IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 117 , Issue 8
Showing 1-19 articles out of 19 articles from the selected issue
  • Toshiyuki Furuie, Ken Takanashi
    1997 Volume 117 Issue 8 Pages 921-926
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (2589K)
  • Ricardo Y. Igarashi, Isao Takahashi
    1997 Volume 117 Issue 8 Pages 927-932
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The development of fast and low cost switching devices resulted in large use of high frequency power sources also in small equipments for home use. The capacitor input type rectifier is widely used in such equipments owning to simple configuration and high efficiency, but the effect of the harmonics present in its input current to the power system is becoming not negligible. Therefore, rectifiers with sinusoidal input current is strongly desired. The authors proposed a new rectifier topology named dither rectifier, which achieves over 99% power factor with few modifications to conventional circuits, in both power circuitry and controller. In this paper, the various configurations and control methods that can be used in the dither rectifier are presented. Three experimental circuits are also presented, using different configurations.
    Download PDF (1296K)
  • Akio Seki, Toru Akahoshi, Yoshichika Tanaka, Tsutomu Furuki
    1997 Volume 117 Issue 8 Pages 933-939
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper treats of the system safety evaluation method applied to the superconducting maglev system at its design stage. The maglev system is a large-scale system under development and required to achieve high safety as a public transportation system. Taking account of these features, the maglev system should be evaluated at its design stage and their results should be considered into the design. The authors propose a new system safety evaluation method, referring to the conventional standards, criteria and methods for railways, aviation, nuclear power plants and so on. This method consists of two ways: evaluation of the compliance with the system safety design criteria and evaluation in hazard reports based on analysis of scenario of accidents assumed. With these two ways, the maglev system is evaluated thoroughly from viewpoints of not only inherent safety function, but also personnel's operation and countermeasures to natural disasters. As a result, the method contributes much to eliminating various kinds of hazardous elements causing serious accidents; collision, derailment, fire and fatality.
    Download PDF (1645K)
  • Hisao Kubota, Daisuke Yoshihara, Kouki Matsuse
    1997 Volume 117 Issue 8 Pages 940-945
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The vector control method is widely used for induction motor drives. In these applications, a rotational transducer such as a shaft encoder is used. A rotational transducer, however, cannot be mounted in some cases such as motor drives in a hostile environment, high speed motor drives, etc. Several sensorless vector controlled induction machine drive methods have been proposed. These methods have a disadvantage that the rotor resistance variation causes the estimation error of the motor speed. It is difficult to estimate the motor speed and the rotor resistance simultaneously, because the equivalent rotor resistance is the ratio between the rotor resistance and the slip under steady states. Therefore, we have proposed a method of estimating simultaneously the motor speed and the rotor resistance of an induction motor by superimposing AC components on the field current command. This paper presents a modified method of the rotor resistance adptation. The validity of the proposed method is verified by the experimentation.
    Download PDF (1204K)
  • Bin Kaku, Ichirou Miyashita, Satoru Sone
    1997 Volume 117 Issue 8 Pages 946-954
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In recent years, due to the benefits of high efficiency and saving energy, induction motors fed by inverter have been widely used. Because of the distorted output waveform of an inverter, the magnetic noise emitted from the motor is becoming a serious environment problem. To reduce the magnetic noise, the harmonic current must be depressed. Raising the switching frequency of an inverter is a very efficient method to reduce the harmonic current, but it can only be used for high switching speed devices like IGBT's, and another problem of switching loss occurs as the switching frequency is raised.
    This paper proposes a new PWM method that can be used to reduce the harmonic current. The integrated area of the differences between the locus of ideal flux vector and the actual flux vector can be considered as the total harmonic current RMS value. The proposed new PWM method determines the vector output timing to let the integrated area to be minimum. For the evaluation of low acoustic magnetic noise, the motor acoustic magnetic noise vs. harmonic current characteristic curve is defined, and a new kind of acoustic magnetic noise evaluating method based on this characteristic curve is proposed. At the end of this paper, the experimental results are shown to verify the effectiveness of the proposed method.
    Download PDF (1007K)
  • Yoichi Ikeda, Tadashi Inoue
    1997 Volume 117 Issue 8 Pages 955-961
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The idea of 2nd-order delta-sigma modulated inverter is applied to the control of parallel-connected multiple voltage-source PWM inverters and single-phase PWM inverter bridges. A single 2nd-order integral feedback controller (PI-I controller) accommodates all the unit inverters or the half bridges in the system. The control is expected to take full advantage of the switching bandwidth increased by the multiplication of unit inverters, as the loop-gain, which governs the contorl performances such as disturbance rejection, is roughly proportional to the squared band-width. The synchronization condition for the output multi-level PWM pulse to triangular carrier signals is derived and tested. The suppressing ability of disturbances is compared with a current-feedback system. The characteristics of the control are tested in an experimental study.
