IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 115, Issue 12
Displaying 1-18 of 18 articles from this issue
  • Hideaki Fujita, Kiyoto Miyoshi, Hirofumi Akagi
    1995 Volume 115 Issue 12 Pages 1440-1447
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    A specially designed twelve-pulse thyristor rectifier of 5-8MVA is required as a low-voltage high-current dc power supply for super-conductive material tests. It is, however, too susceptible to low frequency variation of the utility voltage, or to the so-called “flicker” to generate a strong magnetic field with high stability.
    This paper presents a flicker and harmonic compensator based on the combined system of a small-rated series active filter and a conventional shunt passive filter. The main purpose of the compensator is to remove susceptibility to the flicker from the thyristor rectifier. The series active filter, which is connected in series with the utility, can compensate for flicker components present at the utility grid, the frequency range of which is from 1Hz to 20Hz. In addition, it helps almost all harmonic currents produced by the thyristor rectifier to flow into the shunt passive filter installed in parallel with the harmonic-producing load, i.e. the thyristor rectifier.
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  • Tokuo Ohnishi, Masaya Furuhashi, Kensuke Kawasaki
    1995 Volume 115 Issue 12 Pages 1448-1455
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    We propose a local power network system by using solar power generation system installed individually. The power network system can be constructed only by connecting the controlled outputs of individual inverter systems. The individual inverter in this system is operated by a frequency-tracking scheme not by a phase control one based on the common synchronous signal. The inverter system can feed the electric power to the common network line in accordance with the individual power capacity. Moreover, the inverter circuit can be easily constructed only by using a three phase inverter module as proposed before.
    The features of the proposed power network system are as follows; 1) simple circuit configurations, 2) power balance control, 3) maintenance free system, 4) easy extension 5) multifunctional control system and so on.
    In this paper, we investigate the control scheme to obtain the above requirements. We show the inverter control system by using a frequency-tracking scheme. Then, we analyze the relationship of the system. Some simulation and experimental results are shown to verify the system operation.
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  • Hiroyuki Kitamura, Yoshiaki Tamura
    1995 Volume 115 Issue 12 Pages 1456-1465
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The authors and the others devloped 15kW revolving armature type commutatorless motor deriving high mag-netic loading. At first we manufactured the commutatorless motor with inter-pole and compensating windings having the construction which attached and taked out inter-pole easily as an experiment and recognized by the experiment that this motor was improved fairly in the aspect of over load torque and the effect of inter-pole did not reach a little to the effect of compensating windings in the aspect of the spare angle improvement.
    Next time we manufactured the compound commutatorless motor (with compensating windings) as an experiment. And it was verified by the experiment that high output of 190% power was derived by this motor and compensating windings did not needed, if series field windings were provided. By the characteristics analysis and the simulation, we recognized that the main factor which this high output power was realized was that the leakage reactance X_??_ of this motor was half degree value of old commutatorless motors. Furthermore, we report this effect including the experimental data.
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  • Hiroyuki Ogiwara, Mutsuo Nakaoka
    1995 Volume 115 Issue 12 Pages 1466-1475
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper is mainly concerned with a switching device voltage-clamped type half-bridge topology of new instantaneous resonant current vector-regulated high-frequency inverter with phase-shifting control which efficiently operates at zero-current soft switching mode in order to minimize switching losses and electrical stresses of the switching device over a wide voltage regulation range.
    This resonant inverter using two resonant switches and a resonant tank is more suitable for high-power induction-heating power supplies high-intensity ultrasonic generators and switched-mode DC-DC converters.
    This ZCS high-frequency inverter for induction-heating load are analyzed introducing normalized resonant and load circuit parameters and control variable on the basis of the computer-aided simulation. The load and frequency regulation characteristics of the proposed inverter are illustrated with a normalized expression in addition to voltage and current peak values of the power semiconductor device. Its simulation results are illustrated as compared with the experimental results obtained from trially-produced breadboard.
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  • Masaaki Shibata, Toshiyuki Murakami, Kouhei Ohnishi
    1995 Volume 115 Issue 12 Pages 1476-1483
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The paper describes a nobel method to plan the collision avoiding trajectory for a robot manipulator in the existence of obstacles. The method is based on Distortional Configuration Space, proposed in this paper, which a conventional C-Space is transformed into by artificial attractive potentials. In the Distortional C-Space, all the forbidden areas are eliminated by the potentials, and then a collision-free path is planned without considering the interference with them. In order to obtain a feasible trajectory, it is important to define appropriate potentials in the C-Space. The definition of the potentials depends on the positions and the shapes of forbidden areas, though it needs enormous calculation time to get exact information of C-Space. By applying the approximate forbidden area and by determining the appropriate potential function, the processing time gets shorter, and then the proposed method realizes a quick trajectory planning. The validity of the method is confirmed in the results of numerical experiments.
