IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 114 , Issue 4
Showing 1-20 articles out of 20 articles from the selected issue
• Isao Somiya
1994 Volume 114 Issue 4 Pages 353-356
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
• Chobei Yamabe, Eiji Sakai
1994 Volume 114 Issue 4 Pages 357-361
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
• Sigeki Nakayama, Nariko Shinriki
1994 Volume 114 Issue 4 Pages 362-369
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
• Tomotsugu Kubota, Genjiro Wakui, Hiroyuki Mikami
1994 Volume 114 Issue 4 Pages 370-376
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
As the rotor ring of a hysteresis motor becomes tihck, the magnetic field inside the rotor ring is expressed by an elliptic rotating field in general. For the motor of the thick ring, or the multipolar, and also permeability of the rotor ring is very small, the field inside the rotor ring becomes an elliptic rotating field, and becomes a circular rotaing field in the extreme case. In this paper, two calculation methods in which the elliptic rotating field is considered are proposed. In the first method, the actual elliptic rotating hysteresis loss is replaced with the equivalent circular rotating hysteresis loss which is equal to the elliptic one. The motor characteristics are calculated from the equivalent circuit of this circular rotating hysteresis. In the second method, the magnetic constants of the rotor ring for the elliptic rotating field, for example, a permeability, a hysteresis angle, are determined. The former is determined from the equivalent circuit of the alternating field, the latter is determined from the elliptic rotating hysteresis loss. This method is one proposed newly by this paper. The motor characteristics are calculated from the equivalent circuit of the elliptic rotating field. From the comparison between the calculated and experimental results, it is clear that the first method is useful when the axial ratio of the elliptic rotating field inside the rotor ring is from 0.8 to 1, and that the second method is useful when the field configuration inside the rotor ring is the ellipse in general.
• Kazumasa Ide, Haruo Koharagi, Miyoshi Takahashi, Yukiyoshi Yanagisawa, ...
1994 Volume 114 Issue 4 Pages 377-386
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
This paper describes a useful analyzing method of saturatable magnetic flux flowing in rotating machines which considers higher harmonic sequences. Conventional analysis based on permeance distributions can calculate higher harmonic flux, however, it can not easily analyze saturatable higher harmonic flux quantitatively. The numerical field analysis method can calculate higher harmonic flux under the saturatable condition. But numerical approaches need large computation times generally, and they are not suited to consideration of the mechanism of higer harmonic generation under the saturatable condition. In order to analyze quantitative higher harmonic sequences of magnetic flux under the saturatable condition for practical use, an analysis based on permeance distribution is needed.
The authors propose a practical method for analysis of higher harmonic seqences of the saturatable magnetic flux quantitatively. They are calculated by generation of saturatable permeance distribution quantitatively. The analytical results show good agreement with the experimental results and confirm the ability and usefullness of the method for analyzing saturatable characteristics of the magnetic flux distribution.
• Tomohiro Yoshikawa, Takeshi Furuhashi, Yoshiki Uchikawa
1994 Volume 114 Issue 4 Pages 387-392
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
For computer aided design (CAD)/design automation (DA) for printed circuit board (PCB), automatic placement of parts has been strongly needed. It is, however, very difficult to realize the automatic placement, since the parts have wide variety in size and these parts should be placed under various constraints.
This paper studies a method of placement on the PCB using genetic algorithm (GA). This paper also studies an application of a new representing method for maintaining diversity of chromosomes to the GA. Simulations are done to show the feasibility of the new automatic placement method. A chromosome is converted into multiple phenotypes by the methods.
• Yasuyuki Shirai, Tanzo Nitta, Toshikazu Shibata, Syuichi Yajima, Takao ...
1994 Volume 114 Issue 4 Pages 393-399
Published: April 20, 1994
Released: December 19, 2008
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Energy transfer circuits between two superconducting magnets have been proposed, discussed and tested. We have studied on power supplies for superconducting magnets which consists of a small power converter, a superconducting magnet for an energy storage, and an energy transfer circuit of inductor converter bridges (ICB). We derived analytical solutions on the basic characteristics of ICB energy transfer circuits. In this paper, from the analytical solutions, a new control method of ICB trasnsfer circuit to reduce voltage ripples across a load superconducting magnet is proposed and discussed. Availabilities of the proposed control method are confirmed by the computer simulations.
• Haruyuki Kometani, Shigekazu Sakabe, Yoshihiro Jizo, Motoaki Terai
1994 Volume 114 Issue 4 Pages 400-408
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
For the practical design of the superconducting magnet for high speed trains, the heat encroachment to the liquid helium and the mechanical deformation of the magnet must be solved.
