Special Session
New Motors -Innovation of Mature Devices-
New Motors
The Special Session is scheduled for the first day of the JMAG Users Conference 2010 after receiving rave reviews from those who participated. The theme for the Special Session this year is “New Motors.” Motor developments based on new concepts are being actively pursued following stricter demands for higher performance and a much wider range of applications for motors that are continually advancing. Ingenuity has expanded to new avenues of innovation such as slot combinations, materials, and drive methods. This year’s JMAG Users Conference will focus on this type of ingenuity. Each of the presenters asked to participate is involved in their own unique motor development. In addition to their groundbreaking ideas, each presentation will shed light on the methodology that brought them into existence.
Presentations
Novel Permanent Magnet Brushless Machines and Applications
Professor. Zi-Qiang Zhu, University of Sheffield, UK
The first to present this year is Professor Zi-Qiang Zhu from the University of Sheffield. Professor Zhu is known for his ongoing and enthusiastic research in the field of motor design and he is currently leading PM motor development in the world based on new operating principles. Professor Zhu’s research department at the University of Sheffield doesn’t simply provide design methodology, but consistent and thoroughly documented evidence of their research from actual experimentation performed on prototypes. In this presentation, Professor Zhu will explain in simple terms part of the advanced theory which is the source of new ideas while discussing how simulation technology is being utilized.
Variable-Magnetic-Flux Motors for Creating New Generation Motor Drives
Dr. Kazuto Sakai, Associate Professor, Department of Electrical, Electronic and Computer Engineering Faculty of Science and Engineering, Toyo University
Following Professor Zhu, Professor Kazuto Sakai will present his research in new types of variable magnetic flux motors. Energy saving of electrical appliances and electric vehicles (EV) require the reduction of power consumption of motors. Professor Sakai’s presentation takes an ingenious look at a new type of motor for the future that focuses on memory motors and variable flux motors which directly vary the magnetic characteristics of permanent magnets to overcome the challenges of reducing the total power consumption of variable speed drive permanent magnet motors used to achieve higher efficiency.
Study of Flux-Intensifying Interior Permanent Magnet Synchronous Machine
Mr. Yuichi Shibukawa, Nissan Research Center, EV system Laboratory, NISSAN MOTOR CO., LTD.
Mr. Shibukawa from Nissan presents a flux-intensifying interior permanent magnet synchronous machine. IPM motors with conventional positive salient structures are known to have trouble obtaining sufficient torque while sustaining their positive saliency. The structure of the motor introduced in this presentation resolves this problem and improves the self-sensing control in very low speed regions. Mr. Shibukawa will also discuss the results of his testing compared to conventional motors.
Studies on Less Rare-Earth and High Power Density Hybird Excitation Motors
Dr. Takashi Kosaka, Associate Professor, Graduate School of Engineering, Omohi College, Nagoya Institute of Technology
Mr. Kosaka from the Nagoya Institute of Technology presents the results of his high power density hybrid excitation motor. A high power density hybrid excitation motor is a motor which utilizes both the magnetic force of the magnets and the efficient 3-dimensional magnetic circuit. The number of rare-earth magnets can be reduced by half while still achieving the same output density when compared to the IPM motors installed in hybrid automobiles.
Furthermore, there validity for variable magnetic force and higher torque performance is indicated by the testing of the miniaturized prototype. Mr. Kosaka will deliver a fascinating presentation about countermeasures to resolving the problems of rare-earth resources expected so highly in recent years.
Innovation of Mature Devices
Although the sub-session, “Innovation of Mature Devices,” may seem to already be standardized, JMAG strives to facilitate further innovation by dissecting the development approach of motors, transformers, etc.
The optimal method to meet the needs of a world demanding environmental conservation is not by replacing mature devices with something new, but rather addressing ways to comprehensively improve the performance and development process by rethinking how they are viewed.
In 2007, Dr. Shigekazu Sakabe from Tabuchi Electric, Co., Ltd demonstrated this theme when he discussed the demands for electromagnetic field analysis and problems specific to transformers. In 2008, Dr. Kazumasa Ide from Hitachi discussed the long history of design and development of large rotating machines and the efforts to improve their performance using cutting edge simulation technology.
