IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 137 , Issue 3
Showing 1-26 articles out of 26 articles from the selected issue
Special Issue on “JIASC 2016”
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  • Kenji Noguchi, Satoshi Takahashi, Daisuke Suzuki, Atsushi Teramoto
    2017 Volume 137 Issue 3 Pages 213-219
    Published: March 01, 2017
    Released: March 01, 2017
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    An X-ray computed tomography (CT) apparatus is required for the inspection of semiconductor packages to detect fine voids with high accuracy. However, obtaining high-quality CT images stably is difficult because of object misalignment. In this paper, we propose a method for improving the X-ray CT image quality by estimating the mechanical misalignment of each projection image. The estimation is conducted by using an iterative method based on the characteristic features obtained from the reconstructed image. In experiments, we verified the effectiveness of proposed method by using projection images with simulated misalignments added. The results indicated that the proposed method may be useful for improving the quality of CT imaging.

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  • Takahiro Kaneko, Keiji Wada, Akira Tokumasu
    2017 Volume 137 Issue 3 Pages 220-229
    Published: March 01, 2017
    Released: March 01, 2017
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    In this paper, a control method for reducing the switching ripple currents flowing to a DC-link capacitor in a two-stage single-phase charger is presented. The switching sequences of both converter circuits are addressed by applying triangular and saw-tooth carrier waveforms in order to reduce the switching ripple current of the DC capacitor. Moreover, a sampling method of the current that is suitable for application in the control procedure is proposed. The proposed method varies the sampling frequency and points according to the input and output voltage conditions. The reduction effect of the switching ripple current is confirmed by analysis and the results of an experiment in which a DC-DC converter with power factor correction was used under the conditions of a source voltage 100V and an output power 1 kW.

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  • Masahiro Hori, Mamoru Kimura, Takayuki Koizumi
    2017 Volume 137 Issue 3 Pages 230-237
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper describes the inverter drive characteristics of a 2.4 MW permanent magnet generator (PMG) for a diesel electric propulsion system. We demonstrated the relations between the PWM (Pulse-Width Modulation) pulse patterns and temperature rise in a permanent magnet in a PMG. Additionally, we demonstrated that inverter failure has a significant impact on the current and torque in a PMG.

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  • Yudai Okajima, Kan Akatsu
    2017 Volume 137 Issue 3 Pages 238-245
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper proposes the harmonic current control of a permanent magnet synchronous machine using complex vector form PI controllers. The complex vector form PI controllers are designed based on voltage equations written in complex vector notation in multiple reference frames that synchronize with the harmonic current. Thus, a decoupling control in each reference frame can be achieved that has been difficult to realize in the past. The proposed method improves the transient response of the harmonic current control by realizing the decoupling control in each reference frame. Moreover, the proposed harmonic current control method can be designed and implemented easily because the PI gain design method for all harmonic orders is the traditional pole-zero cancellation method, which is well known. This paper presents the transient response and parameter sensitivity of the proposed harmonic current control that were obtained from the results of the simulation and experiment conducted, which reveal the effectiveness of the proposed method.

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  • Yushi Koyama, Ryuta Hasegawa, Takuro Arai, Daichi Suzuki
    2017 Volume 137 Issue 3 Pages 246-255
    Published: March 01, 2017
    Released: March 01, 2017
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    In this study, a static synchronous compensator (STATCOM) with a delta-connected modular multilevel converter (MMC) was considered. Because a low harmonic distortion is realized with MMC topology, the switching frequency can be reduced to one-pulse, and an extremely low switching loss can be achieved. However, details on one-pulse control of an MMC-STATCOM have not been clarified. This paper describes control strategies for one-pulse control of a delta-connected MMC-STATCOM and proposes an individual balance control to balance all capacitor voltages with a low modulation index or redundant configuration. Experimental results verified the proposed balance control and one-pulse operation under stable and system fault conditions.

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  • Akira Tanaka, Shu Yamamoto, Takahiro Ara, Kazuto Sakai, Shuji Komuro
    2017 Volume 137 Issue 3 Pages 256-266
    Published: March 01, 2017
    Released: March 01, 2017
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    This study proposes a method for determining the equivalent circuit constants of synchronous machines. First, a new approach to calculate the equivalent circuit constants considering mutual leakage reactance between field and damper windings is proposed. This method can determine the constants by substituting synchronous machine constants (time constants and reactances) in simple formulae. As these machine constants are easily obtained from the frequency characteristics of the d-axis and q-axis operational impedances measured through the standstill DC test, determining the equivalent circuit constants is considerably simplified. Second, an improved DC test that can measure the operational impedances of a synchronous machine with a brushless excitation system is proposed. This method allows for performing the DC test without separating the diode rectifier circuit from the field winding of a rotor. As a practical example, the proposed method is implemented on a 10-kW salient-pole synchronous generator with an external diode bridge rectifier connected to field winding terminals. Using the determined equivalent circuit constants, the field and armature transient currents at a sudden three-phase short circuit are simulated. By comparing the simulation results with measurement test data, the validity of the proposed method is verified.
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  • Akihiro Nomoto, Kengo Ohnishi, Toshimasa Haneyoshi, Hideo Tomita
    2017 Volume 137 Issue 3 Pages 267-273
    Published: March 01, 2017
    Released: March 01, 2017
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    The weld-bonding method uses adhesion and spot welding it has the advantages of high fatigue resistance, high rigidity, no need of a jig for adhesion, and so on. However, the conventional adhesive is an epoxy resin, which is cured by a chemical reaction. Therefore, the adhesive needs a long curing time. In an automobile assembly factory, the adhesive is cured by drying during the body painting process. The standby period before the drying process influences the quality of the adhesive. To solve this problem, we propose a new method that uses an epoxy resin with a thermal agent added and induction heating (IH) for quick curing. We obtained the fundamental data of IH coil heating steels for practical application of the new method. Based on the experimental and analytical results, suitable conditions regarding the frequency and IH coil position for automobile steel models were selected. Finally, we determined a semi-cured heating temperature for the adhesive of more than 120°C and IH coil movement of 10cm/s for practical application.

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  • Masatoshi Uno, Akio Kukita
    2017 Volume 137 Issue 3 Pages 274-281
    Published: March 01, 2017
    Released: March 01, 2017
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    Partial shading on a photovoltaic (PV) panel comprising of multiple substrings connected in series leads to major issues, such as decreased power generation and occurrence of multiple power point maxima. Various PV equalizers have been proposed to preclude partial shading issues. However, system complexity increases because of the addition of PV equalizers, and circuits are prone to complexity because each PV equalizer contains switches. This study proposes a single-switch PWM converter integrating a PV equalizer using a series-resonant voltage multiplier (SRVM) for PV panels under partial shading. A PWM converter and PV equalizer can be integrated into a single unit, which decreases the switch count, achieving system- and circuit-level simplifications. Detailed operation analysis was performed for the SRVM, using which a dc equivalent circuit was mathematically derived. Experimental tests using a prototype for three substrings connected in series were performed with solar array simulators. The integrated converter successfully precluded the occurrence of multiple power point maxima and significantly improved the extractable maximum power as compared to that without equalization, demonstrating its efficacy.

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