KOSAKA Takashi

写真a

Affiliation Department etc.

Department of Electrical and Mechanical Engineering
Department of Electrical and Mechanical Engineering

Title

Professor

Mail Address

E-mail address

Research Fields, Keywords

Motors for HEV/EV Traction Applications, Rare-earth less Motors, Control and Design of Motors with Low Noise and Vibration

Graduating School

  •  
    -
    1994.03

    Nagoya Institute of Technology   Faculty of Engineering   Department of electrical and computer engineering   Graduated

Graduate School

  •  
    -
    1999.03

    Nagoya Institute of Technology  Graduate School, Division of Engineering  Department of electrical and computer engineeringDoctor's Course  Completed

  •  
    -
    1996.03

    Nagoya Institute of Technology  Graduate School, Division of Engineering  Department of electrical and computer engineeringMaster's Course  Completed

Degree

  • Nagoya Institute of Technology -  Master (Engineering)

  • Nagoya Institute of Technology -  Doctor (Engineering)

External Career

  • 2002.11
    -
    2004.10

    Faculty of Engieering, University of Leicester, United Kingdom, Studies on Computer Aided Optimum Design for Application Specific Electric Motors  

Academic Society Affiliations

  • 2003.10
    -
    Now

    IEEE(Institute of Electrical and Electronic Engineers)

  • 1994.07
    -
    Now

    The Institute of Electrical Engineers of Japan

  • 2001.04
    -
    Now

    The Japna Institute of Power Electronics

  • 2009.10
    -
    Now

    The Insititute of Electrical Installation Engineers of Japan

  • 2012.11
    -
    Now

    Society of Automotive Engneers of Japna, Inc.

Field of expertise (Grants-in-aid for Scientific Research classification)

  • Control engineering/System engineering

  • Power engineering/Power conversion/Electric machinery

 

Papers

  • Comparative Study on Hybrid Excitation Flux Switching Motors without and with Variably Magnetizable Permanent Magnets for Electrified Vehicle Propulsion

    T. Okada, T. Kosaka, H. Matsumori, and N. Matsui

    World Electric Vehicle Journal ( MDPI )  12 ( 2 ) 58   2021.04  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    A demand for high efficiency traction motors has been accelerated by the promotion of electrified vehicles, such as battery and fuel cell electric vehicles. As a part of development of the high efficiency traction motor, this paper reports a comparative study on two kinds of hybrid excitation flux switching motors (HEFSM) as a variable flux machine. One is the conventional HEFSM, which consists of a stator with constantly magnetized-permanent magnets, field excitation coils (FECs) and three-phase armature windings, and a rotor with salient poles like a switched reluctance motor. The other is a HEFSM employing variably magnetizable-permanent magnets (VM-PMs) that replace a part in the FEC slot area in the conventional one. Based on the variable magnetization nature of VM-PMs, the latter HEFSM promises that the replacement of magnetomotive force (mmf) of FECs with that of the VM-PMs makes the motor efficiency better at both low- and high-speed under the low-torque condition, that is, at both urban driving or highway cruising. To verify that, finite element analysis- (FEA)-based design simulations, as well as experimental performance evaluations for the two kinds of HEFSM, were conducted under reasonable dimensional and electrical constraints. As a result, it is shown that the latter HEFSM can achieve higher motor efficiency at the low-torque and high-speed region while keeping the motor efficiency at the low-torque and low-speed region.

  • Power Conversion Efficiency Prioritized AC Filter Inductor Design for Three-Phase PWM Inverter

    H. Matsumori, D. Mizutani, T. Kosaka, N. Matsui, T. Miyazaki, and Y. Okawauchi

    AIP Advances ( American Institute of Physics )    11, 015338 - 11, 015338-4   2021.01  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    This study was conducted to develop a design method of power density and efficiency maximization for three-phase pulse-width modulated (PWM) inverters that include AC filter. A tradeoff relationship exists between power density and efficiency. In general, increasing the switching frequency is known to increase the switching device loss and decrease the volume of the passive components. A three-phase PWM inverters design should consider the balance between conversion efficiency and inverter volume. However, best of our knowledge, no practical study has focused on the optimal design of a three-phase PWM inverter that includes an AC filter. This is because the iron loss of the AC filter inductor changes in complicated ways depending on the DC-bias excitation, amplitude of switching ripple current, etc. Therefore, the present authors clarified this iron loss mechanism and realized a highly accurate iron loss calculation method in previous studies. In this paper, the relationship between efficiency and volume for the switching frequency was analyzed when the AC filter inductor was designed for minimal loss by adjusting the core diameter, height, and number of winding turns. The efficiency and volume optimization achieved by designing a proper inductor was verified via comparison with a base design.

