Papers - KOSAKA Takashi
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Windage loss reduction for hybrid excitation flux switching motors based on rotor structure design Reviewed International journal
Yasuhiro Okada, Takashi Kosaka, Nobuyuki Matsui
Proc of 2017 IEEE International Conference on Electric Machines and Drives Conference (IEMDC) 1 - 8 2017.05
Language：English Publishing type：Research paper (international conference proceedings) Publisher：IInstitute of Electrical and Electronics Engineers
This paper presents design study on windage loss reduction for hybrid excitation flux switching motor employing two types of rotor structure. Conventional flux switching motors have a rotor structure with salient poles, by which windage loss at high speed region becomes serious. To reduce the windage loss, two types rotor are built: One is a cylindrical rotor employing iron rib between adjacent salient poles and shrouds placed at both ends in axial direction of rotor body and, the other is only employing the shrouds. Experimental tests using two machines combining with an existing stator and two rotors are conducted. As a result, the rotor with only the shrouds can greatly reduce the windage loss while keeping the maximum torque and power, and motor efficiency at high speed region as it is. From a viewpoint of windage loss reduction, different rotor configurations with and without the shroud are investigated by 3D-FEA based fluid analyses and discussed.
DOI： 10.1109/IEMDC.2017.8002360
Other Link： http://ieeexplore.ieee.org/document/8002360/
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Drive Characteristics of High Efficiency Hybrid Excitation Motor for Automobiles Reviewed
Takashi Kosaka, Akira Ozeki, Nobuyuki Matsui
Journal of the Japan Society of Applied Electromagnetics and Mechanics 24 ( 3 ) 246 - 251 2016.09
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society of Applied Electromagnetics and Mechanics
This paper presents design studies on a hybrid excitation motor (HEM) and experimental drive characteristics of the HEM for hybrid electric vehicle drive applications. Taking an IPMSM installed on PRIUS'2010 as the object of a comparison, the HEM is designed by means of trial and error using 3-dimensional finite element analysis (3D-FEA) and built as a test machine. With comparisons between the measured and the 3D-FEA-computed drive performances of the test motor, it is verified that the proposed HEM is a viable candidate as high efficiency motor for the target application.
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Experimental Study on Windage Loss Reduction using Two Types of Rotor for Hybrid Excitation Flux Switching Motor Reviewed International journal
Hiroki Nakane, Yasuhiro Okada, Takashi Kosaka and Nobuyuki Matsui
Proc. of 2016 XXII International Conference on Electrical Machines (ICEM) 1707 - 1713 2016.09
Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Electrical and Electronic Engineers
This paper presents experimental studies on windage loss reduction using two types rotor for hybrid excitation flux switching motor that is intentionally designed so as to compete with an interior permanent magnet synchronous motor installed on TOYOTA PRIUS-2010. This machine makes it possible to vary its field flux by combining the two different mmf sources such as field excitation coils and permanent magnets. Generally, as hybrid excitation flux switching motors have a rotor with salient pole structure like a switched reluctance motor, a large amount of windage loss at high speed region damages motor efficiency. In this paper, two types of rotor, one with cylindrical shape and the other with covered by only shroud located at both axial end of rotor core are built and tested. Compare with a conventional salient pole rotor, it is found that the rotor with only shroud can dramatically reduce windage loss while keeping other drive performances as it is.
DOI： 10.1109/ICELMACH.2016.7732754
Other Link： http://ieeexplore.ieee.org/document/7732754/
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Three-phase variable flux outer-rotor switched flux permanent magnet machine Reviewed International journal
M. Z. Ahmad, E. Sulaimanm, G. M. Romalan, M. Jenal, T. Kosaka
Proc. of 2016 XXII International Conference on Electrical Machines (ICEM) 2563 - 2569 2016.09
Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Electrical and Electronic Engineers
High torque density and robust rotor structure outer-rotor switched flux permanent magnet (SFPM) machine with DC excitation is proposed for emerging candidates to replace conventional electric motor of direct drive electric vehicle (EV). The extraordinary of DC excitation coil provides higher generated flux and flux control capability that suitable for various operating conditions. With the concept of motor housing inside the wheel, mechanical transmission as conventionally applied in centralized drive can be eliminated. In this paper, the proposed machine operating principle, predicted back electromagnetic force, cogging torque and torque production based on 2D-FEA are validated experimentally on the developed prototype. The results obtained show that there is good agreement between 2D-FEA and experiments.
