IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 121, Issue 7
Displaying 1-15 of 15 articles from this issue
  • Akira Chiba, Tadashi Fukao
    2001 Volume 121 Issue 7 Pages 724-729
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    A bearingless motor is a motor with a magnetically integrated bearing function. Both torque and magnetic suspension force is generated in one electromagnets. Several windings are wound and connected to a few inverters. Inverters are controlled so that motor rotational speed is regulated, in addition, rotor radial positions are also controlled by inverter currents.
    Bearingless drives have been investigated by researchers for more than one decade. A few applications and extensive developments are going on in several countries.
    In this paper, the state of the art is surveyed in the world wide developments of bearingless drives. Basic concepts and definitions are shown as well as related technologies. Based on a technical paper database including more than 100 papers written in English, technical terms, countries, machine types, winding structures, configurations are summarized. Characteristics are summarized for various types of bearingless machines. Several machine developments in bearingless technologies by manufacturers are also introduced.
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  • Katsuji Shinohara, Kichiro Yamamoto, Kenichi Iimori, Yoshitaka Minari, ...
    2001 Volume 121 Issue 7 Pages 730-738
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    When a transformer is connected to a circuit, under certain conditions, magnetizing inrush currents may be about ten times the full load current of the transformer. The currents contain a large amount of harmonic components and cause some relays to trip out. In this paper, the magnetizing inrush currents are compensated using a PWM inverter. The magnetizing inrush currents are detected and the PWM inverter generates compensating currents for the inrush currents. Hysteresis current controllers are used for fast response. The validity of this compensation is investigated by the simulation results. In addition, hardware implementation for the compensator is accomplished to verify the simulation results. Moreover, for the compensator, the relation between the compensating characteristics, the maximum switching frequency and the coupling reactor is discussed based on the simulation results. Finally, characteristics of two current controllers (hysteresis band current controller and ramp-comparison controller) are compared and it is shown that the hysteresis band current controller is more suitable for the compensator. The electromagnetic transient simulator named PSCAD/EMTDC is used for the simulations.
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  • Application to a Position-Sensorless IPM Motor Drive System
    Yu Kazunori, Satoshi Ogasawara, Hirofumi Akagi
    2001 Volume 121 Issue 7 Pages 739-746
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    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.
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  • Yasushi Matsumoto, Satoru Ozaki, Atsuo Kawamura
    2001 Volume 121 Issue 7 Pages 747-755
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In the field of the rolling stock traction system, one inverter often drives multiple induction motors connected in parallel, because of its compactness, lightness and economical advantages. A high performance three level invereter system using high voltage and large current IGBTs that can drive multiple induction motors has been widely adopted. On the other hand, in order to provide passengers of comfortable ride feeling and to keep the train schedule even in rainy days, an accurate and responsive motor torque control is demanded. Considering this situation, we have already developed a stator-flux-oriented vector control method for the rolling stock traction system in which one inverter feeds multiple induction motors. Here, we have newly developed a novel vector control method which can improve the stability of the traction system and the motor torque response. We have also evaluated the proposed control method through stability analysis, simulations and experiments. This paper presents the principle of this control method and the mechanical and electrical models of the rolling stock traction system, as well as stability analysis, simulation and experimental results.
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  • Shuji Watanabe, Hiroshi Takano, Eiji Hiraki, Mutsuo Nakaoka
    2001 Volume 121 Issue 7 Pages 756-763
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper deals with a two-paralleled switch-mode PWM power amplifier using current pattern tracking scheme in order to generate a gradient magnetic field in the Magnetic Resonance Imaging (MRI) system. This power conversion circuit has 8-IGBTs at their inputs/outputs so as to realize further high-power density, and to reduce current switching ripple of the Gradient Coils (GCs) as well as to raise current responses. The modern optimal preview control implementation in 2 parallel bridge type PWM power amplifier can improve the quick and precise current pattern tracking control responses in accordance with the specified values for the magnetic field in GCs. It is clearly proven from a theoretical point of view that the proposed control software is to be enlarged highly the diagnostic target and improves the image quality of MRI systems.
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  • Mario Cacciato, Alfio Consoli, Donato Tagliavia, Antonio Testa
    2001 Volume 121 Issue 7 Pages 764-769
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Time domain simulation is essential in computer aided design and debug of Power Integrated Circuits. Behavioral models allow to largely increase simulation speed and flexibility and are ideal for time domain simulations. A new technique is presented that allows to obtain a neural network based behavioral model of the output stage of a VlPowerTM Integrated Circuit including temperature effects and employing only input/output measurements. Using the proposed approach, a temperature dependant model of a monolithic cascode switch has been developed and tested.
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  • Nakajima Kazuki, Mizukami Yoshiki, Tanaka Kanya, Tamura Toshiyo
    2001 Volume 121 Issue 7 Pages 770-776
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper proposes a new biometrics method based on footprint for personal classification. We introduce a normalization procedure to improve the accuracy rate of classification. The normalization procedure is composed of two main steps: 1) left and right footprints are separated automatically; 2) each footprint is normalized in direction and in position. In the experiment, the pressure distribution of the footprint was measured with a pressure-sensing mat. Ten volunteers contributed their footprints for testing the proposed method. The obtained results show that a) our normalization procedure makes classification stable, that b) Euclidean distance between the pressure distributions of input and registered footprints gives 82.64% accuracy rate, and that c) Euclidean distance used together with the subject's weight information and the geometric information of footprint achieves the highest rate 86.55%.
