研究者データベース

小笠原 悟司(オガサワラ サトシ)
情報科学研究院 システム情報科学部門 システム融合学分野
教授

基本情報

所属

  • 情報科学研究院 システム情報科学部門 システム融合学分野

職名

  • 教授

学位

  • 工学博士(長岡技術科学大学)

ホームページURL

J-Global ID

研究キーワード

  • エネルギー変換   EMI/EMC   電動機制御   パワーエレクトロニクス   

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 電力工学

職歴

  • 2003年 - 2007年 宇都宮大学 教授
  • 2003年 - 2007年 Professor
  • 2007年 北海道大学大学院 教授
  • 2007年 - Professor
  • 1993年 - 2003年 岡山大学 助教授
  • 1993年 - 2003年 Associate Professor
  • 1992年 - 1993年 Research Associate
  • 1983年 - 1992年 長岡技術科学大学 助手
  • 1983年 - 1992年 Research Associate
  • 1992年 岡山大学 助手
  • 1992年 Research Associate

学歴

  •         - 1983年   長岡技術科学大学   工学研究科
  •         - 1983年   長岡技術科学大学
  •         - 1981年   長岡技術科学大学   工学部
  •         - 1981年   長岡技術科学大学
  •         - 1979年   高松工業高等専門学校   電気工学科

所属学協会

  • パワーエレクトロニクス学会   電気学会   IEEE   IEEE   

研究活動情報

論文

  • Shotaro Takahashi, Satoshi Ogasawara, Masatsugu Takemoto, Koji Orikawa, Michio Tamate
    IEEJ Transactions on Industry Applications 140 6 433 - 441 2020年 [査読有り][通常論文]
     
    © 2020 The Institute of Electrical Engineers of Japan. This study investigates the relationship between filter inductor impedance and dimensional resonance of MnZn ferrite. Experimental results clarify that multiple factors affect inductor impedance resonances. These can be classified into three factors: the inherent characteristics of a magnetic material, self-resonance due to winding stray capacitance, and winding that acts as a distributed constant line. Next, based on the measurement results, the dimensional dependencies of complex permeabilities (dimensional resonance) and the influence of dimensional resonance on inductor impedance are discussed in detail. Finally, this study verifies that the influence of dimensional resonance on complex permeability can be mitigated, and filter inductor impedance can be increased in the high frequency range by core lamination. All experiments are performed using off-the-shelf magnetic core products.
  • Shotaro Takahashi, Satoshi Ogasawara, Masatsugu Takemoto, Koji Orikawa, Michio Tamate
    2019 IEEE 4th International Future Energy Electronics Conference, IFEEC 2019 2019年11月 [査読有り][通常論文]
     
    © 2019 IEEE. This paper explores the relationship between filter inductor impedance and dimensional resonance in magnetic cores. Experimental results were obtained showing multiple factors behind the resonances that appear in the frequency characteristics of inductor impedances: the inherent characteristics of a magnetic material, the self-inductance of an inductor and stray capacitance in its winding, and the winding acting as a distributed constant line. Next, based on the measurement results, the dimensional dependencies of the complex permeabilities (dimensional resonance) and the influence of dimensional resonance on inductor impedance are discussed in detail. Finally, this paper shows that the effect of dimensional resonance on complex permeability can be mitigated and filter inductor impedance can be increased in the high frequency range by a core lamination. These results are verified by the experiments described in this paper.
  • Hwang Soonhwan, Ogasawara Satoshi, Orikawa Koji, Takemoto Masatsugu
    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 14 5 780 - 791 2019年05月 [査読有り][通常論文]
  • Shotaro Takahashi, Satoshi Ogasawara, Masatsugu Takemoto, Koji Orikawa, Michio Tamate
    IEEE Transactions on Industry Applications 55 3 2721 - 2730 2019年05月 [査読有り][通常論文]
     
    © 1972-2012 IEEE. The switching speeds of next-generation power semiconductor devices, such as those made of silicon carbide and gallium nitride are roughly ten times those of conventional devices (e.g., silicon insulated-gate bipolar transistors). This increases the frequency range of the electromagnetic noise accompanying the switching operations of pulsewidth modulated (PWM) converters and worsens the influence of radiated noise. The authors have previously proposed an active common-mode filter (ACF) that reduces the radiated noise from the power cables connected to a PWM converter and evaluated its effect in reducing radiated noise by using a function generator as a common-mode (CM) noise source. In this paper, the ACF is applied to a motor drive system fed by a three-phase PWM inverter, and the attenuation characteristics of the CM voltage are evaluated. To avoid saturating the ACF, the combination of an active common-noise canceller and the ACF is discussed. The experimental results show that the system constructed in this paper can suppress the CM voltage produced by the PWM inverter over a wide frequency range from 100 to 100 MHz.
  • 小山兼司, 田中三博, 小笠原悟司
    パワーエレクトロニクス学会誌 44 135‐141  2019年03月31日 [査読無し][通常論文]
  • Shotaro Takahashi, Satoshi Ogasawara, Masatsugu Takemoto, Koji Orikawa, Michio Tamate
    2019 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 2859 - 2866 2019年 [査読有り][通常論文]
     
    High switching speed in next-generation power devices such as silicon carbide allows increased switching frequencies in power converters. Higher switching frequencies increase power densities, but also increase frequencies of electromagnetic noise accompanying switching operations, resulting in more serious electromagnetic interference (EMI). Radiated EMI will thus soon become a major concern when developing power converters. Most previous works have focused on conducted EMI, resulting in a dearth of research on radiated EMI from power converters. We thus investigated the generation mechanism of radiated noise from power converters to identify effective reduction methods. We identify two propagation paths of high-frequency (HF) common-mode (CM) noise currents, primary CM (PCM) and secondary CM (SCM). SCM constructs a large propagation loop, thus becoming a major source of radiated noise. To suppress HF CM current flow through each mode, we fabricate two types of CM inductors (CMI). HF CM currents are measured in a simple buck converter system. CM current measurements verify the effectiveness of CMI for reduction of HF CM currents and clarify how SCM voltage source is generated. The described generation mechanism of SCM voltage source and radiated noise is verified by measurements of radiated noise in a fully anechoic chamber.
  • 高橋翔太郎, 小笠原悟司, 竹本真紹, 折川幸司, 玉手道雄
    電気学会論文誌 D 139 3 339 - 347 2019年 [査読無し][通常論文]
     
    © 2019 The Institute of Electrical Engineers of Japan. The switching speed of next-generation power devices based on wide-bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), are more than ten times those of conventional silicon insulated-gate bipolar transistors (Si-IGBT). This may increase the frequency range of electromagnetic noise produced by pulse-width-modulated converters. Further, the operating frequency ranges of noise filters are limited by the parasitic components of passive elements, so it is difficult to realize a high-frequency (HF) noise filter whose operating frequency exceeds several tens of megahertz. This paper proposes a novel and simple analytical method to calculate the winding stray capacitance of an HF three-phase common-mode (CM) inductor for the purpose of estimating its operating frequency range at the design stage. Results of measuring the CM impedance confirm that the proposed method can estimate the operating frequency range of an HF three-phase CM inductor while ensuring practically sufficient precision. Furthermore, the obtained results also show that the reduction in the number of turns does not always contribute to the enhancement of the operating frequency ranges of filter inductors.
  • Ren Tsunata, Masatsugu Takemoto, Satoshi Ogasawara, Asako Watanabe, Tomoyuki Ueno, Koji Yamada
    IEEE Transactions on Industry Applications 54 1 254 - 262 2018年01月01日 [査読無し][通常論文]
     
    In general, radial gap motors employing neodymium sintered permanent magnet (Nd sintered PM) are used to achieve high torque density in many applications. However, the motors are not suited to a flat, disk-like shape because the dead space, such as the coil ends, occupies most of the motor volume. Therefore, axial gap motors are frequently used for flat shape instead of radial gap motors. Nd sintered PM is a well-known high-performance magnet that has high residual magnetic flux density, but eddy current loss easily occurs in the magnet because of its high conductivity. In axial gap motors for industrial applications, it is difficult to take measures against eddy current loss of Nd sintered PM in terms of cost. Therefore, general axial gap motors employing Nd sintered PM often have unsatisfactory characteristics, such as low efficiency, even though the motor produces high torque. On the other hand, radial gap motors can take measures to suppress eddy current in PMs easily if radial gap motors employ interior permanent magnet structure. Accordingly, this paper discusses an axial gap motor employing neodymium bonded permanent magnet (Nd bonded PM) for flat shape. Compared with Nd sintered PM, Nd bonded PM has lower residual magnetic flux density, but also lower cost. In addition, Nd bonded PM has extremely low eddy current loss due to its low conductivity. It is found from three-dimensional finite element analysis and experimental results that the axial gap motor employing Nd bonded PM can achieve higher torque and higher efficiency compared with the radial gap motor employing Nd sintered PM with the same PM weight and a flat shape.
  • Toru Ogawa, Toru Ogawa, Tomohira Takahashi, Masatsugu Takemoto, Satoshi Ogasawara, Hideaki Arita, Akihiro Daikoku
    IEEJ Transactions on Industry Applications 138 8 659 - 668 2018年01月01日 [査読無し][通常論文]
     
    © 2018 The Institute of Electrical Engineers of Japan. The traction motors used in electric vehicles (EVs) should satisfy trade-off requirements such as high torque at low speed, high efficiency at low torque regions, and a constant output in a wide speeds. To achieve this, several types of motors such as variable flux machines and variable parameter machines have been developed. Our research team focuses on a consequent-pole-type ferrite permanent magnet (PM) axial gap motor with field windings, in which the magnetic flux density can be varied. Although consequent-pole-type motors have previously been researched, no extant study has focused on the influence of the slot combination on the motor performance. This study investigates the magneto-motive force and rotor permeance of several motors.
  • Tatsuya Matsuzaki, Masatsugu Takemoto, Satoshi Ogasawara, Satoru Ota, Kazunobu Oi, Daiki Matsuhashi
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 53 6 5383 - 5392 2017年11月 [査読有り][通常論文]
     
    A bearingless motor (BelM) integrates the characteristics of an electric motor and a magnetic bearing. Typically, a surface-mounted permanent magnet (SPM)-type BelM with a ring magnet magnetized in parallel is employed for high-speed operation. It is noteworthy that a carbon fiber bandage is needed to fix the ring magnet. However, when an SPM-type BelM is applied to a high-output motor, it becomes difficult to generate sufficient suspension force because of the wide magnetic gap arising from the carbon fiber bandage and the ring magnet. In addition, the manufacturing cost for the large-scale ring magnet and the carbon fiber bandage is high. Therefore, to realize a high-output and highspeed BelM at a low cost, we have focused on an interior permanent magnet (IPM)-type BelM with 2-pole motor windings and 4-pole suspension windings. Moreover, a rotor structure for suppressing suspension force ripple arising in the IPM-type BelM has been proposed based on a three-dimensional finite element analysis. In this study, a prototype of the IPM-type BelM with the proposed rotor structure is produced. Experiments with this prototype show that the proposed rotor structure is effective in reducing suspension-force ripple. Additionally, the operational characteristics of the prototype are shown in detail.
  • Tomohira Takahashi, Masatsugu Takemoto, Satoshi Ogasawara, Wataru Hino, Kenichi Takezaki
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 53 4 3927 - 3935 2017年07月 [査読有り][通常論文]
     
    In-wheel type permanent-magnet synchronous motors for electric commuter cars are required to be compact and light to use limited wheel space effectively and reduce unspringing weight. Therefore, our previous papers presented a low-cost in-wheel axial-gap motor that uses ferrite permanent magnets. This motor adopted an open slot structure to reduce production costs. However, to achieve further size and weight reduction, we examine here in detail the adoption of a semiclosed slot structure instead of an open slot structure. Experimental results show that the semiclosed slot structure is effective in realizing size and weight reduction.
  • Koji Orikawa, Satoshi Ogasawara, Jun-Ichi Itoh
    PCIM Europe 2017 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management 2017年 [査読有り][通常論文]
     
    This paper describes a 2.5 MHz high frequency inverter based on a frequency multiplying method. A proposed circuit consists of a five-phase inverter and multi-core transformers. An operation frequency of the five-phase inverter and multi-core transformer is 500 kHz which is one-fifth of an output frequency of 2.5 MHz. Therefore, the proposed circuit can realize high efficiency by utilizing available semiconductor switches and magnetic materials. In this work, a principle of suppression of iron loss is experimentally clarified by measuring B-H curves of a single transformer without a load when sinusoidal voltage is applied. Next, power losses of semiconductor switch and multi-core transformer are formulated. Finally, a power loss distribution is clarified based on theoretical analysis and the measured efficiency of the prototype circuit.
  • Ren Tsunata, Masatsugu Takemoto, Satoshi Ogasawara, Asako Watanabe, Tomoyuki Ueno, Koji Yamada
    2017 IEEE INTERNATIONAL CONFERENCE ON MECHATRONICS (ICM) 278 - 283 2017年 [査読有り][通常論文]
     
    In recent years, flat shape motors are desired for many industrial applications such as robot arm, automobiles and so on. Thus, this paper discusses axial gap motors which have advantage for flat shape. In general, axial gap motors have high torque density with flat shape because of its wide air-gap area. Axial gap motors are therefore used for limited space like disk shape instead of radial gap motors which are the most general motor. However, compared with radial gap motors, the acceleration of axial gap motors is relatively lower because of the larger moment of inertia. In this paper, rotor structure to enhance the acceleration of axial gap motors is proposed and analyzed by 3D-FEA. In addition, material for permanent magnet of axial gap motors is properly selected in order to enhance efficiency at high speed and high torque area. Finally, prototypes of both axial and radial gap motor with flat shape are evaluated by some experiments. It is found that proposed axial gap motor can achieve the higher torque and efficiency compared with the radial gap motor with flat shape. Proposed axial gap motor additionally achieved the slightly larger acceleration compared with the radial gap motor.
  • 高橋翔太郎, 小笠原悟司, 竹本真紹, 折川幸司, 玉手道雄
    電気学会論文誌 D 137 8 639 - 646 2017年 [査読無し][通常論文]
     
