IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 127, Issue 4
Displaying 1-14 of 14 articles from this issue
Paper
  • —Motor Volume Minimization of IPM Motor for Low-Speed, High Torque Applications—
    Yoshiaki Kano, Takashi Kosaka, Nobuyuki Matsui
    2007 Volume 127 Issue 4 Pages 349-359
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    Interior Permanent Magnet Synchronous Motors (IPMSM) have been found in many applications because of their high-power density and high-efficiency. The existence of a complex magnetic circuit, however, makes the design of this machine quite complicated. Although FEM is commonly used in the IPMSM design, one of disadvantages is long CPU times.
    This paper presents a simple non-linear magnetic analysis for a multi-pole IPMSM as a preliminary design tool of FEM. The proposed analysis consists of the geometric-flux-tube-based equivalent-magnetic-circuit model. The model includes saturable permeances taking into account the local magnetic saturation in the core. As a result, the proposed analysis is capable of calculating the flux distribution and the torque characteristics in the presence of magnetic saturation. The effectiveness of the proposed analysis is verified by comparing with FEM in terms of the analytical accuracy and the computation time for two IPMSMs with different specifications. After verification, the proposed analysis-based optimum design is examined, by which the minimization of motor volume is realized while satisfying the necessary maximum torque for target applications.
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  • Masaaki Ohshima, Katsuhisa Inagaki, Hirofumi Shinohara
    2007 Volume 127 Issue 4 Pages 360-367
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    In this paper, the authors present the system configuration and control scheme of a dispersed power source equipped with quick backup function, which acts as a dispersed power source when there exists no fault in commercial power network and functions as a backup power supply in case of a fault of the network. If a fault, e.g., a voltage interruption occurs on the network, the dispersed power source disconnects critical loads from the network in an instant, and continues supplying power to the loads. We also discuss the method of disconnecting power network sufficiently quick when some fault occurs on the network, adopting non-gate-turn-off devices such as thyristors to the ac interconnecting switches. Since it takes only 2 milliseconds to disconnect the loads from a faulted network, there bring no negative effects on the loads. Simulations and experimental tests are carried out to confirm the practicability of the proposed power source.
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  • Keiju Matsui, Isamu Yamamoto, Guan Erdong, Masaru Hasegawa, Kenji Ando ...
    2007 Volume 127 Issue 4 Pages 368-374
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    For small capacity rectifier circuits such as those for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies to improve these effects have been presented so far. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. The authors had proposed a power factor correction scheme using a LC resonance in commercial frequency without switching devices. This method makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency. It is found that the output high voltage can be obtained easily by means of LC resonance in this PFC circuit, whose dc output voltage becomes even ten times ac input voltage and the like. In this paper, the results are reported and confirmed by the theoretical and experimental implementations.
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  • Yukimori Kishida, Akihiko Iwata, Yuzuru Yonehata, Hajimu Yoshiyasu, Ko ...
    2007 Volume 127 Issue 4 Pages 375-381
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    The converter in the Yamanashi Maglev system, which has PWM inverters connected in series via output transformers, has some points to be improved. One is that the transformers are costly and require a large space the other is that a large filter is required to suppress the zero sequence current. In this paper, we propose a gradationally controlled voltage inverter without transformers for the Maglev system. It has one set of three-phase, 3-level inverters and three sets of 7-level, single-phase inverters, which are connected in series. It can output 21 gradational voltage levels and can suppress the zero-sequence voltage which causes the zero sequence current. We at first explain the principle, features, and expected problems of the inverter system. Then we demonstrate the generation of a gradationally controlled voltage with an experimental inverter model. Finally, we explain how to suppress the changeover voltage surge which occurs at the point when changing the level. We conclude that the gradationally controlled voltage inverter without transformers will be useful for the Maglev system.
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  • Kazuaki Mino, Yasuyuki Nishida, Johann W. Kolar
    2007 Volume 127 Issue 4 Pages 382-390
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    A novel injection scheme to improve the input current harmonics of a hybrid 12-pulse line-interphase-transformer rectifier with controlled output voltage by a two-switch boost-type output stage is presented in this paper. A theoretical derivation of the modulation for achieving purely sinusoidal input currents is introduced. Finally, the proposed scheme is analyzed and verified by numerical simulations and experimental results.
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  • Tamio Okutani, Nobuyuki Nakamura, Natsuki Terada, Mitsuyoshi Fukuda, Y ...
    2007 Volume 127 Issue 4 Pages 391-399
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    In this paper we report advancement of an analysis method for electromagnetic screening effect of mountain tunnel with a multiple conductor circuit model. On A.C. electrified railways it is a great issue to manage the influence of electromagnetic induction caused by feeding circuits. Tunnels are said to have a screening effect to reduce the electromagnetic induction because a large amount of steel is used in the tunnels. But recently the screening effect is less expected because New Austrian Tunneling Method (NATM), in which the amount of steel used is less than in conventional methods, is adopted as the standard tunneling method for constructing mountain tunnels. So we measured and analyzed the actual screening effect of mountain tunnels constructed with NATM. In the process of the analysis we have advanced a method to analyze the screening effect more precisely. In this method we can adequately model tunnel structure as a part of multiple conductor circuit.
