{"id":126,"date":"2022-08-23T11:41:57","date_gmt":"2022-08-23T02:41:57","guid":{"rendered":"https:\/\/www.ssil.co.jp\/product\/EMSolution\/en2\/?post_type=case&p=126"},"modified":"2022-08-23T14:02:15","modified_gmt":"2022-08-23T05:02:15","slug":"coil_force","status":"publish","type":"case","link":"https:\/\/www.ssil.co.jp\/product\/EMSolution\/en\/case\/coil_force\/","title":{"rendered":"COIL inductance and electromagnetic force calculations"},"content":{"rendered":"
Summary<\/h3>\n
This section introduces how to calculate the inductance and electromagnetic force of an external current magnetic field source (COIL). <\/p>\n
Table 2.\u3000Inductance calculation results by A-Ar method \n\n
\n\n
\n\t
boundary condition<\/th>
normalization<\/th>
unknown number<\/th>
Number of non-zero elements<\/th>
ICCG<\/th>
CPU Time<\/th>
L (H) A\u30fbJ Integral<\/th>
<\/th>\n<\/tr>\n<\/thead>\n
\n
\n\t
Brn=0<\/td>
\u00d7<\/td>
883,920<\/td>
14,699,871<\/td>
545<\/td>
333.1<\/td>
4.30087E-07<\/td>
Divergence at 4.2E-07<\/td>\n<\/tr>\n
\n\t
Brn=0<\/td>
\u3007<\/td>
883,920<\/td>
14,699,871<\/td>
534<\/td>
342.3<\/td>
4.30087E-07<\/td>
<\/td>\n<\/tr>\n
\n\t
Htrt=0<\/td>
\u3007<\/td>
900,260<\/td>
14,973,253<\/td>
388<\/td>
295.3<\/td>
4.30590E-07<\/td>
<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/p>\n
Table 3 and 4 show the results of electromagnetic force calculations for both methods, showing the total force in each direction for each section \u2460, \u2461, and \u2462 in Fig. 1. It can be seen that the results of both methods are almost identical. <\/p>\n
Table 3.\u3000Electromagnetic force calculated by the A method \n\n
As shown above, the results of the A method with SDEFCOIL and the A-Ar method with COIL are almost in good agreement and both analyses are equivalent. In the above example, the mesh is sufficiently fine and the far boundary is sufficiently far away. However, please note that differences may appear if such conditions are not used. <\/p>\n
<\/p>\n
How to use<\/h3>\n
To calculate the inductance of COIL internally in EMSolution, set the CALC_IND option to 1. The inductance calculation is performed by the MAKE_SYSTEM_MATRICES process. <\/p>\n
To calculate the electromagnetic force of COIL, set COIL_FORCE in "10. Input\/Output File" to 1. Please note that previously "11.1. Output Options" FORCE_J_B=2 was used, but this has been changed. The INTEG_OPT option was added as a new input data. With INTEG_OPT=1, the element integration point in a finite element is set to the element center point; with INTEG_OPT=0, the element Gaussian integration point is used. When INTEG_OPT =1 is used, computation time is significantly reduced. This option is also applicable for the calculation of conventional evaluation point magnetic fields. For calculations at a sufficient distance from magnetic materials or conductors, INTEG_OPT =1 is sufficient. <\/p>\n
When calculating inductance with CALC_IND=1 or electromagnetic force with COIL_FORCE=1, the definition of integral elements is required. These definitions are done by LOOP-, GCE-, and ARC-. These have the same input format as LOOP, GCE, and ARC, respectively. However, the number of divisions and the number of Gaussian integral points must be entered at the end. These data are included in the coil definition. For example, the integral region in Fig. 1 is represented as follows. Since the upper half is defined here, CURRENT is also half. In this example, the number of coil turns is set to 100T. \nNDIV (default value 1) is the number of divisions that divide the integral element equally in the current direction. Three-dimensional Gaussian integration is performed in the divided region. The electromagnetic force is output for each division; INT_X, INT_Y, and INT_Z are the number of integration points in each direction. The default values are 5, 5, and 3, respectively. INT_X and INT_Y are the number of integration points in the cross-sectional direction and INT_Z is the number of integration points in the current direction, with a maximum value of 12. The number of divisions and integration points required depends on the distribution of the magnetic field within the element, so increase the number of divisions and integration points as needed to make sure the results do not change. Since the electromagnetic forces are processed in POST_PROCESSING, you can change the number of integration points, etc., by performing post-processing in the restart calculation. <\/p>\n
As described above, when calculating the inductance and electromagnetic force of a COIL, the COIL information must be entered twice. On the one hand, the entire domain of the coil must be input as a conventional one, the coil that generates the magnetic field. On the other, the integral element does not create a magnetic field, but basically only the part within the finite element mesh region should be entered. For CIRCUIT or NETWORK, REGIONFACTOR is entered, and the inductance is integrated in the integral element, and using symmetry, REGION<\/em> FACTOR is multiplied. The electromagnetic force is integrated only within the divided integral elements and output to the output file without REGION_FACTOR multiplication. The number of integrating elements is also included in the NO_ELEMENTS of the COIL data. This function can be applied to LOOP, GCE, and ARC, but not to line current elements such as FGCE and FARC. <\/p>\n
![\"\"](\"\/product\/EMSolution\/en\/wp-content\/uploads\/coil_force01.png\")
<\/a><\/p>\n![\"\"](\"\/product\/EMSolution\/en\/wp-content\/uploads\/coil_force02.png\")
<\/a><\/p>\n