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  • Tetsuya Hibi, Masaki Kamata
    1995 Volume 115 Issue 12 Pages 1484-1490
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    An image processed recognition ratio of road signs as high as 97% has been successfully achieved by using novel HSL and coordinates transformation. The purpose of this research is to construct algorithm that recognizes certain road signs on roads by the image processing. A digitized color image is transformed into a color-phase image by the HSL transformation. It is then converted into a binary image, using n×n matrix filter for noise reduction. Each pixel in an extracted binary image is allocated seven boundary patterns. The road sign is, then, extracted and converted by a coordinates transformation, using the Complex-log mapping method to remove influence of expansion, reduction and rotation. The matching is, also, carried out by using the Fourier transformation to remove an influence of difference in position.
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  • Haruyuki Kometani, Shigekazu Sakabe
    1995 Volume 115 Issue 12 Pages 1491-1497
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Recently, high efficiency and low noise are required in the permanent magnet synchronous motors, such as DCBLM. The DCBLM generally has a conductive support ring, which prevents the permanent magnets from scattering by the centrifugal force, but eddy current loss in the support ring cannot be ignored for high efficiency. This paper's purpose is to analyze the eddy current loss in the support ring and the torque ripples by dynamic electro-magnetic analysis. For the purpose, the rotor rotation and the external inverter circuit which contains the diode circulating circuit at phase change interval are necessary to be taken into consideration in the field analysis.
    In the paper, we give the dynamic electro-magnetic analysis method combined with the inverter circuit equations, and calculate the eddy current loss in the support ring and the torque ripples. In addition, the effect of the carrier frequency and the duty ratio to the loss is calculated.
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  • Moriaki Takechi
    1995 Volume 115 Issue 12 Pages 1498-1505
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    An optimal design approach is presented for high homogeneity superconducting magnet with superconducting passive shield especially for use in magnetic resonance imaging system. Fundamental solutions for magnetic field are obtained in a form of polynominal harmonics expansion taking the induced current in the superconducting passive shield into account. Influences of superconducting passive shield on the magnetic field in the internal and external region are studied to investigate an optimal design approach for superconducting magnet passively shielded by superconducting sheets or superconducting windings. A method is presented to obtain optimal coil configuration considering constraints for magnetic field homogeneity and leakage field. Some examples of coil configurations are obtained by the proposed method.
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  • Roberto Rojas, Tokuo Ohnishi, Takayuki Suzuki
    1995 Volume 115 Issue 12 Pages 1506-1513
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper examines the neutral voltage variations on a neutral point clamped (NPC) inverter circuit and proposes a new PWM technique which allows a great reduction in the capacitor values. Conventional and advanced control methods of the neutral point potential are analyzed demonstrating that the use of medium size vectors generates voltage fluctuations which can only be reduced by increasing the capacitor values. In this paper a new PWM control method is introduced. Different from former techniques, the use of the medium size vectors is avoided, increasing the neutral voltage controllable region to the whole range of operation under any load conditions making it possible to operate the NPC inverter with very small DC-link capacitors. The suitable voltage vector is carefully selected to reduce the output waveform distortion. The proposed PWM technique is experimentally verified on a low-power prototype and is compared with advanced control methods. The simulation and experimental results have shown that the proposed technique allows a great reduction in the capacitor values.
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  • Yoshitaka Ikeda, Rokusaburoh Sakai, Shinji Mizumura, Masahiko Kubo
    1995 Volume 115 Issue 12 Pages 1514-1520
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Various kinds of the flip-flop linear motors (FFLM) are discussed in comparison with the usual linear synchronous motors (LSM), from the view point of propulsive efficiency. The essential difference of them exists in the waveforms of the current flowing in the ground coils. They are rectangular with various conduction angles for FFLM's and sinusoidal for LSM. The typical circuit configurations of the FFLM's for 180°-, 120°-, 90°-and 60°- conduction modes are described at first. The magnetic fields caused by the periodical arrangement of permanent magnet pole pairs which are mounted on vehicles are analysed for the respective conduction modes including LSM. Considerations on the economical aspects of both the actuators and the driving circuits are described. The optimum arrangement of the magnet pole pairs is concluded to depend on the current conduction modes. It is also concluded that if the total length of the actuater is given and the higher power is required, 120°- FFLM is most preferable and if the least weight of the vehicle or the most efficient use of the magnets is required for frequent-service traffics, 60°-FFLM is most preferable.
