著者
藤村 靖
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.87, no.951, pp.2291-2305, 1967-12-01 (Released:2008-04-17)
参考文献数
20
著者
鈴木 貴志 狩野 孝明 小出 英延 彦坂 知行
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.129, no.8, pp.975-979, 2009-08-01 (Released:2009-08-01)
参考文献数
5
被引用文献数
5 8

We have developed new vegetable based insulating oil for transformers called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. The oxidative stability, biodegradability and acute toxicity to fish of PFAE has also been determined to be superior to mineral oil. In this paper, in order to optimize the characteristics of fatty acid esters originating from palm oil, several kinds of fatty acid alkyl esters were first synthesized in the laboratory by the molecular design technique and the transesterification from fatty acid methyl esters and alkyl alcohols. Next the electro-chemical characteristics of the fatty acid alkyl esters as insulating oil were analyzed.
著者
兒玉 学 平井 秀一郎
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.142, no.3, pp.199-204, 2022-03-01 (Released:2022-03-01)
参考文献数
12
被引用文献数
2

Applying a magnetic field to a water electrolyzer is one of the methods to improve energy conversion efficiency from electrical energy to hydrogen energy. In this study, experiments of alkaline water electrolysis with a magnetic field are carried out to elucidate the influence of a magnetic field direction and a magnetic flux density on cell voltage and bubble movement. In the case with B⊥electrode, the cell voltage decreases with the increase in current density and magnetic flux density, because the bubbles are removed from the electrode and the electrolyte is mixed with Lorentz-force. In the case with B∥electrode, the cell voltage is suppressed in low current density conditions. However, in high current density conditions, the bubbles are trapped in the electrolyte and the cell voltage is increased.
著者
兒玉 学 木内 豪士 鳥居 健次郎 平井 秀一郎
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.140, no.7, pp.617-622, 2020-07-01 (Released:2020-07-01)
参考文献数
16
被引用文献数
3 5

Three dimensional magnetohydrodynamic, two-phase flow and electrochemical reaction coupling numerical simulation of alkaline water electrolysis with magnetic field is conducted to estimate and reveal the mechanism of overvoltage suppression with the magnetic field. The numerical results shown that both vertical magnetic field to the electrode and parallel magnetic field to the electrode suppress the overpotential by the mixing of the electrolyte. This mixing is induced by the secondary flow in both cases. The overvoltage suppression is constantly increased with the increase in magnetic flux density in the case with parallel magnetic field, however, that is saturates in the case with vertical magnetic field to the electrode due to the bubble position is changed by the flow.
著者
鶴岡 美緒 田中 学 奥野 喜裕
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.138, no.3, pp.236-241, 2018-03-01 (Released:2018-03-01)
参考文献数
28
被引用文献数
1 1

Power generating characteristics of seed-free linear shaped Faraday type and disk shaped Hall type MHD generators are examined by two-dimensional numerical simulation with changing the inlet ionization degree. A liner shaped Faraday type generator can get stable and high power output at high inlet ionization degree. The net enthalpy extraction ratio, however, is reduced owing to the increase in the required preionization power. At low inlet ionization degree, on the other hand, ionization instability occurs and the enthalpy extraction ratio decreases. A disk shaped Hall type generator can get high net enthalpy extraction ratio even at low inlet ionization degree under a low preionization power. The net enthalpy extraction ratio decreases for an excessive inlet ionization degree because of a strong MHD interaction.
著者
卓 新民 田中 学 奥野 喜裕
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.136, no.10, pp.779-784, 2016-10-01 (Released:2016-10-01)
参考文献数
17
被引用文献数
2 2

The performance and plasma stability in a high-temperature inert gas plasma MHD generator with a high enthalpy extraction ratio have been simulated numerically. To achieve a high enthalpy extraction ratio, various generator channel lengths and magnetic flux density distributions are examined so as to improve the MHD interaction strength and effective electrical conductivity. It is found that an enthalpy extraction ratio of 30% is reachable for high-temperature inert gas plasma MHD generator, and as being similar to an experimental small-scale generator, steady and homogeneous plasma can be realized at a high inlet total temperature even for a high enthalpy extraction generator with long channel length and shaped magnetic flux density distribution.
著者
田中 学 泉 裕一朗 奥野 喜裕
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.136, no.2, pp.205-210, 2016-02-01 (Released:2016-02-01)
参考文献数
22

MHD (magnetohydrodynamic) electrical power generation experiments have been conducted with a seed-free high temperature inert gas plasma in a disk-shaped Hall-type generator driven by a single-pulsed shock tunnel. Xenon is used as a working gas to archive a high performance at a low inlet total temperature, where the total gas temperature is varied in the range of 4600-10000K at the generator inlet. An enthalpy extraction ratio of 4.8% is obtained at the inlet total temperature of 7000K, and this value is much higher than that for argon at the same inlet total temperature. The unstable and non-uniform plasma attributed to ionization instability is observed at a high magnetic flux density and a high load resistance.
著者
田中 学 奥野 喜裕
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.135, no.8, pp.527-532, 2015-08-01 (Released:2015-08-01)
参考文献数
22
被引用文献数
5 3