    Download PDF (1414K)
  • Hisaichi Irie, Haruhisa Yamana
    1997 Volume 117 Issue 8 Pages 962-969
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    An immittance converter has fine performance in many power electronics applications. Its function is to convert voltage sources into current sources and current sources into voltage sources. The immittance converter has an input impedance that is proportional to the admittance of loads connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source. When an immittance converter operates at a resonant frequency and is inserted to high-frequency link systems, voltage source outputs turn into current source outputs and current source outputs also turn into voltage source outputs. Some power electronics applications of this converter are photovoltaic inverters, DC-DC converters with a constant current output.
    It is well known that the quarter-wavelength transmission line shows immittance conversion characteristics. However, it has very long line length for its switching frequency (e. g., 20kHz), and is not suitable for power electronics applications. So we propose five immittance converters that consist of lumped elements L, C and show immittance conversion characteristics at a resonant frequency. Those immittance converters are much smaller and lighter than the transmission line. Its principles, basic circuits, and basic characteristics are described in this paper. And more we evaluate them to apply to high-frequency link systems of power electronics.
    Download PDF (1395K)
  • Toshihiro Koyama, Tohru Umebayashi, Takayuki Yamamoto
    1997 Volume 117 Issue 8 Pages 970-979
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The road-traffic flow causes tunnel vetilation load. It changes seasonally and year by year and so the tuning of tunnel ventilation systems takes a lot of time. With these points as background, this paper proposes a online-learning type of ventilation control system. This system uses two types of neural networks. One is NNVI (Neural Network for VI control) which learns the change of VI (Visibility Index) successively. The other is NNAF (Neural Network for Air-Flow control) which learns the change of air-flow successively. NNVI also outputs control instructions to keep VI higher than a permissible level in parallel with the above learning. NNAF also outputs the ventilation control instructions to keep air-flow higher than a permissible level so that air-flow does not turn over. This paper describes the construction of the proposed ventilation control system and the automatic learning method. And using the dynamic digital simulator it shows the estimation results of the control performance based on the road-traffic flow data.
    Download PDF (1268K)
  • Toshihiro Koyama, Yoshikazu Ohba, Shigehito Shimada, Hideki Ueno
    1997 Volume 117 Issue 8 Pages 980-985
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In expressway, there exist a lot of requirements for traveling time prediction as the information on express way traffic-flow. It is a problem to be solved to predict traveling time with high accuracy in case traffic-flow changes dynamically like the beginning or the end of traffic congestion. It is therefore important to make the trafficsimulation model using time-series data by vehicle detectors. In this case, it is necessary to cope with secular change of traffic-flow characteristics like constructions of new expressways or environment condition changes. Thispaper proposes the new traffic-flow prediction system which has the model learning function by time-series data processing. The system makes the relation model between traffic density and vehicle velocity using neural networks. The neural networks is used as on-line learning model VENN(Vehicle velocity Estimation model on Neural Network). The system simulates the traffic-flow using the VENN and predicts traveling time using the simulation results. The proposed system was already estimated in the actual expressway, which ended in satisfactory results.
    Download PDF (1201K)
  • Yoshiyuki Shibata, Nuio Tsuchida, Koji Imai
    1997 Volume 117 Issue 8 Pages 986-991
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We have developed a unique induction motor that has free rotating magnets inside its rotor. In the experimental results of a prototype motor, we have obtained superior performance over existing motors in terms of the power factor, efficiency and output torque. The experimental details are as follows. The power factor of the test motor is significantly improved as compared with that of conventional induction motor. The power factor can be controlled to be unity, leading or lagging by changing the line frequency and/or source voltage. It is quite a unique feature, because the power factor of usual induction motor is always lagging. The improvement of the power factor becomes effective not only against the decrease of the current loss but against the decrease of voltage drop in line and the increase of installation capacity. The efficiency of the motor, over a wide output power range, is remarkably higher than that of the same size conventional induction motor. Actually, in ordinary induction motor, the efficiency is reduced as the power and/or the source voltage is decreased. However, the proposed motor is driven in the high efficiency by lower source voltage at lower range of power. The efficiency is improved by reducing the secondary current and the magnetizing current.
    Download PDF (1443K)
  • Hiroyuki Mikami, Kazumasa Ide, Satoshi Kikuchi, Haruo Koharagi, Miyosh ...
    1997 Volume 117 Issue 8 Pages 992-1000
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes a method to analyze hamonic magnetic fields on squirrel-cage induction motors considering rotor skew and higher harmonics in the secondary current. The proposed method is based on a 2-dimensional finite element method. The rotor skew structure is considered by plural 2-D finite element mesh models, produced in suitable axial positions, and the magnetic field in each mesh model is calculated by the revised secondary current taking account of the skew effect.
