IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 123, Issue 1
Displaying 1-7 of 7 articles from this issue
Paper
  • Mihoko Niitsuma, Hiroshi Hashimoto, Yukio kimura, Shintaro Ishijima
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 1-8
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    This paper proposes a movement model of a human walking behavior in order to investigate walking behavior of crowd humans. This model contains functions of the collision avoidance and the trajectory decision of each human taking one’s own inertia into account. The trajectory decisition is realized as a servo system.
    Collision avoidance is attained by quasi Coulomb force generated among humans and also between a human and a wall. Simulation results that humans simultaneously advance to the destination are shown.
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  • Toshiaki Murai, Masaru Iwamatsu, Hiroshi Yoshioka
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 9-14
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    The 8-figure null-flux ground coils in EDS (Electro-Dynamic Suspension) including the PLG (combined Propulsion, Levitation and Guidance) system, which can both suspend and propel maglev vehicles simultaneously, have mainly longitudinal and vertical dimensions such as coil pitch and heights of upper and lower coils. In this paper we investigate these dimensions not only to balance the basic performance for levitation, guidance and propulsion, but also to reduce magnetic disturbance of superconducting magnet. By using an optimization program, we induced the relationship between the basic performance and these dimensions. Furthermore, by implementing a modal analysis, we predicted the vibration of superconducting magnet in different pitches, and thereby proposed these dimensions to decrease the vibration.
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  • Shoji Fukuda, Yuya Furukawa
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 15-20
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    An active filter (AF) is required to have a high control capability of tracking a time-varying current reference. However, a steady-state current error always exists if a conventional proportional and integral (PI) regulator is used because the current reference varies in time. This paper proposes the application of adaptive digital signal processing (ADSP) to the current control of voltage source PWM inverters. ADSP does not require any additional hardware. It can automatically minimize the mean square-error. Since the processing time available by a computer is limited, ADSP cannot eliminate higher order harmonics but can eliminate lower order harmonics such as 5th to 17th. Experimental results demonstrate that ADSP is useful for improving the reference tracking performance of voltage source inverters.
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  • Mineo Tsuji, Katsutaka Tsuboi, Eiji Yamada
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 21-29
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    To perform the vector control, relatively complicated control algorythm is required. The digital sampling control system is apt to be unstable dependent on its sampling period. To equip with many functions under the limitation of lower cost, the longer sampling period is inevitable and the performance of the system becomes less stable. Therefore it is important to evaluate the permissible maximum sampling period of each system.
    To evaluate it, software simulation tools such as PSIM and EMTP can be used. However these tools require a long execution time even for the sole model under each circuit condition. Therefore simpler methods are necessary to investigate the stability rapidly for many cases of the circuit conditions.
    In this paper, we propose three kinds of stability judging methods using root loci in a z-plane. The first metod is the most practical one based on a simple approximated model. The second and third methods are based on detailed models each having continuously rotating axis and stepwise rotating axis of the motor coordinates.
    To evaluate the proposed analytical methods, these results are compared with those obtained from detailed simulation taking PWM control into account.
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  • Sompob Polmai, Toshifumi Ise, Sadatoshi Kumagai
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 30-37
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    A voltage sag compensating system using a micro-SMES is presented. Based on the previous works, we have carried out experiments for voltage sag compensation on the laboratory-built system to validate the proposed minimum energy injection voltage sag compensation algorithm. In order to improve the compensating performance of the system, two-degree of freedom voltage control is proposed. In this paper, the circuit configuration and the feedback voltage control system of compensator are described and the experimental results are reported.
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  • Keiji Kawahara, Shin-ichi Hase, Hiroaki Morimoto, Shigeki Umeda, Norio ...
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 38-47
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    In DC electric railways, power is supplied to trains from DC substations. The voltage gets declined at a pantograph on the way due to the voltage drop caused by impedance, in particular the resistance of feeding wires. In case the load of rolling stock gets heavy, the significant voltage drop may hinder the train from continuous operations. Two methods have been conventionally used to deter the voltage drop. One ways is to decrease resistance of the circuit by the application of feeder with bigger diameter. Another is to compensate the voltage drop by the installation of the new substation between two existing substations. These two methods are effective; however, there are problems of term and cost for installation. Based on these issues we have recently developed the new method which we call "substation support equipment". In this paper we report the basic concept and overview for the substation support equipment together with results of performance test on site and artificial fault test.
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  • Makoto Hagiwara, Hirofumi Akagi
    Article type: Others
    Subject area: Others
    2003 Volume 123 Issue 1 Pages 48-55
    Published: 2003
    Released on J-STAGE: March 31, 2004
    JOURNAL FREE ACCESS
    A self-commutated BTB(Back-To-Back) system for the purpose of achieving power flow control and/or frequency change in transmission systems has attractive features of reliable and continuous operations even under power fault conditions. However, an overvoltage appearing across the dc link during the fault conditions should be suppressed as small as possible because it does affect the voltage ratings of power devices.
    This paper proposes a new control method for effectively suppressing the overvoltage under power fault conditions. This method based on a combination of feedback and feedforward controls is characterized by compensation of power flow imbalance between two power converters. The validity of both the proposed method and the developed theory is confirmed by computer simulation.
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