IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 117 , Issue 4
Showing 1-21 articles out of 21 articles from the selected issue
  • Yoichi Muraoka
    1997 Volume 117 Issue 4 Pages 403-404
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Masazumi Tsubakizaka
    1997 Volume 117 Issue 4 Pages 405-407
    Published: March 20, 1997
    Released: December 19, 2008
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  • Takeiki Aizono, Hirosi Wataya
    1997 Volume 117 Issue 4 Pages 408-410
    Published: March 20, 1997
    Released: December 19, 2008
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  • Fusao Sawachika
    1997 Volume 117 Issue 4 Pages 411-412
    Published: March 20, 1997
    Released: December 19, 2008
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  • Toshiya Ohnuki
    1997 Volume 117 Issue 4 Pages 413-419
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Line-current harmonics generated by semiconductor power converters and other nonlinear loads in power systems have undesirable influence such as overheating on the power apparatuses. This is one of the most important problems to be solved in electrical engineering in recent years. To reduce or eliminate such harmonics, active power filters (APF) tend to be used as a promising solution to the problems. It is, however, pointed out that faster response is required in APF's in order to improve the current distortion and the transient performance when the load changes.
    In this paper, a new single-phase APF with a predictive-instantaneous-current PWM controller is proposed. The controller predetermines a pulsewidth at the beginning of each switching period and controls the switching devices of the APF so that the total power factor approaches unity and the line-current harmonics are reduced. The controller can be composed of digital or analog circuits. This paper deals with an analog-technique approach. Four different control schemes are discussed: the basic control scheme and its modifications with a linear extrapolation method and/or a method with a double pulsewidth composed of double-frequency sampling. These schemes effectively improve the line-current waveform and the transient performance of the APF for abrupt changes of the load.
    This paper describes the control schemes, implements the controller, and discusses the performance characteristics of the APF. The usefulness of the proposed methods is verified by computer simulation and experiment.
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  • Koji Toyama, Osamu Mizuno, Takaharu Takeshita, Nobuyuki Matsui
    1997 Volume 117 Issue 4 Pages 420-426
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    As a high performance current-source three-phase AC/DC converter, the PWM control is promising to achieve a unity power factor and to improve the input current distortion. In contrast to the voltage-source converter, the LC filter connected between the source and the converter may cause a LC resonance both in steady and transient states. Many reports have been published to improve the current distortion in steady state and to suppress the current oscillation in transient state of the current-source PWM converter.
    The paper gives an analysis of voltage oscillation of the filter voltage and proposes the suppression approach for the current-source three phase PWM AC/DC converter. The effectiveness of the proposed approach has been verified by experiments.
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  • Takashi Kosaka, Yo-ichi Taniguchi, Nobuyuki Matsui
    1997 Volume 117 Issue 4 Pages 427-433
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The comparative studies on the torque characteristics of the reluctance motor for bi- and uni-polar sinusoidal drives are given. The 3-phase test motor with 6/8 stator and rotor pole combination is used for the non-linear FEM analysis and experiments. The analysis shows that the different flux paths are produced, depending on bi-and uni-polar current drives, which makes two significant differences in torque-current characteristics. Since the unipolar current drive produces shorter flux path and, therefore, higher air gap flux density, higher torque for the given winding current can be expected. Another important point is the effect of magnetic saturation. The examination of the yoke flux with respect to various rotor angles suggests the yoke is apt to be saturated in the bipolar current drive.
    The experimental verification has been made by using the test motor. From these experiments and analysis, it is concluded that the unipolar sinusoidal current drive is preferred to have a linear relation between torque and current and to avoid the effect of magnetic saturation.
