, an initial value is set in advance, the preset initial value is displayed on a display device, and a portion corresponding to the portion where the initial value is to be changed is set. A selection command for specifying is received, and the direction indicated by the initial value set for the selected part can be determined by the forced current flowing through the part. Change in other orientations, with the direction of flow of the modified forced current, recalculating the forced current density vector.

In the above-described electromagnetic field analysis method according to the present invention, the conductive wire may be regarded as a permanent magnet, and the forcible current density vector may be regarded as a magnetization vector, thereby obtaining a magnetization vector distribution in the permanent magnet. .

In order to achieve the above object, a storage medium according to the present invention stores a program for causing a computer to execute the above-described electromagnetic field analysis method according to the present invention.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In one embodiment of the electromagnetic field analysis according to the present invention, a process including at least a characteristic procedure as shown in FIG. 1 is performed.

That is, first, in addition to designating an element group constituting a conductor, an absolute value of a forced current flowing in each conductor and a direction vector for designating a direction of the forced current flowing in each conductor are defined. It is given as input data (step S101). Here, the absolute value of the forced current may be given as a norm of the direction vector.

After inputting these, as in the conventional case, a simultaneous equation using the current vector potential and the potential as unknown variables is solved (step S102), and the forced current density vector in each element constituting the conductor is calculated using the equation. It is determined (step S103). Then, an electromagnetic field analysis of the entire analysis target area is performed using the obtained forced current density vector (step S104).

As described above, in the analysis processing of the present embodiment, it is not necessary to designate a predetermined conductor surface (inflow surface or outflow surface of the forced current or other side surface) by input data. The time and effort required for data creation can be greatly reduced.

The analysis processing of the present embodiment can be applied not only to the case of obtaining the forced current density vector distribution in the conductor, but also to the case of obtaining the magnetization vector distribution in the permanent magnet.

FIG. 2 shows an example of the configuration of an analyzer according to the present invention. In this example, a case will be described in which an analysis device is realized using a computer. Reference numeral 20 denotes an input device such as a keyboard for inputting data required for electromagnetic field analysis. Input data is sent to a computer via an input / output port (not shown).
Supplied to 21. The computer 21 has a ROM in which an arithmetic program for executing the electromagnetic field analysis method described below is stored, a CPU that performs arithmetic in accordance with the program,
In this configuration, a RAM for storing the calculation results is provided, and the calculation results stored in the RAM are supplied to the CRT 22 of the display means and displayed.

The above-mentioned arithmetic program may be recorded in a storage medium in advance, and when performing the electromagnetic field analysis processing, the arithmetic program may be read from the storage medium and executed by the CPU.

Next, an example of an electromagnetic field analysis process performed by the analyzer having the configuration shown in FIG. 2 will be described with reference to FIG.

First, after initialization is performed in step S1, various data are input in step S2. The data entered here is the nodal coordinate data of the elements obtained by dividing the analysis target area,
The data includes physical property data such as magnetic permeability and electrical conductivity of each part, and boundary condition data of an analysis target area. Further, here, data necessary for setting the direction of the control current is input as data required for calculating the forced current density vector flowing through the conductor, which is the subject of the present invention. A specific input method will be described later with reference to FIGS.

Next, in order to calculate the electromagnetic field using the edge element finite element method, in step S3, unknown variables are set on the sides of each element in the analysis target area. In this example, the magnetic vector potential is selected as an unknown variable.

Next, in step S4, a current vector potential is set as an unknown variable on each side of the conductor portion in order to obtain a forced current density vector flowing through the conductor.

Next, in step S5, a simultaneous equation is formed for each element of the conductor portion from the equation to be satisfied by the current vector potential.

Next, in step S6, these simultaneous equations are added for all elements of the conductor portion to form an overall simultaneous equation to be solved.

Next, in step S7, this system of simultaneous equations is converted into a PCG (Preconditioned Conj
ugate Gradient) to find the current vector potential on each side of the conductor. Then, it is stored in the memory. The above simultaneous equations may be solved by another method.

Next, the electromagnetic field in the entire analysis target area is calculated using the edge element finite element method.

First, in step S8, the value of the forced current density vector at the integration point in each element of the conductive wire portion is determined using the current vector potential on each side of the conductive wire portion previously stored in the memory.

Next, in step S9, the above-mentioned step S8
Using the value of the forced current density vector at the integration point in each element of the conductor portion obtained in the above, a simultaneous equation is formed for each element relating to the previously set unknown variable (here, magnetic vector potential).

Next, in step S10, these simultaneous equations are added for all elements in the analysis target area to form an overall simultaneous equation to be solved.

