著者

岡崎 佑平 萩原 誠 赤木 泰文

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.133, no.12, pp.1157-1164, 2013

被引用文献数

2

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A modular multilevel cascade inverter based on double-star chopper cells (MMCI-DSCC) is expected as one of the next-generation multilevel PWM inverters for medium-voltage motor drives. This paper presents theoretical and experimental discussions on a practical speed-sensorless start-up method for an induction motor driven by the MMCI-DSCC from a standstill to a middle speed. This motor drive is suitable, especially for a large-capacity fan- or blower-like load, the torque of which is proportional to a square of the motor mechanical speed. Unlike the so-called “volts-per-hertz” control, three-phase stator currents are based on “feedback” control, whereas their amplitude and frequency are based on “feedforward” control. Although the motor drive has no speed sensor attached to the motor shaft, this method makes a slow start-up stable with the help of a stator current-feedback loop. Experimental results obtained from a 400-V, 15-kW downscaled system verify the stable operating performance from a standstill to a middle speed of 590min^-1 with a 40% load torque.

著者

森 拓哉 渡邉 翔一郎 古関 隆章

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.135, no.12, pp.1153-1159, 2015

被引用文献数

2

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Smart timetabling optimization is a cost-effective way to improve the quality of railway service. Partial introduction of rapid trains is one of the effective methods for improving passenger service quality. However, it is difficult to concretely perform smart train scheduling. In this paper, we apply mixed integer programming for minimizing the total travelling time of passengers to obtain optimal train scheduling for the combination of all-station and partially introduced rapid trains. This method requires higher computational time to obtain the optimal solution than other metaheuristic methods; however, the solution guarantees to be an optimal one. We also propose an appropriate method to digitize the OD (Origin Destination)-patterns, i.e., the traffic demand inputs between two stations, which are suitable for the framework of the proposed mixed integer programming method. We apply the method to a case study of a commercial subway and demonstrate the advantages of the proposed train service with the partial introduction of rapid trains.

著者

宮脇 慧 伊東 淳一 岩谷 一生

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.131, no.10, pp.1175-1183, 2011

被引用文献数

1 2

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This paper proposes a new circuit topology for a high efficiency isolated DC/DC converter using series compensation. The proposed converter consists of a high efficiency resonance half-bridge converter and a series converter. The series converter regulates the output voltage the provides only the differential voltage between the input voltage and output voltage. Therefore, the circuit achieves high efficiency when the input voltage is almost equal to the output voltage, because then only the resonance converter will operate.<br>In this paper, the approach employed to achieve a high efficiency by using the proposed series compensation method is introduced. In addition, the fundamental operation and the method of designing the proposed circuit are described. The suitability of the proposed circuit was confirmed by performing an experiment and loss analysis, maximum efficiency achieved was 96.2%.

著者

大石 潔

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.137, no.4, pp.NL4_8, 2017

著者

田島 宏一

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.133, no.6, pp.NL6_3, 2013

著者

水野 秀俊 近藤 潤次

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.136, no.5, pp.375-376, 2016

被引用文献数

1

---

This letter proposes a self-excitation method for diversion of static-excitation synchronous generators such as automotive alternators. In the proposed method, a voltage doubling rectifier circuit is used to start a synchronous generator at practical rotational speed through the residual magnetism of its rotor. An experiment was performed assuming a diversion of an automotive alternator, and it was possible to configure the proposed method where only three components were added by sharing the internal components of the alternator. Finally, it was confirmed that the proposed method could generate the output voltage by the demonstration experiment at approximately 1400rpm.

著者

渡邉 翔一郎 楊 哲 古関 隆章 近藤 圭一郎 水間 毅 濱﨑 康宏

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.134, no.8, pp.767-775, 2014

被引用文献数

15

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This paper presents a manual train operation assistance method for limiting braking power to avoid regeneration cancellation and to save train operation energy. This assistance system consists of on-board computers and interface devices. The braking assistance command is generated from a "dictionary" prepared to increase regenerated energy without any extension of train running time. In order to consider the power limitation and resolve assistance operation problems in terms of the operation delay time, this method was evaluated on a revenue service line. This paper proposes a "best effort method" for energy-saving train operation that does not use the conditions of other trains since train drivers cannot obtain information on the actual status of other trains in present railway systems. On-track tests showed that the power-limiting brake was effective on energy-saving for a train operation. The practical problem of the man machine interface for driver assistance was also intensively studied.