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  • Toshihisa Shimizu, Tsutomu Fujita, Gunji Kimura, Jun Hirose
    1997 Volume 117 Issue 4 Pages 434-442
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The generation of harmonics and their subsequent propagation into power line is a topic of increasing concern to power supply authorities. To prevent obstacles on the power system, Unity-Power-Factor PWM converter is going to apply to AC-DC power conversion plant. However, PWM converter, especially at single phase circuit, has some serious defects, that is low frequency ripple current which flows into the DC line and low frequency ripple voltage which appears on the DC output In usual case, it is necessary to connect a very large capacitor or a passive L-C resonant circuit to the DC line for the reduction of low frequency ripple voltage. However, in case of the Batteries are connected with the DC output, most of the DC ripple current flows into the Battery even if previous circuits are used because the impedance of the Battery is very low compared with that of previous circuit. The low frequency ripple current cause power loss on the Battery and the temperature has risen. It is well known that the life of the Battery is deeply influenced by the temperature. The ripple current, therefore, should be reduced to as possible as low.
    To accomplish the reduction of the low frequency ripple current, a novel topology of the PWM rectifier is presented in this paper. The main circuit is constituted by adding only a pair of switching devices to conventional PWM converter circuit. With simple control technique, the ripple energy on the DC line is converted into the stored energy on the input AC capacitors though the additional switches. The theoretical characteristics are obtained by using statespace-averaging-method. The effect of the ripple reduction is confirmed by experiments using a bread board set-up.
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  • Toshiyuki Fujii, Masato Koyama
    1997 Volume 117 Issue 4 Pages 443-448
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The circulating current type cycloconverters have been applied to large capacity motor drive systems. A coupling of load current exists in the circulating current control loop, and deteriorates the control performance. In this paper, the circulating current control using rotational reference frame is proposed to suppress the coupling. The frequency of the fundamental component of the coupling is twice that of load. In addition, the circulating current is usually regulated to a constant dc current. Authors have, therefore, applied the rotational reference frame synchronized with twice frequency of load to the circulating current control for a three-phase cycloconverter. The main component of the coupling can be compensated by the feedback control without the decoupling control. The effect of the proposed control scheme is confirmed by the digital simulation of an induction motor drive system.
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  • Shinji Tominaga, Hideaki Fujita, Hirofumi Akagi
    1997 Volume 117 Issue 4 Pages 449-455
    Published: March 20, 1997
    Released: December 19, 2008
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    This paper discusses the potential of applying the soft-switching technique to a dc voltage-controlled static var compensator. The main circuit of the static var compensator (SVC) consists of quad-series voltage-source six-step inverters and four three-phase transformers. The SVC is characterized by a “commutation capacitor” connected in parallel with each switching device, without any additional active or passive element. The commutation capacitor plays an essential role in achieving soft-switching.
    Experimental results obtained from a small-rated laboratory model of 10kVA verify the operating principle and effectiveness of the soft-switched SVC proposed in this paper. The zero-voltage-switching enables to reduce dv/dt across each switching device, thus resulting in reduced EMI and switching losses.
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  • Makoto Iwasaki, Yoshiaki Kitoh, Nobuyuki Matsui
    1997 Volume 117 Issue 4 Pages 456-462
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Solid friction in various machines is one of dominant nonlinearities limiting the control performance of servo drive systems. Nonlinear friction gives tracking errors and undesired stick-slip motion due to stiction (breakaway friction) and/or Stribeck effect. A wide variety of studies have been reported, which formulated nonlinear friction models, identified its parameters, and compensated for the friction. Those compensation schemes can significantly improve the conventional control performance, however, deterioration of the control accuracy is still the problems due to the inaccurate friction model and/or the restricted bandwidth of the compensation control loop.
    This paper presents the disturbance observer-based compensation for nonlinear friction in servo drive systems to improve the control performance. The proposed scheme uses a new disturbance observer which is designed on the basis of Coulomb friction characteristics. This scheme can realize the precise speed/position control without response delay which is caused by the restricted bandwidth in the conventional compensation scheme. Experimental results and analytical studies show the distinct performance improvement of the proposed scheme, comparing to the conventional compensation schemes.
