JP6286331B2 - Electromagnetic field analysis device, display device thereof, and calculation system using them - Google Patents

Description

  The present invention relates to an electromagnetic field analysis device, a display device thereof, and a calculation system using them.

  The following techniques are disclosed as a method for calculating electromagnetic force and torque using electromagnetic field analysis.

  In Patent Document 1, when performing a coupled analysis between an electromagnetic field and a structure by a finite element method, an electromagnetic field analysis is performed using a first mesh suitable for electromagnetic field analysis, and each node included in the first mesh or Using the value of the electromagnetic field at each element side, the electromagnetic field at each node or each element side included in the second mesh suitable for structural analysis is calculated, and is included in the second mesh from the calculated electromagnetic field. A method is shown in which a nodal force, which is an expression of an electromagnetic force at each node, is calculated and a structural analysis is performed using a second mesh.

  In Patent Document 2, based on a numerical analysis model of an induction motor including a stator having a coil and a rotor having a conductor portion, a magnetic field analysis apparatus that calculates a magnetic vector potential in a steady state of the numerical analysis model is described above. An acquisition means for acquiring a first frequency of a current or voltage to be applied to the coil, a first frequency acquired by the acquisition means, and a second frequency obtained by multiplying the slip amount of the rotor with respect to the stator When the magnetic vector potential in the stator portion of the numerical analysis model sine wave vibrates at a first frequency and the magnetic vector potential in the rotor portion of the numerical analysis model sine wave vibrates at a second frequency A frequency response analyzing means for calculating the magnetic vector potential is shown.

Japanese Patent Laid-Open No. 2004-29930 JP 2010-026595 A

  For example, at the design stage of a rotating electrical machine, the torque that becomes an output is increased on the basis of the electromagnetic field analysis result, so that the time change of the torque due to the change in the shape of the iron core constituting the magnetic circuit may be calculated. However, in the conventional contact force method used to calculate the electromagnetic force acting on the magnetic material, the electromagnetic force acting on the nodes constituting the element is calculated. The error due to interpolation is inevitable in the same way as when switching to the mesh for use.

  Therefore, an object of the present invention is to provide an electromagnetic field analysis device that calculates the density of torque acting on a magnetic material or a coil for each element in electromagnetic field analysis, a display device thereof, and a calculation system using them.

  In order to solve the above problems, for example, the configuration described in the claims is adopted.

  The present application includes a plurality of means for solving the above-described problems. For example, the present invention is characterized in that the torque density in each of the elements is calculated from a complex magnetization vector for each element.

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic field analyzer which calculates the density of the torque which acts on a magnetic body or a coil in an electromagnetic field analysis for every element, its display apparatus, and a calculation system using these can be provided.

  Problems, configurations, and effects other than those described above will become apparent from the description of the following examples.

It is a figure which shows the calculation system containing the analysis apparatus by Example 1 of this invention. It is a figure which shows the calculation procedure of the torque density by Example 1 of this invention. It is a figure explaining the torque which acts on the description of the torque calculation method of this invention, and acts on the magnetic body of a polygon cross section by the electric current of a polygon cross section. It is a figure explaining the torque which concerns on description of the torque calculation method of this invention, and acts on the magnetic body of a polygon cross section with the magnetization vector in the magnetic body of a polygon cross section. It is a figure which shows the relationship between the node and element by a calculation method, and electromagnetic force. It is a figure which shows the calculation result of the torque density by Example 1 of this invention. It is a figure which shows the calculation result of the torque density by Example 2 of this invention. It is a figure which shows the calculation procedure of the torque density by Example 3 of this invention. It is a figure which shows the calculation procedure of the torque density by Example 4 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following explanation, it is assumed that the method of combining the present invention and the electromagnetic field analysis result by the finite element method, which is often used in electromagnetic field analysis, but it is based on an analysis method using other differential equations or an integral equation. It may be combined with an analysis method.

  An example of the configuration of a calculation system including an analysis apparatus according to the present invention is shown in FIG.