DOI： 10.1109/ICELMACH.2016.7732882
Other Link： http://ieeexplore.ieee.org/document/7732882/
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Design Studies on Hybrid Excitation Flux Switching Motor with High Power and Torque Densities for HEV Applications Reviewed International journal
Yuya Maeda, Takashi Kosaka and Nobuyuki Matsui
Proc. of 2016 XXII International Conference on Electrical Machines (ICEM) 2522 - 2528 2016.09
Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Electrical and Electronic Engineers
This paper presents design studies on hybrid excitation flux switching motor (HEFSM) that can compete with an interior permanent magnet synchronous motor (IPMSM) installed on TOYOTA PRIUS-2010. A stator of the HEFSM consists of not only laminated core and three-phase armature windings, but also field excitation coils and permanent magnets as field mmf sources. This machine makes it possible to vary its field flux by combining the two different mmf sources and thus, the name is capped by “hybrid excitation” as a variable field flux motor. The first trial manufacturing of HEFSM has been built for tests to assess its drive performances. Based on analysis of the test results, design refinements on the first test motor are ex-amined to make the second trial manufacturing. Various ex-perimental test results using the second test motor demon-strate that drive performances of the HEFSM are comparable to those of the PRIUS’s IPMSM.
DOI： 10.1109/ICELMACH.2016.7732876
Other Link： http://ieeexplore.ieee.org/document/7732876/
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Digital PWM Control-Based Active Vibration Cancellation for Switched Reluctance Motors Reviewed International journal
Hiroaki Makino, Takashi Kosaka, Nobuyuki Matsui
IEEE Transactions on Industry Applications 51 ( 6 ) 4521 - 4530 2015.11
Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE
This paper presents a study on a control strategy for active vibration cancellation (AVC) and noise reduction in switched reluctance (SR) motors. It has been revealed that two-stage commutation control based on the natural frequency of the stator body has been effective in suppressing the vibration occurring on the stator body at the commutation. According to some considerations on the generation mechanism of the vibration, a new AVC control for variable-speed SR motor drives under digital PWM control is proposed. Experimental studies using a 12-kW three-phase 12/8 SR motor demonstrate that the proposed two-step commutation control using negative voltage PWM is much effective as an AVC and noise reduction technique. Moreover, the proposed control is evaluated from the viewpoints of drive performances such as torque ripple and copper loss.
Other Link： http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7128684&filter%3DAND%28p_IS_Number%3A7331695%29
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Torque-Maximizing Design of Concentrated-Winding IPMSM for Saliency-Based Sensorless HEV Drives Reviewed
Yoshiaki Kano, Takashi Kosaka, Nobuyuki Matsui
IEEJ Transactions on Industry Applications 135 ( 9 ) 929 - 938 2015.09
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan
This paper presents the design of a signal-injection-based sensorless interior permanent magnet synchronous motor (IPMSM) for a traction drive in hybrid electric vehicles (HEVs). To realize an accurate design, the sensorless safety operation region (SSOR) is introduced to account for the cross-coupling magnetic saturation and harmonics of inductance distributions. The SSOR defines a working point on the maximum torque per ampere trajectory at which the motor can perform sensorless operation with a guaranteed performance in the steady state. The reliability of the SSOR was verified in experiments using a prototype. The influence of the IPM motor geometry on the SSOR was then examined. Under the given dimensional constraints, the design of a 100Nm-10 kW 12-pole, 18-slot IPMSM was optimized to meet the requirements for the target traction drive in an HEV. The validity of the proposed design was verified by using a MATLAB/SIMULINK-based dynamic simulator.