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  • Yasuhiko Neba
    1997 Volume 117 Issue 4 Pages 463-469
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A converter-inverter fed induction motor system is widely used for many industrial applications, and a PWM strategy is employed to obtain sinusoidal inputs and outputs. For a railway and a air-conditioner etc., a single-phase PWM converter is often utilized. In the single-phase system, the dc voltage and current are pulsated by the power variation with twice the ac power source frequency. In result, the output waveforms of the inverter are distorted and then a beat phenomenon of an induction motor. The theoretical examinations of this system necessitate complicating the calculations because of the PWM operations of the converter and the inverter.
    This paper proposes a model for the single-phase PWM converter and deals with the three-phase PWM inverter-induction motor drive system. The models for the voltage source type and the current source type PWM converters, first of all, are given. Next, the inverter-induction motor system is analyzed by employing the model, and the experimental and the calculated waveforms are shown. Finally, the results at the beat operation of the motor are given. A close agreement between the measured and the theoretical results prove the validity of the proposed models for the PWM converters.
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  • Michihiro Yamashita, Masashi Furuya, Toshiaki Murata, Takeshi Tsuchiya
    1997 Volume 117 Issue 4 Pages 470-478
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Induction motor is expressed as a nonlinear system on a synchronously rotating reference frame. In applying linear control theory, we have usually derived a linear approximated model with a specific operating point. However, the model obtained by this method is not much accurate.
    In this paper, we derive a linearized model for induction motor from a magnetic energy point of view. In this linearized model, the torque and the stored energies in the rotor field are choosen as state variables, and these magnetic energies are decoupled. This suggests that torque-producing component current and flux-producing conponent current become decoupled. Availability of a control system used the linearized model is illustrated by simulation and experiment results.
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  • Taro Yamamoto, Kazuo Bekki, Ken Nagakura, Koichiro Sawa
    1997 Volume 117 Issue 4 Pages 479-486
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The automotive electronic fuel pump is installed inside a fuel tank or on the way of a tubular fuel line due to the introduction of reduced displacement. Therefore, a small d. c. motor operating the fuel pump has a distinctive feature that its commutation is carried out in gasoline. That is to say, the commutation arc of this motor ignites in gasoline environment.
    Since there are few literatures dealing with the commutation arc in liquids and some trouble with the fuel delivery system directly affect vehicle's running performance itself, it is significant to make clear properties of commutation arc in gasoline. In the previous letter, basic electrical properties of commutation arc in gasoline such as the residual current, the arc duration and the arc voltage were measured and compared with those in air. In this paper, relationship between these electrical properties is calculated with a circuit equation and is in accordance with measured values. Moreover, we conclude that a contact resistance variation before arc ignition determine the smaller residual current in gasoline and, by means of the spectroscopic measurement, hydrogen dissociated from gasoline is related to the increased arc voltage in gasoline.
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  • Susumu Torii, Takeshi Yoshimura, Masaya Watada, Daiki Ebihara
    1997 Volume 117 Issue 4 Pages 487-492
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently, complicated transport system is demanded in the field of factory automation for the reduction of labor in large-scale factory. Linear synchronous motor can produce large thrust force and high speed. Linear synchronous motor was not suitable for the long stroke transport system which needs high positioning precision and high speed simultaneously. The problem in improving the positioning precision is the large detent force arisen by permanent magnet. We analyzed the static thrust and detent force using FEM. Generally, if detent force is enough smaller than static thrust force, high positioning precision can be achieved.
    We investigated the mechanisms of detent force generation. As the results, we proved that detent force is generated by the thrust caused by the difference between the magnet end and the tooth. We proved that if the width of the permanent magnet is too wide, the total detent force can be estimated by the superposition of each detent force. As the results of the study, we developed the method of design to reduce the detent force of permanent magnet linear synchronous motor. The detent force is reduced to 0.6 per cent of the maximum thrust force.
