巻号一覧
21 巻, 5 号
選択された号の論文の6件中1～6を表示しています
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論文
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岩原 正吉, 山田 外史, F. P. Dawson1997 年 21 巻 5 号 p. 907-910
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスA passive magnetic fault current limiter (FCL) was developed to avoid serious power failures in power transmission lines. This limiter is composed of two cores with opposite polarities: a permanent magnet with high remanent magnetic flux density and high coercive force, and a ferrite core with high rectangularity and low saturating flux density. The limiter works as an inductor, and is inserted between the power source and the load. This paper describes its core configuration, B-H characteristics of the FCL, and current limit performance. The flux distribution in the FCL is analyzed to investigate leakage flux around the permanent magnets using the 3D finite element method. Experimental results of a trial use of the FCL in a testing circuit show that it has good performance.抄録全体を表示PDF形式でダウンロード (281K) -
宇山 浩子, 大谷 義近, 深道 和明, 北上 修, 島田 寛, 越後谷 淳一1997 年 21 巻 5 号 p. 911-914
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスThe exchange-coupling mechanism of Cr70Al30/Fe19Ni81 bilayer films was investigated in terms of the crystallographic orientation, interface roughness, and grain size. The exchange-coupling field Hex appears when the Cr70Al30 layer is thick enough to accommodate the one-dimensional antiferromagnetic domain wall. The value of Hex decreases with an increase in the degree of the <110> orientations associated with the grain growth, but increases with increasing the interface roughness. These results can be qualitatively explained by considering the exchange-coupling field evaluated from the random field approximation.抄録全体を表示PDF形式でダウンロード (277K) -
沢井 淳, 村瀬 琢, 野村 武史1997 年 21 巻 5 号 p. 915-918
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスThe effects of substitutive CuO for MgO on the core loss characteristics of MnMgZn ferrite were studied with reference to the initial permeability, microstructure, and conductivity. Superior core loss was achieved by CuO 2-5 mol % subsititution in MnMgZn ferrite. Subsititution of CuO is effective in reducing both hysteresis and eddy current losses. This improvement can be correlated with uniformly sized grains and high resistivity. High resistivity attained by CuO substitution in MnMgZn ferrite reduced core loss at high frequencies.抄録全体を表示PDF形式でダウンロード (360K) -
丸山 耕一, 佐藤 駿, 大野 湶, 沼田 博雄1997 年 21 巻 5 号 p. 919-922
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスA bimetal, composed of an amorphous alloy ribbon with an electroless metallic film deposited on it, was investigated as a candidate for perpendicular magnetic recording materials. Electroless CoFeB films (the positive saturation magnetostriction (λs>0)) were formed on non-ferromagnetic amorphous NiSiB ribbons, and the characteristics of the bimetals were obtained. Perpendicular magnetization of the film layer was enhanced by heat treatment, during which compressive stresses may be induced into the layer by crystallization of the ribbon.抄録全体を表示PDF形式でダウンロード (325K) -
竜田 藤男, 田所 睦雄1997 年 21 巻 5 号 p. 923-928
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスParametric oscillation of a ferroresonant-based two-phase circuit is used in power devices, such as phase converters, parametric transformers, and parametric motors. When the load conductance of the device is very small, the parametric oscillation becomes unstable and the operation of the device is hindered. The authors have reported that these unstable phenomena can be classified into four categories: subharmonic oscillations, quasi-periodic oscillations, chaotic oscillations, and interruptions of the parametric oscillations. In this paper, the authors clarify the conditions in which the parametric oscillations change to unstable oscillations or shift to chaotic oscillations, and also analyze the mechanism of the interruptions of the parametric oscillations.抄録全体を表示PDF形式でダウンロード (371K) -
大平 膺一, 古関 隆章, 正田 英介1997 年 21 巻 5 号 p. 929-934
発行日: 1997年
公開日: 2007/08/20
ジャーナル オープンアクセスX-Y LIM is a linear induction motor that generates separate thrusts in two orthogonal directions (along the X and Y axes). For this purpose, it incorporates two sets of windings around the surface of a single iron core. The resulting structure prevents the symmetrical arrangement of the motor’s magnetic circuits, and thus the thrust characteristics in the X and Y directions do not match. This paper examines the six-pole-type X-Y LIM through two-dimensional analysis based on the Fourier series method, and also through numerical analysis in which magnetic paths in the X and Y directions are developed into a model, in order to identify the following factors based on the difference between the two magnetic circuits: (1) the distribution of the magnetic flux density and secondary currents, (2) the end-effect phenomenon attributable to the finite length on the secondary side, (3) the relation between the ratio of the effective flux existing between the X and Y directional windings, and (4) the relation between the starting thrust and each slip frequency.抄録全体を表示PDF形式でダウンロード (425K)
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