  • Open Device Fault Detection and Fail Safe Action Strategy for a Premium Class Electric Vehicle with a Dual Inverter fed Open Winding Motor

    Hiroaki Matsumori, Yuto Maeda, Takashi Kosaka, Nobuyuki Matsui, Hiroki Iwai, Teppei Tsuda, Subrata Saha

    Proc. of 2021 IEEE Energy Conversion Congress and Exposition (ECCE) ( IEEE )    1527 - 1533   2021.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    A premium class electric vehicle (EV) needs high
    drive system efficiency, low motor noise and limp-home capability
    of the traction drive when there is a component failure. A dual
    inverter fed open winding interior permanent magnet
    synchronous motor (DIF-OW-IPMSM) drive system satisfied all
    the above needs. In this paper, a new algorithm of inverter open-
    circuit fault diagnosis and fail-safe action strategy for the DIF-
    OW-IPMSM drive system are proposed and presented to prove its
    high reliability. The proposed new algorithm is verified by suitable
    simulation and experimental results, and the safe limp-home
    capability of the DIF-OW-IPMSM drive system is demonstrated.

  • New PWM Switching Strategy for a Dual Inverter Fed Open Winding Motor Drive System

    Yuto Maeda, Hiroaki Matsumori, Takashi Kosaka, Nobuyuki Matsui, Hiroki Iwai, Teppei Tsuda, Subrata Saha

    Proc. of 2021 IEEE Energy Conversion Congress and Exposition (ECCE) ( IEEE )    4803 - 4809   2021.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    The dual inverter fed open winding interior permanent magnet synchronous motor (DIF-OW-IPMSM) is a promising traction drive system configuration for a high power
    and high efficiency electric vehicle. In this paper, a new PWM switching strategy of the inverters is presented when the motor is operating in the medium and high speed region. The PWM switching strategy consists of operating one of the inverters in the low switching frequency 1 pulse (square wave) mode and the other
    inverter in the high switching frequency specialized continuous pulse width modulation (SCPWM). The new PWM strategy has been verified from suitable simulation and experimental results in the medium speed range. Finally, a dual inverter configuration with a hybrid combination of Si IGBT inverter and SiC MOSFET inverter is recommended for a premium class electric vehicle to
    improve the drive system efficiency.

  • Optimum Design Study on HEFSM Using Variably Magnetizable PM with Low L/D Ratio and Novel PM Arrangement for EV/HEV Traction Applications

    Takeshi Okada, Mitsuru Saito, Hiroaki Matsumori, Takashi Kosaka, Nobuyuki Matsui

    Proc. of 2021 IEEE Energy Conversion Congress and Exposition (ECCE) ( IEEE )    3737 - 3744   2021.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    This paper focuses on a hybrid excitation flux switching motor (HEFSM) using variably magnetizable permanent magnets (VM-PMs) as variable flux motors for EV/HEV propulsion. The HEFSM makes an energization of field excitation coil unnecessary for most of the operating conditions so that it enlarges high efficiency operating area thanks to reductions of both copper and iron losses by adequately controlling magnetization state of the VM-PMs according to given operating conditions. In this paper, a new HEFSM design is proposed, which employs a novel PM arrangement as well as a flat motor shape with an optimum L/D ratio aiming at total PM usage reduction and the variable flux capability and maximum torque improvement. FEA-based simulation results show that the motor efficiency and variable flux capability of the proposed HEFSM are comparable with those of a previous PM-rich HEFSM while satisfying the target maximum torque and demagnetization tolerability of PMs under the total PM usage limitation.