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  • Tetsuo Uzuka, Shin-ichi Hase, Yoshifumi Mochinaga, Masatoshi Takeda, T ...
    1995 Volume 115 Issue 12 Pages 1521-1528
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In this paper, authors describe a basic figure of static voltage compensator for electric railway, named RPC (Railway Static Power Conditioner), its compensating philosophy and successful result of its test using a small model of RPC.
    An AC electric railway is placed under a load single phase, rapidly changing. To avoid voltage fluctuations under single phase loads, electric power is received from a larger source. And at a feeding substation, 3-phase electric power is transferred to paired directional single-phase feeding electric power.
    Authors already proposed a static voltage compensator for AC electric railway, called “RPC”. The RPC links a pair of feeding circuits using 2 self-commutated inverters.
    At the substation, the RPC accommodate_??_ an active power of the directional pair of feeding circuits to balance 3-phase power and compensate a reactive power to regulate a 3-phase voltage fluctuation. At a sectioning post, it can compensate for voltage drop using a reactive power. Also it can act as an active filter to compensate higher-harmonics.
    Authors have made a small model (220V, 20kVA) of RPC. And we report on the results of tests using this small model under various conditions. The results indicate that RPC can accommodate single phase loads such as transformers and thyristors, can handle an exciting rush current of transformer, can compensate higher-harmonics and so on.
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  • Proposal of Simulator-based Foresight Control
    Motomiki Uchida, Kazushi Nakano
    1995 Volume 115 Issue 12 Pages 1529-1536
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    A new control concept to achieve an ideal transient control performance is described. It is also possible to examine control performances on the frequency domain. Generally speaking, better control performances will be achieved by using more exact information on the plant as a basis. A simulator is to be built which has both correct initial values of state variables and parameters on domainant parts of the plant. The internal states of the simulator are used to represent the internal states of the plant, and control input is synthesized with the internal states of the simulator and the plant output.
    Taking advantage of information on the simulator, we can obtain an ideal control performance at a dominant frequency area, in spite of the exsistence of unmodeled dynamics at a highter frequency domain . This control system is called SFC (Simulator-based Foresight Control), and is also available for nonlinear and/or time-varying plants.
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  • Satoshi Ema
    1995 Volume 115 Issue 12 Pages 1537-1544
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The MAGLEV (magnetically levitated train) is now well along in development testing in Japan. MAGLEV is unlike conventional railways, so various problems lie in the technology of MAGLEV. One of them is surge analysis of the MAGLEV coil for propulsion and guidance (“coil for propulsion” for short). The coil for propulsion is installed on each side of the outdoor guideway. Thus, the power system of MAGLEV is always exposed to lightning and circuit switching. Accordingly, it is very important to do a rational insulation plan to prevent damage when surges enter the coils. In view of this situation I performed experiments using the mini model coils and clarified impulse voltage distribution at the end of each coil and simulated the surge characteristics by giving the inverted L equivalent circuit to the coil for propulsion.
    As a result, the measured values and calculated values were almost equal in the surge characteristics. Further, the surge characteristics of the Miyazaki test track and the future MAGLEV were examined.
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  • Norihiko Saga, Yoshiyuki Iwaki, Masaru Nakazawa
    1995 Volume 115 Issue 12 Pages 1545-1550
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    To reduce the noise emitted from the automobile alternator tends to serious subject recently especially concerning with improvement of amenity of driving. This paper intends to simulate the vibration of the alternator by substructure synthesis method. This method consists of the following two stepts: (1) Division of the alternator into four substructures, i. e. a stator, two housings and a rotor, and measurement of the transfer function for each substructure by the impact testing with a FFT analyzer. (2) Synthesis of the transfer function for the total structure by using the computer. Obtained results is applicable to the alternator to estimate its noise peak frequencies.
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  • Tetsuo KUBOTA, Kohji KOSHIJI, Eimei SHU
    1995 Volume 115 Issue 12 Pages 1551-1552
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Tadao Fujimaki, Katsumi Ohniwa, Akihisa Komoto
    1995 Volume 115 Issue 12 Pages 1553-1554
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Hitoshi Onogaki, Shuichi Yokoyama, Tomoyuki Yamazaki
    1995 Volume 115 Issue 12 Pages 1555-1556
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Yasuhiko Neba, Jun'ichiro Mori
    1995 Volume 115 Issue 12 Pages 1557-1558
    Published: November 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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