    © 2017 The Institute of Electrical Engineers of Japan. Power electronics devices can cause serious electromagnetic interference (EMI) because of their high-speed switching. Such switching disturbances then propagate along power cables, which can act as antennas to radiate noise. Typically, a passive filter composed of inductors and capacitors is used to reduce EMI. However, when a power cable is connected to the passive filter, the cable acts as a distributed constant line that worsens the attenuation characteristic of the passive filter at the anti-resonant frequencies of the cable. This study proposes a solution to this problem in the form of an active common-mode filter that uses a high-speed amplifier. Experimental results show that the proposed filter improves the attenuation characteristics of the passive filter and reduces radiated noise from the cable over a wide range of frequencies from 10MHz to 100 MHz.
  • Minglei Gu, Satoshi Ogasawara, Masatsugu Takemoto
    IEEE TRANSACTIONS ON POWER ELECTRONICS 31 9 6461 - 6475 2016年09月 [査読有り][通常論文]
     
    This paper proposes novel pulsewidth modulation (PWM) schemes for multi-space-vector pulsewidth modulation (MSVPWM), which is used in position sensorless control of interior permanent-magnet synchronous motor drives. The estimation of the rotor position is based on magnetic saliency and employs high-frequency components of voltage and current, which are excited by MSVPWM. The difference between the instantaneously applied voltage vector and the reference voltage vector causes current ripple. Since six or four voltage vectors are generated during a PWM period, the sequences of the error voltage vectors lead to different types of current ripples. In this paper, the proposed MSVPWM schemes employ six sequences for zero-/low-speed operation and 24 sequences for high-speed operation to reduce line current ripple. Experimental results confirm that the proposed MSVPWM schemes lead to significant reduction in harmonic current while maintaining high performance of sensorless estimation.
  • Tatsuya Matsuzaki, Masatsugu Takemoto, Satoshi Ogasawara, Satoru Ota, Kazunobu Oi, Daiki Matsuhashi
    IEEE TRANSACTIONS ON MAGNETICS 52 7 2016年07月 [査読有り][通常論文]
     
    Magnetic bearings (MBs) are useful for suspending the rotor shaft of a high-speed, high-output motor because they can do so without mechanical contact. In [2], we have proposed a three-axis active-control-type MB (3-axis AMB) with a cylindrical rotor whose diameter is equal to that of the rotor of a radial MB (RMB) or a motor. The proposed 3-axis AMB integrates an RMB and a thrust MB in one unit. However, the assembly of the conventional 3-axis AMB is complex, and the rotor iron loss is large. Thus, in order to simplify the assembly of the 3-axis AMB and to reduce rotor iron loss, this paper discusses a novel structure for the 3-axis AMB in which small auxiliary permanent magnets (PMs) are inserted in the radial winding slots. The suspension force and the rotor iron loss of the proposed device are evaluated by 3-D finite-element analysis in comparison with a 3-axis AMB without small auxiliary PMs.
  • Yizhanyi Tang, Satoshi Ogasawara, Masatsugu Takemoto, Tsuyoshi Tokiwa, Masaki Kanamori
    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 11 2 243 - 249 2016年03月 [査読有り][通常論文]
     
    This paper deals with common-mode (CM) electromagnetic interference (EMI) in an inverter-fed motor drive system. A simplified CM equivalent circuit including -type equivalent circuit for the motor winding is proposed by using the waveform of the common-mode current flowing in the ground conductor. Moreover, a parameter identification method applying the computer-aided software modeFRONTIER is proposed to decide objectively the circuit parameters of the proposed simplified equivalent circuit. Validity and effectiveness of the proposed equivalent circuit are confirmed by comparing the measured impedance characteristics with the calculated ones. Finally, the possibility of a nonlinear phenomenon is discussed in this system. It is shown that the accuracy of simulation result can be improved by introducing the nonlinear element. (c) 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
  • Takao Mori, Hirohito Funato, Satoshi Ogasawara, Fumihiro Okazaki, Yukitsugu Hirota
    ELECTRICAL ENGINEERING IN JAPAN 194 3 59 - 69 2016年02月 [査読有り][通常論文]
     
    The authors have devised a new method to decrease high-frequency harmonics in a specific frequency band by modifying the switching transient slope. In previous studies, there were several problems in applying modified transient pulse width modulation (MT-PWM) to actual converters. In this paper, three problems are solved using an improved MT-PWM method. First, the MT-PWM signal was obtained using a trial-and-error approach that involved complex computation procedures in the previous studies. In this paper, a new calculation procedure for obtaining the MT-PWM waveform using a simple calculation is proposed. Second, a new VDS controller (drain-source voltage controller) based on voltage feedback is proposed in order to realize a modified switching transient to increase the stability of the switching operation. Third, the dependency of MT-PWM on source voltage variation is investigated in order to implement MT-PWM in an actual step-down converter. From this result, the concept of a new type of VDS controller with the source voltage variation taken into consideration is proposed. Finally, the authors attempted to apply MT-PWM to an H-bridge converter to expand the application of MT-PWM. An H-bridge converter with MT-PWM for a dc motor drive is successfully operated in an experiment.
  • 牧村和樹, 竹本真紹, 小笠原悟司
    電気学会論文誌 D 136 2 100 - 109 2016年 [査読無し][通常論文]
     
    In the analysis of switched reluctance motors (SRMs), the analytical error of 2D FEA caused by the magnetic flux change in the direction of the axis, which is not considered in 2D FEA, is a serious problem. In this paper, a novel method for making a 2D-FEA model of an SRM, which can equivalently consider the influence of the threedimensional effect, is proposed. A 2D-FEA model of an SRM can be easily made by adjusting only the shape of two regions in a rotor by employing the proposed method. The optimum values of two parameters, defined in this paper for adjusting the shapes of the rotor with the proposed method, are easily extrapolated. A comparison of the experimental results with 2D FEA using the proposed method confirms that the proposed method is effective in considering the three-dimensional effect.
  • Tatsuya Matsuzaki, Masatsugu Takemoto, Satoshi Ogasawara, Kazuo Nishihama, Daisuke Kori, Koichiro Nagata
    IEEE TRANSACTIONS ON MAGNETICS 51 11 2015年11月 [査読有り][通常論文]
     
    A magnetic bearing (MB) can suspend a rotor shaft with noncontact, so the MB has been used for high-output and high-speed machines. In general, heteropolar-type MB structure is used, because of its simple structure and low cost. However, the heteropolartype MB structure has a problem in terms of rotor iron loss caused by an alternating magnetic field on a rotor core. On the other hand, general homopolar-type MB structure has a low rotor iron loss caused by a dc magnetic field on a rotor core. However, as the general homopolar-type MB has a complicated structure and needs a large magnet for generating the bias flux, it becomes costly. Therefore, this paper discusses a novel homopolar-type MB structure unifying four C-shaped cores for high output and low iron loss. It is shown with three-dimensional finite element analysis that the novel homopolar-type MB has lower iron loss and lower cost than the general homopolar-type MB, which is known for its low iron loss.
  • TANG Yizhanyi, 小笠原悟司, 竹本真紹, 金森正樹, 石田圭一, 遠藤隆久
    日本冷凍空調学会論文集 32 3 255 - 261 2015年09月30日 [査読無し][通常論文]
  • Katsuhiko Urase, Noboru Yabu, Kyohei Kiyota, Hiroya Sugimoto, Akira Chiba, Masatsugu Takemoto, Satoshi Ogasawara, Nobukazu Hoshi
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 51 4 2874 - 2883 2015年07月 [査読有り][通常論文]
     
    A new switched reluctance (SR) generator was designed for possible application in hybrid electric vehicles. The proposed generator was designed to be mostly competitive with the target interior permanent-magnet (IPM) generator currently used in mass-produced hybrid vehicles. The energy efficiencies of the SR and IPM generators were compared in typical driving cycles, such as US06, HWFET, and UDDS modes. We found that the energy efficiency of the SR generator was close to the IPM generator in high-speed driving cycles because the SR generator has no iron loss during the generator idling period due to the fact that it has no PM.
  • 宮本和弥, 竹本真紹, 小笠原悟司, 平櫛真男
    日本AEM学会誌 23 2 250 - 257 2015年06月10日 [査読無し][通常論文]
  • Akira Chiba, Kyohei Kiyota, Nobukazu Hoshi, Masatsugu Takemoto, Satoshi Ogasawara
    IEEE TRANSACTIONS ON ENERGY CONVERSION 30 1 175 - 182 2015年03月 [査読有り][通常論文]
     
    The increased price and the limited supply of rare-earth materials have been recognized as a problem by the international clean energy community. Rare-earth permanent magnets are widely used in electrical motors in hybrid and pure electrical vehicles, which are prized for improving fuel efficiency and reducing carbon dioxide (CO2) emissions. Such motors must have characteristics of high efficiency, compactness, and high torque density, as well as a wide range of operating speeds. So far, these demands have not been achieved without the use of rare-earth permanent magnets. Here, we show that a switched reluctance motor that is competitive with rare-earth permanent-magnet motors can be designed. The developed motor contains no rare-earth permanent magnets, but rather, employs high-silicon steel with low iron loss to improve efficiency. Experiments showed that the developed motor has competitive or better efficiency, torque density, compactness, and range of operating speeds compared with a standard rare-earth permanent-magnet motor. Our results demonstrate how a rare-earth-free motor could be developed to be competitive with rare-earth permanent-magnet motors, for use as a more affordable and sustainable alternative, not only in electric and hybrid vehicles, but also in the wide variety of industrial applications.
  • Minglei Gu, Satoshi Ogasawara, Masatsugu Takemoto
    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 9 4 434 - 441 2014年07月 [査読有り][通常論文]
     
    This paper proposes a novel magnet polarity identification method for initial position estimation during startup for interior permanent magnet synchronous machine (IPMSM) drives. The rotor's initial position estimation is based on magnetic saliency and employs high-frequency (HF) components of the voltage and current that are excited by the multi space-vector pulse-width modulation (MSVPWM) pattern. However, there is a common trouble in the estimation methods based on the magnetic saliency: it is necessary to identify the magnet polarity in order to distinguish the north and south poles since the estimated position angle is a periodic function with p radians. In this paper, a novel inductance estimation method is presented and the magnet polarity is uniquely identified by the relationship between the estimated inductance and the magnetic saturation effect. Experimental results confirm the advantages of the proposed method: it is reliable, accurate, and convenient, and can be done in real time. (C) 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
  • Minglei Gu, Satoshi Ogasawara, Masatsugu Takemoto
    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 9 2 219 - 227 2014年03月 [査読有り][通常論文]
     
    This paper presents a position-sensorless interior permanent magnet synchronous motor (IPMSM) control system at low and zero speed based on a multi-space-vector pulse-width modulation (MSVPWM) pattern with the elimination of nonlinear inverter effects. In conventional sensorless methods based on the MSVPWM pattern, the high-frequency (HF) components of voltage and current are used to estimate the rotor position information. However, the inverter nonlinear effects, such as forward voltage drops and deadtime, distort the HF components of the voltage and current so that an error occurs in the position estimation. Therefore, an improved position estimation scheme is developed in this paper. The compensated HF components of the voltage taking account of the inverter nonlinear effects can be used to decrease the estimation error. The proposed method can be implemented without increasing any hardware cost. Experimental results confirm the effectiveness of the proposed method. (c) 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
  • 石川勝美, 佐々木正貴, 小笠原悟司
    電気学会論文誌 D 134 9 807 - 814 2014年 [査読無し][通常論文]
     
    This paper deals with the development of a 600V high-voltage half-bridge gate driver IC used to drive large-current IGBT (insulated gate bipolar transistor) inverters such as those used in HEVs (hybrid electric vehicles). In order to improve the robustness of a short-circuit operation, a new short-circuit protection circuit is proposed. Furthermore, a reduction in the short-circuit current is observed. Thus, the developed high-voltage IC can drive almost all types of IGBT modules up to 400A/600V.
  • 森雄生, 船渡寛人, 小笠原悟司, 岡崎文洋, 廣田幸嗣
    電気学会論文誌 D 134 5 496 - 504 2014年 [査読無し][通常論文]
     
    The authors have proposed a new method to decrease high-frequency harmonics at a specific frequency band by modifying the switching transient slope. In previous studies, there were several problems in applying modified transient pulse width modulation (MT-PWM) to actual converters. In this paper, three problems are solved using an improved MT-PWM method. First, the MT-PWM signal was obtained with a trial-and-error method that involved complex computation procedures in the previous studies. In this paper, a new calculation procedure for obtaining the MT-PWM waveform with a simple calculation is proposed. Second, a new VDS controller (drain-source voltage controller) based on voltage feedback is proposed to realize a modified switching transient to increase the stability of the switching operation. Third, the dependency of MT-PWM on source voltage variation is investigated in order to implement MT-PWM in an actual step-down converter. From this result, the concept of a new type of VDS controller considering the source voltage variation is proposed. Finally, the authors attempted to apply MT-PWM to an H-bridge converter to expand the application of MT-PWM. An H-bridge converter with MT-PWM for a DC motor drive is successfully operated in the experiment. © 2014 The Institute of Electrical Engineers of Japan.
  • Kotaro Tagami, Satoshi Ogasawara
    ELECTRICAL ENGINEERING IN JAPAN 185 4 33 - 43 2013年12月 [査読有り][通常論文]
     
    Advances in power semiconductor devices have contributed to the realization of high-performance power converters and high-precision motor positioning. However, high-speed switching of power devices leads to a high-frequency leakage current and/or electromagnetic interference (EMI). On the other hand, it has been considered that the leakage current has no relation to motor position control in servo drive systems. This paper analyzes the influence of high-frequency leakage current on motor positioning and describes its mechanism. Experimental and simulation results show that high-frequency leakage current may cause variations in the motor position with a frequency that is twice the line frequency. (c) 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(4): 33-43, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22479
  • 松崎達也, 土方規実雄, 宮本和弥, 竹本真紹, 小笠原悟司, 平櫛真男
    日本AEM学会誌 21 2 196 - 202 2013年06月10日 [査読無し][通常論文]
  • 岡崎文洋, 青木亨, 廣田幸嗣, 小笠原悟司, 森雄生, 船渡寛人
    Calsonic Kansei Technical Review 9 82 - 90 2013年03月 [査読無し][通常論文]
  • Hirohito Funato, Takao Mori, Tomohiko Igarashi, Satoshi Ogasawara, Fumihiro Okazaki, Yukitsugu Hirota
    IEEJ Journal of Industry Applications 2 3 161 - 169 2013年 [査読有り][通常論文]
     
