Patents by Inventor Teruyuki ISHIZUKI
Teruyuki ISHIZUKI has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10291159Abstract: According to one embodiment, a control system includes a chopper, a short-circuit unit, a voltage detector circuit, and a controller. The chopper reduces a direct current voltage between a converter connected to a stator in a wound induction machine and an inverter connected to a rotor in the wound induction machine. The short-circuit unit shorts a wire used for connection between the rotor and the inverter and the voltage detector circuit is to detect the direct current voltage. The controller causes driving the chopper and, at the same time, outputting from the inverter an alternating current over which a direct current component is superimposed when a voltage value exceeds a first predetermined value, and causes driving the short-circuit unit and, at the same time, halting the inverter when the voltage value exceeds a second predetermined value.Type: GrantFiled: February 8, 2018Date of Patent: May 14, 2019Assignees: Kabushiki Kaisha Toshiba, Toshiba Energy Systems & Solutions CorporationInventors: Ryuta Hasegawa, Takahisa Kageyama, Kiyoshi Kusunoki, Teruyuki Ishizuki, Yuichi Shiozaki, Takashi Fujita, Hironari Kaneda
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Publication number: 20180278183Abstract: According to one embodiment, a control system includes a chopper, a short-circuit unit, a voltage detector circuit, and a controller. The chopper reduces a direct current voltage between a converter connected to a stator in a wound induction machine and an inverter connected to a rotor in the wound induction machine. The short-circuit unit shorts a wire used for connection between the rotor and the inverter and the voltage detector circuit is to detect the direct current voltage. The controller causes driving the chopper and, at the same time, outputting from the inverter an alternating current over which a direct current component is superimposed when a voltage value exceeds a first predetermined value, and causes driving the short-circuit unit and, at the same time, halting the inverter when the voltage value exceeds a second predetermined value.Type: ApplicationFiled: February 8, 2018Publication date: September 27, 2018Applicants: Kabushiki Kaisha Toshiba, Toshiba Energy Systems & Solutions CorporationInventors: Ryuta Hasegawa, Takahisa Kageyama, Kiyoshi Kusunoki, Teruyuki Ishizuki, Yuichi Shiozaki, Takashi Fujita, Hironari Kaneda
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Patent number: 9887617Abstract: According to one embodiment, there is provided a power conversion device, including a control unit configured to control ON/OFF of a switching element of a neutral-point-clamped power conversion device unit, wherein the control unit drives the power conversion device unit by a one-pulse control, controls a phase difference of an output voltage of the power conversion device unit with respect to a reference phase of to control an active current component of an output current of the power conversion device unit, and controls ON/OFF based on: (a) a phase angle for eliminating a predetermined odd-order harmonic component of the output voltage; and (b) a sum of the reference phase and the phase difference.Type: GrantFiled: December 11, 2015Date of Patent: February 6, 2018Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta Hasegawa, Shinya Kono, Takashi Fujita, Teruyuki Ishizuki
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Patent number: 9780692Abstract: According to one embodiment, there is provided a control device of a neutral-point-clamped power converter apparatus including a converter configured to convert current which were obtained by passing a d-axis current and a q-axis current of a rotating coordinate system through a filter having a time constant which is greater than an inverse number of a fundamental wave frequency of a three-phase currents, to three-phase currents, and a controller configured to calculate, based on the three-phase currents converted, a zero-phase voltage instruction value for controlling voltages into which a DC input voltage is divided at a neutral point, as an instruction value which is superimposed on three-phase voltage instruction values.Type: GrantFiled: October 12, 2015Date of Patent: October 3, 2017Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta Hasegawa, Teruyuki Ishizuki, Takashi Fujita
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Patent number: 9548685Abstract: According to one embodiment, an over-voltage prevention device includes a first short-circuit device provided between a secondary side of a wound-rotor induction machine and a frequency converter configured to excite the secondary side by a three-phase AC current and having a function of short-circuiting between phases of the three-phase AC current, resistors each connected between the first short-circuit device and the frequency converter for each phase, and second short-circuit devices connected respectively to the resistors in parallel and having a function of short-circuiting between the frequency converter and the secondary side of the wound-rotor induction machine.Type: GrantFiled: January 26, 2015Date of Patent: January 17, 2017Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta Hasegawa, Teruyuki Ishizuki, Takashi Fujita, Takahisa Kageyama, Yutaro Kitamori, Sho Sato
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Patent number: 9478972Abstract: According to one embodiment, an over-voltage prevention device is provided between a secondary-winding side of a wound-rotor induction machine and a frequency converter configured to excite the secondary-winding side of the wound-rotor induction machine through a three-phase excitation power supply line. The over-voltage prevention device includes a first short-circuit device having a function of short-circuiting between phases of the excitation power supply line, and a second short-circuit device having a function of short-circuiting between phases of the excitation power supply line with a short-circuit impedance greater than a short-circuit impedance of the first short-circuit device.Type: GrantFiled: February 6, 2015Date of Patent: October 25, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yutaro Kitamori, Takahisa Kageyama, Teruyuki Ishizuki, Takashi Fujita