    The secondary currents, magnetic flux densities and electromagnetic forces are calculated by the proposed method. Then the differences between a skew rotor and a no-skew rotor are discussed. From the comparison between calculated and experimental results, the proposed method is shown to be appropriate and useful for quantitative estimation of harmonic components on induction motors.
    Download PDF (2562K)
  • Shingo Kitamura, Yoshiyuki Ishihara, Toshiyuki Todaka, Yoshiaki Inoue
    1997 Volume 117 Issue 8 Pages 1001-1007
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper we propose an analytical method of DCBLM with the polar anisotropic plastic rotor magnet. The orientation of the polar anisotropic plastic magnet is different each place.
    In our method, the magnetic flux distribution of injection mold for polar anisotropic plastic magnet is analyzed by FEM first. Next, the orientation is decided from the magnetic flux distribution. Finally, based on it, non-linear dynamic magnetic field of DCBLM is analyzed. The analysis value gave good agreement with the experiment value of magnetic flux distribution in the magnet unit and the characteristic of DCBLM.
    Download PDF (1042K)
  • Masayuki Nashiki, Akiyoshi Satake, Yoichi Kawai, Takanori Yokochi, Shi ...
    1997 Volume 117 Issue 8 Pages 1008-1014
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Torque ripple reduction methods of synchronous reluctance motors are studied in this paper. The first method is to distribute magnetic circuits generated by a slit rotor at pitches of (π+1/2•slit pitch, π-1/2•slit pitch) . The second one is to distribute them at pitches of (π+2/3•slit pitch, π-1/3•slit pitch). The third one is the vernier construction which is used in induction motors. And the forth one is the skew construction . These methods are analyzed by the finite element method. They are also studied experimentally. As the results, these methods are shown to be very effective to reduce torque ripples.
    Download PDF (1521K)
  • Kotaro Higashi, Shunsuke Ohashi, Hiroyuki Ohsaki, Eisuke Masada
    1997 Volume 117 Issue 8 Pages 1015-1023
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The damping characteristic of the bogie motion is one of the most important issues to be investigated in the superconducting magnetically levitated system based on the Electrodynamic Suspension (EDS). We have therefore studied the damping characteristics and the mechanism of magnetic damping. Electric circuits consisting of coil resistances and inductances can describe the electromagnetic behavior of the levitation system. By numerical calculation based on the electric circuit equations combined with the equations of motion, damping characteristics of the bogie are examined for the system consisting only of levitation coils and superconducting coils and also for the configuration with magnetic shielding structures incorporated. Furthermore, paying attention to the energy balance in the levitation and propulsion system when the bogie is forced to oscillate sinusoidally, we have investigated the relation between the input energy and the running speed and compared the waveforms of levitation force and bogie oscillation to consider the characteristics and the mechanism of the damping.
    Download PDF (1816K)
  • Shinji Shinnaka
    1997 Volume 117 Issue 8 Pages 1024-1032
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper presents a new adaptive vector control scheme for inverter-fed induction motors. The scheme proposes new system structure consisting of two subsystems for adaptive vector control, a vector control system realized on synchronous frame and a parameter identification system on stationary frame. Proposed adaptive identification system can perform in different rate from that of the control system, which adaptively identifies motor parameters varying dynamically with temperature and magnetic saturation and determines critical parameters of vector control system. The high performance of the proposed scheme verified by a real drive system is also shown.
    Download PDF (1766K)
  • Koji Toyama, Takaharu Takeshita, Nobuyuki Matsui
    1997 Volume 117 Issue 8 Pages 1033-1038
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    PWM control is promising to achieve a unity power factor and to improve the input current distortion in a high performance current-source three-phase AC/DC converter system. In contrast to the voltage-source converter, the LC filter connected between the source and the converter may cause an 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 by using the feedback control.
    This paper gives an analysis of the transient oscillation of the filter voltage and current, and proposes a simple open-loop suppression method by using the rate limiter of the input current reference. Furthermore, the design rule of the LC filter for the suppression control of the transient oscillation is described. The effectiveness of the proposed approach has been verified by experiments.
    Download PDF (1384K)
  • Hiromasa Higasa, Masanori Yamashita, Makoto Hirose
    1997 Volume 117 Issue 8 Pages 1039-1040
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (1062K)
  • Kansuke Fujii, Junji Kondoh, Shunji Tsuji-Iio, Ryuichi Shimada
    1997 Volume 117 Issue 8 Pages 1041-1042
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (1654K)
  • Takanori Sugita, Jun-ichi Kawai, Yukihiko Sato, Teruo Kataoka
    1997 Volume 117 Issue 8 Pages 1043-1044
    Published: July 20, 1997
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (1167K)
feedback
Top