    High-performance power switching devices are used to realize high-performance power converters. These devices tend to generate high-speed switching harmonics that cause electromagnetic interference (EMI). There are several methods for reducing undesirable effects of EMI. An EMI filter or shielding is one of the most popular ways to reduce EMI however, both EMI filter and shielding increase the cost, size, and weight of power modules. It is well known that the shape of the switching transient strongly affects the harmonics distribution. This paper proposes a new method for reducing high-frequency noise at specific frequency bands by modifying switching transient slopes. This paper describes the improvement in the method of transient wave calculation for obtaining more effective waveforms. In addition, it provides experimental verifications to show the feasibility of the proposed method.
  • 久保 祐輝, 小笠原 悟司, 竹本 真紹
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 133 7 7 - 720 一般社団法人 電気学会 2013年 [査読無し][通常論文]
     
    This paper proposes simulation methods based on the forward Euler method that are suitable for real-time simulators. However, real-time simulation using the forward Euler method has the following problems: A simulation error caused by a time step limitation and a delay in the simulated waveforms. The authors have proposed a simulation method suitable for real-time simulators, but the physical meaning of the state variables is diluted by diagonalization of the system matrix. This paper proposes a simulation method to obtain the same characteristics as the previous method, without diagonalization. Off-line and real-time simulation results demonstrate the validity and usefulness of the proposed simulation method.
  • 小川 将司, 小笠原 悟司, 竹本 真紹
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 133 10 970 - 977 一般社団法人 電気学会 2013年 [査読無し][通常論文]
     
    This paper proposes a new feedback-type dead-time compensation method. The proposed method compensates the output voltage by employing two operations. First, the normal compensation matches the width of the output pulse to that of the input pulse with reduced delay time from the input pulse to the output pulse compared with the conventional method. Second, the short pulse compensation generates an output pulse after a few pulses are input so that the average value of the output signal equals that of the input signal. The voltage utilization factor of the proposed method is almost 100%, because there is no limit to the compensation and the decrease in the fundamental output caused by dead time is eliminated. The experimental results using a 100-kHz input signal show that there is no discrepancy between the output pulse width and the input pulse width. Furthermore, the THD of the compensated output current, when the output frequency is 50Hz, is eliminated, compared with that of the output current without compensation. These results show that the proposed method has low distortion and high voltage utilization factor characteristics.
  • 尾田善彦, 星伸一, 平谷多津彦, 竹本真紹, 千葉明, 小笠原悟司
    ふぇらむ 17 12 823 - 828 2012年12月01日 [査読無し][通常論文]
  • Yoshihiko Oda, Tatsuhiko Hiratani, Akira Chiba, Nobukazu Hoshi, Masatsugu Takemoto, Satoshi Ogasawara
    TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN 98 12 823 - 828 2012年12月 [査読有り][通常論文]
  • Kodai Sone, Masatsugu Takemoto, Satoshi Ogasawara, Kenichi Takezaki, Hidekatsu Akiyama
    IEEE TRANSACTIONS ON MAGNETICS 48 11 2961 - 2964 2012年11月 [査読有り][通常論文]
     
    Electric city commuters are vehicles used for commuting from suburbs to inner cities and for movement within cities. Because of the short distances that they cover and their small battery size, such vehicles are beginning to attract attention. Generally, a high-performance permanent magnet (PM) composed of rare earth elements, such as neodymium and dysprosium, is used in the in-wheel PM synchronous motor (PMSM) of an electric city commuter. However, rising prices of rare earth elements and export restrictions on them are serious problems. Development of an in-wheel PMSM that does not utilize rare earth PMs is therefore highly desirable for electric city commuter vehicles. Accordingly, our research group has focused on a surface PM type axial gap structure that can achieve a high torque density and a short motor length in the axial direction. The designed motor structure with ferrite PMs replacing the rare earth PMs and the results of a 3-D finite element analysis are introduced in detail in this paper. Moreover, to examine the fundamental characteristics of the designed motor, a prototype is produced and tested.
  • Akira Chiba, Motoki Takeno, Nobukazu Hoshi, Masatsugu Takemoto, Satoshi Ogasawara, M. Azizur Rahman
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 48 6 2333 - 2340 2012年11月 [査読有り][通常論文]
     
    This paper shows a winding design consideration of a 50-kW switched-reluctance motor (SRM) for hybrid-electric-vehicle (HEV) applications. Increasing the number of turns in stator windings is effective in reducing the maximum current; thus, the inverter current rating is reduced. However, motor output power falls significantly at high speed because of the increased back electromotive force. Continuous current operation can enhance output power at high rotational speed. In this operation, phase current is increased, and hence, the motor output power is maintained at high rotational speed. However, continuous current operation results in a decrease in efficiency. Thus, there is a trade-off in selecting the number of series turns. In this paper, two SRMs are constructed with the same dimensions, and their performance results, i.e., torque and efficiency ranges, are compared with those of the automotive industry standard interior-permanent-magnet motor for HEV applications.
  • Motoki Takeno, Akira Chiba, Nobukazu Hoshi, Satoshi Ogasawara, Masatsugu Takemoto, M. Azizur Rahman
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 48 4 1327 - 1334 2012年07月 [査読有り][通常論文]
     
    A switched reluctance motor (SRM) has been developed as one of the possible candidates of rare-earth-free electric motors. A prototype machine has been built and tested. It has competitive dimensions, torque, power, and efficiency with respect to the 50-kW interior permanent magnet synchronous motor employed in the hybrid electric vehicles (Toyota Prius 2003). It is found that competitive power of 50-kW rating and efficiency of 95% are achieved. The prototype motor provided 85% of the target torque. Except the maximum torque, the most speed-torque region is found to be covered by the test SRM. The cause of discrepancy in the measured and calculated torque values is examined. An improved design is attempted, and a new experimental switched reluctance machine is designed and built for testing. The results are given in this paper.
  • Takashi Imakawa, Kenta Chimata, Nobukazu Hoshi, Akira Chiba, Masatugu Takemoto, Satoshi Ogasawara
    2012 IEEE International Electric Vehicle Conference, IEVC 2012 1 - 8 2012年 [査読有り][通常論文]
     
    Interior permanent magnet synchronous motor (IPMSM) is the most popular traction electric motors for hybrid electric vehicles (HEVs). In general, rare earth permanent magnets are used in the IPMSMs. However, the price of the rare earth materials has been rapidly rising in recent years. This is recognized as a serious problem for the automobile industry. A switched reluctance motor (SRM) is one of the possible solutions for the problem. In our previous paper, a prototype machine has been designed and experimented on a test bed. In this paper, the characteristics of vibration and acoustic noise are investigated on electric vehicle (EV) with a prototype SRM. © 2012 IEEE.
  • 田上 耕太郎, 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 132 7 709 - 717 一般社団法人 電気学会 2012年 [査読無し][通常論文]
     
    Advances in power semiconductor devices have contributed to the realization of high-performance power converters and high-precision motor positioning. However, high-speed switching of power devices lead to a high-frequency leakage current and/or electromagnetic interference (EMI). On the other hand, it has been considered that the leakage current has no relation to motor position control in servo drive systems. This paper analyzes the influence of the high-frequency leakage current on motor positioning and describes its mechanism. Experimental and simulation results show that the high-frequency leakage current may cause variations in the motor position with a frequency that is twice the line frequency.
  • 竹野 元貴, 千葉 明, 星 伸一, 竹本 真紹, 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 132 8 9 - 848 一般社団法人 電気学会 2012年 [査読無し][通常論文]
     
    Permanent magnets made of rare earth materials are used in interior permanent magnet synchronous motors (IPMSMs), which are major component of hybrid electric vehicles. The recent remarkable increase in the cost of rare earth materials is a major concern. A switched reluctance motor (SRM) without permanent magnets is one of the possible alternatives. Two types of SRMs have been designed with different materials. The SRMs have been investigated full loading tests. This paper reports a comparison between experimental and analysis results for the SRMs. The efficiency of both SRMs can exceed 90%, and the output power can be in excess of 50kW.
  • Tatsuro Arakawa, Masatsugu Takemoto, Satoshi Ogasawara, Koji Inoue, Osamu Ozaki, Hirofumi Hojo, Hiroyuki Mitani
    IEEE TRANSACTIONS ON MAGNETICS 47 10 3602 - 3605 2011年10月 [査読有り][通常論文]
     
    Hybrid electric vehicles (HEVs) that emit less carbon dioxide have attracted much attention and rapidly become widespread, but further popularization of HEVs requires further technical advancement of mounted traction motors. Accordingly, our research group focuses on axial gap motors that can realize high torque density. In this paper, an axial gap motor with a novel interior permanent magnet (IPM) rotor structure is proposed and an examination of the proposed motor at the actual motor size of an HEV is presented. For comparison, we selected the newest radial gap-type 60kW IPM synchronous motor equipped in the third-generation Toyota Prius. Under the condition that the size of the proposed motor be the same as the comparison motor, we confirmed through three-dimensional finite-element analysis that the proposed motor could output twice the maximum torque of the comparison motor. In addition, a comparison was made with a previously reported conventional IPM-type axial gap motor, and the proposed motor was found to be more effective in generating reluctance torque. Moreover, the proposed motor exhibited sufficient durability to irreversible demagnetization of the permanent magnets, to stress caused by rotating the rotor, and to unbalanced electromagnetic forces caused by axial rotor eccentricity.
  • 茅野真治, 三浦昂彦, 竹本真紹, 小笠原悟司, 千葉明, 星伸一
    日本AEM学会誌 19 2 121 - 127 2011年06月10日 [査読無し][通常論文]
  • 三浦昂彦, 茅野真治, 竹本真紹, 小笠原悟司, 千葉明, 星伸一
    日本AEM学会誌 19 2 128 - 133 2011年06月10日 [査読無し][通常論文]
  • 今川聖, 星伸一, 千葉明, 竹本真紹, 小笠原悟司
    日本AEM学会誌 19 2 90 - 96 2011年06月10日 [査読無し][通常論文]
  • 竹野元貴, 千葉明, 星伸一, 小笠原悟司, 竹本真紹
    日本AEM学会誌 19 2 372 - 377 2011年06月10日 [査読無し][通常論文]
  • 山本直人, 竹本真紹, 小笠原悟司, 平櫛真男
    日本AEM学会誌 19 2 146 - 152 2011年06月10日 [査読無し][通常論文]
  • Akira Chiba, Yuichi Takano, Motoki Takeno, Takashi Imakawa, Nobukazu Hoshi, Masatsugu Takemoto, Satoshi Ogasawara
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 47 3 1240 - 1246 2011年05月 [査読有り][通常論文]
     
    A machine design of a switched reluctance motor having competitive torque and efficiency as well as compactness with respect to an interior permanent-magnet (IPM) synchronous motor (IPMSM) in a hybrid electric vehicle (Toyota Prius 2003) has been investigated. A torque of 400 N . m is set as a target with an outer diameter of 269 mm with an axial length of 156 mm, including coil end lengths. In addition, a 50-kW field weakening capability must be competitive to the IPMSM. The highest efficiency of 95% is also aimed. Stator and rotor structures and iron material are investigated. Test machines are built. Static and light load tests are carried out.
  • Naoto Yamamoto, Masatsugu Takemoto, Satoshi Ogasawara, Masao Hiragushi
    2011 IEEE International Electric Machines and Drives Conference, IEMDC 2011 148 - 153 2011年 [査読有り][通常論文]
     
    Bearingless motors are characterized by integration of electrical motors and magnetic bearings. These motors can realize magnetic suspension of rotor shafts without mechanical contacts. If the bearingless motor is applied to a canned motor pump, it is possible to levitate and rotate a impeller and a rotor shaft of a centrifugal pump. Therefore, the bearingless canned motor pump can realize next several advantages (1) high power and high head, (2) clean liquid sending, (3) maintenance free, (4) longer operating life, (5) high chemical resistance. On the other hand, the rotor shaft and the stator must be covered with thick bulkheads, because fluid flows into the gap between the rotor shaft and the stator. It becomes difficult to generate sufficient suspension force for magnetic suspension, as a magnetic gap length is increased by the thick bulkheads. Accordingly, a novel structure of a 5-axis active control type bearingless motor, that can generate the sufficient suspension force under the wide-gap condition, has been proposed. This paper introduces pump characteristics with experiments using a prototype of the proposed novel structure. © 2011 IEEE.
  • Yuki Kubo, Satoshi Ogasawara, Masatsugu Takemoto
    8th International Conference on Power Electronics - ECCE Asia: "Green World with Power Electronics", ICPE 2011-ECCE Asia 571 - 576 2011年 [査読有り][通常論文]
     
    The series-parallel hybrid system using a planetary gear realizes low-fuel consumption and restraining of the exhaust gas by performing an optimal control of the internal combustion engine (ICE) with various driving modes. On the other hand, the hybrid system using electric variable transmission (EVT) has been proposed. This paper presents a theoretical consideration on equivalency of the series-parallel hybrid system and the hybrid system using the EVT. Additionally, some experimental results and simulation results are compared to confirm equivalency of the two systems. © 2011 IEEE.
  • A ferrite permanent magnet axial gap motor with segmented rotor structure for the next generation hybrid vehicle
    Takahiko Miura, Shinji Chino, Masatsugu Takemoto, Satoshi Ogasawara, Akira Chiba, Nobukazu Hoshi
    "Conference records on XIX International Conference on Electrical Machines - ICEM 2010, Rome" 1 - 6 2010年09月 [査読有り][通常論文]
  • 高野祐一, 星伸一, 千葉明, 竹本真紹, 小笠原悟司
    電気協会報 1029 14 - 17 2010年08月01日 [査読無し][通常論文]
  • Tomohiko Sanada, Satoshi Ogasawara, Masatsugu Takemoto
    2010 International Power Electronics Conference - ECCE Asia -, IPEC 2010 2366 - 2371 2010年 [査読有り][通常論文]
     
    This paper deals with a new PWM control scheme of matrix converters, which have been proposed by the authors. The PWM control scheme is characterized by the calculation algorithm using pseudo inverse and the performance that the output voltage can be controlled completely even if the input voltage is distorted. An experimental system, which consists of a matrix converter main circuit and a control circuit using a DSP and an FPGA, has constructed and tested. An PWM generator and a commutation sequencer are developed and implemented in the FPGA. Some experimental results show validity and usefulness of the proposed PWM control scheme. In addition, a new PWM control scheme for improvement of the output voltage utilization is also evaluated experimentally and tested. © 2010 IEEE.
  • Yuichi Takano, Motoki Takeno, Nobukazu Hoshi, Akira Chiba, Masatsugu Takemoto, Satoshi Ogasawara, M. Azizur Rahman
    2010 International Power Electronics Conference - ECCE Asia -, IPEC 2010 1801 - 1806 2010年 [査読有り][通常論文]
     
