著者

新藤 孝敏

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.12, pp.NL12_10, 2016-12-01 (Released:2016-12-01)

著者

小野 紘平 小中 英嗣

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.138, no.5, pp.627-634, 2018-05-01 (Released:2018-05-01)

参考文献数

13

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Differential equations are considered to be a fundamental tool in many areas of engineering. The goal of our project is to develop an education system that teaches differential equations, in which exercise and assessment problems are automatically generated and delivered to the students. A student's comprehension is identified using his or her answer history record of past answers, and problems at the appropriate level of difficulty are selected and delivered to the student. The proposed education system is implemented by MATLAB.Item characteristic parameters of each class of problem are equated using test result from 183 students in advance. The implemented proposed system has been examined by 13 examinees in 4 weeks. The experimental results show that the proposed system can deliver suitable problem for each student, and all students can improve their performance on solving differential equation through the experiment.

著者

根岸 信太郎

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.141, no.5, pp.NL5_6, 2021-05-01 (Released:2021-05-01)

参考文献数

4

著者

阪本 捷房

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.95, no.6, pp.501-502, 1975-06-20 (Released:2008-04-17)

著者

青木 義男 横田 隼

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.141, no.3, pp.163-166, 2021-03-01 (Released:2021-03-01)

参考文献数

5

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1.天のケーブルカー構想「天体力学の法則によって物体が空に静止していられるものなら,そこからケーブルを地上へ垂らし,地球と宇宙空間とを結ぶエレベータができないだろうか?」(1978年『楽園の泉』アーサーC. クラーク著,山高昭訳,ハヤカワ文庫)。これは今から40年以上前にアメリカのSF作家

著者

児玉 浩憲

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.140, no.6, pp.343, 2020

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<p>今年の春休み中に甲子園球場で催されるはずであった第92回選抜高校野球大会は,新型コロナウィルス感染症(肺炎)の世界的流行のため中止となった。いったんは「選手たちを落胆させたくない」と無観客試合も模索</p>

著者

進藤 貞和

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.101, no.2, pp.85-86, 1981-02-20 (Released:2008-04-17)

著者

鶴田 和寛

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.139, no.1, pp.4-7, 2019

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<p>1.はじめに</p><p>福岡県西方にある糸島半島の北側には風光明媚な海岸線(二見ヶ浦,野北海岸)が連なり,おしゃれなカフェやレストランが立ち並ぶ。福岡空港から直結するJR筑肥線の九大学研都市駅</p>

著者

熊井 巧 青山 真大

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.141, no.4, pp.354-365, 2021-04-01 (Released:2021-04-01)

参考文献数

27

被引用文献数

4

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This paper reports a variable flux PM motor based on a new principle of self-excitation utilizing space harmonics that are inevitably generated in concentrated winding structures. In addition, it has a passive variable flux function. Its rotor is composed of consequent poles for each N- and S-pole pair and self-excited wound-field poles. The effects of the passive variable flux function on the driving performance and its efficiency map are demonstrated via the prototype.

著者

石原 孝二

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.124, no.10, pp.626-629, 2004-10-01 (Released:2008-04-17)

参考文献数

7

被引用文献数

3 3

著者

寺山 祐樹 星 伸一

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.141, no.4, pp.366-373, 2021-04-01 (Released:2021-04-01)

参考文献数

20

被引用文献数

2

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Undesirable torque ripples in permanent magnet synchronous motors occur because of the spatial harmonics of the inductance and permanent magnet fluxes. Previous studies have proposed several methods for suppressing these torque ripples based on mathematical models. However, most of them do not consider the magnetic saturation. Hence, the torque ripple estimation accuracy may deteriorate, and the torque ripple suppression performance is reduced in the magnetic saturation range. Therefore, this paper proposes a torque ripple suppression method by considering the magnetic saturation based on the estimated harmonic component of the flux linkage and clarification of its effectiveness through simulations and experiments. From the experimental results, the proposed method is seen to suppress the 6th-order torque ripple by 69.1%, which is higher than that of the conventional method. Therefore, it is verified that the proposed method can suppress torque ripples, including those in the magnetic saturation range.