R-θ two dimensional numerical simulations have been carried out to clarify the plasma behavior in a high-temperature inert gas plasma disk-shaped MHD generator. At low inlet total temperature and high load resistance, the plasma has spiral structure which is similar to the non-uniform structure under the weak noble gas ionization condition in a seed-plasma MHD generator. As seen in a linear-shaped faraday-type MHD generator, the plasma becomes stable with increase in the inlet total temperature because the coulomb collision of electrons becomes dominant. Even at low inlet total temperature, the ionization instability can be suppressed for low load resistance, because the relatively low electron temperature due to less Joule heating makes the ionization relaxation time longer than plasma residential time.
著者
小松 文彦 田中 学 村上 朝之 奥野 喜裕
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.134, no.7, pp.620-625, 2014 (Released:2014-07-01)
参考文献数
9
被引用文献数
5 5

High temperature inert gas (argon) plasma MHD electrical power generation using a linear shaped channel with Hall and diagonal connections has been conducted. It is revealed from the observation by using a high-speed camera that the MHD power-generating plasma is almost stable regardless of the connection type. Enthalpy extraction ratios of 5.6% for the Hall connection, 6.7% for the diagonal connection (diagonal angle 53∼66 degree), and 10.1% for the diagonal connection (diagonal angle 36∼48 degree) have been achieved under the operating conditions of an inlet total temperature of 9000K, an inlet total pressure of 0.105MPa, and a magnetic flux density of 4.0T. The output power can suffer from a low electric field in the upstream region in a Hall connection, and is improved for no Hall current condition in a diagonal connection.
著者
田中 学 村上 朝之 奥野 喜裕
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.134, no.7, pp.614-619, 2014 (Released:2014-07-01)
参考文献数
13

MHD power generation experiments have been conducted by using a single-pulsed shock-tunnel facility, where the high temperature inert gas (pure argon) at a fixed total temperature of 9000K is introduced into a linear shaped Faraday type generator without any seeding. The fluctuations in the output power and the light emission from the plasma are found to be small, and the pure inert gas plasma seems to be rather stable free from the ionization instability. The output power is improved with increasing the magnetic flux density in almost quadric way and the enthalpy extraction ratio does not depend on the inlet total pressure (11.2%-12.9% for 0.063MPa-0.105MPa). The generator performance obtained here is surely competitive or superior to that of conventional seed plasma MHD generators in the past.
著者
田中 学 村上 朝之 奥野 喜裕
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.134, no.5, pp.464-469, 2014 (Released:2014-05-01)
参考文献数
16
被引用文献数
3 3

The plasma fluid flow behavior and power generation characteristics in a Faraday-type magnetohydrodynamics (MHD) generator using high temperature inert gas (argon) plasma has been examined by a time-dependent two-dimensional numerical simulation. The inhomogeneous and unstable plasma at an inlet total temperature of 7000K results in the reduction and fluctuation of the output power. The plasma changes to homogeneous and stable one with the increase in the inlet total temperature to 9000K. One of the reasons of the suppression of the ionization instability can be due to the weakness of the dependency of the electrical conductivity on the electron number density because the coulomb collision of electrons becomes dominant under the departure from Saha equilibrium.
著者
鈴木 元哉
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.142, no.8, pp.959-970, 2022-08-01 (Released:2022-08-01)
参考文献数
33
被引用文献数
2

Estimated response iterative tuning (ERIT) can updated the feedforward controller so as to realize desired closed-loop responses. If ERIT can be applied to vehicle yaw-rate control of automated vehicle, good autonomous driving can be realized. However, ERIT cannot realize desired control performance in the case where the control signal velocity is saturated. To solve this problem, I propose a new data-driven tuning method for vehicle yaw-rate control. Proposed method can update the feedforward controller by using estimation method of a closed-loop transfer function. Compared to ERIT, the proposed method can realize desired control performance even when the initial steering angle velocity is saturated. Furthermore, the proposed method can predict vehicle yaw-rate/steering angle velocity responses. The validity of proposed method is verified through vehicle simulators.
著者
松前 重義 篠原 登
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.53, no.544, pp.978-986, 1933-11-10 (Released:2008-11-20)
参考文献数
6

長距離通信網としての無裝荷ケーブルと裝荷ケーブルとの經濟比較を行つたものであつて,無裝荷ケーブルは裝荷ケーブルに比し建設費及び維持費共に經濟的となる事を述べてゐる。更に通信施設に對する經濟比較の基準を説明し社會的意義より見るも無裝荷ケーブルは最も優秀なる通信回線方式である事を述べてゐる。
著者
荒井 和弘
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.114, no.9, pp.551-555, 1994-08-20 (Released:2008-04-17)
参考文献数
1
被引用文献数
1