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Volume 118, Issue 4
Displaying 1-18 of 18 articles from this issue
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Tatsuo Take1998 Volume 118 Issue 4 Pages 431-436
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (3648K) -
Shogo Tanaka, Nobuyuki Takeuchi1998 Volume 118 Issue 4 Pages 437-443
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDepending on the size and weight of the load being transferred, various types of cranes are used in industry. Many attitude measurement and control systems for crane lifters have been developed. These systems are mainly used to suppress swings of the lifters when the trolleys come to a stop. To improve the efficiency, however, not only the measurement of attitude but also the exact load position is important. Therefore, is developed, for a cylindrical object such as an iron-plate coil, an automatic sensing system which uses fiber optical gyros and range sensors to measure the swing of the lifter and the load position.View full abstractDownload PDF (1627K) -
Tsutomu Mizuno, Toshihito Miyashita, Hisashi Yajima, Yu Qi Tang, Hideo ...1998 Volume 118 Issue 4 Pages 444-449
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSLinear DC motors (LDMs) are widely used for servo-actuator, compressor and so on. High-efficiency LDMs are strongly desired for compressors. To realize the LDMs with high-efficiency characteristics, decreasing the copper losses, namely, thrust-to-input ratio, F/P, must be increased. This paper describes an optimization method for the F/P of a moving coil type LDM. The following results are obtained:
(1) Simplified expression for the F/P of the LDM is derived from the permeance analysis method. The effects that dimensions of the LDM influence the F/P of the LDM are investigated through the simplified expression for the F/P. As a result, the optimum dimension of the LDM for maximizing the F/P exists.
(2) When the static thrust is 100 N, the measured F/P of the initial LDM is 7.9 N/W, and the errors by using the simplified expression for the F/P and the finite element method (FEM) are 33% and 8%, respectively. Derived simplified expression for the F/P is useful because the F/P can be calculated easily.
(3) An improved LDM, which has 26% higher F/P than those of the initial LDM, is designed by using the permeance analysis method and the FEM.View full abstractDownload PDF (1451K) -
Mutuwo Tomita, Hideyuki Yamaguchi, Shinji Doki, Shigeru Okuma1998 Volume 118 Issue 4 Pages 450-459
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSSensorless starting and low speed drive of a cylindrical brushless dc motor with un-known load have been a difficult problem because an electro-motive force does not arise enough at the starting and at low speeds and an inductance is constant irrespective of rotor position. In this paper, it is proposed to paste non-magnetic material and to measure a voltage of an opened phase to realize sensorless starting and low speed drives. The method is shown very feasible by experiments.View full abstractDownload PDF (1497K) -
Norihisa Yanagihara, Takao Terayama, Kazuo Sakai, Nobuyoshi Oowada1998 Volume 118 Issue 4 Pages 460-467
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe moment of inertia of the tape reel of VTR varies depending on the reel size and the volume of the tape winding around the reel. Due to the variation, the tension control of the tape in the reel-to-reel drive is difficult.
To overcome this problem, the paper presents a new method to identify the tape reel without using additional sensors. Based on this identification scheme, the tape transport control is also presented to achieve the precise tension/speed control.
This real-time identification approaches are presented for spinning and running. When the tape reels start spinning up, the tape speed is changed stepwise, by which the inertia of the reel can be estimated using the variation of the tape tension at each reel. The process is repeated to improve the accuracy of identification. Under running condition, the changing inertia can be calculated from the tape radii of two reels. The changing tape radius can be detectable with the speed of capstan.