著者

長山 格 宮原 彬 島袋 航一

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.158-165, 2019

被引用文献数

2

---

<p>This paper proposes a new lazy learning algorithm, named balanced-kNN, for high performance robust classification of noisy patterns. K-nearest neighbor (k-NN) is a simple and powerful method with a high accuracy for various real world applications using unbiased datasets. However, noisy datasets are often gathered in real world applications. This paper presents a new robust algorithm, balanced-kNN, and compares the prediction accuracy with some conventional methods by using UCI datasets. The experimental results show that the balanced-kNN algorithm can perform more efficient classification of noisy data than the normal-kNN and weighted-kNN algorithms.</p>

著者

長田 康敬 河口 万由香 山田 親稔

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.143-148, 2019

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<p>In this paper, a design technique for ternary logic function circuits based on CMOS design are proposed. The circuits operate as B-ternary (binaric ternary) logic functions that are useful in asynchronous systems or self-checking circuits of fault-tolerant systems. Further, a special logic circuit, D-element, is proposed. D-element is designed for asynchronous systems like Mullers C-element in binary circuits. The circuits' SPICE simulations are provided to show their efficacy.</p>

著者

長山 格 上原 和加貴 宮里 大也

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.149-157, 2019

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<p>An alternative learning and its application to construct an overviewing human detection system (OHDES-V2) of flying drone for emergency rescue and investigation is presented in this paper. In this system, a deep neural network and alternative learning are used key techniques for object recognition from a free viewpoint. Simple appearance-based characteristics is determined from captured images, and the system uses a deep neural network to automatically classify human body, automobiles and so forth. The proposed system shows that several objects can be recognized from a bird's-eye view. Experimental results show that the system can effectively recognize four types of objects and walking persons with accuraces of 98.5% and 97.12%, respectively.</p>

著者

安里 健太郎 長堂 勤

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.136-142, 2019

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<p>In this study, we developed a current sensorless voltage driven magnetic levitation system with a Hall element displacement sensor using Kalman filter. The system costs less and has higher portability than the current driven system developed in a previous study, and is utilized effectively for model-based development education. However, the use of the displacement sensor for a voltage driven magnetic levitation system causes two problems, namely compensation for measurement error and correction of Hall element output voltages in the sensor. Therefore, we have proposed compensation and correction methods using Kalman filter. To verify the validity of the proposed methods, a magnetic levitation control experiment with the developed system was conducted.</p>

著者

城間 康 安富祖 仁 諏訪 竜一 金城 篤史 殿岡 裕樹 加賀 武史 長山 格 玉城 史朗 マハラジャン ガウリ

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.166-173, 2019

被引用文献数

1

---

<p>Mango is a popular seasonal fruit in summer, and mango production in the Okinawa prefecture is the largest in Japan. However, the growth process of mangoes is susceptible to changes in sunshine, temperature, and other factors. In this research, to produce mangoes without being influenced by the natural environment, we will develop a production system that can positively realize environmental measurement and control by using an IoT sensing system. Specifically, we introduced local CO₂ application technology and a supplemental LED lighting system with the aim of activating photosynthesis by mango trees.</p>

著者

加藤 司 長山 格 玉城 史朗

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.127-135, 2019

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<p>We developed a mobile learning system for fishery and ocean techniques using video contents. The system aims to improve the current situation in the field of education on fishery and ocean for skill succession. The proposal is based on the industry-school education process for skill succession. By accessing the web site and watching practical videos, the users can learn methodologies on fishery and ocean. As a result, we showed that the system is effective for sharing and succession of techniques for the learner. Application of the proposed system in the class showed improvement in the students' autonomous learning.</p>

著者

城間 康 安富祖 仁 金城 篤史 長山 格 玉城 史朗

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌 (ISSN:09136339)

巻号頁・発行日

vol.139, no.2, pp.174-179, 2019

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<p>Crop growth is influenced by various environmental factors. As a condition for effective plant growth, it is necessary that control of the habitat environment, such as soil moisture content, temperature, humidity, solar radiation amount, is adequately delivered. We focused the fact that soil moisture is important. It is desirable that moisture is uniformly distributed in the soil. In order to avoid physiological disorders caused by water related stress on agricultural crops, it is necessary to use soil with appropriate permeability. By calculating and estimating some characteristic amount related to water permeability, it is possible to identify soil with appropriate water permeability. In this research, we realize the visualization of the planar soil moisture volume by arranging the soil moisturemeter at multiple points. In addition to a system that realizes planar visualization of soil moisture, we propose a method for estimating soil permeability parameters in combination with computer simulation.</p>

著者

浅野 有康 大野 佳樹 栗田 壮一郎 近藤 圭一郎 篠宮 健志 石川 勝美

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. D, 産業応用部門誌

巻号頁・発行日

vol.137, no.5, pp.369-376, 2017

被引用文献数

5

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<p>Hybrid power source three level inverter is proposed as a main circuit system with energy storage device for increasing regenerative power. This paper proposes a charge and discharge control method to utilize the regenerated energy. The proposed method is verified by experimental tests with a scaled-down model and numerical simulation.</p>