Kabushiki Kaisha Toshiba

Toshiba Kikai Kabushiki Kaisha

Satake Corporation

Toshiba Corporation

Japan Rice Millers Association

Hiroyuki Maehara

Minoru Saito

Tadashi Koshizuka

Shiro Maruyama

Yoshimasa Sato

Koji Suzuki

Shigeharu Kanemoto

Yoshinari Sasaki

Naoki Kurita

Etsuji Oda

Hirozumi Nagata

Toshio Tanaka

Takeshi Fukumori

Itsuo Shuto

Tomonori Nishida

Nobuhiro Matsumoto

Noriyoshi Suga

Shigeki Katayama

Minoru Saitoh

Yusuke Yanagihashi

Hiroyuki Shirakawa

Satoru Satake

Akihiko Kato

Jun Takehara

Yoshihiro Tokui

Keishi Wakabayashi

Michiko Matsuda

Osamu Hosokawa

Hidenori Mizuno

Kunihiko Noda

Hiroshi Kusuyama

Keisuke Udagawa

Kazuo Amano

Kaoru Shitadera

Satoru Takashita

Yuka Kuribayashi

Takamasa Mesaki

Yukihiko Maede

Syuji Morito

Wataru Yamamori

Takaya Shono

According to one embodiment, a magnetizing inrush current suppressing device is configured to measure a three-phase alternating current flowing from the power supply bus to the load, detect a first interruption phase as a phase of an electric current which is interrupted first among the three phases, detect a phase of a phase voltage zero point through which a phase voltage of the first interruption phase of the three-phase AC voltage passes when changing from the same polarity as that of an electric current immediately before interruption of the first interruption phase to an opposite polarity, and close the circuit-breaker at a phase within 60&#xb0; from the detected phase.

Magnetizing inrush current suppression device

According to one embodiment, there is provided an inrush current suppression apparatus that suppresses an inrush current generated when shunt capacitors are connected to a power system, the apparatus including a voltage measurement unit measuring power source voltages, a current measurement unit measuring circuit breaker currents, a polarity determination unit determining the polarities of residual voltages, a phase section detector detecting a phase section in which the polarities of the residual voltages match the polarities of the power source voltages, and a circuit breaker closing unit closing the circuit breaker within the phase section.

Inrush current suppression apparatus

According to one embodiment, a magnetizing inrush current suppressing device includes, a first closing unit closes the circuit-breaker at the notable phase by the first phase determined by the first-phase determination unit, a second-phase determination unit determines a second phase at which the notable phase detected by the notable phase detection unit from the three-phase AC voltage measured by the power-supply-side voltage measurement unit becomes a zero point after the first phase determined by the first-phase determination unit, and a second closing unit closes the circuit-breaker at two phases other than the notable phase by the second phase determined by the second-phase determination unit.

Magnetizing inrush current suppressing device

According to one embodiment, there is provided an inrush current suppression apparatus that suppresses an inrush current generated when shunt capacitors are connected to a power system. The apparatus includes a power supply voltage measurement unit measuring a power supply voltage, a circuit breaker current measurement unit measuring a circuit breaker current, a residual voltage polarity determination unit determining the polarities of three phases of a residual voltage, a specific phase determination unit determining a specific phase, a closing phase detector detecting a closing phase, and a circuit breaker closing unit closing the circuit breaker in the closing phase.

According to one embodiment, there is provided a magnetizing inrush current suppression device. A closing phase determination unit determines a phase position for suppressing the magnetizing inrush current among phase positions in which the prospective magnetic flux calculated by the prospective magnetic flux calculation unit and the residual magnetic flux calculated by the residual magnetic flux calculation unit coincide between the lines of the minimum residual magnetic flux determined by the minimum residual magnetic flux determination unit, as a closing phase position. A closing unit simultaneously closes the three phases of the circuit-breaker at the determined closing phase position.

A residual magnetic flux estimation deviceincludes a DC power-source control devicewhich controls a DC power sourceto apply a DC voltage across two terminals of a &#x394; connection that is a secondary winding or a tertiary winding, a voltage measuring devicewhich measures a terminal voltage at the primary side of a three-phase transformera computing devicethat determines a phase having a high voltage between the two phases other than the phase to which the voltage is applied, and a residual magnetic flux measuring devicethat measures a phase-to-phase residual magnetic flux between the two phases other than the high-voltage phase, and estimates a measured value of the phase-to-phase residual magnetic flux as a maximum residual magnetic flux in the measurement-target three-phase transformer.

Method of estimating the residual magnetic flux of transformer and residual magnetic flux estimation device

According to one embodiment, a current input converter includes a first metal plate having a solid shape, which has one end attached to the terminal table and one other end attached to one end of a primary-side coil of the transformer, and connects the terminal table and the one end of the primary-side coil of the transformer to each other, and a second metal plate having a solid shape, which has one end attached to the terminal table and one other end attached to one other end of the primary-side coil of the transformer, and connects the terminal table and the other end of the primary-side coil of the transformer to each other.