The validity of the proposed method has been approved by experiments using VTR.View full abstractDownload PDF (1460K) -
Shin-ichi Motegi, Akeshi Maeda, Yasuyuki Nishida1998 Volume 118 Issue 4 Pages 468-473
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSIn recent years, a wide variety of high-power-factor converter schemes have been proposed to solve the harmonic problem. The schemes are based on conventional boost, buck or buck-boost topology and their performance, such as output voltage control range in the boost and buck topology or efficiency in the buck-boost topology are limited. To solve this, the authors propose a single-phase high-power-factor converter with a new topology obtained from a combination of buck and buck-boost topology. The power stage performs the buck and buck-boost operations by a compact single stage converter circuit while the simple controller/modulator appropriately controls the alternation of the buck and buck-boost operation and maintains a high quality input current during both the buck and buck-boost operations. The proposed scheme results in a high performance rectifier with no limitation of output voltage control range and a high efficiency. In this paper, the principle and operation of the proposed converter scheme are described in detail and the theory is confirmed through experimental results obtained from a 2 [kW] prototype converter.View full abstractDownload PDF (2793K) -
Optimization of Robust Stability based on Quadratically Stabilized ControlKoji YAMADA, Satoshi KOMADA, Muneaki ISHIDA, Takamasa HORI1998 Volume 118 Issue 4 Pages 474-479
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSA high order disturbance observer can realize a fast and precise servo system with simple structure, which has low-sensitivity to parameter variation and disturbance. However, the conventional design methods for the disturbance observer can hardly satisfy specifications for the robust stability and the relative stability for parameter variations. On the other hand, a quadratically stabilized control design method based on LQ design theory satisfies those specifications. The weight matrices design in LQ design theory, however, is not systematic. In this paper, we propose a simple design method for the quadratically stabilized servo system using high order disturbance observer, which satisfies the robust stability and realizes the optimal relative stability for parameter variations. We then apply this strategy to the design of a position servo system, such as a linear drive table with inertia variation, and realize the robust stability optimized servo system.View full abstractDownload PDF (1507K) -
Shuichiro Kobayashi, Yoshiyuki Sakamoto, Akihiro Nagaiwa, Tadashi Naka ...1998 Volume 118 Issue 4 Pages 480-490
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDistrict heating and cooling (DHC) plants are appointed a mission to provide always enough heated or cooled water economically for time variable demand. Especially for the DHC Plant using electricity, it is important to use electricity in night time, and to cut using electricity in peak time in day time. To perform it, solving of the scheduling problem for plant operation is required.
This kind of DHC plant operation scheduling problem is represented as an integer programming (IP) one. For solving the IP problem including discrete variables takes much time for on-line use in many cases. In this paper, a method of solving IP problem for scheduling DHC plant operation in practical time for on-line use, using Genetic Algorithm (GA) is proposed. Also, the effectiveness is discussed by simulation examination.View full abstractDownload PDF (2509K) -
Masahito Ikeda, Susumu Aiba1998 Volume 118 Issue 4 Pages 491-500
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThere are some problems in many separately controlled, large scale thyristor converters/inverters on the same electric power system. This paper proposes a new method for canceling the existing electric current harmonics by installing a “current harmonics canceler” on the thyristor converter/inverter. The current harmonics canceler cancels the two current harmonics through phase angle control between the power source angle and the converter/inverter angle, and through control of the voltage level of the converter/inverter. The characteristics of harmonics at the initial phase angle were analyzed in the cases of 6 pulse and 12 pulse converter models by digital computer simulation. As the result of the simulation, we found the existing current harmonics were canceled by installing the “current harmonics canceler” on the thyristor converter/inverter. Further more, we found that the application of it is limited due to the phase angle difference between two current harmonics.View full abstractDownload PDF (2056K) -
Takashi Sasakawa, Naoto Tagawa, Toshiki Herai, Masaru Tomita1998 Volume 118 Issue 4 Pages 501-510
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSMagnetic shielding is an important task for superconducting magnetically levitated train. We previously proposed optimal design method of magnetic shielding for minimazation of magnetic shield weight. In this paper, we report the test result of the magnetic shielding facility based on the optimal design method. We can atain magnetic flux density less than 2mT in the region surrounded by magnetic shield, whose weight is lighter than any other test facility constructed previously.View full abstractDownload PDF (1451K) -
Hisaji Fukuda1998 Volume 118 Issue 4 Pages 511-517
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThanks to various countermeasures taken railway crossing accidents have decreased generally. Recently, however, many accidents are happening caused by cars violating the gate, posing a serious problem. Various proposals for improvement of the situation include, “fixed time control” and “crossing-mechanization with traffic signals”, in addition to better visibility, but to be effective and efficient they must be submitted to preliminary assessment of their effect. We aim to realize a system which increases safety and harmonizes rail-road traffic by crossing gate control considering not only rail-side but also road-side.