Next, in step S11, this system of simultaneous equations is converted into an ICCG (Incomplete Chole) which is one of the iterative methods.
Solve using the Sky Conjugate Gradient) method to find the value of the unknown variable on each side of the analysis target area. The above simultaneous equations may be solved by another method.

Next, in step S12, the above step S
A desired electromagnetic quantity, for example, a value of a magnetic flux density is obtained from the value of the unknown variable obtained in 11.

Next, in step S13, the obtained distribution data of the electromagnetic quantity is output, and the processing is terminated.

It should be noted that a potential may be used instead of the current vector potential as an unknown variable when obtaining the forced current density vector distribution in the conductor. Further, the processing described above is for the case of linear static magnetic field analysis, but the present invention can also be applied to the case of nonlinear static magnetic field analysis or eddy current analysis.

Next, a specific example in the case where the calculation is actually performed by the above analysis processing will be described.

(First Example) FIG. 4 shows a conceptual diagram of a forced current data input method used in this example. Fig. 4 (a) shows the case of an annular conductor closed in the analysis area, and Fig. 4 (b) shows only the inflow and outflow faces of the forced current appearing on the boundary of the analysis area, and they are mutually separated. This is the case of linear conductors that are separated.

In the method of the present embodiment, a lead wire is used as input data.
In addition to designating the element group that constitutes 10, the absolute value of the forced current 11 flowing through the conductor 10 and the forced current 11
A direction vector (not shown) for specifying the direction 13 of the magnetic field to be generated is given. Here, the direction vector only needs to indicate the general direction of the direction 13 of the magnetic field to be specified. For example, the angle θ formed with the direction 13 of the magnetic field is an acute angle (0
(° ≦ θ <90 °). As the predetermined portion 12, the position of the center of gravity of the conducting wire is substantially taken.

FIG. 5 shows an element division diagram used in this embodiment. According to the above method, the absolute value (for example, 1 A) of the forced current 11 flowing through the conductor 10 and the direction vector which forms an acute angle with the direction 13 of the magnetic field generated at the center of gravity (center of the ring) 12 of the conductor by this forced current 11 (For example, n = (1,0,0)) is given as input data.

Then, based on them, a simultaneous equation using the current vector potential as an unknown variable is solved, and the forced current density vector in each element of the conducting wire is obtained using the solution. FIG. 6 shows the forced current density vector distribution thus obtained.

As described above, according to the analysis processing of the present embodiment, the forced current density vector distribution required for the analysis can be obtained without giving any position coordinates, node numbers, and surface numbers for designating the conductor surface. Electromagnetic field analysis can be performed efficiently.

In particular, the data input method used in the present embodiment has an effect that it can be applied to an annular conductor closed in the analysis target area.

(Second Example) FIG. 7 shows a conceptual diagram of a forced current data input method used in this example. In this method, as input data, in addition to designating the elements constituting the conductor 10, the absolute value of the forced current 11 flowing through the conductor 10 and the forced current
A direction vector (not shown) for specifying the direction 16 from the inflow surface 14 to the outflow surface 15 of 11 is given. For example, a direction vector is input such that the angle ψ that forms the direction 16 to be specified is an acute angle (0 ° ≦ ψ <90 °).

FIG. 8 shows an element division diagram used in this embodiment. Then, in accordance with the above method, the forced current 11 flowing through the conductor 10 is
(For example, 1 A) and a direction vector (for example, n = (0, −1,0)) that forms an acute angle with the direction 16 from the inflow surface 14 to the outflow surface 15 of this forced current. In this case, the input direction vector and the direction 16 match.

Then, based on them, a simultaneous equation using the current vector potential as an unknown variable is solved, and the forced current density vector in each element of the conductor is obtained using the solution. FIG. 9 shows the forced current density vector distribution thus obtained.

As described above, the forced current density vector distribution required for the analysis can be obtained without giving any position coordinates, node numbers, and surface numbers for designating the conductor surface, and the electromagnetic field analysis can be performed efficiently. It becomes possible.

In particular, although the input method used in the present embodiment cannot be applied to an annular conductor, it can be applied to a linear conductor of an arbitrary shape in which a current inflow surface and a current outflow surface are separated from each other. Therefore, a more versatile electromagnetic field analysis tool can be constructed by selectively using the input method used in the first example and the input method used in the present example according to the shape of the conductor.

For the conductor having the shape shown in FIG.
The input method used in the first example is also applicable.

Next, another example of the electromagnetic field analysis processing executed by the electromagnetic field analysis apparatus according to the present invention will be described with reference to FIGS.

The analysis processing of FIG. 3 and the first and second
In the data input method according to the example, a general direction corresponding to the direction in which the forced current flows, or a direction vector indicating the general direction of the magnetic field generated by the forced current is set, but the present invention specifies the direction of the forced current. Are not limited to these.