  Model information 40, element shape data 50 of a target model (usually called a mesh in the electromagnetic field analysis using the finite element method), magnetic flux density data 60 in each element, and the like are input from the input device 20 to the analysis device 10. This is designated by the instruction 30.

  The calculation program 70 includes a magnetization vector calculation block 80 that calculates a magnetization vector at each element at each step of the analysis time based on the magnetic flux density data 60, and an electromagnetic force calculation block 90 that calculates an electromagnetic force based on the calculated magnetization vector. Including. When calculating the torque of the rotating electrical machine, the distance of each element is calculated from the rotation center coordinates designated by the model information 40 and the element shape data 50, and the torque is calculated.

  The volume or area of each element is calculated by a volume calculation block 110 that calculates the volume or area of the element in parallel with these or based on the element shape data 50 before and after. It is assumed that the element shape 50 data and the magnetic flux density 60 data calculated using a calculation system different from the analysis device 10 are introduced into the analysis device 10 in advance using communication means or a storage medium. Yes.

  Next, in the torque density calculation block 100, the torque per volume or area of each element is calculated from the electromagnetic force or torque acting on each element calculated previously and the volume or area of each element (in the description of this embodiment, (Referred to as torque density).

  FIG. 2 shows a torque density calculation procedure by the calculation program 70 when the shape of the magnetic body or coil to be analyzed does not change within the analysis time step. The input shows the case where the transient analysis result by the electromagnetic field analysis by the finite element method is used and the torque of each element (hereinafter referred to as torque density) is calculated as post processing.

  When the calculation is started (200), element shape data is first read into the storage area (210). Next, the volume or area of each element is calculated from the shape data of each element (220). The calculated volume or area data of each element is stored in a storage area or saved in a file.

  Next, the magnetic flux density of each element at the time corresponding to each time step is read (230), and the magnetization vector is calculated (240). Subsequently, the electromagnetic force exerted by each element is calculated (250). A torque density is calculated based on the calculated electromagnetic force, the volume or area for each area, and the distance from the center coordinate (260).

  The torque density calculation block 290 for each time step is repeatedly executed by the end step determination 270 until the time step to be calculated ends. The reading of the magnetic flux density data may be a procedure in which the target time steps are first read together and stored in the storage area.

  A method for calculating the torque density used in the present invention will be described below.

  The complex torque acting on the magnetic material having the polygonal cross section by the current having the polygonal cross section as shown in FIG. 3 is calculated by the following mathematical formulas (1) to (10). The real part of Equation (1) is the torque generated in the target region.

Further, the complex torque around the point Z ₀ acting on the whole magnetic body in the region Ω ′ from the electromagnetic force acting on the magnetic body having two polygonal cross sections as shown in FIG. Calculated in (17). The same symbols are the same as in equations (6) to (9). The real part of Equation (11) is the torque generated in the calculation target region.

  In the torque calculation in the rotating electrical machine, the case of electromagnetic force acting on the coil and the magnetic body, and the magnetic body and the magnetic body is considered. That is, the torque around the center of rotation due to the electromagnetic force exerted by each other is calculated with the elements in which uniform currents or magnetization vectors are distributed as polygonal regions Ω and Ω ′. A torque density calculation result is obtained by dividing this torque by the volume or area of each element.

  FIG. 5 schematically shows the location where the electromagnetic force is calculated by the Maxwell stress method and the nodal force method, which have been used for the calculation of the electromagnetic force in the past, and the method of the present invention. In the Maxwell stress method, calculation is performed using a normal vector of an integration surface covering a magnetic material to be calculated. In the nodal force method, the electromagnetic force is calculated for each node constituting the element. In both cases, the electromagnetic force applied to the element itself is not directly calculated, so interpolation calculation is indispensable for the difference converted into the element, and calculation errors due to the element shape and the boundary between the magnetic body and air are inevitable. .

