Kabushiki Kaisha Toshiba

National Institute of Advanced Industrial Science and Technology

Toshiba Energy Systems & Solutions Corporation

Tohoku University

Agency of Industrial Science and Technology

Ministry of International Trade & Industry

Koji Ando

Shinji Yuasa

Akio Fukushima

Hitoshi Kubota

Hiroaki Yoda

Tadashi Kai

Tadaomi Daibou

Taro Nagahama

Kay Yakushiji

Toshihiko Nagase

Eiji Kitagawa

Katsuya Nishiyama

Makoto Nagamine

Masafumi Fujita

Minoru Amano

Junichi Ito

Shigemi Mizukami

Terunobu Miyazaki

Takahide Kubota

Vadym Zayets

Masatoshi Yoshikawa

Masahiko Nakayama

Naoharu Shimomura

Takahiro Sato

Norio Takahashi

Koji Ueda

Yasuo Kabata

Yoshihiro Taniyama

Toshio Hirano

Ken Nagakura

Masashi Kobayashi

Hidekazu Saito

Kei Yakushiji

Takashi Ueda

Yutaka Hashimoto

Takashi Harakawa

Yuichiro Gunji

Masaru Tokou

Yoshinori Torii

Yoichi Tomoe

Shinji Kubo

Ryo Fuchimoto

Hirotada Endo

According to an embodiment, a field winding interlayer short-circuit monitoring device comprises: an input unit configured to obtain field winding current values and field winding voltage values at a predetermined sampling cycle; a memory configured to store field winding resistance versus current characteristic curves at an abnormal state and a normal state; and a field winding resistance calculator configured to calculate a field winding resistance value by dividing the field winding voltage value by the field winding current; an average value calculator configured to calculate an average resistance value and an average current value by averaging those obtained during a predetermined time interval; and an image data generator configured to generate image data to display a predetermined number of average value data along with the field winding resistance versus current characteristic curves at the normal state and the abnormal state.

Field winding interlayer short-circuit monitoring device and field winding interlayer short-circuit monitoring method

In general, according to one embodiment, there is provided an abnormality detection system of a rotary electrical machine. The system includes a plurality of magnetic flux sensors disposed at intervals on a back of a stator core in a circumferential direction or an axial direction, and configured to detect a magnetic flux, and an abnormality detection apparatus configured to detect an abnormality of the stator core from a predetermined event that appears in a composite signal or a differential signal obtained from signals respectively output from at least two magnetic flux sensors of the plurality of magnetic flux sensors.

Abnormality detection system of rotary electrical machine

According to one embodiment, a rotor includes a coil slot, a sub-slot, and coil airflow paths arranged in the rotor axial direction. At least one coil airflow path among the coil airflow paths includes a first wall surface disposed on a core central portion side of a cooling gas inlet portion of the coil airflow path, a second wall surface disposed on the core central portion side of an inside of the coil airflow path, and located more on the rotor radially outward side and more on a core end portion side than the first wall surface, and a third wall surface configured to connect the first wall surface and the second wall surface, the third wall surface including a surface perpendicular to a rotor radial direction.

Rotor with coil airflow paths

According to one embodiment, a winding interlayer short-circuit detection apparatus includes a processor configured to perform at least an interlayer short-circuit detecting process to detect, based on a difference between a measurement value of a field current in a field winding of a brushless exciter and a reference value, and based on a difference between a calculated value of an armature reaction voltage induced in the field winding of the brushless exciter and a reference value, a presence or absence of an interlayer short-circuit that may occur in any of the field winding of the brushless exciter, an armature winding of the brushless exciter, and a field winding of a rotary electric machine body.

Winding interlayer short-circuit detection apparatus and winding interlayer short-circuit detection method

According to the embodiment, a field winding interlayer short-circuit detection apparatus comprises: a field winding resistance calculator to calculate, for a field winding of a rotating electrical machine, a field winding resistance calculated value from a detected value of a field winding current and a detected value of a field winding voltage; a determiner to determine presence or absence of an interlayer short-circuit in the field winding by using a comparison result between the field winding resistance calculated value and the reference resistance value.