Other Link： https://www.jstage.jst.go.jp/article/ieejias/135/9/135_929/_article/-char/ja/
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An Experimental Verification of High Power Production Mechanism by Increasing Field Winding Current in Wound Field Flux Switching Motor for HEV Traction Drive Reviewed
Yu Kuwahara, Takashi Kosaka, Yoshinobu Kamada, Hiroaki Kajiura, Nobuyuki Matsui
IEEJ Transactions on Industry Applications 135 ( 9 ) 939 - 947 2015.09
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan
This paper presents the design of a signal-injection-based sensorless interior permanent magnet synchronous motor (IPMSM) for a traction drive in hybrid electric vehicles (HEVs). To realize an accurate design, the sensorless safety operation region (SSOR) is introduced to account for the cross-coupling magnetic saturation and harmonics of inductance distributions. The SSOR defines a working point on the maximum torque per ampere trajectory at which the motor can perform sensorless operation with a guaranteed performance in the steady state. The reliability of the SSOR was verified in experiments using a prototype. The influence of the IPM motor geometry on the SSOR was then examined. Under the given dimensional constraints, the design of a 100Nm-10 kW 12-pole, 18-slot IPMSM was optimized to meet the requirements for the target traction drive in an HEV. The validity of the proposed design was verified by using a MATLAB/SIMULINK-based dynamic simulator.
Other Link： https://www.jstage.jst.go.jp/article/ieejias/135/9/135_939/_article/-char/ja/
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Torque Ripple Reduction Design of Concentrated-Winding IPMSM with New Flux Barrier for Saliency-Based Sensorless Drives Reviewed
Yoshiaki Kano, Takashi Kosaka, Nobuyuki Matsui, Toshihito Nakanishi
IEEJ Transactions on Industry Applications 135 ( 6 ) 725 - 733 2015.06
Language：Japanese Publishing type：Research paper (scientific journal)
Other Link： https://www.jstage.jst.go.jp/browse/ieejias/-char/ja
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Instantaneous Current Profile Control of Four Phases SR Motor for Industrial Servo Drives Reviewed
Hiroaki Makino, Takashi Kosaka, Shinya Morimotoi, Motomichi Ohto, Nobuyuki Matsui
IEEJ Transactions on Industry Applications 135 ( 6 ) 711 - 717 2015.06
Language：Japanese Publishing type：Research paper (scientific journal)
Other Link： https://www.jstage.jst.go.jp/browse/ieejias/-char/ja
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10.1541 /ieejjia Reviewed
4 ( 3 ) 196 - 203 2015.05
Language：English Publishing type：Research paper (scientific journal)
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Design Studies on Hybrid Excitation Flux Switching Motor with High Power and Torque Densities for HEV Applications Reviewed
Hiroki Nakane, Takashi Kosaka, Nobuyuki Matsui
Proc. of the 2015 IEEE International Electric Machines and Drives Conference(IEMDC) 234 - 239 2015.05
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents design studies on hybrid excitation flux switching motor (HEFSM) that can compete with an interior permanent magnet synchronous motor (IPMSM) installed on TOYOTA PRIUS-2010. A stator of the HEFSM consists of not only laminated core and three-phase armature windings, but also field excitation coils and permanent magnets as field mmf sources. This machine makes it possible to vary its field flux by combining the two different mmf sources and thus, the name is capped by “hybrid excitation” as a variable field flux motor. The first trial manufacturing of HEFSM has been built for tests to assess its drive performances. Based on analysis of the test results, design refinements on the first test motor are ex-amined to make the second trial manufacturing. Various ex-perimental test results using the second test motor demon-strate that drive performances of the HEFSM are comparable to those of the PRIUS’s IPMSM.
