IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 122 , Issue 3
Showing 1-16 articles out of 16 articles from the selected issue
  • Kiyoshi Ohishi, Yasuaki Ogawa, Hideo Dohmeki
    2002 Volume 122 Issue 3 Pages 209-216
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a new speed control method for PM motor using a low resolution encoder and a speed observer. The servo system should be economical and simple. For this purpose, this paper realizes the high performance speed control system using a low resolution encoder, whose performance is nearly equal to the performance of speed servo system using a conventional optical encoder. The speed observer uses the information of motor current and motor voltage. The rotor position is calculated by the estimated value of speed observer. This observer has the influence of electrical parameter variation. This paper proposes the correction algorithm of both the voltage error of PWM Inverter and the electrical parameter variation. The experimental results and numerical simulation results point out that the proposed speed control system has the desired speed response, on condition of parameter variations and load torque perturbation.
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  • Shin-ichiro Nagai, Shinji Sato, Youichi Ito, Koichi Morita
    2002 Volume 122 Issue 3 Pages 217-222
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, a soft switching system investigated on the 50 kVA medium capacity power supply system is reported. The main circuit is composed of a full bridge PWM converter/inverter connecting a capacitor in parallel to each main switch. The converter is provided with a commutation circuit for AC link resonance, while the inverter with a commutation circuit for DC link resonance respectively. Compared with the ordinary soft switching system, the proposed system has low part count. The commutation control circuit detects input current, output current and DC capacitor voltage to control commutation switches Q1-Q4 in a manner that commutation current can be minimized. As a result of experiments on the 50 kVA system, it was confirmed that the proposed circuit could reduce conduction noise below 10 MHz and improve the conversion efficiency from 88.5% to 90.5%, when compared with the hard switching circuit.
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  • Akira Murai, Norio Tahara, Tsuyoshi Nakajima
    2002 Volume 122 Issue 3 Pages 223-234
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We found that it is possible to detach ozone from silica gel under the same temperature and same pressure conditions which silica gel adsorbed ozone. The extra energy, which is required for removing ozone, is unnecessary. Only the oxygen-purging step is required We changed the temperature of the silica gel and measured the differences in the amount of stored ozone. The amount of adsorption became linear. It followed the expression of van't Hoff. We made a computer program to simulate the phenomenon of the storage and removal. The results of the program demonstrated this phenomenon. We propose to use this method as a storage method for ozone. The ozone storage system, according to this principle, is compact and inexpensive to construct.
    In this system, we calculated the power consumption of a sewage plant, which processes 100, 000 tons of wastewater per day. The generation ability of the ozonizer can be decreased approximately 40 percent by introducing the ozone storage unit. The storing temperature is minus 17 degrees Celsius constant, in this result the cost of storage and removal equipment is not expensive.
    From these results, it is clarified that this method is effective to power load leveling.
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  • Jun Suzuki, Toshiyuki Murakami, Kouhei Ohnishi
    2002 Volume 122 Issue 3 Pages 235-240
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently, a lot of studies for vibration control of flexible manipulators have been reported. In 2 mass resonant system, “Resonance ratio control” is one of effective control methods. However, in this method, the robustness against the arm disturbance decreases. To improve this issue, the resonance ratio control with the arm disturbance observer is proposed. The arm disturbance observer is powerful. But, it is not robust enough to suppress friction-depending disturbance. There exists stick-slip friction effect when the arm moves slowly. The arm disturbance observer cannot compensate such a friction effect, and the vibration due to the stick-slip motion is induced.
    This paper proposes vibration control of flexible manipulator taking friction-depending disturbance into account. Here, the command generation is divided into two stages. First, friction is estimated by the arm disturbance observer. Second, the friction-depending disturbance can be rejected with the estimation result. The validity of the proposed method is also shown by simulations and experiments.
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  • Katsuhiro Hirata, Yoshio Mitsutake, Yoshitsugu Tamai
    2002 Volume 122 Issue 3 Pages 241-246
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The rapid-start lamp has total of three discharge conditions until it comes to a continuous lighting condition, (1) starting mode, (2) weak discharge mode, (3) steady-state discharge mode, and it is very difficult to design an optimum ballast for each discharge condition through a cut and try method. It is very important to obtain the accurate waveforms of input/output voltage and current in order to design and estimate the efficiency and the power factor of a lamp. Therefore, it is useful to estimate dynamic characteristics through an analytical approach. We have performed a dynamic performance analysis using a 2-D finite element method taking account of external circuit. But, it is difficult that the analyzed results of dynamic performances agree well with the measured results, because leakage magnetic flux, distributed three-dimensionally, cannot be considered by 2-D analysis.