Last year, Prof. Thomas M. Jahns from the University of Wisconsin was followed by Mr. Toshiaki Idemitsu from the YASKAWA MOTOR CORPORATION, Mr. Akihede Takehara from the TOYOTA MOTOR CORPORATION, and Professor Katsumi Yamazaki from the Chiba Institute of Technology to clearly present their perspectives toward mature PM motors focusing on the rapid innovations of IPM motors as key components to energy conservation devices and whether this type of motor development is changing the world we live in today.
The evolution and innovation of mature motors, which has exceeded many people’s expectations, provides a solid stepping stone for the design and development of other mature devices.
In addition to the special session, the JMAG Users Conference 2010 is packed with user examples as well as introductions to new products and technology.
We look forward to seeing all of you there.
Takashi Yamada
Engineering and Technology Division
JSOL Corporation
icon-user Professor. Zi-Qiang Zhu
icon-building University of Sheffield, UK
Compared with induction machines and switched reluctance machines, one of the novel features of permanent magnet brushless machines is that there exhibit numerous machine topologies. In this presentation, novel topologies and performance features of various permanent magnet brushless machines will be presented and potential applications highlighted. These include (a) Halbach machines, (b) Fractional slot machines, c Magnetic geared machines, (d) Double salient and flux reversal machines, (e) Various switching flux machines, (f) Various hybrid excited machines, (g) Other machines, such as soft magnetic composite (SMC) machines, dual mechanical port machines, and fault-tolerant machines, as well as (h) Magnet less machines.
icon-user Dr. Kazuto Sakai
Associate Professor
icon-building Department of Electrical, Electronic and Computer Engineering Faculty of Science and Engineering, Toyo University
Energy saving of electrical appliances and electric vehicles (EV) require reduction of power consumption of motors. The motors applied to these apparatus operate at variable speed. Furthermore, the motors operate with small load at stationary mode and with large load at starting mode. A permanent magnet motor can operate with high efficiency at rated point. However, the efficiency is lower at small load or high speed because the large constant-magnetic-force generates the large core loss. Furthermore, the flux-weakening current to depress voltage at high speed generates the large copper loss. Then, a new technology, which controls the magnetic flux of permanent magnets depending on the load or speed of the motor, is investigated. We introduce new motors that can change magnetic flux of permanent magnets.
icon-user Mr. Yuichi Shibukawa
icon-building Nissan Research Center, EV system Laboratory, NISSAN MOTOR CO., LTD.
This paper proposes a new rotor design for flux-intensifying interior permanent magnet synchronous machine (FI-IPM SM) which has similar torque-speed and power capabilities to a traditional flux-weakening IPM SM (FW-IPM SM). Design steps for the rotor structure of the new machine are laid out and discussed to emphasize key designing challenges. The proposed FI-IPM SM and a FW-IPM SM with similar torque-speed capability, are made to evaluate performances in power conversion as well as self-sensing capability at very low speed. Finite-element analysis (FEA) is used to evaluate the machine performances. The proposed FI-IPM SM shows less variation in the saliency when the machine is loaded, leading to a possibility of better self-sensing performance at very low speed as compared to the traditional FW-IPM SM. Experimental results on the self-sensing performance of these two machines are also shown for verification.
icon-user Dr. Takashi Kosaka
Associate Professor
icon-building Graduate School of Engineering, Omohi College, Nagoya Institute of Technology
In response to recent issues concerning rare-earth materials, this paper presents research and development results of hybrid excitation motor (HEM) as a candidate of less rare-earth permanent magnet and high power density machine for electric propulsion system installed on automotives, which is supported by NEDO. 3D-FEA-based design and performance prediction using JMAG-Studio demonstrates that the proposed motor makes possible to reduce the volume of rare permanent magnet by approximately half of that used in IPM motor for LEXUS RX400h while keeping the power density intact. The design and performance prediction results in terms of variable flux control and high torque capabilities are verified by experimental test using a trial manufacturing of the downsized motor.