  For this reason, normally, in the case of torque calculation by the contact force method, the force inside the magnetic body is not calculated and displayed. On the other hand, according to the method of the present invention, the torque density is also calculated for each element in the magnetic body or coil, so that the torque density of each element can be displayed particularly corresponding to the shape of the electromagnetic device.

  FIG. 6 shows a calculation result of torque density calculated using the analysis apparatus of the present invention and displayed by applying the display method of the present invention. A part of the torque density distribution calculation result of the permanent magnet motor having the permanent magnet 430 in the rotor core 420 is enlarged and displayed. The direction of rotation is counterclockwise toward the plane of the paper. The torque zero is white, and the darker the black, the larger the positive torque. From the display result as shown in this figure, it can be seen that a relatively large positive torque is distributed in the outer peripheral portion of the rotor core 410 and the tooth tip portion of the stator core 400 in the calculated time step.

  FIG. 7 shows a calculation result of torque density calculated using the analysis apparatus of the present invention and displayed by applying the display method according to the second embodiment of the present invention. A part of the torque density distribution calculation result of the permanent magnet motor having the permanent magnet 430 in the rotor core 420 is enlarged and displayed. The rotation direction is counterclockwise toward the paper surface. The negative maximum torque density is white, and the darker the black, the larger the positive torque. From the display results as shown in this figure, it can be seen that relatively large positive and negative torques are distributed in the outer peripheral portion of the rotor core 410 and the tooth tip portion of the stator core 400 in the calculated time step.

  FIG. 8 is a diagram showing a calculation procedure executed by a calculation program in the analysis apparatus according to the third embodiment of the present invention.

  The torque density integration (310) is added to the calculation procedure in the first embodiment.

  Thereby, the integrated value and average value through the calculation target step can be calculated, and the time-averaged electromagnetic force and torque density in each element can be calculated.

  FIG. 9 shows a calculation system according to the fourth embodiment.

  In addition to the analysis apparatus 10, a mesh model creation program 510 and an electromagnetic field analysis program 520 are provided in one calculation system 150.

  The mesh model creation program 510 generates the element shape data 50 and passes it to the electromagnetic field analysis program 520 and the analysis apparatus 10. The electromagnetic field analysis program 520 calculates the magnetic flux density data 60 for each element of the element shape data 50 and passes it to the analysis apparatus 10. In the case of analysis involving movement of an object in the analysis region, either the element shape data 50 or the magnetic flux density data 60 is described including the displacement amount, or a separate displacement amount data file is prepared.

  Element shape data and magnetic flux density data necessary for calculating electromagnetic force or torque can be generated in one calculation system, so that calculation can be executed without moving data via a medium or the like. it can.

DESCRIPTION OF SYMBOLS 10 Analysis apparatus 20 Input apparatus 40 Model information 50 Element shape data 60 Magnetic flux density data 70 Calculation program 80 Magnetization vector calculation block 90 Electromagnetic force calculation block 100 Torque density calculation block 110 Volume calculation block 130 Display apparatus 400 Stator core 420 Rotor core 430 Permanent magnet 510, 540, 570 Node 520, 550, 580 Element 530, 560, 590 Direction of electromagnetic force

Claims (5)

  An electromagnetic field analyzer that calculates a torque density at each of the elements from a complex magnetization vector for each element. The electromagnetic field analysis apparatus according to claim 1 ,
An electromagnetic field analyzer that integrates or averages the calculated torque density with respect to the time step of analysis. The electromagnetic field analysis device according to claim 1 or 2,
A display device for displaying the torque density calculated by the electromagnetic field analyzer. The display device according to claim 3,
About the torque density calculated by the electromagnetic field analyzer,
A display device that performs contour display of torque density values in color or shade based on the moving direction. Including the electromagnetic field analysis device according to claim 1 or 2, or the display device according to claim 3 or 4,
A mesh model creation program to create element shapes;
Including an electromagnetic field analysis program for calculating the magnetic flux density,
A calculation system that passes the element shape data and magnetic flux density data to the analyzer and performs calculations.