    This paper describes a 3-D dynamic performance analysis of ballast for a rapid start lamp, and verifies its acceptability through a comparison with 2-D analysis results and experimental results.
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  • Hirokazu Nakamura, Akihiro Koyanagi, Yasunori Suzuki, Naoya Eguchi, Yo ...
    2002 Volume 122 Issue 3 Pages 247-252
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Nowadays, the Wind Turbine Generator (WTG) system is remarkably increasing as one of the renewable energy resources in Japan. But in the WTG, the power fluctuations caused by the wind speed fluctuation are the most crucial issue in providing their energy to the utility. It was found that the power compensation system (PCS) with the suitable capacity is still unknown. In this paper, the argument to time range and standardized wind speed including fluctuations is discussed. We estimated the storage capacity of PCS at a wind profiles by standardization of wind speed and verified the validity of their capacities using a computer simulation. It was determined the suitable capacity of the power compensation system with this argument.
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  • Jun-ichi Ito, Jiro Toyosaki, Hiroshi Ohsawa
    2002 Volume 122 Issue 3 Pages 253-259
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a novel V/f control method for PM motor drive system without position sensor. Unlike sensorless vector control, V/f method does not require high performance digital processing.
    This paper presents three novel topics for V/f control. At First, instability of conventional V/f control is shown, and a stabilization method consisting of a high-pass -filter and a feed back from d-axis current is proposed. After that, a control strategy yielding high efficiency is introduced. It is shown that the condition id=0, corresponding to high efficiency operation for SPM, can be achieved without explicit estimation of dq-axis. Furthermore, since this method is based on the evaluation of the reactive power, knowledge of R_??_ and e. m. f. is not required. At last, a starting method that does not need flux saturation to decode NS pole of permanent magnet, is proposed. The structure of the resulting control system is very simple and its effectiveness has been confirmed experimentally by using 1.5kW, 3600r/min and 3.7kW, 7200r/min PM motors.
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  • Hirokazu Kobayashi, Yu Nakayama, Kiyoshi Fujikawa
    2002 Volume 122 Issue 3 Pages 260-265
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    As speed control method of Two-Inertia system, conventional PID control is used well. However, when a gear or a coupling backlash exists in the 2-I system, the conventional PID control may not be able to suppress vibration caused by the backlash. To solve above problem, this paper deduces a sufficient condition of Multi-inertia system stability with PID control. Therefore, if the parameters of the PID controller are designed to meet the sufficient condition of control system stability, stable speed control without backlash vibration can be produced without relation to the presence of the backlash. The parameters of the PID controller can be designed by Coefficient Diagram Method (CDM). The effectiveness of the proposed speed control method will be shown by both simulations and experiments.
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  • Hiroshi Murakami, Yukio Honda, Shigeo Morimoto, Yoji Takeda
    2002 Volume 122 Issue 3 Pages 266-272
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Permanent magnet motors have attracted a lot of attention recently for their potential energy saving. However, they are only used for certain applications because of expensive magnets. This paper discuss the optimum design of the low cost and highly efficient magnet assisted reluctance motors with a minimum amount of magnets. The motor considered in this study is a multi flux barrier reluctance motor. The configuration by which permanent magnets are embedded to the innermost side of the rotor to obtain maximum output with the minimum amount of magnets was evaluated through simulation and experiments with a prototype motor. As a result, we established a method for designing motors capable of realizing the same efficiency as permanent magnet motors with only one-fourth the amount of magnets. In our experiments, we achieved a high efficiency of 94.5% with a 750W motor.
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  • Motoki Asano, Fumihiko Saitoh
    2002 Volume 122 Issue 3 Pages 273-279
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a method to recognize poses of figures which have arbitrary locations, sizes and rotations for measuring poses of two-dimensional industrial components. A template figure is represented by line segments that consist of the edge directions and curvature ratios of a pair of pixels. In the matching process, the values in the addresses that mean the candidates for pose parameters are accumulated by using the invariable geometric parameters for pose recognition including in line segments. The location of objective figures are extracted at the peak addresses in the voting space, and the sizes and the rotation angles are obtained by relative poses included in the voting log. The experimental results, show that the poses of objective components were recognized successfully even if the components were overlapped.