Our purpose is the estimation of very small Joule loss in the liquid helium vessel and magnetic force distribution caused by the ‘6-th harmonics’ flux from the ground coils for levitation. To estimate this small loss and magnetic force distribution accurately, a big scale 3-dimensional analysis considering the complex structure is necessary. However, the full model of the magnet couldn't be analyzed. The conventional thin conductor approximation method cannot solve this model accurately, because the vacuum vessel is thicker than its skin depth.
In this paper, by using the finite element method with edge elements and EWS mounted full memory 512MByte, the small loss, magnetic force distribution and eddy current phase varying on thickness of the vacuum vessel is solved accurately.
• Tadashi Iokibe, Takasi Kimura, Kazuyuki Aihara
1994 Volume 114 Issue 4 Pages 409-414
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
One of the possible applications of the chaos theory for engineering is nonlinear short-term prediction. Hetherto, many prediction methods have been proposed. But most of them are based upon linear theories. Therefore, it is difficult to obtain high performance when timeseries is produced by nonlinear dynamics. In this paper, we apply deterministic nonlinear short-term prediction to timeseries data of water demand. As a result, this paper shows timeseries data of water demand have structure of a possible attractor, and prediction accuracy by deterministic nonlinear short-term prediction is higher than that by a typical conventional prediction method with an autoregression method combined with Kalman filter.
• Tetsuo Yamada, Masayuki Mori, Yasuhiro Yoshida, Masaaki Date
1994 Volume 114 Issue 4 Pages 415-423
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
In the speed control system of motors using the low resolution rotary encoder, the period of the encoder pulses becomes longer than that of the speed control at the very low speed region. It gets impossible to obtain the accurate speed information in the period of the speed control.
So we suggest an easy speed estimating method at the very low speed region using the least order disturbance observer that has been used widely. And we investigate an estimating method of the motor inertia that especially affects the speed estimation.
This paper shows these principle of the method, the simulation result and the experimental one. It makes it clear that the characteristics of the speed control at the very low speed region is improved by using the least order disturbance observer.
• Instantaneous Speed Observer and Identification of the Inertia Moment
Yoichi Hori, Hiroaki Kamei
1994 Volume 114 Issue 4 Pages 424-431
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
Due to the recent development of DSP (Digital Signal Processors), we can control a servomotor with a very short sampling period, e. g. 100 [μs]. The speed information is usually calculated from the increased pulse number of a shaft encoder within one sampling period. However, in this simple method, the speed resolution in lower speed range is easily lost. If we use a longer sampling period for maintaining the speed resolution still high, the system will be unstable. To overcome this problem, we proposed the instantaneous speed observer to estimate the instantaneous speed at every 100μs sampling point and greatly improved the system stability. Also, we realized the disturbance rejection control using the disturbance observer inherently included in the speed observer. However, this speed observer needed the exact value of the inertia moment. In this paper, we propose an identification method of the inertia moment by applying some adaptive methods. We implemented the basic least square method, the recursive least square method and the fixed trace method, and compared their identification performances. We realized the stable operation of the speed observer. Further, we designed STR (Self Tuning Regulator) type speed controller by feeding back the identified inertia moment for further performance improvement. The proposal in this paper is one suggestion to combine the robust and adaptive methods in servo motor control.
• Teruo Azukizawa
1994 Volume 114 Issue 4 Pages 432-437
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
In a superconductive electrodynamic suspension system, superconducting coils experience space harmonic magnetic field generated by induced current in the levitation coils installed along the guideway. Current in a superconducting coils varies to keep the total magnetic flux constant when the coil is exposed in an external magnetic field. However, superconducting coil current was treated as constant in the conventional analysis, because the electromagnetic forces can be estimated easily.
The purpose of this paper is to know the behaviour of the persistent current to make reliable and tough superconducting magnets. A simple method to analyze fluctuating persistent current in a superconducting coil is proposed at first. Calculated results for the normal running condition showed that the fluctuations of persistent current is less than 1% of the initially excited current for the side-wall levitation system, and less than 2% for ground levitation coil system. Even when the null flux guidance cable is short-circuited, the fluctuation is less than 5%. Considering that the magnetic shield effects by the conductive cryostat vessels was neglected in this analysis, the fluctuating magnetic field by levitation coils will never affect stability for a superconducting magnet.
• Shigeyuki Funabiki, Hitoshi Komatsubara, Takashi Kanbara, Koichiro Tan ...