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Experimental Studies on Drive Performances of Wound Field Synchronous Motor Drive Integrated with ZSI "jointly worked" Reviewed
Genki Tajima, Takashi Kosaka and Nobuyuki Matsui
Conference Proceedings of Thirtieth Annual IEEE Applied Power Electronics Conference and Exposition 262 - 269 2015.03
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents experimental studies on drive
performances of wound field synchronous motor (WFSM)
integrated with Z-source inverter (ZSI) system. WFSM is a nonpermanent
magnet machine and employs two field coils as dc
field mmf sources. The conventional WFSM drive uses a three
phase inverter for the armature windings and a dc chopper for
the field coils, separately. On the other hand, ZSI works as a
three phase inverter with a function of dc voltage boost-up by
using an impedance-network inserted between the DC-bus and
the three phase inverter. The impedance-network consists of two
dc reactors and two capacitors. The “integrated” means that in
the proposed drive system, two field coils of WFSM are employed
not only as dc field mmf sources for the motor, but also as dc
reactors for the impedance-network. Thus, the proposed system
eliminates the use of DC chopper, resulting in size and cost
reductions as the total drive system. The comparison of operable
range between the conventional system and the proposed system
through various experimental studies using a test drive system is
demonstrated and discussed. -
Operation Evaluations in High Speed Range of Wound Field Synchronous Motor Drive Integrated with ZSI "jointly worked" Reviewed
G. Tajima, T. Kosaka and N. Matsui, K. Tonogi, N. Minoshima and T. Yoshida
Proceedings of the 2015 IEEE International Conference on Mechatronics (ICM) 681 - 686 2015.03
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents experimental evaluations of
drive performances in high-speed range of a wound field
synchronous motor (WFSM) drive system integrated with a zsource
inverter (ZSI). The WFSM has two field coils as DC field
mmf sources instead of permanent magnets. On the other hand,
the ZSI employs an impedance-network that consists of two DC
reactors and two capacitors. A uniqueness of the proposed drive
system lies in that this system makes it possible to reduce size and
cost because the two DC reactors serve as both two field coils as
the DC field mmf sources in the WFSM and the DC boosting
reactors in the ZSI. The comparisons of drive performances in
high-speed range between the proposed integrated system and a
non-integrated system are experimentally demonstrated and
discussed. -
Active Vibration Reduction based on Digital PWM Control for SR Motors Reviewed
H. Makino, T. Kosaka and N. Matsui
Proc. of the 2014 International Conference on Electrical Machines (ICEM2014) 679 - 685 2014.09
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents a study on control strategy for active vibration cancellation and noise reduction in SR motor. It has been revealed that 2-stage commutation control based on natural frequency of stator body has been effective to suppress the vibration occurring on the stator body. According to some considerations on generation mechanism of the vibration, a new active vibration cancellation control for variable speed SR motor drive under digital PWM control is proposed. Experimental studies using 12kW three-phase 12/8 SR motor demonstrates that the proposed 2-step commutation control using negative voltage PWM is much effective as active vibration cancellation and noise reduction technique.
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Didital PWM Control-Based Active Vibration Cancellation for Switched Reluctance Motors Reviewed
H. Makino, T. Kosaka and N. Matsui
Proc. of the sixth IEEE ENERGY CONVERSION CONGRESS & EXPOSITION (ECCE2014) 3834 - 3841 2014.09
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents a study on control strategy for active vibration cancellation and noise reduction in SR motor. It has been revealed that 2-stage commutation control based on natural frequency of stator body has been effective to suppress the vibration occurring on the stator body at the commutation. According to some considerations on generation mechanism of the vibration, a new active vibration cancellation control for variable speed SR motor drive under digital PWM control is proposed. Experimental studies using 12kW three-phase 12/8 SR motor demonstrates that the proposed 2-step commutation control using negative voltage PWM is much effective as active vibration cancellation and noise reduction technique. Moreover, the proposed control is evaluated from the viewpoints of drive performances such as torque ripple and copper loss.