Current input converter

A switching controller for circuit breaker in which a switching control arithmetic operation unit performs arithmetic operations to determine for each circuit breaker a synchronous delay count value which is sent to each switching command control unit of the corresponding circuit breaker, which upon receiving a switching command signal from a superordinate device, counts the synchronous delay count value D, to turn on a semiconductor switch of the switching command output unit after counting completes. The switching command signal (circuit breaker drive current) is output after the synchronous switching control to the circuit breaker drive coil of the circuit breaker. The switching controller can implement cost saving and space saving, even if switching of a circuit breaker in a lower branch system, such as a power distribution system, is controlled.

Switching controller and switching control system for circuit breaker

According to one embodiment, there is provided a breaker-phase-control switching system including a merging unit, a superordinate unit, and a circuit-breaker control unit. The circuit-breaker control unit includes a waveform-zero-point-calculation processing unit configured to calculate a current phase, based on absolute time kept by an internal clock and waveform data, and a predicted-breaker-operating-time-calculation processing unit configured to predict a predicted operating time. Further, a command-output-timing-determination processing unit is included which determines a timing for electrically conducting a coil from the absolute time, a preset target phase, a current phase, and a predicted operating time.

Breaker-phase-control switching system and circuit-breaker control unit

According to one embodiment, there is provided a protection relay. The protection relay includes an input circuit that detects a state of an external device according to whether or not an external input voltage is larger than a preset threshold voltage. The input circuit includes switching unit that is made conductive by a divided voltage obtained by voltage-dividing resistors that divide the external input voltage when the external input voltage is higher than or equal to the threshold voltage, and a photocoupler that is operated by a constant current of a constant current output circuit supplying a constant current and outputs an operation signal to the operation unit when the switching unit is made conductive.

Protection relay

In some embodiments, a method is disclosed that includes measuring a waveform of a power source side voltage of a circuit breaker; measuring a waveform of a transmission line side voltage of the circuit breaker; calculating a waveform of a voltage between contacts of the circuit breaker that is a difference between the waveform of the power source side voltage and the waveform of the transmission line side voltage; calculating a waveform of an absolute value of the waveform of the voltage between contacts; extracting a waveform of a component in a frequency band which is lower than a frequency of the power source and higher than a frequency of a DC component from the waveform of the absolute value; detecting a cycle of the extracted waveform; and closing the circuit breaker based on the cycle.

Overvoltage suppressing device

An overvoltage suppression device which suppresses overvoltage that occurs when breakers which turn on/off the connection between a power source bus and a power transmission line, are turned on after the breakers are turned off. The overvoltage suppression device measures the waveform of voltage on the side of the power source and the voltage on the side of the power transmission line, and extracts the waveform of a component in a predetermined frequency band on the basis of the waveform obtained by multiplying the wave shape of the voltage on the side of the power source by the waveform of the voltage on the side of the power transmission line. The breakers are turned on on the basis of a cycle wherein the waveform is peaked.

Over-voltage suppression apparatus

A substation instrument control system is disclosed. The substation instrument control system includes a plurality of transformers that generate a plurality of waveform signals representing electric properties of a substation instrument main body. A merging unit is communicatively coupled to the plurality of transformers and includes a signal processing unit and a control unit. The signal processing unit receives the plurality of waveform signals from the plurality of transformers and converts the plurality of waveform signals to a digital signal. The control unit controls operation of the signal processing unit using a setting data. An intelligent electronic device is communicatively coupled to the merging unit and receives the digital signal from the merging unit.

Substation instrument control system

The system of the invention includes a circuit breaker switching control section () and a setting control section () connected therewith through a communication network (). The circuit breaker switching control section () transmits a circuit breaker state quantity acquired by a signal input section () through the communication network to a set value calculation section () of the setting control section (). The set value calculation section () of the setting control section calculates a set value to be set in the switching control section () of the circuit breaker, using the state quantity of the circuit breaker that was transmitted thereto. The setting control section () transmits to the circuit breaker switching control section the set value calculated by the set value calculation section () through the communication network. A switching control calculation processing section () provided in the switching control section of the circuit breaker corrects the circuit breaker switching actuation time in accordance with this set value and calculates a delay time in respect of the zero-cross point in accordance with this corrected switching actuation time and power system period.

Circuit breaker switching control system

There is provided a coating apparatus capable of continuously producing coated rice having powdered coating material adhered to the grains and including a drying process to prevent the grains from being bonded to one another and make the grain surfaces smoother upon drying of the grains. The coating apparatus comprising a binder coating unit for applying liquid binder to the grains being conveyed through a coating and stirring chamber to coat the grain surfaces with the binder; a adhering unit for adding powder material to the grains conveyed through a adhering and stirring chamber to adhere the powdered material to the grain surface by the binder; and a drying unit including a drying and stirring chamber through which the grains are conveyed while being stirred, a blow passage for blowing hot air into the drying chamber to dry the grains, and an exhaust passage for exhausting the hot air from the drying chamber.

Growing community of inventors

Fuchu, Japan

Hiroyuki Maehara