Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Toshie Takeuchi

Mitsuru Tsukima

Hiroyuki Akita

Hidetoshi Kitanaka

Takashi Miyamoto

Kenichi Koyama

Hiroyuki Sasao

Yukimori Kishida

Toshiyuki Yoshizawa

Toyomi Ooshige

Hiroshi Kigawa

Kenji Shimohata

Tatsuo Matsuoka

Takafumi Nakagawa

Tae Hyun Kim

Nobumoto Tohya

Yasushi Takeuchi

Tetsuya Matsuda

Masao Morita

Toshihiro Matsunaga

Toru Yamashita

Takeo Kawaguchi

Takao Tsurimoto

Katsuhiko Horinouchi

Tadatoshi Yamada

Shigeyuki Yamamoto

Yuji Yoshitomo

Kazuki Kubo

Masafumi Sugawara

Hideo Okayama

Kazuhiko Kagawa

Shinichi Furutani

Yoshiharu Kobayashi

Shunji Yamamoto

Chie Takahashi

Akihiko Maruyama

Hitoshi Gotou

Yoshiaki Yamazaki

Eiji Moritoh

Shirou Nakamura

Makiko Kawada

Kazutaka Seo

Ituo Kodera

Tetuya Matuda

An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level).

Driving controller for AC motor

When electric discharging occurs inside a gas insulated apparatus in which sulfur hexafluoride is filled, hydrogen-fluoride gas is generated, which abrades a part formed of glass fiber reinforced plastics included in the apparatus. Previously, resin for preventing the abrasion has been coated on the surface of the part; however, a problem has occurred that the coating film peels off. Organic fiber woven cloth woven using organic fiber such as aramid fiber or the like having hydrogen fluoride resistance and mechanical toughness is wrapped around the surface of glass fiber reinforced plastics, and thermosetting resin is wettably impregnated into weave patterns of the organic fiber woven cloth and then heat cured; thereby, an abrasion-preventing protection layer that does not peel off is formed.

Gas insulated apparatus

A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

State grasp device, and switching control device of power switching apparatus employing the state grasp device

An actuator used in a safety stop device for an elevator has: a movable portion displaceable between an actuation position where the safety stop device for the elevator is actuated and a normal position where the actuation of the safety stop device is released; and an electromagnetic coil for displacing the movable portion when a current flows through the electromagnetic coil. A device for inspecting operation of the actuator has a feeder circuit for supplying an amount of electricity required for a semi-operation which is less than that required for a full operation for displacing the movable portion from the normal position and the actuation position to the electromagnetic coil.

Method for inspecting operation of actuator and actuator operation inspector

An actuator has a driving first coil and a driving second coil. A capacitor is electrically connected to both the first coil and the second coil through a discharge switch using electric power accumulated in a capacitor which can be selectively supplied. An operation portion for operating the discharge switch is electrically connected to the discharge switch. For example, when an electric power supplied to the operation portion is cut due to a power failure, the second coil and the capacitor are electrically connected to each other through the discharge switch.

Actuator driving method and actuator driving circuit

A magnetic actuator includes a first yoke, an armature which is provided inside the first yoke and made movable in reciprocating motion along a first direction inside the first yoke, first and second coils fitted inside the first yoke, a pair of second yokes affixed to the first yoke along a second direction, and permanent magnets affixed to the second yokes in a manner that the permanent magnets are positioned face to face with the armature. In the magnetic actuator thus constructed, fluxes generated by the first and second coils pass through first magnetic circuits whereas fluxes generated by the permanent magnets pass through second magnetic circuits differing from the first magnetic circuits.

Magnetic actuator

In an actuator, coils are kept from being displaced along a y-axis direction as projections of coil bobbins are sandwiched between first and second iron cores along the y-axis direction. Also, the coils are kept from being displaced excessively along x- and z-axis directions due to shocks, for instance, because they are fitted in groovelike channels fitted in the first and second iron cores. Since two bearings are sandwiched and fixed between third and fourth iron cores along the x-axis direction, the bearings can be easily set on a common axis with high accuracy. It is therefore possible to prevent displacement of the coils during operation of the actuator. Slidable support plates ensure smooth movements of an armature and thereby provide improved reliability, even when the distance between the support plates and the first to fourth iron cores is reduced.