著者

熊谷 崇宏 伊藤 健 西川 滉大 伊東 淳一 山根 和貴 山田 伸明 名和 政道

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.141, no.4, pp.313-323, 2021-04-01 (Released:2021-04-01)

参考文献数

41

被引用文献数

2

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This study proposes a reduction method for iron loss in stator core using the optimum pulse pattern for a high-speed interior-permanent-magnet-synchronous-motor (IPMSM). In this paper, a simple evaluation function for iron loss of stator core in a pulse-width-modulation (PWM) drive is introduced. In particular, the iron loss in stator core is approximately estimated from the flux level obtained from the integral of the line-to-line voltage of the PWM drive. In addition, the pulse pattern is optimized to reduce the iron loss in stator core based on the introduced evaluation function. To validate the evaluation function, the correlation coefficient between the evaluation value and the measured iron loss is calculated in 12 random pulse patterns applied to the inductor and IPMSM. As a result, the correlation coefficients are 0.991 and 0.982 in the inductor and IPMSM, respectively. In addition, the iron loss of the IPMSM with the optimum pulse pattern is reduced by 8.5% and 3.7% in comparison with a carry-asynchronous PWM and carry-synchronous PWM, respectively.

著者

菅 哲朗

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌E(センサ・マイクロマシン部門誌) (ISSN:13418939)

巻号頁・発行日

vol.141, no.4, pp.NL4_1, 2021-04-01 (Released:2021-04-01)

著者

徳山 寛 和田 圭二 五箇 繁善

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.141, no.4, pp.324-329, 2021-04-01 (Released:2021-04-01)

参考文献数

21

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In power converter circuits, a gate drive circuit is connected to the power devices for the switching operation. The gate drive circuit transmits both signal and power to the power devices, simultaneously. At present, multi-level converter circuits using large numbers of devices have been proposed for power electronics circuits, but these are complicated to implement in a circuit. Hence, simplification of the signal and power transmissions of the gate drive circuit is required for circuit implementations. This paper proposes a gate drive circuit using SAW (Surface Acoustic Wave) devices that can transmit signal and power to the power devices, simultaneously. To use the several-hundreds MHz signal output from the SAW filter as the gate signal, this paper presents the design procedure for the internal parameters of the detection circuit that demodulates the signal into a several kHz signal. The usefulness of the proposed design is demonstrated by experimental evaluation of a half-bridge inverter and gate drive circuit with SAW filters.

著者

赤崎 勇

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.124, no.2, pp.107-113, 2004 (Released:2004-05-01)

参考文献数

37

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Breakthroughs in crystal growth and conductivity control of nitride semiconductors during last two decades have led to such developments as high-brightness blue, green and white light-emitting diodes and long-lived violet laser diode and so forth. The high electron saturation velocity in GaN is also suitable for application in high-speed/high power electronic devices. All of these nitride-based devices are the most environmentally-friendly ones available. They are tough and should enable a tremendous saving in energy. Further progress in the area of crystal growth and device engineering is necessary for the development of new frontier devices based on nitride semiconductors.

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

三澤 哲也

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.125, no.5, pp.457-460, 2005 (Released:2005-08-01)

参考文献数

18

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Recently, the wholesale electric power exchange has been founded in Japan. With the progress of the electricity market, some management schemes of electricity price risk will be necessary. In financial markets or the preceding electricity markets, various “derivatives" on assets in the markets are often used as management tools to hedge the price risk. This paper gives a short commentary on some fundamental concepts of the derivatives and the pricing theory in the financial engineering, and discusses the problems on the financial engineering approach to electricity derivatives.

著者

脇坂 俊幸 松嶋 徹 古賀 久雄 奥村 浩幸 桑原 伸夫 福本 幸弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.140, no.12, pp.557-564, 2020-12-01 (Released:2020-12-01)

参考文献数

30

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In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.

著者

新 政憲 堺 和人

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.128, no.4, pp.231-234, 2008-04-01 (Released:2008-04-01)

参考文献数

10

被引用文献数

2 3

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本記事に「抄録」はありません。

著者

犬飼 哲夫

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.97, no.9, pp.753-756, 1977-09-20 (Released:2008-04-17)