JMAG Newsletter June, 2014Product Report
Introduction of JMAG-Designer Ver.13.1
JMAG Ver.13 will be released in June, 2014.
Ver.13.1 will have over 40 additional features including large-scale models, magnetic material, and multiphysics.This product report will introduce new unique features in JMAG Designer 13.1.
JMAG-Designer Ver.13.1 will be released in June, 2014. Ver.13.1 is equipped with new features beginning with large-scale models, magnetic material, and multiphysics. Large-scale models have improved processing speed to enhance the handling of required parts in detailed analysis focusing on large machinery and large-scale mesh. As for magnetic material, specific magnetization direction and coercive force distribution can be set on the analysis model from the GUI. Multiphysics allows the confirmation of mapping preview and data conservation of mapping data handled in the multi-purpose file output tool.
Supports Large-scale Models
With the large improvement in solving speed with the high parallel solver realized in Ver.13.0, detailed analysis of large-scale models have become accessible to users. As a result, operation other than the solving process of large-scale models have become the theme.
In Ver. 13.1, the operability of large-scale models have been enhanced with the acceleration of pre-post processing. Also, by removing unnecessary items from large-scale calculation data obtained in the analysis, the file size has been slimmed down, and has made efficient data management possible.
Support for Large-scale Mesh / Models with Numerous Parts
Ver. 13.1 sets a standard of models with 1000 parts and 10 million elements with the acceleration around the pre-post, and has accelerated each function including loading and display, setting materials/conditions, and the loading of results. As applications, motors and transformers are picked up, and processing speed of each function is displayed as results in comparison with Ver.13.0 (Fig.1). Approximately how much processing time has decreased in a relative comparison by operation item is shown. It can be seen that the processing speed has largely improved for each application, as well as in general.
Fig.1 Processing speed improvement ratio for operatibility of each application and model information
Reduction of Result Files
We have received comments from many users that due to large model sizes and transient analyses with numerous steps, the result files became too large and that it took up too much hard drive space.
To simplify the management of result files (jplot file) of large-scale models, after confirming the analysis results in Ver.13.1, unnecessary distribution amount data and analysis steps, as well as output items can now be specified and removed. By only retaining important data, hard drive space is efficiently used.
Results obtained from magnetic field analysis of the motor in voltage drive to run an iron loss analysis is organized with this function (Fig.2). Iron loss analysis requires magnetic flux density and displacement data of the last 1 electric angle periodicity data. It can be seen that the full-set initial data had a file size of more than 1.5GB but the final stage has been shrunk to 19MB.
Fig.2 Change of file size after deleting output items by stages
JMAG has been continually developing on the material modeling feature. Up until now, we have been adding functions focused on iron loss but from Ver.13.1, we have put emphasis on the magnet function. The function introduced here is the arbitrary magnetization direction specification function, the coercive force distribution function that can specify the arbitrary coercive force distribution and the sinusoidal magnetization function. The characteristic that is common amongst these features is that it is not dependent on creating a program such as a user subroutine but can be supported through the GUI settings.
Specifying Arbitrary Magnetization Direction
With the increase in variety of magnets used in motors, various magnetization pattern settings can be obtained in the analysis.
The arbitrary magnetization direction specification function can specify the distribution state of the magnetization direction of the magnet through the GUI (Fig.3). Define the orientation direction by creating an angle distribution table to each direction (X/Y direction or R/θ direction) of the rectangular coordinate and cylindrical coordinate depending on the magnet geometry. Since an arbitrary value can be entered in the table, specific orientation information can be specified.
Fig.3 Example of magnetization direction specification by arbitrary magnetization direction specification function
Coercive Force Distribution
Dy diffused magnets are used in high-precision motors as magnets using rare-earth elements, and retains specific coercive force distribution. In terms of modeling, since specification of region divisions depending on the coercive force of each magnet, and coercive force / magnetization direction for each region after division is necessary, this became a lengthy process.
