IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 132, Issue 10
Displaying 1-27 of 27 articles from this issue
Paper
  • Shin'ya Okazaki, Takayuki Tanaka, Shun'ichi Kaneko, Hidenori Takauji, ...
    2012 Volume 132 Issue 10 Pages 942-950
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This study is aimed at developing a high-reliability motion stereo system through the consideration of camera vibration. In stereo measurement, we can approximate the distribution of measurement the error in images as a uniform distribution, and the distribution of the disparity error as a triangular distribution. Therefore, the parameters of the distributions are the mean value µ and the standard deviation σ, while the amplitude A and the frequency F are regarded as parameters of camera vibration. In our previous work, we constructed a model of the measurement error resulting from camera vibration. In this study, we define the existing probability of objects by using the measurement error model, and the reliability of object position. In addition, we verify the validity of the existing probability and reliability.
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  • Takashi Fukushige
    2012 Volume 132 Issue 10 Pages 951-957
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    In this study, the influence of the combination of slot number and pole number of permanent magnet machines on the iron loss is mathematically investigated in order to obtain guidelines that can help reduce iron loss; such reduction can facilitate miniaturization and improve the efficiency. By simplifying the machine electromagnetic model, the iron loss can be evaluated for any combination of slot number and pole number. The distribution of the magnetomotive force on the stator teeth and its complex Fourier series expansion are obtained so that coordinate transform can be easily done and the rotor iron loss can thereby be calculated. A core factor is defined on the basis of the calculated iron losses, and a core factor map of slot and pole number combinations is prepared.
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  • Yuuki Ishii, Hideaki Fujita, Kazuhiro Ozaki, Naoki Uchida
    2012 Volume 132 Issue 10 Pages 958-965
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This paper proposes a coil current control method for zone-control induction heating (ZCIH) systems based on the transformation to rectangular coordinates. A ZCIH system comprises two or more sets of a high-frequency inverter and a work coil, and it controls the amplitude of the coil current to adjust the heat/temperature distribution on a workpiece. For proper operation, the coil currents should be controlled in phase with each other. The proposed method controls the real and the imaginary parts of each coil current instead of its amplitude and phase angle. As a result, the proposed method makes it possible to achieve stable control in a wide amplitude range of heating power. Experimental results obtained from a 3-kW three-zone ZCIH laboratory setup are shown to verify the validity of the proposed method and to demonstrate a quick response in the coil current control.
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  • Koji Takuzaki, Nobukazu Hoshi
    2012 Volume 132 Issue 10 Pages 966-975
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    Contactless power transfer (CPT) system is of interest because of its potential for use in electric vehicle chargers. The system can make convenient to charge the battery on electric vehicles even on a rainy day. However, there are some barriers that should be overcome for the practical realization of the CPT system. These include parameter variation associated with the parking position at a parking lot and the low system efficiency. Several CPT schemes have been proposed and researched. This paper reviews inductive CPT system in these schemes. First, a theoretical formula suitable for treating two kinds of parameter variations associated with the caused by coupling state between the primary and secondary coils or parking position is derived. Next, a maximum efficiency operation scheme is proposed on the basis of the formula and theoretical analysis. Experimental results show the effectiveness of the proposed operation scheme.
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  • Takashi Ishigami, Yuichiro Tanaka, Hiroshi Homma
    2012 Volume 132 Issue 10 Pages 976-982
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    A motor stator with a rectangular wire lap winding and an automatic process for its production were developed in order to obtain small high-power motors with excellent efficiency characteristics. The structure of two continuous α-shaped coils and the coil production method involving simultaneous coil forming and coil insertion made mass production of this stator possible. A prototype's slot-fill rate was 80.5%, and the total size of the coil end was 60 to 72mm. On the basis of the ratio between sectional areas of coils, its efficiency was estimated to be higher than those of motor stators with a round wire concentric winding by 3.7% (1000min-1). In addition, the number of coil parts and the number of welding points were greatly reduced compared to those of a stator with a segmented coil wave winding.
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  • Hiroki Kaihara, Norio Takahashi, Masanori Nakano, Morio Kawabe, Takuma ...