  • Magnetization State Control of Variably Magnetizable Permanent Magnets Employed in HEFSM at Starting Up

    T. Okada, M. Saito, T. Kosaka, H. Matsumori, and N. Matsui

    Proc. of 2021 IEEE International Electric Machines & Drives Conference (IEMDC) ( Institute of Electrical and Electronics Engineers(IEEE) )    1 - 8   2021.06  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    This paper presents the magnetization state control of variably magnetizable-permanent magnets (VM-PM) - for a hybrid excitation flux switching motor (HEFSM) at the initial starting up. The HEFSM employing Nd-Fe-B type magnets with low coercive force as VM-PMs can achieve higher efficiency driving over the whole operating area compared with the conventional HEFSM without VM-PMs by appropriately adjusting the magnetization state according to a given operating condition. To put such the HEFSM into practical use for automotive traction applications, it is essential to be able to intentionally control the magnetization state by applying a pulsewise current to field excitation coil (FEC) during rotation as well as at starting up aiming at initialization of the magnetization state of VM-PMs. At first, a difference in the magnetization state controllability during middle-speed rotation and at a standstill and the angular dependence of the magnetizing magnetic field applied on VM-PM are investigated and discussed. Subsequently, the “quasi-impulse current train magnetization method” at starting up is proposed as a novel magnetization state control scheme. The effectiveness of the proposed control scheme is experimentally verified using a 60kW test motor. As a result, it is revealed that the magnetization control at the starting up can be achieved similar to that during the middle-speed rotation.

  • Torque Ripple Minimization Control in SRM Based on Magnetizing Curve Model Considering Mutual Coupling

    Sungyong Shin, Hikaru Naruse, Takashi Kosaka, Nobuyuki Matsui

    IEEJ Journal of Industry Applications ( 一般社団法人電気学会 )  9 ( 6 ) 637 - 649   2021.01  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    In order to minimize torque ripple in a switched reluctance motor (SRM), various control methods have been proposed. One such method is current profiling control based on a mathematical motor model concerned with the relationship between torque position and current, which can be derived from measured magnetizing curves. However, current profiling control faces issues with an increase in torque ripple at the current overlapping region depending on the load condition. In this study, through magnetic analysis using 2D-FEA and mathematical analysis based on a test SRM (four-phase, 400W, and 8/6 pole configuration), the reason why the torque ripple increases is revealed, and a modified torque-position-current model considering mutual coupling is proposed for better control of torque ripple minimization. Experimental studies on torque ripple minimization using the test motor show that the proposed current profiling control offers better torque ripple control performance.

  • Modeling and Simulation of Battery-powered Electric Vehicle on MATLAB/Simulink

    Yu Inoue, Hiroaki Matsumori, Takashi Kosaka, Nobuyuki Matsui

    Proc. of 2021 International Conference on Electrical Machines and Systems (ICEMS) ( The Korean Institute of Electrical Engineers (KIEE) )    694 - 698   2021.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    This paper presents MATLAB/Simulink based modeling and simulation of battery-powered electric vehicle (BEV) to estimate power consumption rate at development stage of a new electric motor. The model of BEV consists of not only the main power components such as a motor, an inverter and a battery, but also includes a driver, a controller and vehicle dynamics. In the model, a simple vehicle model based on Newtonian mechanics is constructed and it is possible to simulate the vehicle running by a motor using electricity obtained from a battery as a power source. JC08 mode as one of the driving pattern mode for evaluating the power consumption rate is used to determine the commanded values for the vehicle running. The power consumption rate is calculated from the distance and the power consumption of the battery. To demonstrate the validity
    of the model, this paper deals with NISSAN LEAF EV specifications to compare power consumption rates.

  • Design Study on High Torque Density Multiphase Pole-Change Induction Motor for Vehicle Propulsion Drive

    Yuya Matsuyama, Kota Ishizuka,, Hiroaki Matsumori, Takashi Kosaka, Nobuyuki Matsui

    Proc. of 2021 International Conference on Electrical Machines and Systems (ICEMS) ( The Korean Institute of Electrical Engineers (KIEE) )    426 - 431   2021.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    To realize an induction motor with high torque density for vehicle traction drives, this paper presents a design study on a multiphase pole-change induction motor (MPCIM). A principle of the pole-change is based on a harmonic operation of a multiphase inverter connected with the MPCIM where the multiphase windings are mesh-connected with a span. Major variables to be designed for the MPCIM are the phase number,the time harmonic order of phase current and the span. 2D-FEA based design investigations are conducted and conclude that the MPCIM with eight-phase winding of spanning with three and changing eight- and twelve-pole achieves high-torque density compete with an IPMSM installed on a commercialized EV.