    Rare earth permanent magnet (PM) materials are used in interior permanent magnet synchronous motors (IPMSM) as mainstream motors in hybrid electrical vehicles (HEV). In mass produced HEVs, the steep rise of price for the recent rare earth materials like Neodymium, Dysprosium, Boron, and etc is one of serious concerns. Therefore, a switched reluctance motor (SRM) without permanent magnets is one of the possible candidates. Design of stator and rotor have been investigated to achieve competitive torque and efficiency profiles at same dimensions of an IPMSM used for mass production in electric and hybrid electric vehicles. © 2010 IEEE.
  • Yuichi Takano, Motoki Takeno, Takashi Imakawa, Akira Chiba, Nobukazu Hoshi, Masatugu Takemoto, Satoshi Ogasawara
    2010 IEEE Energy Conversion Congress and Exposition, ECCE 2010 - Proceedings 2653 - 2659 2010年 [査読有り][通常論文]
     
    A prototype machine of a Switched Reluctance Motor (SRM) having competitive torque and efficiency as well as compactness with respect to an IPMSM in a HEV (Toyota Prius 2003) has been investigated. A torque of 400Nm is set as a target with an outer diameter of 269mm with an axial length of 156mm including coil end length. In addition 50kW field weakening capability must be competitive to the IPM. The highest efficiency of 95% is also aimed. Stator and rotor structures and iron material are investigated. Test machines are built. Static and light load tests are carried out. © 2010 IEEE.
  • 船渡 寛人, 櫻井 知之, 小笠原 悟司
    電気学会論文誌D 130 12 1 - 1289 一般社団法人 電気学会 2010年 [査読無し][通常論文]
     
    Recently, global warming has become a major problem. Therefore, the development of technologies for generating clean energy without producing CO<sub>2</sub> is required. Micro-hydroelectric power generation is one of the promising options as it requires small simple facilities, and a stable output. The authors have proposed a new system for generating micro-hydroelectric power. The proposed system has a simple mechanism and high efficiency. The proposed system was tested in a real river; however, it was very difficult to study all the characteristics of the system, including those of the hydraulic turbine, because it was very difficult to vary the water flow in a real river. In this paper, the authors propose a new test facility for micro-hydroelectric generation systems. In this system, water flow is generated using a general-purpose pump that can be used to increase pressure of the water flow in order to simulate a head. The fundamental characteristics of the proposed system are determined using the proposed facility and a water head between 1m and 10m and water flow of up to 500L/s. The study of the test facility is very useful in developing high-efficiency micro-hydroelectric generation system.
  • 原光雄, 廣田幸嗣, 青木亨, 菊池義行, 小笠原悟司, 船渡寛人
    Calsonic Kansei Technical Review 6 94 - 97 2009年11月 [査読無し][通常論文]
  • Kimio Hijikata, Masatsugu Takemoto, Satoshi Ogasawara, Akira Chiba, Tadashi Fukao
    IEEE TRANSACTIONS ON MAGNETICS 45 10 4617 - 4620 2009年10月 [査読無し][通常論文]
     
    Thrust magnetic bearings, which can regulate axial displacement of a rotor shaft, have been used for high-speed rotation. However, conventional thrust magnetic bearings have many problems in manufacturing and assembling caused by a large disk rotor of itself. Therefore, we have proposed a novel structure of a thrust magnetic bearing without the large disk rotor. A cylindrical rotor, that has a small diameter as well as a simple shape, is used in the proposed thrust magnetic bearing. This paper introduces the structure and the principle of the proposed thrust magnetic bearing. In addition, it is shown with experiments on high-speed operation that the proposed thrust magnetic bearing is equipped with the sufficient performance in order to make for practical use.
  • Yasuhiro Yamamoto, Hirohito Funato, Satoshi Ogasawara
    JOURNAL OF POWER ELECTRONICS 8 4 301 - 308 2008年10月 [査読無し][通常論文]
     
    This paper proposes a method of improving the stability in sensor-less control of permanent magnet synchronous motors. The control method for low-speed region is divided into two: One is a high frequency method, which involves a problem of reverse rotation once misdetection of the permanent magnet polarity should occur, and another one is a current drive method, which has a problem that phase and speed oscillations are caused by quick speed changes. Hence, authors propose adoption of the current drive method for the basic control system with added compensation of stabilization by means of the high frequency method. This combination secures stable control with no risk of reversal and less vibration. In addition, authors have also considered a frequency separation filter of a shorter delay time so that current control performance will not lower even when high frequencies are introduced. This filter has achieved simplified compensation using repetitive characteristic through the utilization of the periodicity of high frequency current. Simulation and experiment have been conducted to verify that the stable performance of this system is improved.
  • Jo Kamada, Hirohito Funato, Satoshi Ogasawara
    ELECTRONICS AND COMMUNICATIONS IN JAPAN 91 10 1 - 10 2008年10月 [査読有り][通常論文]
     
    High efficiency and low noise ill Output Voltage and current are required ill audio-video equipment, medical apparatus, and many other applications. This paper proposes a power amplifier in which a PWM inverter is used as the main Circuit. In the proposed power amplifier, a hybrid filter consisting of a simple conventional type I-C filler and it small-capacity linear amplifier is connected to the inverter output. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and I-C resonances are considerably suppressed by controlling the amplifier using (lie proposed method, thus implementing I low-distortion switching power amplifier. The effects of the proposal circuit are verified by simulation and experiments. As a result, the proposed Circuit achieves low noise about THD = 0.68%, in simulation and THD = 1.5% in experiment. (C) 2009 Wiley periodicals, Inc. Electron Comm Jpn, 91(10): 1-10,2008; published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10161
  • Jo Kamada, Hirohito Funato, Satoshi Ogasawara
    Electronics and Communications in Japan, Part II: Electronics (English translation of Denshi Tsushin Gakkai Ronbunshi) 91 10 1 - 10 2008年 [査読有り][通常論文]
     
    High efficiency and low noise in output voltage and current are required in audio-video equipment, medical apparatus, and many other applications. This paper proposes a power amplifier in which a PWM inverter is used as the main circuit. In the proposed power amplifier, a hybrid filter consisting of a simple conventional type LC filter and a small-capacity linear amplifier is connected to the inverter output. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and LC resonances are considerably suppressed by controlling the amplifier using the proposed method, thus implementing a low-distortion switching power amplifier. The effects of the proposal circuit are verified by simulation and experiments. As a result, the proposed circuit achieves low noise about THD = 0.68% in simulation and THD = 1.5% in experiment. © 2009 Wiley Periodicals, Inc.
  • 電気学会論文誌D 128 8 969 - 978 2008年 [査読無し][通常論文]
  • 小笠原悟司, 竹本真紹
    電気学会誌 128 10 697-697 (J-STAGE)  2008年 [査読無し][通常論文]
  • 綾野秀樹, 稲葉博美, 小笠原悟司
    電気学会論文誌D(産業応用部門誌) 128 3 4 - 192 一般社団法人 電気学会 2008年 [査読無し][通常論文]
     
    This paper proposes a large-scale matrix converter system which connects two main circuits in parallel and in which the carriers operating each main circuit have a phase difference of 180 degrees. A matrix converter needs an LC filter, not only because it acts as a conventional filter which reduces high frequency ripples caused by the converter switching, but also because the capacitor of the LC filter acts as a virtual voltage source. Therefore, this filter must be connected at the input side. The proposed system uses a miniaturized LC filter because the harmonics of the current flowing into the LC filter contain only the even number harmonics of the carrier and the cut-off frequency of the LC filter can be raised. For example, when the cut-off frequency is doubled, the inductor or the capacitor of the LC filter can be reduced to 1/4. The principle of raising the filter current's frequency is verified theoretically using simulations. Furthermore, in the proposed system, the distortion of the output voltages become less than with a conventional single matrix converter, and the common mode voltage and the common mode current, which cause electromagnetic interference (EMI), can also be decreased.
  • 鎌田浄, 船渡寛人, 小笠原悟司
    電気学会論文誌D(産業応用部門誌) 127 5 457 - 464 一般社団法人 電気学会 2007年05月01日 [査読無し][通常論文]
     
    The higher efficiency and the low noise in output voltage and current has been required in some applications, i.e. audio-video equipment, medical equipment and so on. This paper proposes a power amplifier in which a PWM inverter is used as a main circuit. In the proposed power amplifier, a hybrid filter composed of a simple and general LC filter and a small capacity linear amplifier is connected to the output of the inverter. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and LC resonances are considerably suppressed by controlling the amplifier using the proposed method and a low distortion switching power amplifier is realized. The effects of the proposal circuit are verified by simulations and experiments. As a result, the proposed circuit achieves low noise about THD=0.68% in simulation and THD=1.7% in experiment.
  • 田上 耕太郎, 小笠原 悟司, 船渡 寛人, 金澤 秀俊, 植杉 通可, 茂泉 健一
    電気学会論文誌D(産業応用部門誌) 127 3 286 - 292 一般社団法人 電気学会 2007年03月01日 [査読無し][通常論文]
     
    This paper analyzes shaft voltage and bearing current in a nongrounded motor driven by a voltage-source PWM inverter. First, the shaft voltage of the nongrounded motor is measured. The experimental results indicate that a bearing current, which can not be explained by the conventional theory, exists, and that the bearing current may shorten the life of the motor bearing. To investigate the mechanism, some experiments and parameter measurements are done, and simulation models are built. As a result, it is shown that this issue is caused by unbalance in the inductance and stray capacitance of the motor windings and these resonant phenomena.
  • 山本康弘, 東義高, 松野浩晃, 小笠原悟司
    電気学会論文誌D(産業応用部門誌) 127 12 3 - 1204 一般社団法人 電気学会 2007年 [査読無し][通常論文]
     
    This paper reports our study of a phenomenon in which magnetic saturation causes a step-out in sensorless control of IPMSM motors using the magnetic flux observer. The Finite-Element-Method (FEM) can simulate the flux distribution and electromotive force at any armature current. The obtained voltage is supplied to the flux observer containing model errors. Under stable condition, the estimated phase error of this observer is calculated by easy vector operational expression. By the phase error characteristics, it was found that the unstable current appeared in the region, where the error fluctuation increases to the negative direction. We described this problem was caused by the voltage equivalent to interference component arising from the phase error fluctuation. Finally, we suggested a method of avoiding this unstable phenomenon and showed the improved result obtained through some experiments.
  • 田上 耕太郎, 小笠原 悟司, 船渡 寛人
    電気学会論文誌D 127 2 131 - 138 一般社団法人 電気学会 2007年 [査読無し][通常論文]
     
    This paper develops a probe for measuring the high frequency grounding potential and demonstrates its effectiveness. The developed probe is applied to a motor drive system and measures a potential difference between a grounding terminal and the motor frame connected by a grounding conductor. Moreover, this paper attempts to visualize noise propagation in a grounding system. An experimental system is constructed on a lattice-shaped ground plane. A three-phase cable stretched on the ground plane connects between a common-mode voltage source and a motor, and the motor frame is earthed to the ground plane. In experiment, the developed probes detect 25-point potentials, and reconstructing these 25 waveforms makes it possible to visualize noise propagation. In addition, influence of a common-mode choke upon the noise propagation are shown experimentally.
  • 小笠原 悟司
    電気学会誌 126 6 352 - 355 一般社団法人 電気学会 2006年06月01日 [査読無し][通常論文]
     
    本記事に「抄録」はありません。
  • 綾野秀樹, 伊君高志, 稲葉博美, 小笠原悟司
    電気学会論文誌D 126 3 292 - 299 一般社団法人 電気学会 2006年03月01日 [査読無し][通常論文]
     
    This paper discusses an instantaneous calculation method of matrix converter using Venturini control algorithm. This algorithm can stabilize output voltages in the low speed operation because a narrow PWM pulse disappears on the condition of low output voltages, and it can drive by few computational complexities. This algorithm calculates matrix elements, which include trigonometric functions using the angles of input voltages, mathematically. Conventional methods estimated the angles using the zero crossing points of input voltages. The proposal method calculates matrix elements directly using the instantaneous values of input voltages. Especially, this method can calculate trigonometric functions include triple angle accurately and easily, even when a power supply has distortion. A permanent magnet synchronous motor as a load is driven desirable by using the proposal method. In addition, the simulation and experimental results show that the proposal method can stabilize output voltages when any phase input voltage has distortion.
  • 船渡 寛人, 柳田 幸宏, 小笠原 悟司, フォライ アレキサンドウル
    電気学会論文誌D 126 3 285 - 291 一般社団法人 電気学会 2006年03月01日 [査読無し][通常論文]
     
    The objective of this study is to find out a simple, time and cost-effective method for the assessment of state of batteries. In this study, the targets of estimation are NiCd, NiMH batteries that are widely used in portable equipments, but are difficult to estimate exact state. In our previous studies, the mathematical model was successfully derived from short-time measurement of voltage and current of battery using proposed signal processing scheme suitable for batteries characteristics. This paper presents a novel estimation method of state of NiMH battery using parameter fluctuations of internal impedance. In the proposed method, an equation for estimation was obtained as a function of parameters. Using this equation, state-of-charges of NiMH batteries were experimentally estimated with error less than 10%.
  • インバータ駆動非接地モータの軸電圧とベアリング電流の解析
    電気学会論文誌D 126 12 0  2006年 [査読無し][通常論文]
  • J Kamada, H Funato, S Ogasawara
    ISIE 2005: Proceedings of the IEEE International Symposium on Industrial Electronics 2005, Vols 1- 4 609 - 614 2005年 [査読有り][通常論文]
     
    The higher precision and low noise in output voltage and current has been required in some aplications i.e. audio-video equipmant, medical equipment and so on. In this paper, a new power converter which realizes low noise output with high efficiency is proposed. In the proposed converter, a hybrid filter is inserted to the output of a PWM inverter. The hybrid filter is composed of LC filter and a power amplifier. The amplifier is inserted in series to the filter capacitor to improve the LC filter. Noise suppression effects of the proposal circuit are verified by simulations and experiments.
  • J. Hamar, H. Funato, S. Ogasawara, O. Dranga, C. K. Tse
    2005 IEEE International Conference on Industrial Technology - (ICIT), Vols 1 and 2 81 - 86 2005年 [査読有り][通常論文]
     
