Not Simple Simulations, But a Tool Stimulating Creativity
- Why did you decide to implement JMAG in the late 1990's?
Mr. Nomura JMAG provides a way for us to attain and progress our implementation of
computer aided engineering (CAE). In the late 1980's, we established a
CAE center and began supporting our design process with analysis software
that used the finite element method I . At that time, it was a trial and error process using both magnetic field
analysis software that we internally developed and other universal analysis
In the field of industry, the development of permanent magnet (PM) motors,
or a type of motor that uses permanent magnets on the rotor, was a huge
turning point. Three dimensional magnetic field analysis was required in
the 1990's when the technological development of PM motors gained momentum.
We needed a tool that could accurately calculate the torque because the
torque ripple II directly affects the ride of elevators using PM motors. However, there
is a problem that the path of eddy currents which exists in the magnet
cannot be evaluated by means of a two-dimensional analysis. Therefore,
a tool with three-dimensional magnetic field analysis is necessary.
We tried several magnetic field analysis tools when we stumbled upon JMAG.
JMAG was an easy-to-use software suite that satisfied our need for three
dimensional simulations that could analyze the transient phenomena of rotating
motors and the eddy currents that existed. Personally, I was astonished
by the analysis of the eddy currents in the permanent magnets of PM motors.
We could enhance our techniques during design processes by verification
of the simulation with measurement.
Mr. Matsuhashi When we originally implemented JMAG we needed an analysis specialist because
JMAG operated on a workstation, but today, JMAG, which now runs on personal
computers, is much more user friendly allowing us to use it in many different
departments. We have been able to increase the level of our prototypes
and reduce the number of prototypes as JMAG has become more accessible
to designers as well as engineers. We had to examine the technology and
quality of our products, build and rebuild prototypes at various stages
of product development, which is not limited to PM motors. We strive for
a front-loading type of development process using analysis software to
guarantee only a single prototype is required at each stage of development.
Obviously, our ultimate goal is to have a development process that doesn't
require any prototype, but that will still take some time to achieve. However,
JMAG has contributed vastly in reducing the number of prototypes and virtually
eliminated the need to totally overhaul a prototype or start the development
process from scratch.
Magnetic Field Density Contour Plot of a SPM Motor
IPM Motor Model
Eddy Current Loss Distribution of a Permanent Magnet
I Finite element method refers to an analysis method performed by separating
a large object into virtual elements that have a finite size, and then
analyzing the object as the sum of the elements.
II Torque ripple refers to the ripple in the torque (force) when a motor rotates.
The torque ripple causes noise and vibrations and worsens the control.