Usually, the direction of the forced current that can flow through the conductor is
For example, there are only two directions, that is, the directions shown in FIGS. 4 and 8 or the opposite directions. Therefore, in the present invention,
Any input data that can specify one of the directions may be used, and the specific data form is not limited.

For example, a configuration may be used in which a plurality of directions of the forced current that can be taken for each conductor are determined in advance, and data for selecting one of them is used as input data.
Further, the direction of the forced current may be set in advance in the default mode for each conductor, and the direction may be corrected for each conductor as needed.

Another example of the electromagnetic field analysis processing procedure according to the present invention will be described with reference to FIGS.

In the example of the analysis processing according to this example, step S1a
At the same time, at the same time as the initialization of the device, a preset flow of the forced current for each conductor is set as an initial value. Subsequent steps S2 to S7 are the same processing as the steps of the same reference numerals in FIG. 3 described above, and description thereof will be omitted.

Next, in step S8a, a current density vector distribution is calculated from the current vector potential of each side of the conductive wire portion calculated by the above processing, and is displayed on the display device 22. Specifically, for example, as shown in FIG.
The forced current density vector distribution in each of the conductors 10a, 10b, and 10c to be analyzed is displayed on the display screen 22 of the display device 22.
Display on a.

Next, in step S8b, an instruction relating to selection of a conductor whose flow direction of the forced current is to be corrected is received from the user, and the forced current density vector distribution is inverted only in the selected conductor.

More specifically, as shown in FIG. 12B, for example, a user's selection instruction received via the keyboard 20 is displayed on the display screen 22a by the pointer 121, and the selected conductor (this example) is displayed. In this example, the conductor 10b) is displayed in a display form that can be distinguished from other conductors, for example, by surrounding it with a frame 120. Further, the forced current density vector distribution in the selected conductor is inverted, and the state after the inversion is displayed. In the following processing, the forced current density vector distribution after inversion is used.

In steps S9 to S13 which are the subsequent processes, the same processes as those in FIG. 3 are performed, and the electromagnetic field analysis of the entire analysis target area is performed.

According to the electromagnetic field analysis processing of the present example, the user can confirm the forced current density vector distribution generated by the forced current again, and if necessary, select the target conductor, thereby facilitating the forced current density vector distribution. It becomes possible to correct it.

The electromagnetic field analysis processing as shown in FIG.
When the direction of the forced current flowing through each conductor is reversed, it is particularly effective for an analysis target composed of conductors in which the direction of the corresponding forced current density vector distribution simply reverses.

Another example of the analysis processing procedure according to the present invention will be described with reference to FIG.

Steps S1a to S8a of the analysis processing according to this example,
Steps S9 to S13 are the same as the steps denoted by the same reference numerals in the analysis processing of FIG.
Only the processing of c and S8d is different from the processing procedure of FIG. In the following, only the different steps will be described.

In step S8c of the present analysis process, after the calculated forced current density vector distribution is displayed, the user selects the conductor whose flow direction of the forced current is to be corrected, and gives the user the information on the flow direction after the correction. Check if instructions have been entered.

If there is an input (Yes in step S8c), the flow advances to step S8d to correct the flow direction of the forced current of the conductor selected based on the input, and repeat steps S5 to S7 to newly enter A simple forced current density vector distribution.

The electromagnetic field analysis processing as shown in FIG.
Each time a correction is made, the corresponding forced current density vector distribution is recalculated, so not only when there are only two directions of the forced current flowing through each conductor, but also in special cases where there are three or more directions. Is also effective.

According to the electromagnetic field analysis processing of this example, it is possible to select an arbitrary conductor and correct the direction of the flow of the forced current flowing through the conductor to an arbitrary direction.

In the analysis processing of FIGS. 10 and 11, instead of displaying the forced current density vector distribution in step S8a, data indicating the flow of the forced current for each conductor set in step S1a is displayed on the display device. It is good also as a structure to make it.

Further, in the analysis processing of FIGS. 10 and 11, instead of initially setting the direction of the forced current for each conductor, a common direction is set in advance for all conductors, and the set direction is set. The direction of the forced current or the forced current density vector distribution obtained from the forced current may be displayed on a display device, and only the necessary conductor may be selected to correct the direction of the forced current.

According to such a configuration, the user can select only the necessary direction from among the directions of the forcible current set in advance for each conductor, so that the input data processing can be further simplified. it can.

[0073]

According to the method and apparatus for analyzing an electromagnetic field of the present invention, the input data relating to the forced current flowing through the conductor is small and the creation thereof is easy, so that the electromagnetic phenomena of the transformer, reactor, motor, generator, etc. Electricity using
Analysis of an electromagnetic field generated in an electronic device, particularly, a device having a complicated wire structure can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an example of a schematic processing procedure of an electromagnetic field analysis method according to the present invention.