    Exploiting the recent achievements of the information and communication technologies, a new e-learning initiation entitled Yoto project was launched in 2004. On longer run its most important objective is to build up and maintain an electrical engineering knowledge base, on shorter run it helps giving more and more publicity to some relevant fields, especially power electronics, drives and motion control. The multimedia rich content can be utilized in the high level academic education, in the industrial vocational trainings and also in supporting the circuit and system design specialists by fast interactive tools. This paper presents a new e-module attached to the Yoto project about the dynamic operation and modeling of dc-dc converters.
  • P Bartal, P Bauer, J Hamar, RK Jardan, P Korondi, Nagy, I, Z Suto, K Zaban, H Funato, S Ogasawara
    2005 IEEE Power Electronics Education Workshop 74 - 80 2005年 [査読有り][通常論文]
  • 小笠原 悟司
    モータ技術シンポジウム 2005 C5 - 1-1~10 日本能率協会 2005年 [査読無し][通常論文]
  • 天野 耀鴻, 小笠原 悟司
    電気学会論文誌D 124 10 1023 - 1028 一般社団法人 電気学会 2004年09月01日 [査読無し][通常論文]
     
    In this paper, a new universal drive system of synchronous motors used Real-Time Interface (RTI) performs characteristic evaluation of Synchronous Reluctance (SynR) motors and Surface Permanent Magnet (SPM) synchronous motors. The RTI connects directly a simulation model with experimental equipment, and makes it possible to use the simulation model for an experiment. The RTI is very effective in the early detection of an actual problem and examination of solution technique. Moreover, it concentrates on examination of control algorithm, and efficient research and development are enabled.<br>A measuring system of synchronous motors is built by the universal drive system. The examination of various synchronous motors is possible for the measurement system using the same control algorithm. Characteristic evaluation of a SynR motor and a SPM synchronous motor that are the same gap length and stator was performed using the measuring system. The measurement result shows experimentally that motor loss of the SynR motor is smaller rather than the SPM synchronous motor, at the time of high speed and low load operation. For example, the SynR motor is suitable to hybrid cars with the comparatively long time of low load and high-speed operation.
  • 小笠原 悟司, 岡村 晋吾
    電気学会論文誌D 124 2 262 - 263 一般社団法人 電気学会 2004年09月01日 [査読無し][通常論文]
     
    This paper proposes a flux position estimation of induction motors based on magnetic saturation. It is demonstrated experimentally that the method can estimate the flux position even at zero frequency, and that the estimation has a good accuracy at the rated flux level.
  • S Ogasawara, H Akagi
    CONFERENCE RECORD OF THE 2004 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-4 985 - 991 2004年 [査読有り][通常論文]
     
    This paper deals with a position-sensorless IPM motor drive system in which rotor position is estimated from current ripples generated by a PWM inverter. The new circuit configuration of a proposed digital controller makes it possible to reduce number of sample and hold circuits compared with the conventional system and to acquire current ripples automatically. Some experimental results show accuracy, response, and generality of the digital controller, and demonstrates a quick discrimination of magnetic polarity.
  • O Dranga, H Funato, S Ogasawara, J Hamar
    PESC 04: 2004 IEEE 35TH ANNUAL POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-6, CONFERENCE PROCEEDINGS 2703 - 2707 2004年 [査読有り][通常論文]
     
    Since power circuits are significantly influenced by inductances, a variable active-passive reactance (VAPAR) has previously been introduced in order to generate a virtual negative inductance, which has found applications in the rapid power flow control of power systems. It is used to cancel an existing undesired inductance, since the power flow through a simple power system of two voltage buses connected by an inductive power line is essentially restricted by the line inductance. These studies also indicated that the stability of the system could be compromised by the presence of stray capacitances. The present paper aims to offer a more accurate stability assessment of this RLC configuration, estimated so far by linear approximation, by essentially ignoring the switching process within VAPAR. The normal periodic steady-state regime leads to a fixed point in the stroboscopic map used to model the variable-structure piecewise-linear nonlinear system. The stability is indicated by the eigenvalues of the Jacobian matrix of the stroboscopic map, evaluated at this fixed point. The analysis reveals bifurcation behaviour and allows accurate and convenient prediction of the stability boundary in the parameter space of the virtual negative inductance required by the application and the stray capacitance present in the power circuit.
  • O Dranga, H Funato, S Ogasawara, CK Tse, HHC Iu
    2004 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL 4, PROCEEDINGS 772 - 775 2004年 [査読有り][通常論文]
     
    The concept of a variable active-passive reactance (VAPAR), which can generate a virtual variable inductance in power circuits, including negative values, has already been proposed. Since it has found applications in the power flow control of power systems, where the power flow is essentially restricted by a line inductance, the aim of the paper is to report on the stability of this virtual inductance in an RL circuit. The periodic steady-state operation of the variable-structure, piecewise-linear, nonlinear system is modeled by its Poincare map. The stability criterion employs the position of the eigenvalues of the Jacobian matrix of the Poincare map, evaluated at its fixed point. Bifurcation behaviour when varying the virtual inductance is revealed. Such an analysis allows accurate prediction of stability boundaries and facilitates the selection of parameter values to guarantee stable operation.
  • 相磯 秀夫, 高羽 禎雄, 大山 恭弘, 中道 好信, 苗村 潔, 橋本 洋志, 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 12 1391 - 1396 電気学会 2003年12月01日 [査読無し][通常論文]
  • 小笠原悟司, 黒川博之, 赤木泰文
    電気学会論文誌D 123 6 667 - 674 一般社団法人 電気学会 2003年09月01日 [査読無し][通常論文]
     
    This paper proposes a new circuit configuration for a position-sensorless drive system using an interior permanent magnet synchronous motor (IPM motor) rated at 3.7kW. The configuration can decrease the number of the sample and hold circuits to four, though fourteen sample and hold circuits are required for the conventional system. In addition, the configuration makes it efficient to detect current variations. It is shown experimentally that the drive system has good position estimation characteristics with absolute and relative errors within &plusmn;2 deg and &plusmn;0.5 deg in electrical angle, respectively. Moreover, the position control response is improved by adding current control loops to the position-sensorless drive system.
  • 藤田 英明, 丹 光義, 小笠原 悟司, 赤木 泰文
    電気学会論文誌D 123 3 286 - 293 一般社団法人 電気学会 2003年09月01日 [査読無し][通常論文]
     
    This paper points out that dc magnetic-flux deviation may occur in a doubly-fed flywheel genarator with primary-current feedback control. The flux deviation discussed in this paper, which is different from the common flux deviation caused by a dc output voltage of a PWM converter, is induced by an ac output voltage of the PWM inverter operated at the angular frequency of the rotor. It may be impossible to detect such a dc flux from the primary current and/or voltage, because the dc flux induces no voltage on the primary windings. This paper reveals that the primary-current control induces a dc flux in the primary windingsand prevents the dc flux from decaying. A new control method for suppressing the dc flux deviation, which is based on calculating the exciting current from the primary and secondary currents, is proposed. Experimental results verify the viability of the control method proposed in this paper.
  • 小笠原悟司
    電磁環境工学情報EMC 16 4 17 - 27 2003年08月05日 [査読無し][通常論文]
  • 小笠原 悟司
    EMC 16 4 17 - 27 ミマツコーポレーション 2003年08月 [査読無し][通常論文]
  • P Jintakosonwit, H Akagi, H Fujita, S Ogasawara
    ELECTRICAL ENGINEERING IN JAPAN 142 4 56 - 65 2003年03月 [査読有り][通常論文]
     
    This paper discusses automatic gain adjustment in a fully-digital-controlled shunt active filter intended for installation on power distribution systems. This is the first step in cooperative control of multiple shunt active filters based on voltage detection for harmonic damping throughout power distribution systems. In general, an optimal control gain is equal to the characteristic impedance of a distribution line. However, it is difficult to know the circuit parameters of a real distribution line, which depend strongly on feeder connections, shunt capacitors, and loads. Therefore, the main purpose of the gain adjustment is to help the active filter to damp out harmonic propagation without considering the circuit parameters. Moreover, the gain adjustment can reduce the compensating current and losses in the active filter. The active filter having the function of automatic gain adjustment is experimentally compared to that with a constant gain. Experiment results verify the effectiveness of the active filter having the function of automatic gain adjustment. (C) 2003 Wiley Periodicals, Inc.
  • P Jintakosonwit, H Fujita, H Akagi, S Ogasawara
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 39 2 556 - 564 2003年03月 [査読無し][通常論文]
     
    This paper proposes cooperative control of multiple active filters based on voltage detection for harmonic damping throughout a power distribution system. The arrangement of a real distribution system would be changed according to system operation, and/or fault conditions. In addition, shunt capacitors and loads are individually connected to, or disconnected from, the distribution system. Independent control might make multiple active filters produce unbalanced compensating currents. This paper presents hardware and software implementations of cooperative control for two active filters. Experiment results verify the effectiveness of the cooperative control with the help of a communication system.
  • Satoshi Ogasawara
    Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 144 3 69 - 77 2003年 [査読有り][通常論文]
     
    This paper proposes a damping method of rotor natural vibration in three-phase hybrid stepping motors, in which optimal commutation signals are calculated from the period of the natural vibration measured by detecting the motor voltages. Moreover, an acceleration and deceleration pattern is derived from a simple model of the rotor vibration, to suppress undesirable transient oscillation in acceleration, deceleration, and positioning operations. An experimental drive system has been implemented and tested to confirm the effectiveness and versatility of the proposed method. Some experimental results show that the experimental system can damp the rotor natural vibration even if the rotor inertia varies. Compared with the conventional pattern, it is confirmed that the proposed pattern makes a great contribution to damping the undesirable transient oscillations. ©2003 Wiley Periodicals, Inc.
  • H Fujita, H Akagi, M Tan, S Ogasawara
    2003 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-3 1766 - 1771 2003年 [査読有り][通常論文]
     
    This paper deals with dc-flux deviations occurring in a doubly-fed flywheel generator with stator-current feedback control. An ac output voltage of the PWM inverter connected to the rotor produces the dc-flux deviations in the stator. It is difficult to detect the dc flux from the stator current and/or voltage, because the dc flux induces no electromotive force on the stator windings. This paper proposes a new control method for suppressing the dc flux deviations based on calculating the magnetizing current from the stator and rotor currents. Experimental results verify the viability of the proposed control method.
  • S Ogasawara, M Fujikawa, H Akagi
    ELECTRICAL ENGINEERING IN JAPAN 141 4 59 - 68 2002年12月 [査読有り][通常論文]
     
    This paper proposes a new PWM rectifier/inverter system that is capable of suppressing not only supply harmonic currents but also electromagnetic interference (EMI). The conversion system consists of a PWM rectifier and inverter, and an active common-noise canceler (ACC) which has been proposed by the authors. The ACC developed for this system is characterized by the sophisticated connection of a common mode transformer which can compensate for common mode voltages produced by both the PWM rectifier and inverter. As a result, the size of the common mode transformer can be reduced to one-third, compared with the previously proposed ACC. A prototype PWM rectifier/inverter system (2.2 kW) has been implemented and tested. Some experimental results show reduction characteristics of the supply harmonic current and EMI. (C) 2002 Wiley Periodicals, Inc.
  • 奥野 敦, 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 122 9 893 - 898 一般社団法人 電気学会 2002年09月01日 [査読無し][通常論文]
     
    This paper introduces the general purpose computer simulation programs used for the design and analysis of power electronic systems, and their characteristics, such as calculation method, treatment of switching, etc., are organized into a table. Some simulation results of the benchmark test indicate the characteristics of individual simulators. Moreover, this paper comments on modeling method of power electronic systems. The simulation models classified into three levels are tested and evaluated from the point of view of simulation purpose and calculation time.
  • Jintakosonwit Pichai, 赤木 泰文, 藤田 英明, 小笠原 悟司
    電気学会論文誌D 122 1 29 - 36 一般社団法人 電気学会 2002年09月01日 [査読無し][通常論文]
     
    This paper discusses automatic gain adjustment in a fully-digital-controlled shunt active filter intended for installation on power distribution systems. This is the first step in cooperative control of multiple shunt active filters based on voltage detection for harmonic damping throughout power distribution systems. In general, an optimal control gain is equal to the characteristic impedance of a distribution line. However, it is difficult to know circuit parameters of a real distribution line, which depend strongly on feeder connections, shunt capacitors and loads. Therefore, the main purpose of the gain adjustment is to help the active filter to damp out harmonic propagation without considering the circuit parameters. Moreover, the gain adjustment can reduce the compensating current and losses in the active filter. The active filter having the function of automatic gain adjustment is experimentally compared to that with a constant gain. Experiment results verify the effectiveness of the active filter having the function of automatic gain adjustment.
  • Pichai Jintakosonwit, Hirofumi Akagi, Hideaki Fujita, Satoshi Ogasawara
    IEEE Transactions on Power Electronics 17 3 438 - 447 2002年05月 [査読無し][通常論文]
     
    This paper discusses automatic gain adjustment in a fully-digital-controlled shunt active filter. This is the first step in cooperative control of the multiple active filters based on voltage detection for harmonic damping throughout power distribution systems. In general, the active filter should be equipped with an optimal control gain corresponding to the characteristic impedance of a distribution line. However, it is difficult to know circuit parameters of a real distribution line having various shunt capacitors and loads. Therefore, a main purpose of the gain adjustment is to make the active filter damp out harmonic propagation without considering the circuit parameters. In addition, the gain adjustment can reduce the compensating currents and losses in the active filter, and moreover it can avoid over-damping performance. Experiment results obtained from a 200-V, 20-kW laboratory system verify the effectiveness of the active filter equipped with automatic gain adjustment.
  • P Jintakosonwit, H Fujita, H Akagi, S Ogasawara
    CONFERENCE RECORD OF THE 2002 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-4 51 - 58 2002年 [査読有り][通常論文]
     
    This paper proposes cooperative control of multiple active filters based on voltage detection for harmonic damping throughout a power distribution system. The arrangement of a real distribution system would be changed according to system operation, and/or fault conditions. In addition, shunt capacitors and loads are individually connected to, or disconnected from, the distribution system. Independent control might make multiple active filters produce unbalanced compensating currents. This paper presents hardware and software implementations of cooperative control for two active filters. Experiment results verify the effectiveness of the cooperative control with the help of a communication system.
  • 小笠原 悟司
    電気学会論文誌D 122 5 468 - 474 一般社団法人 電気学会 2002年 [査読無し][通常論文]
     