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  • Jun Enomoto, Jun-ichi Kitano, Haruo Ikeda, Yukimori Kishida, Akihiko I ...
    2007 Volume 127 Issue 4 Pages 400-405
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    We are developing a gradationally controlled voltage inverter without output transformers for LSMs in the Maglev Line. In this paper, we propose a space vector active cancellation method for the zero-sequence voltage to make it compatible with the forming sinusoidal wave. We explain the algorithm of this method, and demonstrate that the output voltage is compatible with the forming sinusoidal wave and that the THD of current is below 5% under the experimental conditions of few voltage levels and at low frequency. Also, the zero-sequence current was reduced to 10% in the inverter model with the active cancellation method.
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  • Kenichi Iimori, Katsuji Shinohara, Kichiro Yamamoto, Atsushi Morigami
    2007 Volume 127 Issue 4 Pages 406-411
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    This paper describes the approaches to suppressing the shaft voltage and bearing current by electrostatic shielding the stator end windings of the brushless DC motor driven by PWM inverter. At first, measured shaft voltage and bearing current are compared with those calculated waveforms to verify the common mode equivalent circuit of the brushless DC motor. Next, relationship between shaft voltage and stator winding to rotor capacitance is calculated using the common mode equivalent circuit. Finally, the electrostatic shielding of the stator end windings is evaluated to reduce the shaft voltage by experiments and calculations.
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  • Hiroyuki Takanashi, Shuichi Adachi
    2007 Volume 127 Issue 4 Pages 412-419
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    This paper describes an interface for a system identification device on which system identification theory is implemented. A basic system identification procedure includes following steps; 1) collecting I/O data, 2) preprocessing the I/O data, 3) executing identification algorithm and constructing a model, and 4) validating the estimated model. System identification produces different results depend on various identification conditions. This results in a diversity of system identification. On the other hand, the diversity makes system identification problems more complex. The system identification device supports the user, in particular beginners, who execute above processes. The device utilizes MATLAB as a main processing software with a GUI in order to deal with the system identification processes visually. The system identification device is one of the most desireble ways to standardize system identification operations.
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  • Tadanao Zanma, Akira Yamakaji, Muneaki Ishida
    2007 Volume 127 Issue 4 Pages 420-427
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    In real systems, there exist physical constraints such as voltage limitations imposed on actuators or state restriction due to their structure. Vilotation constraints in systems may cause instability, or in the worst case, result in malfunction. In this paper, a switching algorithm of multimodal controllers in switched systems is proposed. The method is based on the model predictive control. Both simulation and experimental results illustrate the effectiveness of the proposed method.
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  • Akira Tozune, Toru Takeuchi, Masafumi Sakamoto
    2007 Volume 127 Issue 4 Pages 428-434
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    This paper is concerned with the improvement of performance of claw pole type PM stepping motor. First, alternating torque and cogging torque of claw pole PM stepping motor are analyzed in relation to the harmonic components of winding currents and field flux, and the causes of generation of torque variation and their variation frequency are clarified.
    Based on the above analytical results, the method for decreasing these torque variation is discussed, and the double 2 phase PM stepping motor is proposed, in which 2 sets of 2-phase PM motors are connected so that the generated variation torque of both motors may be canceled each other.
    It becomes clear that the double 2 phase PM stepping motor not only brings small alternating torque and small cogging torque but also improves step accuracy and pull-out characteristics.
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  • Daigo Tagami, Susumu Torii
    2007 Volume 127 Issue 4 Pages 435-440
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    The magnetic levitation technology has advantage according to flawless, high-speed and no dust, because it is non-contact. The electro dynamic suspension (EDS) is used for JR-Maglev and transportation of non-magnetic conductor. In EDS, it is important to obtain the characteristic about lift force. By the existing analysis technique, it is difficult to consider the influence of the skin effect within a conductor and electromagnetic force between gaps. The analysis that considers these is possible by the use of a three-dimensional finite element method. However, a long calculation time is needed. In this paper, the rectifying method used for the existing analysis technique is proposed. The validity is verified from examination of an experiment result and an analysis result.
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  • Hiroki Ishikawa, Takayuki Furuno, Satoru Kambe, Haruo Naitoh
    2007 Volume 127 Issue 4 Pages 441-450
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    The spherical solar cells are claimed to have some advantageous characteristics superior to those of the ordinary planar solar cells. The most significant one is that the spherical solar cells have no directivity to light. This paper examines the characteristics based on geometrical consideration. It is proved that a single spherical cell has no directivity as a whole. In practical use, many cells are used in an array configuration, where an individual cell receives the shadows casted by other cells around it. The adjacent shadows, so named in this paper, causes directivity. Their effects are evaluated geometrically and the theoretical consideration is verified by experiments.
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  • Masaki Yamada, Akihiko Iwata, Yoshihiro Hatakeyama, Yasuhiro Ishii
    2007 Volume 127 Issue 4 Pages 451-456
    Published: April 01, 2007
    Released on J-STAGE: July 01, 2007
    JOURNAL FREE ACCESS
    A new voltage sag compensator with a gradationally controlled voltage inverter which exceeds SEMI F47 standard has been developed. It consists of a gradationally controlled voltage inverter in which inverters are connected in series and are charged at different voltages to each other, and which outputs the sum of each output voltage. This system is small and with an extremely low loss.
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