FIG. 2 is a block diagram showing a configuration in a case where the electromagnetic field analyzer of the present invention is implemented by a computer.

FIG. 3 is a flowchart illustrating an example of a calculation procedure in the electromagnetic field analyzer according to the present invention.

FIG. 4 (a) is an explanatory diagram showing a case where the forced current data input method used in the first example of the present invention is applied to an annular conductor. FIG. 4B is an explanatory diagram showing a case where the forced current data input method used in the first example of the present invention is applied to a linear conductor.

FIG. 5 is an explanatory diagram showing a state of element division in the first example of the present invention.

FIG. 6 is an explanatory diagram showing a forced current density vector distribution obtained in the first example of the present invention.

FIG. 7 is an explanatory diagram showing a forced current data input method used in the second example of the present invention.

FIG. 8 is an explanatory diagram showing a state of an element division diagram in a second example of the present invention.

FIG. 9 is an explanatory diagram showing a forced current density vector distribution obtained in a second example of the present invention.

FIG. 10 is a flowchart showing another example of the calculation procedure in the electromagnetic field analyzer of the present invention.

FIG. 11 is a flowchart showing another example of the calculation procedure in the electromagnetic field analysis device of the present invention.

FIG. 12A is an explanatory diagram for explaining an input method in the electromagnetic field analysis device of the present invention. FIG. 12B is an explanatory diagram for describing an input method in the electromagnetic field analysis device of the present invention.

[Explanation of symbols]

10 ...... Conductor, 11 ...... Direction of forced current flow, 12
…… Predetermined part, 13… Direction of magnetic field at a predetermined part, 14… Forced current inflow surface, 15… Forced current outflow surface, 16 …… Direction from forced current inflow surface to outflow surface, 20… … Keyboard, 21… computer,
22 …… CRT.

Continued on the front page (72) Inventor Eiji Fukumoto 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Akiyoshi Komura 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F term in Hitachi Research Laboratory, Hitachi, Ltd. (Reference) 5B046 AA07 JA10 5B056 AA01 BB02 FF05 HH00 9A001 GG01 JJ50 KK37 LL08

Claims (7)

[Claims] 1. A method for analyzing an electromagnetic field in a region to be analyzed including a conductor through which a forced current flows by using a computer, comprising: a process of obtaining a forced current density vector distribution in an element group constituting the conductor; Analyzing the electromagnetic field of the entire analysis target region using a forced current density vector distribution, wherein the forced current density vector distribution is an input of data for specifying a direction in which the forced current flows through the conductor. An electromagnetic field analysis method which is received and calculated using the direction of the flow of the forced current specified by the received data. 2. The electromagnetic field analysis method according to claim 1, wherein the data for specifying the direction in which the forcible current flows through the conductor selects one of a plurality of directions in which the forcible current can flow. An electromagnetic field analysis method characterized in that the data is data for performing an electromagnetic field analysis. 3. The electromagnetic field analysis method according to claim 1, wherein the data for specifying the direction in which the forcible current flows in the conductive wire includes a direction in which the forcible current flows and a magnetic field generated by the forcible current. An acute angle (0 ° ≦ θ <90 °) between the direction and the direction from the inflow surface to the outflow surface of the forced current on the conductor surface.
An electromagnetic field analysis method characterized by using a direction vector of 4. The electromagnetic field analysis method according to claim 3, wherein the absolute value of the forced current is input as a norm of a direction vector for designating a direction in which the forced current flows in the conductor. Electromagnetic field analysis method. 5. A method for using a computer to analyze an electromagnetic field in an analysis target area including a conductor through which a forced current flows, comprising: a process of obtaining a forced current density vector distribution in an element group forming the conductor; Analyzing the electromagnetic field of the entire analysis target area using a forced current density vector distribution, wherein the process of obtaining the forced current density vector distribution includes one of the direction of the forced current and the direction of the forced current density vector. With respect to, an initial value is set in advance, the preset initial value is displayed on a display device, and a selection instruction for specifying a portion corresponding to a portion where the initial value is to be changed is received, and the selected command is received. The direction indicated by the initial value set for the portion is changed to another direction that the forced current flowing through the portion can take, and the flow of the changed forced current is changed. An electromagnetic field analysis method, wherein the forcible current density vector is recalculated using the direction of the electromagnetic field. 6. The electromagnetic field analysis method according to claim 1, wherein the conductive wire is regarded as a permanent magnet, and the forcible current density vector is regarded as a magnetization vector. An electromagnetic field analysis method characterized by determining 7. An electromagnetic field analysis apparatus for performing an electromagnetic field analysis of a region to be analyzed by performing the electromagnetic field analysis method according to claim 1 using a computer.