    This paper proposes a damping method of rotor natural vibration in three-phase hybrid stepping motors, in which optimal commutation signals are calculated from the period of the natural vibration measured by detecting the motor voltages. Moreover, an acceleration and deceleration pattern is derived from a simple model of the rotor vibration, to suppress undesirable transient oscillation in acceleration. deceleration, and positioning operations. An experimental drive system has been implemented and tested to confirm the effectiveness and versatility of the proposed method. Some experimental results show that the experimental system can damp the rotor natural vibration even if the rotor inertia varies. Comparing with the conventional pattern, it is confirmed that the proposed pattern has great contribution to damp the undesirable transient oscillations.
  • パワーエレクトロニクスハンドブック IV 次世代指向のパワーエレクトロニクス,1.2.2 EMI/EMC対策技術,pp. 1022-1033
    R&Dプランニング 2002年 [査読無し][通常論文]
  • S Ogasawara, S Zhang, H Akagi
    ELECTRICAL ENGINEERING IN JAPAN 137 1 57 - 65 2001年10月 [査読有り][通常論文]
     
    This paper deals with active circuits for cancellation and compensation of common-mode voltage caused by a PWM inverter. A nonnegligible amount of leakage or ground current flows through stray capacitors between stator windings and the motor frame due to a large step change in the common-mode voltage at every switching operation of the PWM inverter. First, it is shown experimentally that the active common-noise canceler (ACC), which has been proposed by the authors, is effective in reducing not only conducted EMI but also motor shaft voltage and bearing current. Next, a new ACC characterized by an isolated power supply is developed to enlarge the applicable voltage range in which it is possible to integrate the ACC with a PWM inverter. Furthermore, the authors propose another type of ACC, the purpose of which is not to achieve complete cancellation but to restrain only a slope in a change of the common-mode voltage applied to the motor. As a result, the core size of the common-mode transformer used in the active compensating circuit becomes considerably smaller. Some experimental results show good effects of the proposed active circuits on both ground current and conducted EMI. (C) 2001 Scripta Technica.
  • 小笠原 悟司, 藤川 真人, 赤木 泰文
    電気学会論文誌D 121 10 1075 - 1082 一般社団法人 電気学会 2001年09月01日 [査読無し][通常論文]
     
    This paper proposes a new PWM rectifier/inverter system that is capable of suppressing not only supply harmonic currents but also electromagnetic interference (EMI). The conversion system consists of a PWM rectifier and inverter, and an active common-noise canceler (ACC) which has been proposed by the authors. The ACC developed for this system is characterized by sophisticated connection of a common-mode transformer which can compensate for common-mode voltages produced by both the PWM rectifier and inverter. As a result, the size of the common-mode transformer can be reduced to 1/3, compared with the previously proposed ACC. A prototype PWM rectifier/inverter system (2.2kW) has been implemented and tested. Some experimental results show reduction characteristics of the supply harmonic current and EMI.
  • 森本雅之, 千葉明, 池防泰裕, 小笠原悟司, 小山純, 柏木陽一郎, 北村慎悟, 小原木春雄, 真下明秀
    電気学会技術報告 833 69P  2001年05月10日 [査読無し][通常論文]
  • H Akagi, S Ogasawara, H Kim
    ELECTRICAL ENGINEERING IN JAPAN 135 3 74 - 86 2001年05月 [査読有り][通常論文]
     
    This paper discusses "the p-q theory" and "the cross-vector theory" in three-phase four-wire systems, with the focus on similarities and differences between the two theories. They are perfectly identical if no zero-sequence voltage is included in a three-phase three-wire system. However, they are different in definition of the instantaneous active power and instantaneous reactive power in each phase if a zero-sequence voltage or current is included in a three-phase four-wire system. Based on both theory and computer simulation, this paper leads to the following conclusions: An instantaneous reactive-power compensator without energy storage components can fully compensate for the neutral current even in a three-phase four-wire system including a zero-sequence voltage or current, when a proposed control strategy based on the p-q theory is applied: However, the compensator cannot compensate for the neutral current fully, when a conventional control strategy based on the cross-vector theory is applied. (C) 2001 Scripta Technica.
  • S Ogasawara, H Akagi
    CONFERENCE RECORD OF THE 2001 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-4 2015 - 2021 2001年 [査読有り][通常論文]
     
    This paper proposes a PWM rectifier/inverter system capable of suppressing not only supply harmonic currents but also electromagnetic interference (EMI). An active common-noise canceler (ACC) developed for this system is characterized by sophisticated connection of a common-mode transformer which can compensate for common-mode voltages produced by both PWM rectifier and inverter. As a result, the size of the common-mode transformer can be reduced to 1/3, compared with the previously proposed ACC. A prototype PWM rectifier/inverter system (2.2 kW) has been implemented and tested. Some experimental results show reduction characteristics of the supply harmonic current and EML.
  • 数乗 有, 小笠原 悟司, 赤木 泰文
    電気学会論文誌D 121 7 739 - 746 一般社団法人 電気学会 2001年 [査読無し][通常論文]
     
    This paper deals with a computer simulation method, which can realize high-speed and high-accuracy. The proposed method is characterized by both introducing the so-called discrete-time system with variable-sampling time and treating the digital control system as the discrete-time system with constant-sampling time. The proposed method is applied to a position-sensorless IPM motor drive system, which has been proposed by the authors. Simulated results show that the proposed method achieves more accurate and efficient simulation than conventional methods do.
  • 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 120 10 2000年10月01日 [査読無し][通常論文]
  • 小笠原悟司, 赤木泰文
    電磁環境工学情報EMC 13 3 57 - 65 2000年07月05日 [査読無し][通常論文]
  • 小笠原 悟司, 赤木 泰文
    EMC 13 3 57 - 65 ミマツコーポレーション 2000年07月 [査読無し][通常論文]
  • H Fujita, S Ogasawara, H Akagi
    ELECTRICAL ENGINEERING IN JAPAN 131 4 85 - 95 2000年06月 [査読有り][通常論文]
     
    This paper presents a zero-current-switched voltage-fed inverter equipped with resonant circuits on the ac side. The current flowing through a switching device, that is, IGBT, is the sum of the load current and the resonant current. When the amplitude of the resonant current is larger than that of the load current, the current in the switching device becomes zero at an instant in each resonant cycle. This allows the switching device to be turned on or off at the zero current. The zero-current switching makes a significant contribution to reduction of switching losses and electromagnetic noises. In this paper, the principle of zero-current-switching operation, along with a novel control scheme, is described from a theoretical and practical point of view. Experimental results obtained from a laboratory system of 5 kVA verify the practicability. Moreover, the switching and conduction losses of the proposed soft-switched inverter are compared with those of a conventional hard-switched inverter. (C) 2000 Scripta Technica.
  • S Ogasawara, N Kobayashi, H Akagi
    ELECTRICAL ENGINEERING IN JAPAN 131 3 80 - 90 2000年05月 [査読有り][通常論文]
     
    This paper proposes a drive system for a three-phase hybrid stepping motor, combining sensorless closed-loop control with conventional open-loop control. It is characterized by sophisticated control providing both prevention of pulling out from synchronism and suppression of natural rotor oscillation, without any position sensor attached to the motor shaft. A switching technique in chopper control which can enlarge the speed range controllable in the sensorless closed-loop control is described. Starting and stopping sequences are developed to reduce mechanical natural oscillation produced in the transient state. Finally, the proposed drive system is compared experimentally with a conventional constant-current open-loop drive system. It is shown that the proposed drive system can perform the switchover from starting to sensorless-closed-loop operation within 20 ms, and can reduce the natural oscillation caused just after positioning. (C) 2000 Scripta Technica.
  • S Ogasawara, T Matsuzawa, H Akagi
    ELECTRICAL ENGINEERING IN JAPAN 131 2 68 - 79 2000年04月 [査読有り][通常論文]
     
    This paper describes position-sensorless control of an interior permanent magnet synchronous motor (IPM motor), which is characterized by real-time position estimation based on magnetic saliency. The real-rime estimation algorithm proposed in this paper determines the inductance matrix including rotor position information From current harmonics produced by switching operations of an inverter driving the IPM motor, and then estimates the rotor position every period of pulsewidth modulation (PWM). Position estimation without any special signal injection is achieved with a satisfactory response and accuracy even at a standstill and at low speed. An experimental system consisting of an IPM motor and a voltage-source PWM inverter has been implemented and tested to confirm the effectiveness and versatility of the approach. Some experimental results show that the experimental system has the function of electrically locking the loaded motor, along with a position response of 20 rad/s and a settling time of 300 ms. (C) 2000 Scripta Technica.
  • S Ogasawara, H Akagi
    PESC 2000: 31ST ANNUAL IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-3 928 - 933 2000年 [査読有り][通常論文]
     
    This paper analyzes conducted EMI generated by a PWM inverter-fed induction motor drive system. It is shown experimentally and analytically that resonant phenomena in a high-frequency range beyond a dominant resonant frequency are originated from the behavior of power cables as a distributed-constant circuit. Spectra of common-mode and differential-mode currents are simulated by means of introducing a distributed-constant model of the power cables, which consists of a 20-step ladder circuit. As a result, it is also shown that these resonances can be damped out by a single common-mode transformer (CMT) and three differential-mode filters (DMF's), both of which have been proposed by the authors.
  • S Ogasawara, H Akagi
    IAS 2000 - CONFERENCE RECORD OF THE 2000 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-5 1482 - 1488 2000年 [査読有り][通常論文]
     
    This paper discusses two different circuit configurations of the active common-noise canceler (ACC) which has been proposed by the authors. One is characterized by its de power supply isolated from the de link of a PWM inverter. The configuration makes it possible to integrate the ACC with a medium-voltage PWM inverter. The other compensates a partial frequency component of the common-mode voltage. The purpose is not to achieve complete cancellation, but to restrict only a slope in a change of the common-mode voltage applied to an ac motor. As a result, the core size of the common-mode transformer used in the ACC becomes small considerably Experimental results shaw good effects of the proposed active circuits on both ground current and conducted EMI.
  • 小笠原 悟司
    大学の物理教育 2000 0 42 - 45 一般社団法人 日本物理学会 2000年 [査読無し][通常論文]
  • 小笠原 悟司, 張 松, 赤木 泰文
    電気学会論文誌D 120 5 658 - 665 一般社団法人 電気学会 2000年 [査読無し][通常論文]
     
    This paper deals with active circuits for cancellation and compensation of common-mode voltage caused by a PWM inverter. A non-negligible amount of leakage or ground current would flow through stary capacitors between stator windings and a motor frame due to a large step change in the common-mode voltage at every switching operation of the PWM inverter. First, it is shown experimentally that the active common-noise canceler (ACC), which has been proposed by the authors, is effective in reducing not only conducted EMI but also motor shaft voltage and bearing current. Next, a new ACC characterized by an isolated power supply is developed to enlarge an applicable voltage range in which it is possible to integrate the ACC with a PWM inverter. Furthermore, the authors proposes another type of ACC, the purpose of which is, not to achieve complete cancellation, but to restrain only a slope in a change of the common-mode voltage applied to the the motor. As a result, the core size of the common mode transformer used in the active compensating circuit becomes smaller considerably. Some experimental results show good effects of the proposed active circuits on both ground current and conducted EMI.
  • 赤木 泰文, 小笠原 悟司, Kim Hyosung
    電気学会論文誌D 119 12 1461 - 1470 一般社団法人 電気学会 1999年09月01日 [査読無し][通常論文]
     
    This paper discusses &ldquo;the p-q theory&rdquo; and &ldquo;the cross-vector theory&rdquo; in three-phase four-wire systems, with the focus on similarity and difference between the two theories. They are perfectly identical if no zero-sequence voltage is included in a three-phase three-wire system. However, they are different in definition of the instantaneous active power and instantaneous reactive power in each phase if a zero-sequence voltage or current is included in a three-phase four-wire system. Based on both theory and computer simulation, this paper leads to the following conclusions: An instantaneous reactive-power compensator without energy storage components can fully compensate for the neutral current even in a three-phase four-wire system including a zero-sequence voltage or current, when a proposed control strategy based on the p-q theory is applied: However, the compensator cannot compensate for the neutral current fully, when a conventional control strategy based on the cross-vector theory is applied.
  • 小笠原 悟司, 一宮 弘司, 赤木 泰文
    電気学会論文誌D 119 8/9 1090 - 1098 一般社団法人 電気学会 1999年08月 [査読無し][通常論文]
     
    This paper discusses a distributed constant circuit model of power cables for representing high-frequency oscillatory currents, and evaluates electromagnetic interference (EMI) generated by a PWM inverter-fed induction motor drive system. While the lumped constant circuit model which has already been proposed by the authors has only one resonant frequency, the distributed model proposed here can simulate plural resonant phenomena existing in a high frequency range over the first resonant frequency. Frequency characteristics of both common-mode and normal-mode currents are analyzed by using a circuit simulator with the distributed model. As a result, it is shown experimentally and theoretically that the resonant phenomena in the high frequency range are originated from behavior of the power cables as the distributed constant circuit, and that the common-mode transformer (CMT) and the normal-mode filters (NMF's) can damp the resonances.
  • Satoshi Ogasawara, Hideki Ayano, Hirofumi Akagi
    Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 124 64 - 72 1998年12月01日 [査読無し][通常論文]
     
    This paper proposes an "active common-mode noise canceler" that is capable of eliminating the common-mode voltage produced by a voltage source PWM (pulsewidth modulated) inverter. It generates a compensating voltage which has the same amplitude as, but the opposite phase to, the common-mode voltage produced by the PWM inverter. The compensating voltage is superimposed on the inverter output by a common-mode transformer. As a result, the common-mode voltage applied to the load is canceled completely. The design method of the active common-mode noise canceler is also presented in detail. A prototype has been constructed and tested to verify the effectiveness for an induction motor drive system of 3.7 kW using an IGBT (insulated gate bipolar transistor) inverter. Some experimental results show that the proposed active common-mode noise canceler makes a significant contribution to eliminating the common-mode current or the ground current, and it prevents an electric shock from being received by anyone handling it. © 1998 Scripta Technica.
  • 小笠原 悟司
    自動化技術 30 12 6 - 11 工業調査会 1998年12月 [査読無し][通常論文]
  • 小笠原悟司
    自動化技術 30 12 6 - 11 1998年12月 [査読無し][通常論文]
  • 小笠原 悟司, 松澤 隆, 赤木 泰文
    電気学会論文誌D 118 5 652 - 660 一般社団法人 電気学会 1998年09月01日 [査読無し][通常論文]
     