  • Soft-switching condition and control method of boost chopper for DC-DC converter utilizing GaN power devices for automobile applications

    Asuka Shimodaira, Hiroaki Matsumori, Takashi Kosaka and Nobuyuki Matsui

    Proc. of the 23rd International Conference on Electrical Machines and Systems (ICEMS) ( Institute of Electrical and Electronics Engineers(IEEE) )    2020.11  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

display all >>

Books

Review Papers

  • Trends in Traction Motor for Automobile ~ Efforts of NITech at MagHEM ~

    Takashi Kosaka

    Technical Review of Tamagawa ( TAMAGAWA SEIKI Co.,Ltd. )    2021.12  [Invited]

    Introduction and explanation (others)   Single Author

  • Noise and Vibration Reduction in SR Motor

    Takashi Kosaka

    The Journal of The Institute of Electrical Engineers of Japan ( The Institute of Electrical Engineers of Japan )  137 ( 12 ) 825 - 828   2017.12  [Invited]

    Introduction and explanation (scientific journal)   Single Author

  • Technical Trend in Motor s for xEV Electrical Propulsion

    Takashi Kosaka

    Die and Mould Technology ( THE NIKKAN KOGYO SHIMBUN,LTD )  33 ( 1 )   2017.12  [Invited]

    Introduction and explanation (commerce magazine)   Single Author

  • Introduction of Researches and Deveploments on Motors as Electric Machines

    Takashi Kosaka

    ( The Japan Research and Development Center for Metals )  ( 360 ) 2 - 4   2016.10  [Invited]

    Prompt report, short report, and research note, etc. (bulletin of university, research institution)   Single Author

  • Latest Technologies of SR Motos, PM Motors and Variable Magnetization Motors for Three Major Domestic Appliances

    Takashi Kosaka

    Transistor Gijutsu ( CQ Publishing Co.,Ltd. )  52 ( 12 ) 131 - 136   2015.12  [Invited]

    Introduction and explanation (commerce magazine)   Single Author

Presentations

  • Hybrid Excitation Flux Switching Motor Employing Variably Magnetizable Permanent Magnet ~Touching the Best Paper Awards (First Place) of the IEMDC2021 ~

    Takashi Kosaka  [Invited]

    Technical Meeting on "Rotating Machinery", IEE Japan  (Online)  2021.11  -  2021.11  The Institute of Electrical Engineering of Japan

  • R&D on Hybrid Excitation Motors for Electrified Vehicle Traction Drive under MagHEM Project

    Takashi Kosaka  [Invited]

    2021 International Conference on Electric Machines and Systems  (Gyeongju, Korea)  2021.10  -  2021.11  The Koran Institute of Electrical Engineers

  • Design Study on HEFSM Employing Variably Magnetizable PM for Improving Torque Density and Efficiency Based on Optimizations of Aspect Ratio and PM Arrangement

    Mitsuru Saito, Takeshi Okada, Takashi Kosaka, Hiroaki Matsumori, Nobuyuki Matsui

    Technical Meeting on "Rotating Machinery", IEE Japan  (Online)  2021.11  -  2021.11  The Institute of Electrical Engineering of Japan

  • Design Study on Operating Range Extension and Cogging Torque Reduction of Variable Flux SPMSM based on Mechanical Stator Mover System for the Eco-Car Race

    Kako Yamahata, Takeshi Okada, Takashi Kosaka, Hiroaki Matsumori, Nobuyuki Matsui, Hiroshi Kaneshige

    Technical Meeting on "Rotating Machinery", IEE Japan  (Online)  2021.11  -  2021.11  The Institute of Electrical Engineering of Japan

  • Basic study on a novel AC/DC converter

    Daisuke Endo, Hiroaki Matsumori, Takashi Kosaka, Sadanori Suzuki, Kenichi Nakata

    Joint Technical Meeting on "Semiconductor Power Convertor" and "WQ Motor Drive", IEE Japan  (Tojo Pearl Building 8F, Kawagoe)  2021.09  -  2021.09  The Institute of Electrical Engineering of Japan