In the coercive force distribution funtion, select the rectangular coordinate or the cylindrival coordinate depending on the magnet geometry, and as the correction value, create a coercive force distribution table. By combining with the arbitrary magnetization direction specification function, the time and effort originally needed for the creation of a magnet model is decreased drastically.
Drive analysis of motors using magnets that have executed coercive force distribution correction have been run, and the results comparing magnets without correction with demagnetization state is shown (Fig.4). In contrast to magnets without coercive force distribution correction that have a maximum 33% demagnetization ratio, magnets with correction have a maximum of 10% demagnetization ratio and the range is extremely limited.
Fig.4 Comparison of demagnetization state while driving due to with / without coercive force distribution correction
Without coercive force distribution correction (left) and with coercive force distribution correction (right)
Sinusoidal magnetization supports radial magnetization, parallel magnetization, and axis direction for the radial direction, and linear direction for parallel magnetization (Fig.5).
Evaluation of motor design with magnetization pattern of sinusoidal waveform known to have few high harmonics is possible.
Fig.5 Magnetic distribution inside the magnet along the circumferential direction
(Apply the radial sinusoidal circular pattern)
Multi-purpose File Export Tool
The multipurpose file output tool is an important tool for analysis of results obtained in JMAG using structural analysis and thermal fluid analysis . In Ver.13.1, data conservation of map data and the addition of the preview feature in the map mode has increased its usability.
When running a frequency response analysis of the structure using electromagnetic force of the time series calculated in JMAG, electromagnetic force needs to be converted to the load condition for each frequency with FFT processing. When the frequency range is wide, the file size after mapping may become a few GB and it may affect the solving speed and the loading of files at analysis.
In Ver.13.1, the user can control electromagnetic force data necessary in structural analysis from the mapping of the frequency region and the mapping of the air region. In frequency region mapping, since necessary frequency range can be specified in the analysis, conserving large amounts of data is capable compared to processes before, which mapped all frequency information (Fig.6). In mapping air regions, the output can be controlled by part and by face. It is supported even if the magnetic analysis model and the structural analysis model are different in dimension, and the electromagnetic force on the edge of the 2D magnetic field analysis model can be mapped as the electromagnetic force on the face of the 3D structural anaylsis model (Fig.7). In addition, the output format can be mapped as total stress, which has effect on each face of the solid and not only the map of the nodal force as before.
By combining the output control features, highly controllable analysis environments can be built.
Fig.6 Mapping of coercive force specifying the frequency range
Fig.7 Mapping of coercive force by the face and by part
Confirmation of data after mapping with the preview function
The preview function allows the confirmation of the distribution state for each physical amount after mapping before running the analysis through JMAG (Fig.8). This is a handy feature that allows you to confirm if it has been mapped correctly for different mesh models. Like electromagnetic force distribution, the load data built by numerous frequencies through FFT processing can be confirmed by selecting the frequency you would would like to see.
Fig.8 Data confirmation after mapping with the preview function
Eddy current loss density contour before mapping(left) and eddy current loss density contour after mapping with the preview feature (right)
JMAG has constantly been working on the acceleration of the solver. Although many items have been improved in Ver.13.1, this article wil introduce FQ support of GPU.
Supports frequency response analysis (FQ) of GPU
Demand for GPU in the technology calculation department has increased by the year but GPU boards exclusively for calculation are sold and supported.
With this current trend, JMAG has released a beta version supporting ST/TR of magnetic field analysis from Ver.11 and official support began with the release of Ver.12.
Furthermore, starting from Ver.13.1. there is support for FQ (Fig.9). FQ is a module with high demand in the field of large-scale analyses beginning with large transformer analysis and induction heating analysis, and by combining with SMP and MPP, options for models supported in the calculation environment has increased.
Fig.9 Comparison of calculation time between analysis of IH cooking equipment using GPU (FQ) (left) and 1 CPU (1core)
Added magnetic field analysis and structural analysis functions to analysis conditions. A function has been added to perform uniform current distribution for current conditions and FEM coil conditions in magnetic field analysis. For structural analysis, contact conditions able to handle deformations and deviations due to objects coming in contact have been added.