    This paper describes position-sensorless control of an interior permanent magnet synchronous motor (IPM motor), which is characterized by real-time position estimation based on magnetic saliency. The real-time estimation argorithm proposed in this paper determines the inductance matrix including rotor position information from current harmonics produced by switching operations of an inverter driving the IPM motor, and then estimates the rotor position every period of pulse-width modulation (PWM). Position estimation without any special signal injection is achieved with a satisfactory response and accuracy even at a standstill and at low speed. An experimental system consisting of an IPM motor and a voltage-source PWM inverter has been implemented and tested to confirm the effectiveness and versatility of the approach. Some experimental results show that the experimental system has the function of electrically locking the loaded motor, along with a position response of 20rad/s and a settling time of 300ms.
  • S Ogasawara, H Ayano, H Akagi
    IEEE TRANSACTIONS ON POWER ELECTRONICS 13 5 835 - 841 1998年09月 [査読無し][通常論文]
     
    This paper proposes an active common-noise canceler (ACC) that is capable of eliminating the common-mode voltage produced by a pulsewidth modulation (PWM) inverter, An emitter follower using complementary transistors and a common-mode transformer are incorporated into the ACC, the design method of which is also presented in detail. Experiments using a prototype ACC, whose design and construction are discussed in this paper, verify its viability and effectiveness in eliminating common-mode voltage in a 3.7-kW induction motor drive using an insulated gate bipolar transistor (IGBT) inverter. Some experimental results show that the ACC makes significant contributions to reducing a ground current and a conducted electromagnetic interference (EMI), In addition, the ACC can prevent an electric shock on a nongrounded motor frame and can suppress motor shaft voltage.
  • 小笠原 悟司
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 118 9 975 - 980 一般社団法人 電気学会 1998年09月 [査読無し][通常論文]
  • S Ogasawara, H Akagi
    CONFERENCE RECORD OF THE 1998 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-3 460 - 466 1998年 [査読有り][通常論文]
     
    This paper describes position estimation based on magnetic saliency of an interior permanent magnet synchronous motor (IPM motor) for the purpose of achieving a wide-speed range. The position estimation, which has been proposed by the authors, is characterized by the real-time algorithm estimating the rotor position at every PWM period. Selection of PWM patterns proposed in this paper expands the speed range capable of estimating the rotor position to a higher-speed range. The PWM patterns are switched over, depending on an amplitude and phase of the average output voltage vector. Experimental results obtained from an IPM motor drive system of 100 W demonstrate that the selection of the PWM patterns makes it possible to estimate the rotor position In a wide-speed range from zero to the rated speed.
  • 藤田 英明, 小笠原 悟司, 赤木 泰文
    電気学会論文誌D 118 6 748 - 756 一般社団法人 電気学会 1998年 [査読無し][通常論文]
     
    This paper presents a zero-current-switched voltage-fed inverter equipped with resonant circuits on the ac side. The current flowing through a switching device, i.e., an IGBT is a sum of the load current and the resonant current. When the amplitude of the resonant current is larger than that of the load current, the current in the switching device becomes zero at an instant in each resonant cycle. This allows the switching device to be turned on or off at the zero current. The zero-current-switching makes a significant contribution to reduction of switching losses and electromagnetic noises.<br>In this paper, the principle of zero-current-switching operation, along with a novel control scheme, is described from a theoretical and practical point of view. Experimental results obtained from a laboratory system of 5kVA verify the practicability. Moreover, the switching and conduction losses of the proposed soft-switched inverter are compared with those of a conventional <br>hard-switched inverter.
  • 小笠原 悟司, 小林 直峰, 赤木 泰文
    電気学会論文誌D 118 42559 877 - 884 一般社団法人 電気学会 1998年 [査読無し][通常論文]
     
    This paper proposes a drive system for a three-phase hybrid (HB) stepping motor, combining sensorless closed-loop control with conventional open-loop control. It is characterized by the sophisticated control providing both prevention of pulling out from synchronism and suppression of rotor natural oscillation, without any position sensor attached to the motor shaft. Switching technique in chopper control is described, which can enlarge a speed range controllable in the sensorless closedloop control. Moreover, starting and stopping sequences are developed to reduce mechanical natural oscillation caused in transient state. Finally, the proposed drive system is compared with a conventional constant-current open-loop drive system experimentally. It is shown that the proposed drive system can perform a switchover from the starting to the sensorless closed-loop operation within 20ms, and can reduce the natural oscillation caused just after positioning.
  • OGASAWARA S, AKAGI H
    IEEE Trans. on IA 34 1 163 - 168 1998年 [査読無し][通常論文]
  • OGASAWARA S, AKAGI H
    IEEE Trans. on IA 34 4 806 - 812 1998年 [査読無し][通常論文]
  • H Fujita, S Ogasawara, H Akagi
    PESC'97: 28TH ANNUAL IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE - RECORD, VOLS I AND II 1000 - 1006 1997年 [査読有り][通常論文]
     
    This paper implements a wide range of power control with pulse-density-modulation (PDM) in a voltage-source series-resonant inverter which realizes a corona discharge for surface treatment of film. The use of the pulse-density-modulated inverter, or the PDM inverter, enables the employment of a three-phase diode bridge rectifier as a utility interface. The PDM inverter produces either a square-wave ac voltage state or a zero voltage state at its sc terminals to control the discharge power of a corona surface treater. Moreover, it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) in all the operating conditions, thus leading to a significant reduction of switching losses and electromagnetic noises. A 30 kHz, 6 kW surface treatment system consisting of a voltage-source PDM inverter, a step-up transformer and a corona discharge treater shows the establishment of a stable corona discharge in an extremely wide range of power control from 0.5 % to 100 %, and therefore succeeds in performing both strong and weak surface treatment processes for film.
  • S Ogasawara, H Akagi
    IAS '97 - CONFERENCE RECORD OF THE 1997 IEEE INDUSTRY APPLICATIONS CONFERENCE / THIRTY-SECOND IAS ANNUAL MEETING, VOLS 1-3 464 - 470 1997年 [査読有り][通常論文]
     
    This paper describes position-sensorless control of an interior permanent magnet synchronous motor (IPM motor), which is characterized by real-time position estimation based on magnetic saliency. The real-time estimation algorithm detects motor current harmonics and determines the inductance matrix including rotor position information. An experimental system consisting of an IPM motor and a voltage-source PWM inverter has been implemented and tested to confirm the effectiveness and versatility of the approach. Some experimental results show that the experimental system has the function of electrically locking the loaded motor, along with a position response of 20 rad/s and a settling time of 300 ms.
  • 小笠原 悟司, 綾野 秀樹, 赤木 泰文
    電気学会論文誌D 117 5 565 - 571 一般社団法人 電気学会 1997年 [査読無し][通常論文]
     
    This paper proposes an &ldquo;active common-mode noise canceler&rdquo; that is capable of eliminating the common-mode voltage produced by a voltage-source PWM inverter. It generates a compensating voltage which has the same amplitude as, but the opposite phase to, the common-mode voltage produced by the PWM inverter. The compensating voltage is superimposed on the inverter output by a common-mode transformer. As a result, the common-mode voltage applied to the load is canceled completely. The design method of the active common-mode noise canceler is also presented in detail.<br>A prototype has been constructed and tested to verify the effectiveness for an induction motor drive system of 3.7 kW using an IGBT inverter. Some experimental results show that the proposed active common-mode noise canceler makes a significant contribution to eliminating the common-mode current or the ground current, and it prevents an electric shock from being received by anyone who is touching.
  • OGASAWARA S, AYANO H, AKAGI H
    IEEE Trans. on IA 33 4 1019 - 1026 1997年 [査読無し][通常論文]
  • 小笠原 悟司, 綾野 秀樹, 赤木 泰文
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 116 12 1211 - 1219 一般社団法人 電気学会 1996年11月20日 [査読無し][通常論文]
     
    A voltage-source PWM inverter produces common-mode and normal-mode currents flowing through stray capacitors inside an ac motor every switching. Therefore, the currents may cause radiational EMI to electronic equipment, e.g., AM radio receivers, because its oscillation frequency ranges from 100kHz to several MHz. However, few technical papers related to the radiational EMI have been reported although attention has paid to the EMI.<br>This paper discusses relationships between radiational electromagnetic noises and the commom-mode and normal-mode currents. Reduction methods of both the commom-mode and normal-mode currents are also discussed on the basis of a motor model including the stray capacitors. It is shown theoretically and experimentally that both the currents can be damped by the combination of the common-mode transformer which has already been proposed by the authors and normal-mode filters proposed in this paper. Radiational EMI of a vector-controlled induction motor drive system of 3.7kW is measured according to the VDE 0877. Experimental results show not only that the radiational EMI results from the high-frequency oscillatory currents, i.e., the common-mode and normal-mode currents, but also that the combination of the common-mode transformer and the normal-mode filters is an effective, practical way of reducing the EMI.
  • S Ogasawara, H Akagi
    IAS '96 - CONFERENCE RECORD OF THE 1996 IEEE INDUSTRY APPLICATIONS CONFERENCE, THIRTY-FIRST IAS ANNUAL MEETING, VOLS 1-4 29 - 35 1996年 [査読有り][通常論文]
  • H Fujita, S Ogasawara, H Akagi
    IAS '96 - CONFERENCE RECORD OF THE 1996 IEEE INDUSTRY APPLICATIONS CONFERENCE, THIRTY-FIRST IAS ANNUAL MEETING, VOLS 1-4 1235 - 1241 1996年 [査読有り][通常論文]
  • 小笠原 悟司, リザ, 赤木 泰文, 新川 修
    電気学会論文誌D, 116 2 191 - 197 一般社団法人 電気学会 1996年 [査読無し][通常論文]
     
    This paper describes a position sensorless brushless dc motor drive system, in which an interior permanent magnet (IPM) motor is used as a synchronous motor. It is characterized by the position-sensing technique based on current detection of the free wheeling diodes. A three-phase voltage-source inverter with the conducting interval of 120 degrees in each phase is employed in the drive system. Reluctance torque plays an important role in producing torque of the IPM motor, having <i>q</i>-axis inductance larger than <i>d</i>-axis inductance, so that the control of <i>i<sub>d</sub></i>=0 can not achieve the highest motor efficiency.<br>The characteristic analyses of the position detection and the commutation overlapping angle are done, in which the saliency of the motor and harmonics of the back electromotive force are taken into consideration. It is shown that the detection angle and the commutation leading angle tend to lead with increase of the load torque, while the phase angle of the fundamental armature current lags by half of commutation overlapping angle. As the result, the total leading angle of the fundamental armature current exists near the optimal one which can attain the highest efficiency. The experimental results shows that higher efficiency is achieved at the rated speed without special phase angle control in relation to the load torque.
  • OGASAWARA S, AKAGI H
    IEEE Trans. on IA 32 5 1105 - 1114 1996年 [査読無し][通常論文]
  • 小笠原悟司, 綾野秀樹, 赤木泰文
    電気学会論文誌D 116 12 1211 - 1219 1996年 [査読無し][通常論文]
  • S Ogasawara, H Akagi
    IAS '95 - CONFERENCE RECORD OF THE 1995 IEEE INDUSTRY APPLICATIONS CONFERENCE/THIRTIETH IAS ANNUAL MEETING, VOLS 1-3 29 - 36 1995年 [査読有り][通常論文]
  • インバータドライブハンドブック
    日刊工業新聞社 1995年 [査読無し][通常論文]
  • 小笠原 悟司, 藤田 英明, 赤木 泰文
    電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 115 1 77 - 83 一般社団法人 電気学会 1995年 [査読無し][通常論文]
     
    This paper deals with the high-frequency leakage current caused by a voltage-source PWM inverter. A nonnegligible amount of leakage current would flow through stray capacitors between stator windings and a motor frame due to a, large step change of the common-mode voltage produced by the PWM inverter. An equivalent circuit for the leakage current is proposed, which is expressed by a series resonant circuit. The analysis applying the equivalent circuit gives us such a conclusion that the connection of a common-mode choke in series between the inverter and motor terminal is not effective to reduce the rms and average value of the leakage current, but effective to reduce the peak value. Furthermore, this paper shows that the modeling and analysis are valid in designing a previously proposed suppression method of the leakage current.
  • 藤田英明, 佐藤幾, 小笠原悟司, 赤木泰文
    電気学会論文誌D, 114 4 459 - 465 1994年 [査読無し][通常論文]
     
    The purpose of corona discharge treaters using high frequency inverters is to render the affinity of polyethylene films to inks, glues and coatings. A frequency control scheme for such a high frequency inverter has been proposed to achieve the power control of a corona discharge treater. It is, however, impossible to realize zero current switching except for full-power operation. Partial discharge appears in the frequency control scheme under the condition of a low power because the applied voltage between electrodes is decreased as the output power is reduced. This paper presents a 30kHz 5kW voltage-source inverter using IGBTs for corona discharge treaters, which is characterized by the power control based on pulse density modulation (PDM). Although the voltage-source inverter operates at a constant dc voltage and a constant output frequency, the average output power can be controlled by adjusting a period ratio of the square wave pulse having a constant amplitude to zero voltage. The PDM inverter can always operate with zero current switching, so that switching losses and electromagnetic noises are reduced. The prototype system developed in this paper shows good corona discharge characteristics in a wide output power range from 0.5% to 100%, which makes it possible to realize both strong and weak surface treatment. © 1994, The Institute of Electrical Engineers of Japan. All rights reserved.
  • S OGASAWARA, H AKAGI
    IAS 93, PTS 1-3 965 - 970 1993年 [査読有り][通常論文]
  • 小笠原悟司, 沢田直, 赤木泰文
    電気学会論文誌D, 113 1 41 - 48 1993年01月 [査読無し][通常論文]
  • OGASAWARA S, TAKAGAKI J, AKAGI H, NABAE A
    IEEE Trans. on IA 28 5 1023 - 1030 1992年 [査読無し][通常論文]
  • 小笠原 悟司, 村田 和弘, 赤木 泰文
    電気学会論文誌D 112 4 364 - 370 1992年 [査読無し][通常論文]
     