  • Design Study on Operating Range Extension of Variable Flux SPMSM Employing Adjustable Airgap Structure Based on Mechanical Stator Mover System for Ene-1 Challenge

    Kako Yamahata, Takeshi Okada, Takashi Kosaka, Hiroaki Matsumori, Hiroshi Kaneshige

    2021 IEE-Japan Industry Applications Society Conference  (Hotel New Otani Nagaoka)  2021.08  -  2021.08  The Institute of Electrical Engineering of Japan

  • Study on PWM Carrier Loss Evaluation Model for Claw Pole Type Motor

    Haruki Tsukano, kazuya Ikuta, Takashi Kosaka, Hiroaki Matsumori, Nobuyuki Matsui, Yuki Hidaka, Yu Hirai, Hidetaka Arita, Masahiko Fujita, Toshiyuki Yoshizawa

    Joint Technical Meeting on "Motor Drive", "Rotating Machinery" and "Vehicle Technology", IEE Japan  (Online)  2021.06  -  2021.06  The Institute of Electrical Engineering of Japan

  • Design Study on Multiphase Pole-Change Induction Motor for HEV/EV Drive

    Yuya Matsuyama, Kota Ishizuka, Takashi Kosaka, Hiroaki Matsumori, Nobuyuki Matsui

    Joint Technical Meeting on "Motor Drive", "Rotating Machinery" and "Vehicle Technology", IEE Japan  (Online)  2021.06  -  2021.06  The Institute of Electrical Engineering of Japan

  • Drive Characteristic Evaluations of HEFSM employing Variably Magnetizable Permanent Magnet

    Takashi Kosaka, Takeshi Okada, Hiroaki Matsumori, Nobuyuki Matsui

    2021 JSAE Annual Congress (Spring)  (Online)  2021.05  -  2021.05  Society of Automotive Engineers of Japan, Inc.

  • The forefront of motors and their peripheral technologies

    Takashi Kosaka  [Invited]

    35th Specialized Workshop Organized by The Japan Institute of Power Electronics   (Online by ZOOM)  2020.11  -  2020.11  The Japan Institute of Power Electronics

display all >>

Industrial Property

  • Motor

    特願 特願2018-058261  特開 2019-170128 

    Motor

  • Rotating Electric Machine

    特願 2016-166428  特開 2017-63597  特許 6139007

    Rotating Electric Machine

  • Control Unit of Switched Reluctance Motors

    特願 2012-185300  特開 2014-14552  特許 6069953

    Control Unit of Switched Reluctance Motors

  • Rotating Machine

    特願 2012-69859  特開 2013-201869  特許 5798072

    Rotating Machine

  • Rotating Electric Machine

    特願 13/407472  特許 9083225

    Rotating Electric Machine

  • Rotating Electric Machine

    特願 201210047825.X  特許 ZL201210047825.X

    Rotating Electric Machine

  • Rotating Machine

    特願 2012-3336  特開 2013-14386 

    Rotating Machine

  • Motor Drive Unit and Vehicle Mounting It

    特願 201110083298.3  特許 ZL201110083298.3

    Motor Drive Unit and Vehicle Mounting It

  • Drive Device for Electric Machine and Vehicle installing it

    特願 13/081040  特許 8896252

    Drive Device for Electric Machine and Vehicle installing it

  • Rotating Electric Machine

    特願 2011-045310  特開 2012-182941  特許 5572115

    Rotating Electric Machine

display all >>

Academic Awards Received

  • Excellent Technical Activity Award Group Writing Award

    2019.05.30    

    Winner: Technical Committee on Technologies of Reluctance Torque Assisted Motors

  • Committee Prize Paper Award (Third Prize), The Electric Machine Committee of the IEEE Industry Applications Society

    2007.12    

  • Outstanding Paper Award, Internationa Conference on Electric Machine and Systems

    2007.04    

 
 

Academic Activity

  • 2010.04
    -
    Now

    The Institute of Electrical Engineers of Japan  

  • 2010.04
    -
    Now

    The Institute of Electrical Engineers of Japan  

  • 2001.04
    -
    Now

    The Japna Institute of Power Electronics