Specification of Uniform Current
When setting a current condition or FEM coil condition on a 3D modeled coil of circular shape before, distribution with current biased in the inner radius is shown, and when flowing uniform current, the radial direction was divided numerous times to avoid the problem.
The uniform current function can uniformly specify the current distribution in the coil. With this function, it does not only make handling of coil geometries that has been divided to numerous geometries easier but it also increases the accuracy of magnetic flux distribution.
An example comparing incoming and outgoing distribution of current flow formed by disc-shaped coils is shown below (Fig. 10). Using a modeled wire model in a coil unit as a basis, differences are compared in current distribution depending on whether or not uniform current is specified in a bulk model displayed as a cluster of solids.
A graph showing magnetic flux density distribution from the center axis of the coil in the radial direction (Fig. 11). You can verify that the current distribution and magnetic flux density distribution are almost the same in a wire model and bulk model (uniform current).
Fig.10 To the wire model and bulk model (non-uniform current / uniform current)
Fig 11. Magnetic flux density distribution in the radial direction based on results from fig. 10
(arrows in the figure in the direction of the magnetic flux density section).
Structural contact condition
Deformations and deviations due to objects coming in contact have to be handled in a structural analysis.
Contact condition is a condition to specify when handling objects making contact brought about by static geometry containing centrifugal force. It is possible to obtain the deviation of an object accounting for generated displacement, stress, friction due to contact.
Results are shown for contact and exfoliation produced between the magnet and rotor core due to centrifugal force generated by the rotor of an IPM motor (Fig.15). The magnet is pressed up against the rotor core due to centrifugal force, and causing pressure between them. The magnet can be checked for any horizontal deformations (Fig.12).
Fig.12 Example of applying the contact condition to the magnet and the rotor
Ver.13.1 has improved operability in creating a model as well as faster processing time to import a large-scale model.
Specifying Reference Axis from Coordinate Axis
In the course of model geometry generation, there are numerous operations specifying rotation axis such as revolve from a 2D region or rotation copy of a 3D geometry. Although these operations are required for each part, previous version caused a lot of hassle, such as moving the created intersection to the specified position, when specifying intersection of two planes or specifying the rotation axis off the origin.
This function allows you to set the rotation axis by specifying each coordinate axis directly as a rotation axis or specifying directional vectors that pass through the specified point (Fig. 13).
Fig. 13 Specifying Rotation Axis by Revolve
Creation of helical coil geometry is now supported using the revolve function.
This function facilitates the creation of a model for the target that needs to handle helical coil geometry, such as when examining optimal coil geometry for high-frequency induction hardening, or evaluating dielectric strength or capacitance of windings including transformers (Fig. 14).
Fig. 14 High-Frequency Induction Hardening Model using Helical Coil Function
Post function has added functions of averaging analysis ranges specified by the user and processing effective values.
Specifying Ranges for Graph Average Values and Effective Values
Calculation of the average and effective values of analysis result history data is now available for ranges specified by the user. This function enables evaluation of averaged output values in a constant state except for transient state (Fig. 15).
Fig. 15 Calculation of Averaged Torque by Specifying Analysis Time Range
User Component Range Specification
The new version has a function to display results of operations such as maximization, minimization and averaging for all analysis ranges based on data for each step as process for output value in the contour plot using the user component.
Fig. 16 Iron Loss Density Distribution with Averaged Time by Range Specification
Above: Time average distribution graph, below: Contour figure
New functions described in this issue will be explained in the upgrade seminar in June, 2014.The Event Information in this issue contains the schedule of the upgrade seminars, so please check it out.
Our website also has movie for each function.
1. Product Report - Introduction of JMAG-Designer Ver.13.1 -
2. Product Report - Three-Phase Induction Motor Design with JMAG-Express -
3. Fully Mastering JMAG - Common Questions for JMAG -
4. JMAG University Partner Introduction - KTH Royal Institute of Technology -
5. JMAG Solution Partner Introduction - Advanced MotorTech, LLC -
6. Event Information