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  • Yasutaka Fujimoto, Atsuo Kawamura
    1997 Volume 117 Issue 4 Pages 493-500
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes a new robust control of robot manipulators, which guarantees the robust stability against fluctuation of inertia matrix. In this control, the inertia matrix is calculated as computed torque from the Newton-Euler formulation. As the result, the cut-off frequency of the sensitivity function call be set much higher than one of conventional control systems such as disturbance observer based decentralized robust control system.
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  • Shinji Wakao, Takashi Onuki, Fuyuki Ogawa
    1997 Volume 117 Issue 4 Pages 501-506
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In recent years, the application of optimization methods coupled with magnetic field analysis is receiving ever increasing attention, and a large number and variety of methods have been proposed. For instance, the optimization of shield placement and its geometric boundaries has been of great interest in the area of rapid transit system, medical service adopting superconducting magnets, etc. The optimal design is categorized into sizing optimization, shape optimization, and topology optimization. Generally the topology optimization is effective for lightening the investigated model. However, there are few papers conceming with the topology optimization in which it is difficult to define design variables.
    In this paper we propose the novel approaches to the 3D optimal design of magnetic shields, in which both the shape and topology optimization are implemented. We try to lighten the magnetic shield maintaining its shielding ability by using the hybrid finite element and boundary element method combined with the genetic algorithm. Finally some numerical results which demonstrate the validity of the proposed approaches are presented.
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  • Kinjiro Yoshida, Shigehiro Yoshida, Hiroshi Takami
    1997 Volume 117 Issue 4 Pages 507-512
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Thrust and lift forces in controlled-PM linear synchronous motor (LSM) can be analyzed exactly by using FEM, taking into account the effect of slots. Especially in the controlled-PM LSM Maglev vehicle, large slots are adopted to manufacture quite easily its long-stator guideway. But a vast CPU time is required for FEM simulations of the vehicle dynamics. A method for calculating the thrust and lift forces is presented here which can keep high accuracy of finite element analysis (FEA) and reduce extremely the CPU time. Two-dimensional interpolation of this method is derived on the basis of analytical formulas and FEA of the machine. It is shown from numerical example of 1/2-scale controlled-PM LSM Maglev vehicle that the method proposed here enables us to calculate the thrust and lift forces with the same accuracy as FEM.
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  • Kinjiro Yoshida, Lee Ju, Shogo Matsumoto
    1997 Volume 117 Issue 4 Pages 513-518
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Maglev starting of the controlled-PM (Permanent-Magnet) LSM (Linear Synchronous Motor) Maglev carrier which has five degrees of freedom exclusive of propulsion motion is investigated theoretically and experimentally. The 3D-FEA (Finite Element Analysis) interpolation is proposed for including that lateral force related with sway and yawing motions which is obtained numerically by 3D-FEA. In vehicle dynamics simulation with Maglev starting, the method is of practical use for calculating 3-dimensional forces of thrust, lift and lateral ones, with extremely small CPU time. The modelling is verified experimentally under an integrated robust-control of Maglev starting of the carrier with lateral-motion.
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  • Yoshinobu Nakamura, Motoyasu Mochizuki, Fuminori Ishibashi
    1997 Volume 117 Issue 4 Pages 519-525
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The authors propose the new brushless DC motor for pump with large airgap, 8mm, as compared with conventional gap 1mm. The conventional pump system is composed an induction motor, a magnetic coupling and a magnet rotor with the vane. This rotor is transmitted a revolution power by the magnetic coupling. In new motor, the rotor of the motor has the vane without magnetic coupling. The airgap is very large in order to equip the seal between the stator and rotor. The seal protects stator coil against liquid, such as water and chemical material. The performance of the motor were analyzed by FEM and compare with experimental results. The analyzed results agreed with experimental results with good accuracy. In the experiments using a 4-pole 0.75kW test motor and high-efficiency drive inverter with power factor control, the motor efficiency was about 88%, and the motor power factor was about 98%.
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  • Yasuyuki Nishida, Mutsuo Nakaoka
    1997 Volume 117 Issue 4 Pages 526-527
    Published: March 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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