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Recent technical trends in PMSM Reviewed
S. Morimoto, Y. Asano, T. Kosaka and Y. Enomoto
Proc. of the 2014 International Power Electronics Conference –ECCE ASIA- (IPEC-Hiroshima2014) 1997 - 2003 2014.05
Language：English Publishing type：Research paper (international conference proceedings)
This paper overviews the recent technical trends in permanent magnet synchronous motors (PMSMs), especially the rare-earth less PMSMs in Japan. The rareearth less PMSMs including the PMSMs with reduced rareearth PMs, permanent magnet assisted synchronous motors with ferrite magnets and axial gap PMSMs with ferrite magnets are reviewed.
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Control of Wound Field Synchronous Motor Integrated with ZSI Reviewed
G. Tajima, T. Kosaka, N. Matsui, K. Tonogi, N. Minoshima and T. Yoshida
Proc. of the 2014 International Power Electronics Conference –ECCE ASIA- (IPEC-Hiroshima2014) 2438 - 2444 2014.05
Language：English Publishing type：Research paper (international conference proceedings)
This paper proposes a novel variable speed motor drive, wound field synchronous motor (WFSM) drive integrated with Z-source inverter (ZSI). The proposed WFSM is non-permanent magnet machine and employs two field coils as dc field mmf sources. On the other hand, ZSI has an impedance-network which is composed of two dc reactors and two capacitors. In the proposed drive, the two field coils of WFSM act not only as dc field mmf sources, but also as dc reactors in ZSI, resulting in size and cost reductions of the drive system. In order to achieve both the voltage boost-up and the field current controls simultaneously, its control algorithm is examined. Simulation and experimental results show that the proposed drive under the proposed control works properly.
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Control Performance Comparisons among Three Types of Instantaneous Current Profiling Technique for SR Motor Reviewed
H. Makino, T. Kosaka and N. Matsui
Proc. of the 7th IET International Conference on Power Electronics, Machines and Drives (PEMD2014) 1 - 6 2014.04
Language：English Publishing type：Research paper (international conference proceedings)
This paper presents drive performance comparisons among three-types of current profiling techniques minimizing torque ripple for switched reluctance (SR) motor in terms of current ripple, a number of switching of converter, motor efficiency and noise. As SR motors have strong magnetic nonlinearity, hysteresis current control is commonly used for their drives. In this case, however, switching frequency of converter should be set as high as possible in order to keep the resultant current ripple as small as possible. In contrast, the proposed current control employs feed-forward voltage control based on non-linear magnetizing curves model and is executed under conventional subharmonic PWM voltage control with fixed switching frequency. Experimental results using 400W 4-phase 8/6 SR motor demonstrate that the proposed current control can provide better drive performances than other hysteresis current control techniques.
DOI： 10.1049/cp.2014.0393
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Experimental Drive Performance Evaluation of High Power Density Wound Field Flux Switching Motor for Automotive Applications Reviewed
T. Kosaka, N. Matsui, Y. Kamada and H. Kajiura
Proc. of the 7th IET International Conference on Power Electronics, Machines and Drives (PEMD2014) 1 - 6 2014.04
Authorship：Lead author Language：English Publishing type：Research paper (international conference proceedings)
This paper presents experimental drive performances evaluation of wound field flux switching motor for hybrid vehicle drive applications. A test machine with the maximum torque of 210 Nm and the maximum power of 123 kW expected at its design stage is built. A various experimental test result is demonstrated from viewpoints of the maximum torque and the maximum power capabilities and the motor efficiency up to its base speed of 6,000 r/min. As a result, it is confirmed that the test machine promises well as a machine with very high power density more than 4.2 kW/kg at the maximum power point under water jacket cooling.
DOI： 10.1049/cp.2014.0461