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  • Katsunori Asano, Yoshitaka Sugawara
    2001 Volume 121 Issue 7 Pages 777-784
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Power devices with high capability have been developed. 8kV•3.5kA class light-triggered thyristors have the highest capability among power devices. These devices are used in the Kii channel HVDC transmission system in Japan. In this paper, we report the extracted problems of conventional testing methods of 8kV•3.5kA class light triggered thyristors among manufacturers, and the proposed unified testing methods on the basis of element characteristics and operating conditions in Kii channel HVDC system. Furthermore, we propose a figure of merit for power devices for the practical use, and try to extract elements used at Kii channel HVDC system with small margins and low withstand capabilities.
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  • Shin-ichi Motegi, Atsushi Nakajima, Akeshi Maeda
    2001 Volume 121 Issue 7 Pages 785-791
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The current-fed high-power-factor converters (buck and buck-boost converters) have several advantages, such as no lower-limit of the output-voltage control range and no rush-current of the input-current. However, the single-phase current-fed high-power-factor converter with PWM (Pulse-Width-Modulation) produces undesirable lower order harmonics in the input-current. Thus, the PWM requires a bulky and costly inductor connected in the dc-side of the current-fed converter to reduce the dc-inductor-current ripples. To overcome the problem, the authors have proposed PSM (Pulse-Space-Modulation).
    This paper describes a comparison of the characteristics (THDi (Total Harmonic Distortion of the input-current), the power factor and reducing dc-inductor's inductance) between buck and buck-boost high-power-factor converters with PSM. The buck-boost converter has many advantages over the buck converter in the input-current waveform, power factor and reducing dc-inductor's inductance. To illustrate the validity of the theory, experimental results obtained from a 1.2[kW] setup and computer simulation results are shown.
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  • Fumiyasu Suzuki, Yoichi Hori
    2001 Volume 121 Issue 7 Pages 792-798
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In this paper, the anti-windup strategy for two degree of freedom (TDOF) control system is proposed. In TDOF control system, the input saturation can be avoided by designing the suitable command response property for nominal model. In real controlled systems, however, the input saturation may occur because of unknown disturbance or plant variation. The proposed method can suppress the windup phenomena by modelling the limiter into TDOF controller and adjusting the limitation between feedback and feedforward control. The proposed anti-windup controller (AWC) has the form of left coprime factorization of feedback and feedforward controllers. The proposed method is evaluated by simulation and experiment of position control system of DC servo motor.
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  • Hitoshi Hasegawa, Toshiaki Murai, Takashi Sasakawa
    2001 Volume 121 Issue 7 Pages 799-804
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In the superconducting maglev system it is important to develop a non-contact on-board power source without environmental pollution such as noise and exhaust gas. For this purpose many on-board power sources have been studied, such as fuel cells, ram-air turbine generators, and linear generators. We have studied linear generators as the most realistic system.
    In the combined-type linear generator, much eddy current losses and vibrations occur in the superconducting magnet, because the linear generator coils are attached to the surface of the superconducting magnet. This paper describes the influence of these eddy current losses and vibrations by numerical analyses and measurements of bench tests. It can be considered that there is little effect of load loss in operating the combined type linear generator.
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  • Hideki Ohguchi, Ryo Shimotaya, Toshihisa Shimizu, Hiroyuki Takagi, Mic ...
    2001 Volume 121 Issue 7 Pages 805-813
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper proposes a novel 13.56MHz current source high frequency inverter based on immittance conversion topology. One of the most distinctive characteristics of immittance conversion topology is that the voltage source is converted into the current source and vice versa. Some components contained in rectangular waveform are converted by utilizing immittance conversion element of distributed constant line type. When the operation frequency of the voltage source inverter is set to 4.52MHz, the voltage source with third harmonic frequency on the voltage source inverter, 13.56MHz component, is converted to the current source by the effect of immittance conversion element with the length λ/4. By utilizing these principles, 13.56MHz current source high frequency inverter is derived. The experimental results from a prototype system verify the theoretical procedure.
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  • Manabu Sasaki, Kazuo Shima, Kazumasa Ide, Haruo Koharagi, Miyoshi Taka ...
    2001 Volume 121 Issue 7 Pages 814-820
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In this paper we present a method for calculating torque of a permanent magnet synchronous motor considering magnetic saturation. The proposed method uses two-dimensional numerical magnetic field analysis and dq-axes equations in which the effect of the cross-magnetizing phenomenon is included. First we calculate reactances of the permanent magnet synchronous motor at every step of changing rotor position using this method. And we consider the cause of variations of the reactances. Secondly we separate torque by factors using the results of the reactances. The findings are as follows.
    (1) Numerical values of the mutual reactances between d-and q-axis Xdq are not negligible.
    (2) The reactances vary according to the rotor position because the parts of magnetic saturation are different.
    (3) Torque caused by magnetic coupling between d- and q-axis circuits can be calculated.
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  • M. Yamamoto, E. Hiraki, M. Nakaoka
    2001 Volume 121 Issue 7 Pages 821-822
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper presents a novel type of 3-level 3-phase voltage-fed soft switching inverter with two new Auxiliary Resonant DC Link (ARDCL) snubbers topologies which can operate under a condition of Zero Voltage Switching (ZVS). The feasible operating performances of the proposed soft switching inverter using IGBT module which is more suitable for power systems applications is evaluated on the basis of its experimental results.
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  • H. Yamamoto, H. Iwamoto, M. Yoshida, E. Hiraki, M. Nakaoka
    2001 Volume 121 Issue 7 Pages 823-824
    Published: July 01, 2001
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper presents a three phase voltage source space voltage vector modulated soft switching inverter using bridge leg-side active auxiliary resonant commutation snubbers (ARCS) with a high frequency pulse current transformer which is designed for power regeneration to DC source, along with its performance evaluations under a digital servo control scheme.
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