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  • Makoto Hagiwara, Hirofumi Akagi, Hideaki Fujita
    2002 Volume 122 Issue 3 Pages 280-287
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper deals with a self-commutated BTB (Back-To-Back) system for the purpose of power flow control and/or frequency change in transmission systems. Each BTB unit consists of two sets of 16 three-phase voltage-source converters, and their ac terminals are connected in series each other via 16 three-phase trans-formers. Hence, the BTB unit uses totally 192 switching devices capable of achieving gate commutation. This results in a great reduction of voltage and current harmonics without performing PWM control. Simulation results verify the validity of the proposed system configuration and control scheme not only under a normal operating condition but also under a single-line-to-ground fault condition.
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  • Shinichi Nomura, Naruaki Watanabe, Hiroki Ajikawa, Hiroaki Tsutsui, Yo ...
    2002 Volume 122 Issue 3 Pages 288-293
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Strong electromagnetic force caused by high magnetic fields and coil current is a serious problem in Superconducting Magnetic Energy Storage (SMES) systems and magnetically confined fusion devices. In facing this problem, we proposed the concept of Force-Balanced Coil (FBC) applied to SMES and fusion devices. The FBC is a helically wound toroidal coil which balances the centering force with the hoop force. The helical winding of the FBC is modulated in order to reduce the torsional force. However, the winding of the FBC is a three-dimensional complex shape so that it may be difficult to manufacture the modulated helical windings. To overcome this difficulty, we developed a helically winding machine. In this paper, we discuss the winding techniques by using the winding machine and improve the shape of the helical windings from the view point of the reduction of the time consumed in winding the coil.
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  • Fumihiko Saitoh
    2002 Volume 122 Issue 3 Pages 294-299
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Image template matching is applied to various fields such as the industrial image applications. This paper proposes a new method for image template matching that is based on the position of the pixel with the median gray-level in a local image area. The position of the pixel that has the just intermediate gray-level in the order of all gray-levels of pixels in a local image area is used for the matching. The matching is performed between the templates that have the positioning addresses of the pixels with the median gray-levels and an objective gray-scaled image. The experimental results show that the sharp peaks of the best solutions and the less noises around the peaks were obtained by the proposed method in comparison with the conventional methods. The processing time for the matching was 40% shorter than the normalized correlation matching.
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  • Tadashi Fukami, Toshinari Onchi, Ryoichi Hanaoka, Shinzo Takata, Toshi ...
    2002 Volume 122 Issue 3 Pages 300-306
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, the authors propose a novel application for a three-phase, solid-state, fault current limiter (FCL), consisting of a three-phase full-bridge rectifier and a DC reactor (DCR). Its configuration, operating principle, and a simple design method of the DCR, are presented. The proposed method is a combination of the FCL and a synchronous generator, and the FCL is connected to the neutral-point of the synchronous generator. As a result, an indispensable transformer in the conventional FCL can be removed, and a feature that maintains the current-limiting effect at a one-line ground fault is also obtained. To construct a guideline for creating the optimum DCR design, the current-limiting performance of the proposed method is theoretically analyzed, and the relationship between the fault current to be limited and the required DCR-inductance is derived. The experimental results obtained on a laboratory model demonstrate the effectiveness of the proposed method and validate the theoretical analysis.
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  • J. Yoshitsugu, K. Inoue, Y. Konishi, M. Nakaoka
    2002 Volume 122 Issue 3 Pages 307-308
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A practical active auxiliary quasi-resonant dc link snubber circuit with a diode clamping loop to reduce the switching losses and suppress a voltage ringing which causes in the loop including auxiliary zero current switching device; IGBT with parasitic electrostatic capacity is evaluated experimentally.
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  • Yoshihiro Konishi, Srawouth Chandhaket, Mutsuo Nakaoka
    2002 Volume 122 Issue 3 Pages 309-310
    Published: March 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper presents a novel prototype of utility-interactive soft-switching inverter using high-frequency flyback transformer. The proposed power conditioner circuit has an isolation function, which is cost effective and reliable for small-scale distributed renewal energy system. The discontinuous current mode (DCM) is applied to configure simple circuit and control. The operation principle is described on the basis of simulation evaluations. It is proved that the inverter outputs sinusoidal and unity power factor current synchronized with mains voltage.
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