    The progress of microelectronics and microprocessors has advanced digitization of control circuits so that sensors have been expected to have digital output. Current sensors are basic in electrical drives, and the control accuracy depends on their performance. However, a current sensor using Hall-device has a non-linear error of 1%. In order to solve this problem, a Hall-effect current sensor, or a so-called closed loop current sensor, has been developed, which is combined with a current transformer. The current of a secondary winding is compensated by the Hall-device so that the magnetic field in the toroidal core is kept at zero. In this case, the non-linear error is eliminated. In this paper, a digital output current sensor of 12 bits is developed, which is a combination of a closed loop current sensor with a voltage comparator and a counter. As this circuit includes a nonlinear component such as the voltage comparator, the limit cycle caused by non-linearity is analyzed. It is described that the oscillation can be suppressed by linearization using a flush type A/D converter of 4 bits. © 1992, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 小笠原 悟司, 冨田 雅史, 赤木 泰文
    電気学会論文誌D, 112 9 883 - 890 1992年 [査読無し][通常論文]
     
    Corona discharge treaters have been used to treat surface of Polyethylene films and to improve affinity for inks. The features of a resonant inverter System using IGBT's for Corona discharge treaters developed in this paper are as follows. (1) No external reactors or capacitors are necessary because a series resonant circuit is composed of a leakage inductor of a step-up transformer and a capacitor between discharge electrodes of the treater. (2) A three-phase diode rectifier can be used because the output power is controlled by adjusting Output power factor of the inverter. (3) A capacitor is connected between a collector and emitter of IGBT's to reduce switching losses. An optimal design of the capacitor is done by utilizing an analog circuit Simulator. The authors propose an equivalent circuit of the IGBT because there may be no exact IGBT model for analog circuit Simulators. The validity of the equivalent circuit is verified by comparing experimental results with simulated ones. As a result, it is shown experimentally that the optimal capacitor, which is determined by the Simulation developed in this papaer, leading to higher efficiency. © 1992, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 小笠原 悟司, 水野 順司, 赤木 泰文
    電気学会論文誌D, 112 11 1039 - 1046 1992年 [査読無し][通常論文]
     
    The authors have developed an electrical cart using two direct drive motors. It has two drive wheels and one caster wheel. A driver riding on the cart gives speed and steering commands through a Joystick to operate the cart. Each motor is directly mounted into the drive wheel and is flxed on the body frame. A speed difference between the two drive motors is controlled to turn the cart. Such a steering method which is called "differential-drive method" makes a great contribution to simplification of the mechanical structure. First, modeling of the cart is discussed in this paper, because few researches have been done in which dynamic equations are derived theoretically. The validity of this modeling is verified by comparing experimental results with reasonably calculated ones. Second, the authors propose a control System with fuzzy theory to get stable straight runnig Performance, which can keep the caster wheel stragiht as long as a driver wants the cart to run straight. This fuzzy control System produces such a control signal that the cart automatically runs straight even if anything which may disturb the straight running occurs. It is verified experimentally that the proposed fuzzy control System helps a driver to keep the cart in a straight course. © 1992, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 小笠原悟司, 沢田直, 阿部慶一, 赤木泰文
    電気学会論文誌D, 111 11 930 - 936 1991年11月 [査読無し][通常論文]
  • OGASAWARA S, AKAGI H
    IEEE Trans. on IA 27 5 928 - 933 1991年 [査読無し][通常論文]
  • 小笠原 悟司, 山岸 直行, 戸塚 弘之, 赤木 泰文
    電気学会論文誌D 111 11 937 - 944 1991年 [査読無し][通常論文]
     
    In general, diode rectifiers with electrolytic capacitors on the DC side have been used as DC power supplies for voltage source inverters. This type of rectifiers, however, causes many problems such as poor power factor and harmonics. Recently, voltage source PWM rectifier-inverters have been studied to provide the following advantages (1) harmonic-free on both AC sides (2) unity power factor on the input AC side (3) power flow of either direction or power regeneration (4) reduction of the DC capacitor. It is, however, difficult for a conventional one to regulate the capacitor voltage on transient states because of having only a voltage feed-back loop. This paper describes a voltage source PWM rectifier-inverter with feed-forward control of instantaneous power. Based on the pq theory, the instantaneous power which is calculated in the control circuit of the inverter is fed forward to the control circuit of the rectifier. The feed-forward control of instantaneous power makes a great contribution to sufficiently suppress voltage fluctuation of the DC capacitor on transient states. Transient characteristics are discussed and some interesting experimental results of a laboratory model are shown. © 1991, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 小笠原 悟司, 城市 智幸, 赤木 泰文
    電気学会論文誌D 111 1 63 - 69 1991年 [査読無し][通常論文]
     
    In recent years, attention has been paid to direct-drive for industrial robots which are essential to factory automation. Direct-drive robots, which are directly actuated with no gear reducer, have no backlash, low friction and good mechanical stiffness. This results in the excellent repeatability of positioning, that is, an order of magnitude better than that of gear-drive robots. It is, however, more prominent in the design of control system for direct-drive robots that the arm inertia variation depending on the arm configuration and the Coriolis and centrifugal torques are directly reflected to the motor axes due to the direct coupling. In this paper, a direct-drive robot with a two degree-of-freedom is developed for planer assembly tasks. The motion of the manipulator arm is constrained within a horizontal plane, so that this type of robot is referred to as a SCARA (Selective Compliance Assembly Robot Arm)-type robot. A balanced manipulator arm, the purpose of which is to cancel the inertia variation and nonlinear effects, is introduced to the direct-drive robot, thus leading to improved control performance as well as simple manipulator dynamics. In addition, the combination of feedforward compensation and a new approach to positioning control is proposed to perform stable and fast positioning without overshooting. © 1991, The Institute of Electrical Engineers of Japan. All rights reserved.
  • 小笠原悟司, 鈴木和人, 赤木泰文
    電気学会論文誌D 111 5 395 - 401 1991年 [査読無し][通常論文]
     
    This paper describes a brushless DC motor system without position or speed sensor. The brushless DC motor consists of a permanent magnet synchronous motor and a voltage-source inverter which is capable of controlling the amplitude and frequency of voltage. The rectangular-shaped stator current with a conducting interval of 120° (electrical) is controlled to be in phase with the trapezoidal back electromotive force. This results in producing maximum torque. Variable speed is achieved by adjusting the average motor voltage, just like chopper control of DC motors. In this paper, two sensorless position detecting methods, “indirect method” suited at lower speed range and “direct method” suited at higher speed range, are proposed. The combination of the two makes it possible to detect the rotor position over a wide speed range. Furthermore, a speed-sensorless PLL control is proposed, applying the principle of the direct method. Experimental results obtained from a prototype brushless DC motor are shown to confirm the validity of the sensorless drive. The starting procedure of the motor is also discussed because it is impossible to detect the rotor position at a standstill. © 1991, The Institute of Electrical Engineers of Japan. All rights reserved.
  • S OGASAWARA, H AKAGI
    CONFERENCE RECORD OF THE 1990 IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETINGS, PARTS 1 AND 2 443 - 447 1990年 [査読有り][通常論文]
  • S OGASAWARA, H AKAGI, A NABAE
    ARCHIV FUR ELEKTROTECHNIK 74 1 33 - 41 1990年 [査読無し][通常論文]
  • 田中 俊彦, 小笠原 悟司, 赤木 泰文, 難波江 章
    電気学会論文誌D 110 3 248 - 256 1990年 [査読無し][通常論文]
     
    A parallel connected thyristor converter with an interphase reactor has been used widely as a low voltage high current DC power supply because of high efficiency, compared with a series one. It seems to be the most suitable for superconducting magnetic energy storage systems in particular. If the parallel converter consisting of two thyristor converters is operated under different firing angles in the two due to imperfect adjustment in the control circuit or something like that, unbalance may occur in the output DC current of each converter. The purpose of this paper is to discuss the current unbalance of a parallel thyristor converter in detail. The main points are summarized as follows: (1) It is clarified theoretically that the unbalance of DC output current may occur even when the difference of firing angles is less than 1°. (2) It is verified experimentally that the proposed simple current feedback makes it possible to balance the DC output current of the parallel thyristor converter. (3) An interphase reactor without gap is able to take the place of a conventional interphase reactor with gap which is used widely. Compared with the conventional one, the volume of the interphase reactor without gap is much small. © 1990, The Institute of Electrical Engineers of Japan. All rights reserved.
  • The Generalized Theory of Indirect Vector Control for AC Machines
    IEEE Trans. on IA, IA24 3 470 - 478 1988年 [査読無し][通常論文]
  • A NABAE, S OGASAWARA, H AKAGI
    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 22 4 697 - 701 1986年07月 [査読無し][通常論文]
  • 小笠原 悟司, 赤木 泰文, 難波江 章
    電気学会論文誌 B 電力・エネルギー部門誌 106 3 p209 - 216 電気学会 1986年03月 [査読無し][通常論文]
  • 小笠原 悟司, 西村 倫明, 赤木 泰文, 難波江 章
    電気学会論文誌B, 106 2 89 - 96 電気学会 1986年02月 [査読無し][通常論文]
  • S OGASAWARA, M NISHIMURA, H AKAGI, A NABAE, Y NAKANISHI
    IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 33 1 87 - 91 1986年02月 [査読無し][通常論文]
  • 小笠原 悟司, 赤木 泰文, 難波江 章
    電気学会論文誌B 106 3 209 - 216 1986年 [査読無し][通常論文]
  • 赤木 泰文, 小笠原 悟司, 難波江 章
    電気学会論文誌B 103 7 475 - 482 電気学会 1983年07月 [査読無し][通常論文]
  • 栗原直衛, 小笠原悟司
    高松工業高等専門学校研究紀要 15(1979) 37 - 40 1980年 [査読無し][通常論文]
  • 栗原 直衛, 小笠原 悟司
    高松工業高等専門学校研究紀要 15 p37 - 40 高松工業高等専門学校 1979年 [査読無し][通常論文]

書籍

講演・口頭発表等

その他活動・業績

特許

受賞

  • 2007年 The Best Paper Award of the 7th International Conference on Power Electronics
  • 2007年 Best Paper Award of The 4th Power Conversion Conference
  • 2005年 電気学会 産業応用部門 部門活動功労賞
  • 2003年 Second Prize Paper Award of Industrial Power Converter Committee at IEEE-IAS Annual Conference
  • 2002年 電気学会 産業応用部門 部門活動功労賞
  • 2001年 岡山大学 工学部 教育貢献賞 第1号 電気電子工学科「物理学実験」
  • 1999年 IEEE Power Electronics Society Transactions Paper Award
  • 1997年 First Prize Paper Award of Industrial Drive Committee at IEEE-IAS Annual Meeting
  • 1996年 Second Prize Paper Award of Industrial Power Converter Committee at IEEE Industry Applications Society(IAS) Annual Meeting

共同研究・競争的資金等の研究課題

  • 脱レアアース次世代モータの研究開発
    新エネルギー技術研究開発費
    研究期間 : 2008年
  • 回転センサレスIPM同期発電機を用いた小水力発電システムの開発
    研究期間 : 2007年
  • 電気機械を用いた動力伝達・分配・発生機構に関する研究
    研究期間 : 2006年
  • EMI低減を目的とした電力変換器に関する研究
    研究期間 : 2005年
  • 高性能電力変換器に関する研究
    研究期間 : 2005年
  • 電力変換器のEMI解析法・抑制法に関する研究
    研究期間 : 2004年

教育活動情報

主要な担当授業

  • システム工学概論
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
  • 電気エネルギー変換特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学研究科
    キーワード : パワーエレクトロニクス,電力変換,電動機制御
  • 電気エネルギー変換特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学院
    キーワード : パワーエレクトロニクス,電力変換,電動機制御
  • 電気エネルギー変換特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学研究科
    キーワード : パワーエレクトロニクス,電力変換,電動機制御
  • 電気エネルギー変換特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学院
    キーワード : パワーエレクトロニクス,電力変換,電動機制御
  • パワーエレクトロニクス
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 電力の変換・制御 電力用半導体デバイス 整流回路 直流変換回路 インバータ
  • 線形システム論
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : ダイナミカルシステム, 線形システム, 可制御性, 可観測性, 周波数特性, 安定性
  • 英語演習
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 先端テクノロジー,ロボット,OS,通信ネットワーク,火星探査,電動飛行機
  • システムデザイン
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 設計方法論,事象駆動システム設計,電子回路設計,制御系設計
  • 電気制御システム演習Ⅰ
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 電気回路学,線形システム,電磁気学,最適化理論,システムデザイン
  • 情報エレクトロニクス概論
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 情報理論, 計算機ハードウエア, 電子デバイス, 生体情報, 生命科学, 電子回路, 通信, メディア, ネットワーク, 電気回路, 制御工学

大学運営

委員歴

  • 2010年 - 2012年   電気学会   ICEMS2012 組織委員会 委員   電気学会
  • 2010年 - 2012年   電気学会   ICEMS2012 実行委員会 委員   電気学会
  • 2010年 - 2011年   電気学会   総務会議   電気学会
  • 2010年 - 2011年   電気学会   パワーエレクトロニクスシステムのシミュレーション適用技術協同研究委員会 委員   電気学会
  • 2008年 - 2011年   電気学会   半導体電力変換技術委員会 2号委員   電気学会
  • 2008年 - 2011年   電気学会   パワーエレクトロニクス機器のEMC 解析・抑制技術協同研究委員会 委員長   電気学会
  • 2009年 - 2010年   電気学会   平成22年全国大会グループ委員会 6グループ委員   電気学会
  • 2009年 - 2010年   電気学会   編修専門第3部会   電気学会
  • 2009年 - 2010年   電気学会   2010年 国際パワーエレクトロニクス会議 論文委員会 委員   電気学会
  • 2009年 - 2010年   電気学会   北海道支部 役員会 総務企画幹事   電気学会
  • 2008年 - 2010年   電気学会   2010年 国際パワーエレクトロニクス会議 実行委員会 委員   電気学会
  • 2008年 - 2010年   電気学会   2010年 国際パワーエレクトロニクス会議 組織委員会 委員   電気学会
  • 2010年   電気学会   創立125周年記念事業委員会 委員   電気学会
  • 2008年 - 2009年   電気学会   平成21年全国大会実行委員会 幹事   電気学会
  • 2008年 - 2009年   電気学会   平成21年全国大会グループ委員会 6グループ委員   電気学会
  • 2007年 - 2009年   電気学会   パワーエレクトロニクスシステムの系統的モデリングおよびシミュレーション技術協同研究委員会 委員   電気学会
  • 2009年   電気学会   平成21年電機・情報関係学会北海道支部連合大会実行委員会 幹事   電気学会
  • 2006年 - 2008年   電気学会   産業応用部門 編修広報委員会 副委員長   電気学会
  • 2006年 - 2008年   電気学会   産業応用部門役員   電気学会
  • 2005年   電気学会   論文委員会(D1グループ) 委員   電気学会


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