Field winding interlayer short-circuit detection apparatus and field winding interlayer short-circuit detection method

A magnetoresistive element according to an embodiment includes: a base layer; a first magnetic layer formed on the base layer, and including a first magnetic film having an axis of easy magnetization in a direction perpendicular to a film plane, the first magnetic film including MnGa(45&#x2266;x&#x3c;64 atomic %); a first nonmagnetic layer formed on the first magnetic layer; and a second magnetic layer formed on the first nonmagnetic layer, and including a second magnetic film having an axis of easy magnetization in a direction perpendicular to a film plane, the second magnetic film including MnGa(45&#x2266;y&#x3c;64 atomic %). The first and second magnetic layers include different Mn composition rates from each other, a magnetization direction of the first magnetic layer is changeable by a current flowing between the first magnetic layer and the second magnetic layer via the first nonmagnetic layer.

Magnetoresistive element and magnetic memory

An optical device having a plasmonic waveguide, in which the plasmonic waveguide has a layered structure of at least three layers that a ferromagnetic metal layer, a first dielectric layer, and a second dielectric layer are layered in this order, in which the first and second dielectric layers are layers that allow light to be transmitted therethrough, and in which a refractive index of the second dielectric layer is higher than a refractive index of the first dielectric layer; and an optical isolator, having the optical device.

Optical device using a plasmonic waveguide, and optical isolator

A magnetoresistive element according to an embodiment includes: a first and second magnetic layers having an easy axis of magnetization in a direction perpendicular to a film plane; and a first nonmagnetic layer interposed between the first and second magnetic layers, at least one of the first and second magnetic layers including a structure formed by stacking a first and second magnetic films, the second magnetic film being located closer to the first nonmagnetic layer, the second magnetic film including a structure formed by repeating stacking of a magnetic material layer and a nonmagnetic material layer at least twice, the nonmagnetic material layers of the second magnetic film containing at least one element selected from the group consisting of Ta, W, Hf, Zr, Nb, Mo, Ti, V, and Cr, one of the first and second magnetic layers having a magnetization direction that is changed by applying a current.

A random number generating device is constructed such that it has improved random number generation rate and allows for construction of compact circuit with ease. The random number generating device includes a magnetoresistive element that has three layers consisting of a magnetization free layer, an interlayer, and a magnetization fixed layer, and has at least two resistance values depending on arrangement of magnetization in the magnetization free layer and the magnetization fixed layer, wherein the magnetoresistive element is subjected to be applied with a magnetization current so that the inversion probability of the magnetization free layer assumes a value between 0 and 1, through which the resistance value of the magnetoresistive element is extracted as random numbers.

Random number generating device

According to one embodiment, a magnetoresistive effect element includes a first magnetic layer including perpendicular anisotropy to a film surface and an invariable magnetization direction, the first magnetic layer having a magnetic film including an element selected from a first group including Tb, Gd, and Dy and an element selected from a second group including Co and Fe, a second magnetic layer including perpendicular magnetic anisotropy to the film surface and a variable magnetization direction, and a nonmagnetic layer between the first magnetic layer and the second magnetic layer. The magnetic film includes amorphous phases and crystals whose particle sizes are 0.5 nm or more.

Magnetoresistive effect element, magnetic memory

A nonvolatile optical memory element in which a ferromagnetic body is provided on a semiconductor causes such a problem that in a case where magnetization of the ferromagnetic body is read by light, magneto-optical response becomes very small when the ferromagnetic body is small in volume. The present invention provides a memory element, a memory device, and a data reading method, each of which is applicable to data reading from a nonvolatile optical memory element. In a nonvolatile optical memory element having a structure in which a ferromagnetic body is provided on a semiconductor that is connected to an optical waveguide, electrons are injected into the semiconductor via the ferromagnetic body so that the electrons that are spin-polarized according to a magnetization direction of the ferromagnetic body are injected into the semiconductor, thereby enlarging a region in which a photomagnetic effect occurs effectively. By applying an electric pulse and an optical pulse to the nonvolatile optical memory element, it is possible to effectively read recorded data according to a magnetization direction of the ferromagnetic body.

Nonvolatile optical memory element, memory device, and reading method thereof

According to one embodiment, a magnetoresistive element includes a first magnetic layer with a variable magnetization and an easy-axis in a perpendicular direction to a film surface, a second magnetic layer with an invariable magnetization and an easy-axis in the perpendicular direction, and a first nonmagnetic layer between the first and second magnetic layers. The first magnetic layer comprises a ferromagnetic material including an alloy in which Co and Pd, or Co and Pt are alternately laminated on an atomically close-packed plane thereof. The first magnetic layer has C-axis directing the perpendicular direction. And a magnetization direction of the first magnetic layer is changed by a current flowing through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer.

Growing community of inventors

Tsukuba, Japan

Koji Ando