IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 130, Issue 12
Displaying 1-30 of 30 articles from this issue
Paper
  • Hirohito Funato, Tomoyuki Sakurai, Satoshi Ogasawara
    2010 Volume 130 Issue 12 Pages 1283-1289
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    Recently, global warming has become a major problem. Therefore, the development of technologies for generating clean energy without producing CO2 is required. Micro-hydroelectric power generation is one of the promising options as it requires small simple facilities, and a stable output. The authors have proposed a new system for generating micro-hydroelectric power. The proposed system has a simple mechanism and high efficiency. The proposed system was tested in a real river; however, it was very difficult to study all the characteristics of the system, including those of the hydraulic turbine, because it was very difficult to vary the water flow in a real river. In this paper, the authors propose a new test facility for micro-hydroelectric generation systems. In this system, water flow is generated using a general-purpose pump that can be used to increase pressure of the water flow in order to simulate a head. The fundamental characteristics of the proposed system are determined using the proposed facility and a water head between 1m and 10m and water flow of up to 500L/s. The study of the test facility is very useful in developing high-efficiency micro-hydroelectric generation system.
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  • Takaharu Takeshita, Shuta Ishikawa, Yusuke Andou
    2010 Volume 130 Issue 12 Pages 1290-1297
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    This paper presents the instantaneous effective value theory for selecting the PWM pattern of matrix converters. The two PWM patterns that realize the references of both the output voltage and the input current during the control period are obtained. For the real-time selection of the PWM pattern, the instantaneous effective value theory is developed. The proposed theory can be applied to evaluate the harmonics of the PWM waveforms. For suppressing the output voltage harmonics, the PWM pattern corresponding to a lower instantaneous effective value of the output voltages is selected. The effectiveness of the proposed method for selecting PWM pattern by using the instantaneous effective value has been verified by performing experiments.
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  • Takemasa Furuya, Kenichi Ogawa, Takamitsu Yamamoto, Hitoshi Hasegawa
    2010 Volume 130 Issue 12 Pages 1298-1306
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    A hybrid control system has two main functions: power sharing and equipment protection. In this paper, we discuss the design, construction and testing of a drive control method for an autonomous decentralized hybrid train with 100-kW-class fuel cells (FC) and 36-kWh lithium-ion batteries (Li-Batt). The main objectives of this study are to identify the operation status of the power sources on the basis of the input voltage of the traction inverter and to estimate the maximum traction power control basis of the power-source status. The proposed control method is useful in preventing overload operation of the onboard power sources in an autonomous decentralized hybrid system that has a flexible main circuit configuration and a few control signal lines. Further, with this method, the initial cost of a hybrid system can be reduced and the retrofit design of the hybrid system can be simplified. The effectiveness of the proposed method is experimentally confirmed by using a real-scale hybrid train system.
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  • Ryohei Kitada, Hirofumi Akagi
    2010 Volume 130 Issue 12 Pages 1307-1314
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    This paper discusses a 6.6-kV next-generation BTB system in which bidirectional isolated dc/dc converters are combined with modular multilevel cascade converters. The system consists of N converter cells cascaded in each phase at both front ends. Each converter cell consists of a bidirectional isolated dc/dc converter and two voltage-source H-bridge PWM converters. This circuit configuration can be adopted to significantly reduce harmonic voltages and currents because the voltage steps are extremely low. In a conventional power conversion system, bulky line-frequency transformers are employed. On the other hand, in the present system, light and compact high-frequency transformers are used for providing galvanic isolation. Thus, the overall physical size and weight are reduced. The authors design, construct, and test a single-phase 120-V, 3.3-kW downscaled model with N=3, in order to verify the feasibility and effectiveness. The downscaled model helps to develop an operable 6.6-kV system with focus on control and performance.
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  • Byungjin Yoo, Katsuhiro Hirata, Atsurou Oonishi
    2010 Volume 130 Issue 12 Pages 1315-1322
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    In this study, a coupled analysis method for flat panel speakers driven by giant magnetostrictive material (GMM) based actuator was developed. The sound field produced by a flat panel speaker that is driven by a GMM actuator depends on the vibration of the flat panel, this vibration is a result of magnetostriction property of the GMM. In this case, to predict the sound pressure level (SPL) in the audio-frequency range, it is necessary to take into account not only the magnetostriction property of the GMM but also the effect of eddy current and the vibration characteristics of the actuator and the flat panel. In this paper, a coupled electromagnetic-structural-acoustic analysis method is presented; this method was developed by using the finite element method (FEM). This analysis method is used to predict the performance of a flat panel speaker in the audio-frequency range. The validity of the analysis method is verified by comparing with the measurement results of a prototype speaker.