The paper suggests several methods for quantitatively evaluating the effects of “fixed time control” and “crossing-mechanization with traffic signals” by a simulation considering the road traffic. “Fixed time control” is highly useful with a capacity of calculating different variations for the effect. In the simulation of “crossing control with signal linked to the road traffic”, the result is generally consistent with reported record at an actual crossing. Moreover, conditions for crossing signal are selectively based on simulation taking combined rail-road traffic conditions as parameters.View full abstractDownload PDF (3323K) -
Dehong Xu, Junpei Baba, Eisuke Masada, Hiroyuki Ohsaki1998 Volume 118 Issue 4 Pages 518-524
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSA novel multi modular GTO current source converter structure is presented to application to superconducting magnetic energy storage system. N_??_N converters are arranged in a array form. The GTO current source converter array with appropriate arrangement of modulation and carrier signals can output large power with high quality line current waveforms. With using of only N transformers, 6N2 pulse number converter performance is obtained. Only low switching of GTO is required since PWM is primarily used as a method to control flow of power instead of reducing harmonics. It is compared with conventional direct paralleled multi modular converter structure. The results of simulation are presented in this paper.View full abstractDownload PDF (1488K) -
Satoru Inarida, Mizuguchi Nobuaki, Wataru Miyake, Takashi Hariyama, Ka ...1998 Volume 118 Issue 4 Pages 525-533
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSPower converter systems using GTOs (Gate Turn Off thyristors) are widely used as traction systems for Shinkansen trains. However, it is difficult to reduce harmonic currents of a catenary line, acoustic noise from a transformer and motors of the traction systems, because of the relatively low switching frequency of GTOs.
This paper proposes a three level power converter system using IGBTs (Insulated Gate Bipolar Transistors) for Shinkansen trains. This system is capable of reducing the harmonic currents of the catenary line, and the acoustic noise, because of the relatively high switching frequency of the IGBTs and the three-level output voltage of the converters. The power converter was installed in the STAR21 (Superior Train for the Advanced Railway toward the 21th Century) which is a high speed testing train for the Shinkansen routes of JR East (East Japan Railway Company). The superiority of the new power converter system was verified by test results.View full abstractDownload PDF (3845K) -
Fumio Kitahara, Takao Iwamoto, Satoshi Ito, Kazunori Fujiwara, Michio ...1998 Volume 118 Issue 4 Pages 534-541
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSEast Japan Railway Company (JR EAST) has developed advanced transport operation control system supporting super high-density railway in Tokyo metropolitan area. The system target is to revolutionize existing railway operation and to realize new safe and high efficient railway system. Autonomous Decentralized Transport Operation Control System has many features, including safe and steady traffic control, improved customers service and step by step system construction used by autonomous decentralized system technology. The system has been already introduced to Chuo-line in December of 1996 and is now under construction to expand to all of Tokyo metropolitan area.View full abstractDownload PDF (2004K) -
Tadashi Fukami, Sigeo Hashimoto, Toshio Miyamoto1998 Volume 118 Issue 4 Pages 542-547
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSIn this paper, the authors propose a new form of a self-excited single-phase induction generator with a self-regulating feature. The generator's circuit connection, its operating principles, and a method for predicting its steady-state performance, using the method of symmetrical coordinates, are presented. The proposed generator employs a delta-connected squirrel-cage three-phase induction machine, with two excitation capacitors across two-phase terminals of its stator winding. A series capacitor and a single-phase load are also connected across the terminals of the other phase. By selecting the values of the excitation and series capacitors properly, improved voltage regulation can be automatically obtained. The generator's steady-state performance is theoretically predicted using the presented analytical method, and confirmed through experiment.View full abstractDownload PDF (1251K) -
Yoshihiro Konishi, Naoya Baba, Mutsuo Nakaoka1998 Volume 118 Issue 4 Pages 548-549
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
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Shinji Shinnaka1998 Volume 118 Issue 4 Pages 550-551
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
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Hirofumi Kiyotake, Hidehiko Okada, Kouichi Ishizaka, Ryozo Itoh1998 Volume 118 Issue 4 Pages 552-553
Published: April 01, 1998
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (1256K)
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