1994 Volume 114 Issue 4 Pages 438-443
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
The operating frequency of the inverter based on the resonant performance is fixed at the resonant frequency. Then, it is difficult to regulate the output voltage because the switch-on and -off time can not be set in an arbitrary manner. Therefore, the authors propose the control method of active use of the short-circuit mode to the voltage resonant type of push-pull high-frequency inverter circuit. The characteristics of the proposed inverter are carried out with analytical and experimental manner. The results of the theoretical steady-state analysis agree well with those in the experiment. The circuit efficiency is more than 90% in the wide control range.
Further, the inverter is applied to the lighting circuit of electric-discharge lamp. In the lighting circuit made on an experimental basis, the wide range of output control from 83 V to 113 V of the supply voltage and the stable lighting of electric-discharge lamp can be achieved. Then, the circuit efficiency can be obtained over 88%.
Thus, the proposed high-frequency inverter by using the short-circuit mode is proved to be of much practical use.
• Naoya Eguchi, Mitsutoshi Yamamoto, Kazuya Endo, Shigeo Konishi, Toshih ...
1994 Volume 114 Issue 4 Pages 444-450
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
In recent years, power demand has considerably increased, and there is the need to improve the quality of electric power, such as voltage change and three phase voltage unbalance. Static var compensators have been used for suppressing the disturbance of power distribution lines in mainly industrial fields and now the application is going to be expanded to rail way systems and power transmission systems(1)_??_(3). A conventional static var compensator is a naturally commutated one consisting of thyristor controlled reactors. Recently, self-commutated static var compensators have started to be used in practical applications, and the largest capacity of the self-commutated static var compensators reaches to 100 MVA(4)(5). They have the ability of quick and flexible control to compensate reactive power.
This paper describes the control system for self-commutated static var compensators to suppress three phase voltage unbalance as well as line voltage change. The features of the SVC control system are as follows.
(1) Independent current control of positive-phase and negative-phase sequence components.
(2) P-Q decoupling control
The authors have examined the SVC control system by an experimental model and verified the satisfied characteristics.
• Toshihiko Tanaka, Hirofumi Akagi
1994 Volume 114 Issue 4 Pages 451-458
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
Harmonic interference problems generated by bulk semiconductor power converters become more serious in power systems as they are widely used in industrial applications. Shunt passive filters consisting of LC tuned filters or shunt active filters using PWM inverters have been used to suppress harmonic currents in distribution systems. In order to install the passive or active filters, it is necessary to exactly find a dominant harmonic source in distribution feeders. A harmonic power on each phase and order at a receiving terminal has been investigated by using a digital power meter including an FFT analyzer. However, the conventional detection method has such a problem that it is difficult to exactly discuss harmonic power flow because the detected harmonic power is much smaller compared with a fundamental active power at the receiving terminal. In this paper, the harmonic power in three phases, which can be detected on real time, is defined by applying the pq theory. Next, it is verified by a digital simulation that the proposed method can discuss harmonic flows more easily than the conventional method. As a result, it is more simple and precise to find the harmonic source. Moreover, measurement errors of the harmonic power is revealed quantitatively, and the validity of the proposed method is demonstrated by digital simulation.
• Hideaki Fujita, Chikashi Sato, Satoshi Ogasawara, Hirofumi Akagi
1994 Volume 114 Issue 4 Pages 459-465
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
The purpose of corona discharge treaters using high frequency inverters is to render the affinity of polyethylene films to inks, glues and coatings. A frequency control scheme for such a high frequency inverter has been proposed to achieve the power control of a corona discharge treater. It is, however, impossible to realize zero current switching except for full-power operation. Partial discharge appears in the frequency control scheme under the condition of a low power because the applied voltage between electrodes is decreased as the output power is reduced.
This paper presents a 30kHz 5kW voltage-source inverter using IGBTs for corona discharge treaters, which is characterized by the power control based on pulse density modulation (PDM). Although the voltage-source inverter operates at a constant dc voltage and a constant output frequency, the average output power can be controlled by adjusting a period ratio of the square wave pulse having a constant amplitude to zero voltage. The PDM inverter can always operate with zero current switching, so that switching losses and electromagnetic noises are reduced. The prototype system developed in this paper shows good corona discharge characteristics in a wide output power range from 0.5% to 100%, which makes it possible to realize both strong and weak surface treatment.
• Yositsugu Okamura, Hirotami Nakano, Akira Nabae
1994 Volume 114 Issue 4 Pages 466-467
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS
• Sei Arai, Hirotami Nakano, Akira Nabae
1994 Volume 114 Issue 4 Pages 468-469
Published: April 20, 1994
Released: December 19, 2008
JOURNALS FREE ACCESS