Electric Motor Technology Research Center, Taiwan National Cheng Kung University
Use of JMAG in Renewable Energy Research
In May, 2012, JMAG’s Taiwan distributor, Flotrend, held a JMAG Users Conference in Taiwan attended by around 60 JMAG users.
The JMAG Users Conference benefitted from the cooperation of Associate Professor Min-Fu Hsieh, a researcher at Taiwan National Cheng Kung University’s Electric Motor Technology Research Center (EMTRC), and, like in Japan, saw a lively exchange of ideas among engineers. This report gives an overview of Professor Min-Fu Hsieh’s activities.
Department of Systems and Naval Mechatronics Engineering,
National Cheng Kung University
and The Electric Motor Technology Research Center
Professor Min-Fu Hsieh
Professor Hsieh: The EMTRC was co-founded with the China Steel Corporation to support motor-related industries in Taiwan.
We take part in a wide range of development and promotion activities, from materials to systems. Delta Electronics Inc., SUNON Industry Company, Taiwan HITACHI Corporation and other companies are supporters of ours.
Professor Hsieh: I’m mainly focused on renewable energy (wind, tidal, etc.) and electric vehicles.
I work on rare earth and non-rare earth permanent magnet motors and non-permanent magnet motors (for example, brushless double-fed and reluctance motors), generalized magnetic circuits, and magnetization (especially post-assembly magnetization techniques).
Fig. 1 A small wind turbine and its properties
Professor Hsieh: Electromagnetics covers an extremely wide range. Things from electron spin and magnetic core memory to large-scale wind generators with tens of thousands of watts in output are all closely related to electromagnetics.
A lot of papers are published in the academic societies. Thousands of papers are submitted to INTERMAG (sponsored by IEEE) every year, and COMPUMAG and CEFC also regularly get hundreds of submissions.
In recent years, awareness of energy and ecological issues has grown, and among technologies related to renewable energy and energy efficiency, generators and motors have received particular attention. The field of electromagnetics has greatly expanded because of this.
One example I can give you here is the first large-scale wind generator to use high-temperature superconducting materials. The magnetic field generated by superconducting wires and bulk materials can improve a generator’s torque density, output density, and efficiency. This makes direct drive possible without a step-up gear, which in turn contributes to efficiency. Superconductor technologies are likely to be extremely important for generators.
Professor Hsieh: Before, the problem of efficiency was not considered very important in development of motors and generators.
As motors have come to be used in a variety of fields, energy-reduction, materials, and system control technologies have progressed, and high-performance motors can now be developed Because of this, more and more high-performance motor development is happening in a lot of industries.
For example, the drive of air-conditioning compressors has evolved from fixed-speed drive to variable-frequency drive, and then to DC variable-frequency drive.
Fig. 2 A permanent-magnet generator (prototype)
Fig. 3 JMAG analysis results: electromagnetic force (left) and mesh (right)
Professor Hsieh: Each different motor has its strengths and weaknesses. You have to choose the right motor type based on what is most important for your application, whether it is cost, size, efficiency, etc.
For example, permanent-magnet motors, AC motors, and reluctance motors each have their own problems. Still, each of them fulfill certain needs, and they are all being used as motors for electric vehicles.
In particular, AC motors, which had generally been considered a mature technology, are now expected to see higher performance through advances in materials and design. Even the automobile industry, which had ignored AC motors up to now, is now giving attention to high-performance AC motor development.
Further, integration of motors and generators into overall systems must be taken into consideration in order to achieve high performance. System integration will certainly be seen as even more important in the future.
Professor Hsieh: Motor design has become a lot more efficient thanks to improvements in computer performance and CAE software development.
Design accuracy is increasing through the use of JMAG. This is why developing people who can use CAE software is a key point for the industry.
Emphasis on both theory and practice is needed to develop these human resources.
For one thing, if engineers do not have the fundamental theory and knowledge, they will not be able to use CAE software correctly, and will not be able to verify analysis results or derive physical phenomena from those results.
Also, experience with experiments and physical prototypes allows them to take advantage of CAE’s power in verifying design proposals.
There are excellent electronics makers in Taiwan, but the research capability is not quite there, and there is a shortage of human resources for CAE. For these reasons, the development of CAE human resources is a serious issue for any further expansion of this industry.
Professor Hsieh: I simulate heat dissipation using Acusolve, which is CFD software handled by Flotrend, and JMAG in combination. Flotrend is thoroughly versed in both programs, so setting this up was very quick. I’m sure I will make use of it linked to more and more simulation programs in the future. I hope I can count on your support.
Thank you very much, Professor Min-Fu Hsieh