Actuator, method of manufacturing the actuator and circuit breaker provided with the actuator

A displacement sensor includes a ferromagnetic member for forming a magnetic path, a coil for generating a magnetic field in the magnetic path when fed with a high-frequency current, and a low-resistance magnetic-shielding member that moves across magnetic flux passing through the magnetic path. The sensor is excellent in production is, robust, and useful in high speed operation.

Displacement sensor and solenoid valve driver

In an operation circuit of an electromagnetic switching device, when electric energy is discharged by discharge switches connected in series, respectively, to opening coils and closing coils, an induction current flowing in a direction opposite to a current of the coil of the excitation side is generated. The current flows through the coil on the non-excitation side due to magnetic coupling, and a magnetic flux necessary for driving is cancelled, thereby inhibiting generation of a driving force. The operation circuit includes first and second opening and closing coils, so that a moving element may be driven between those coils. This circuit includes a circuit for suppressing an over-voltage at the moment of interrupting an excitation current of a first coil and for interrupting an induction current generated through the first coil at the time of exciting the second coil.

Operation circuit and power switching device employing the operation circuit

A switching apparatus for multiphase electric power includes switching units corresponding to different phases. Each switching unit includes an operating mechanism having a movable coil disposed between two fixed coils, and a switch portion having a movable contact operatively connected to the movable coil. A separate power supply may be provided for each switching unit to permit individual control of the different phases.

Switching apparatus

A switching device includes a pair of fixed coils and a pair of movable coils, with one pair being disposed between the other pair. Two of the coils may be connected back to back on opposite sides of a support plate to increase the stiffness of the coils and reduce damage due to impact between the fixed and movable coils. The coils include two sets of coils, each set including one of the fixed coils and one of the movable coils. The coil sets can be driven simultaneously or at different times to effect contact opening and closing.

A switching device includes a movable coil which is reinforced by a stiffener to increase the resistance of the movable coil to bending moments. The stiffener may include a nonmagnetic case which surrounds the movable coil. Alternatively or in addition, it may include a resin or other material encapsulating the movable coil.

Switching device

A switching assembly includes a switch portion having a fixed electrode and a movable electrode which are separable, a movable portion secured between a movable shaft connected to the movable electrode and a movable coil by a magnetic body, and a fixed portion having a magnetic body disposed radially inside a fixed coil disposed opposite the movable portion, thereby enabling intensification and swift establishment of magnetic fields generated between the coils.

Switching assembly

A switching apparatus includes a switch, a movable coil, stationary coil members, and a direction-of-conduction setter comprising diodes. The switch has a stationary electrode. The movable coil is fixedly mounted on a movable shaft coupled to the movable electrode. The stationary coil members are opposed to the movable coil. The power supply supplies an excitation current to the coils. The direction-of-conduction setter sets the direction of conduction, in which the excitation current flows from the power supply into the coils, so that the coils will electromagnetically react on each other. This arrangement provides highly efficient electromagnetic driving. Moreover, an opening power supply or closing power supply is required to have only a small capacity.

A superconducting deflection electromagnet apparatus for deflecting an electron beam includes a liquid helium reservoir 21 disposed outside of the magnetic shield 11 surrounding the cryostat 4 accommodating the upper and lower liquid helium containers 2 in which coil assemblies 1, 31, 32 are disposed. Preferably, the upper and lower liquid helium containers 2 are supported from the cryostat 4 by means of the thermally insulating support members 5, 6 and 8 whose positions are adjustable by means of the threaded projections 5a, 6a and 8a and the nuts 52, 53, 62, 63, 82, 83 engaging therewith. The nuts secure the respective thermally insulating support members to the cap-shaped fixing members 44, 47, 49 attached to the extensions 43, 45, 49 of the cryostat 4.

Growing community of inventors

Tokyo, Japan

Toshie Takeuchi