IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 128 , Issue 2
Showing 1-12 articles out of 12 articles from the selected issue
Paper
  • Takeshi Konishi, Shin-ichi Hase, Yoshinobu Nakamichi, Hidetaka Nara, T ...
    2008 Volume 128 Issue 2 Pages 85-93
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    Interest has been shown in the concept of an energy storage system aimed at leveling load and improving energy efficiency by charging during vehicle regeneration and discharging during running. Such a system represents an efficient countermeasure against pantograph point voltage drop, power load fluctuation and regenerative power loss. We selected an EDLC model as an energy storage medium and a step-up/step-down chopper as a power converter to exchange power between the storage medium and overhead lines. Basic verification was conducted using a mini-model for DC 400V, demonstrating characteristics suitable for its use as an energy storage system. Based on these results, an energy storage system was built for DC 600V and a verification test conducted in conjunction with the Enoshima Electric Railway Co. Ltd. This paper gives its experimental analysis of voltage drop compensation in a DC electrified railway and some discussions based on the test.
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  • Kouki Nagura, Yukihiko Sato, Naoki Yamamura, Muneaki Ishida
    2008 Volume 128 Issue 2 Pages 94-101
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    The flash welding is characterized by the high quality, the high production efficiency and the large sectional area welding, and is used to weld rails and hot coils in shop welding mainly. In order to realize high accuracy and high response control of flash welding, the inverter technology has been applied to flash welding in this study. In this paper, a method of process control combined with inverter flash control and mechanical control is proposed. Experiment results of the proposed process control combined with inverter flash control and mechanical control are presented.
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  • Youichi Ito, Hirofumi Akagi, Zhongqing Yang
    2008 Volume 128 Issue 2 Pages 102-109
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    This paper describes the study results of the inverters running in parallel. In the consideration of the operation algorithm, it is important to reveal output impedance characteristics of the inverters. First, simulation results demonstrate that the output impedance depends on the control scheme of the output voltage and characteristics of the circulating current that flows through the inverter differs. Next, as examples, two control schemes and their experimental results are demonstrated. The two schemes are: “PQ droop method” based control and “common current distribution method” based control. In the both case, since the output impedance is resistive, the phase of the output voltage is adjusted by using the reactive component of the circulating current. The amplitude of the output voltage is not manipulated. In the latter control system, quantity of the output-current feedback changes with the output impedance. This characteristic clarifies that the output impedance among the inverters becomes higher and the output impedance of the loads gets smaller. Moreover, suppression of the circulating current and excellent output voltage characteristics can be maintained.
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  • Hironori Abe, Hiroshi Fujimoto
    2008 Volume 128 Issue 2 Pages 110-116
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    In this paper, multirate perfect tracking control is proposed for a single-phase inverter. Although conventional single-rate deadbeat control could not guarantee zero tracking error for arbitrary reference signals, the proposed multirate control can achieve perfect tracking at every sampling point. Feedback characteristic is enhanced by inter sampling technique. Simulations and experiments are carried out to compare the proposed method with a single-rate deadbeat controller for non-sinusoidal reference waveform.
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  • Toshiji Kato, Kaoru Inoue, Kazuya Nishimae, Masayuki Kitagawa
    2008 Volume 128 Issue 2 Pages 117-124
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    It is necessary to consider variations of circuit element values for power electronic converter design to satisfy a given specification for a frequency characteristic or a dynamic transient response because the variations of element values generate those of the designed characteristic. Therefore element values and their variation ranges should be designed to give a satisfactory characteristic within an allowable specification range or a tolerance. This analysis is so-called tolerance or worst-case analysis. The analysis is a sort of nonlinear minimum and maximum (min/max) problem with respect to circuit or system parameters. However it is not possible to solve a transient type problem generally. Hence, the problem is converted to a simpler and easier one with various techniques. This paper proposes a new Genetic Algorithm (GA) method, or a sort of a modified relay-search-GA, which is suitable for practical and efficient tolerance analysis by considering diversity of solutions. Output voltage analysis examples of three types of converters for element parameter variations are investigated for effectiveness of the proposed method.
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  • Kan Akatsu, Nobuhiro Mitomo, Shinji Wakui
    2008 Volume 128 Issue 2 Pages 125-130
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    This paper proposes a speed and position estimation methods by using a Hall effect sensor. The speed is estimated from the fluctuated current which can be observed on the control axis. The position is estimated from the estimated speed and is corrected from the pulse which is generated by the Hall effect sensor mounted on the machine. Although the speed control range is limitted since this method is based on the back EMF, the speed and the position can be estimated without any motor parameter is used. The prposed method is verified by the experiments which 120W SPMSM is used for the tested machine, the currnet control and the speed control results including the controlable speed range are breifly explained.
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  • Toshiaki Murai, Hiroshi Yoshioka, Motohiko Sugino
    2008 Volume 128 Issue 2 Pages 131-136
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    The double null-flux electro-dynamic suspension (EDS) in the superconducting maglev has the coupling lateral and yawing stiffness, which does not coincide with each other, so special attention should be paid to the dynamic stability of lateral and yawing motions. This paper describes their intrinsic dynamic stability by analyzing the lateral and yawing motions of bogie levitated by the double null-flux EDS.
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  • Hirokazu Seki, Kazuki Takahashi, Susumu Tadakuma
    2008 Volume 128 Issue 2 Pages 137-144
    Published: February 01, 2008
    Released: February 01, 2008
    JOURNALS FREE ACCESS
    This paper describes a novel safety driving control scheme for electric power assisted wheelchairs based on the regenerative braking system. “Electric power assisted wheelchair” which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people, however, the safe and secure driving performance especially on downhill roads must be further improved because electric power assisted wheelchairs have no braking devices. The proposed control system automatically switches the driving mode, from “assisting mode” to “braking mode”, based on the wheelchair's velocity and the declined angle and smoothly suppresses the wheelchair's acceleration based on variable duty ratio control in order to realize the safety driving and to improve the ride quality. Some experiments on the practical roads and subjective evaluation show the effectiveness of the proposed control system.
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