    2012 Volume 132 Issue 10 Pages 983-989
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    Recently, because of the development of the power electronics technology, PWM inverters have been used to drive motors for achieving precise and energy efficient control. The precise estimation of the increase in iron loss due to high harmonic components of flux, including carrier frequency, is important in the design of motors excited by a PWM inverter. We measured the iron losses of non-oriented electrical steel sheets that were excited by using a single-phase full-bridge PWM inverter and examined the influence of carrier frequency and circuit resistance on the iron losses. We showed that the iron loss increased because of the generation of minor loops when the circuit resistance was high. Therefore, the circuit resistance should be decreased in an actual motor system.
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  • Hiroshi Matsuki, Yasutaka Fujimoto
    2012 Volume 132 Issue 10 Pages 990-996
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This study aims to replicate the operations performed by an experienced operator of a water supply system. Steering groups of water supply systems face problems because of the decreasing number of experienced operators. Without the skill of experienced operators, it is difficult to carry out safe and stable operations. Regression analysis was adapted in this study to replicate the operations performed by an experienced operator. To resolve the nonlinear regression problems of knowledge acquisition and decreasing number of experienced operators, a support vector machine (SVM) was used. For knowledge acquisition from sensor data, data mining and principal component analysis (PCA) were used. Experimental results showed that when the proposed method was used, the average of the root mean square values of the water level improved by 29.8% as compared to that obtained by the conventional method. Thus, we confirmed that the proposed method can acquire operation knowledge from experienced operators and use it to prepare an operation plan. This method is expected to compensate for the decrease in the number of experienced operators.
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  • Koji Maekawa, Kenji Takahara, Toshinori Kajiwara
    2012 Volume 132 Issue 10 Pages 997-1002
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This paper describes the development of a portable fuel cell (FC) system. This system provides hydrogen to the FC via the reaction of hydrogen generation between activated aluminum particles and water. The developed system includes an FC, a water tank, a pump, a reactor vessel, a storage tank, a pressure sensor, and a controller implemented in a one-chip microcomputer. A PI controller is designed to control the reaction by determining the amount of to be supplied water to the activated aluminum particles in the reactor vessel. The parameters of the control system are determined by trial and error, on the basis of the values obtained by Chien-Hrones-Reswick method. The developed system is confirmed to provide hydrogen to the FC via experiments under many circumstances. Therefore, our proposed system is considered to be useful as a portable FC system.
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  • Shohei Tokunaga, Shota Yamakura, Katsumi Kesamaru
    2012 Volume 132 Issue 10 Pages 1003-1008
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This paper describes a novel small wind turbine generation system with a dual-rotor ring winding slotless permanent magnet synchronous generator (PMSG). In order to improve the machine efficiency of the slotless PMSG, the dual-rotor structure is applied to the ring winding slotless PMSG. Several machine characteristics such as the magnetic flux distribution, linkage flux, induced electromotive force, and machine torque of the dual-rotor ring winding slotless PMSG are calculated by finite element analysis (FEA). Then, motion equation analysis coupled with FEA is used to simulate the dynamic performance of the proposed system with maximum power point tracking (MPPT) control. From the results of the dynamic simulation with quasi-natural wind pattern, it is found that the dynamic characteristics of the proposed system such as the rotor speed, machine torque, mechanical input power, copper loss, and electrical power are represented, and it is confirmed that the proposed system with the dual-rotor ring winding slotless PMSG achieves high machine efficiency for a random wind pattern.
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  • Atsushi Okuyama, Shota Yabui, Takenori Atsumi
    2012 Volume 132 Issue 10 Pages 1009-1015
    Published: October 01, 2012
    Released on J-STAGE: October 01, 2012
    JOURNAL FREE ACCESS
    This paper presents the design method of adaptive feedforward cancellation (AFC) for reducing periodic disturbance. AFC can be designed by considering the phase condition. The results of this study show that the proposed method can achieve a circular vector locus that recedes from the critical point on the Nyquist diagram and can improve the convergence of the adaptive algorithm. The effectiveness of the proposed method is confirmed by numerical simulations of the benchmark problem for hard disk drives (HDDs).
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