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  • Yoshihiro Maeda, Makoto Iwasaki
    2010 Volume 130 Issue 12 Pages 1323-1332
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    This paper presents a novel initial value compensation (IVC) method based on rolling friction characteristics for the precise positioning of linear motor-driven table systems. Rolling friction in mechanism behaves as a nonlinear elastic element in the micro displacement region, and deteriorates the positioning performance with a slow settling response. In order to improve the positioning performance, the overshoot response, which results in the slow settling response, should be suppressed during the positioning. In this study, therefore, IVC based on the specified step settling control framework is employed to achieve the required settling performance without the slow settling response. The effectiveness of the proposed IVC has been verified by experiments performed using a prototype of an industrial positioning device.
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  • Shigeo Masukawa
    2010 Volume 130 Issue 12 Pages 1333-1340
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    A new method for reducing harmonics in the output voltage of a three-phase voltage source inverter is proposed. This method is applied to a conventional six-step inverter with a three-phase output transformer. In the proposed inverter, two capacitors are used as dc source; further, four auxiliary switching devices and a single-phase transformer are included in the inverter, and harmonics are injected to the neutral point of the three-phase transformer. As a result, the output voltage of the proposed inverter becomes almost equal to that of a conventional 18-step inverter, which has 18 switching devices and three three-phase output transformers.
    In this paper, the circuit performances and output voltage waveforms are discussed, and the optimum parameters are determined by taking into account the effect of harmonics reduction. Then, the characteristics of an inverter system connected to a grid are experimentally investigated. Furthermore, the ratings of several components are clarified by the theoretical results.
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  • Kohei Isozaki, Hirofumi Akagi
    2010 Volume 130 Issue 12 Pages 1341-1348
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    This paper describes a hybrid active filter for harmonic-current compensation of a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage motor drive system. This hybrid filter is characterized by the direct series connection of a simple LC filter and a small-rated active filter. This circuit configuration brings low cost, small size, and light weight to the hybrid filter. The authors design, construct, and test a three-phase experimental system rated at 400V and 15kW, which is a downscaled model of the medium-voltage motor drive system. In this experiment, the LC filter is tuned to the 11th harmonic frequency, and the active filter is based on a three-level diode-clamped PWM converter with a dc capacitor voltage as low as 28V. This hybrid filter is connected on either the first or fourth winding of a line-frequency transformer with a first Δ-winding voltage of 400V in the primary, and a second Δ-winding voltage of 220V, a third Y-winding voltage of 220V, and a fourth Δ-winding voltage of 400V in the secondary. Experimental results show that the hybrid filter performs satisfactory filtering in a range from the no-load to full-load conditions.
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  • Hiroyuki Shoji, Junpei Uruno, Masayuki Isogai
    2010 Volume 130 Issue 12 Pages 1349-1355
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    In this paper, we present a novel circuit topology for achieving thezero-voltage switching (ZVS) operation in a high-frequency inverter. The output power of the inverter is regulated over a wide range using a pulse widthmodulation (PWM) technique and by connecting a bypass circuit to a conventional single-ended push-pull (SEPP) high-frequency inverter for induction heating. All the switching devices of the proposed inverter are operated in the ZVS mode.
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  • Hajime Nakajima, Kazuhiko Sumi, Hiroshi Inujima
    2010 Volume 130 Issue 12 Pages 1356-1362
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    When the rectangular slit of an optical encoder projects an image, the containment of higher-order components in the projected image depends on the gap distance. Therefore, we performed the Fourier series expansion of the function describing Fresnel diffraction pattern to obtain a simple relational expression that can show the relation between the gap distance and the containment of each order component and then carried out an experiment to verify the obtained expression. Using this expression, we found that certain orders of the wave components disappear depending on the slit opening ratio and also that the use of a slit with an opening ratio smaller than 0.5 results in lesser distortion of the waveform over a wide range of gap values. Reduction of waveform distortion over such a wide range can prevent increment of errors caused by shaft displacement in the axial direction and assembly errors. Thus, robust performance of the encoder can be achieved. The results of this study are expected to be useful in the design of robust optical encoders.
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  • Takayuki Hasegawa, Takaharu Takeshita
    2010 Volume 130 Issue 12 Pages 1363-1370
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    This paper presents a PWM strategy for minimizing the output voltage harmonics of matrix converters. The authors previously proposed a PWM strategy. In this strategy, the number of commutations in all three phases during the control period can be reduced to four. In this paper, by using the detected output current values for calculating the duty cycles, the continuously varying duty cycles for a control period are developed. The algorithm for selecting the duty cycles in order to minimize the output voltage harmonics is derived. The effectiveness of the proposed PWM strategy has been verified by performing simulations.
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  • Toshikazu Horiuchi, Kazumasa Kawashima
    2010 Volume 130 Issue 12 Pages 1371-1377
    Published: December 01, 2010
    Released on J-STAGE: December 01, 2010
    JOURNAL FREE ACCESS
    Wireless electric power transmission systems are suitable to spread electric vehicles, because non-contact charging systems are convenient tools. Such charging systems recharge automatically without intervention from drivers. In this paper, the results of experiments on the transmitting and receiving antennas of the wireless power transmission systems are presented. To study wireless power transmission efficiency, horn antennas, patch antennas, and array antennas were fabricated and evaluated.
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