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Control system of variable speed pumped storage hydropower system and method of controlling the same
Patent number: 9429136Abstract: In one embodiment, a control system of a variable speed pumped storage hydropower system includes an optimization processing unit configured to calculate a flow rate adjusting valve opening demand value and a first command value, a speed control unit configured to generate a secondary current active power component command value of a secondary excitation device based on the first command value, a mechanical (pump-turbine) output compensation unit configured to calculate a compensation value of the opening of the flow rate adjusting valve and/or a compensation value of the generator-motor output, and an output control unit configured to generate a flow rate adjusting valve opening command value based on the generator-motor output command value, the flow rate adjusting valve opening demand value, the compensation value calculated by the mechanical output compensation unit, and the output detection value of the generator-motor.Type: GrantFiled: December 20, 2013Date of Patent: August 30, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kiyoshi Kusunoki, Yuichi Shiozaki, Teruyuki Ishizuki, Tadahiro Yanagisawa -
Publication number: 20160190908Abstract: According to one embodiment, there is provided a power conversion device, including a control unit configured to control ON/OFF of a switching element of a neutral-point-clamped power conversion device unit, wherein the control unit drives the power conversion device unit by a one-pulse control, controls a phase difference of an output voltage of the power conversion device unit with respect to a reference phase of to control an active current component of an output current of the power conversion device unit, and controls ON/OFF based on: (a) a phase angle for eliminating a predetermined odd-order harmonic component of the output voltage; and (b) a sum of the reference phase and the phase difference.Type: ApplicationFiled: December 11, 2015Publication date: June 30, 2016Applicant: Kabushiki Kaisha ToshibaInventors: Ryuta HASEGAWA, Shinya KONO, Takashi FUJITA, Teruyuki ISHIZUKI
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Patent number: 9374030Abstract: According to one embodiment, there is provided a generator excitation apparatus including a plurality of first power converters and a second power converter. The plurality of first power converters are electrically connected to windings of respective phases of rotors of a wound rotor type induction generator in which the windings of the rotors of the respective phases are electrically independent, and are configured to bidirectionally convert DC and AC. The second power converter is configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase DC power supply. The DC sides of the first power converters are electrically connected together to a DC side of the second power converter.Type: GrantFiled: June 25, 2014Date of Patent: June 21, 2016Assignee: Kabushiki Kaisha ToshibaInventors: Katsuhisa Inagaki, Kentaro Suzuki, Ryuta Hasegawa, Teruyuki Ishizuki, Kiyoshi Kusunoki
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Publication number: 20160111975Abstract: According to one embodiment, there is provided a control device of a neutral-point-clamped power converter apparatus including a converter configured to convert current which were obtained by passing a d-axis current and a q-axis current of a rotating coordinate system through a filter having a time constant which is greater than an inverse number of a fundamental wave frequency of a three-phase currents, to three-phase currents, and a controller configured to calculate, based on the three-phase currents converted, a zero-phase voltage instruction value for controlling voltages into which a DC input voltage is divided at a neutral point, as an instruction value which is superimposed on three-phase voltage instruction values.Type: ApplicationFiled: October 12, 2015Publication date: April 21, 2016Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta HASEGAWA, Teruyuki ISHIZUKI, Takashi FUJITA
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Patent number: 9300185Abstract: In one embodiment, a flywheel power generating facility includes a flywheel power generator including a flywheel for storing rotational energy, and configured to convert the rotational energy into electric power to supply the electric power to a test facility. The generating facility further includes a driving motor configured to rotate the flywheel, and a power supply device configured to supply electric power to the driving motor. The generating facility further includes a detector configured to output a signal related to the rotation of the flywheel, and a controller configured to control operation of the driving motor, based on the outputted signal. The controller controls the operation of the driving motor so that the driving motor provides accelerating torque to the flywheel while the supply of the electric power to the test facility is stopped and while the electric power is supplied to the test facility.Type: GrantFiled: March 13, 2013Date of Patent: March 29, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoshitaka Arihara, Teruyuki Ishizuki, Takahisa Kageyama
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Patent number: 9287797Abstract: In one embodiment, an electric power converting device includes a converter which converts a three-phase AC voltage output from a three-phase AC power source, into a DC voltage of each phase of a three-phase AC load, and an inverter which converts the DC voltage converted by the converter, into a single-phase AC voltage of each phase of the three-phase AC load. The converter includes for each phase of an electric power system a circuit which consists of a plurality of switching elements connected in series. The electric power converting device controls on/off of a switching element corresponding to one of phases of the electric power system in the converter such that a voltage which reduces fluctuation of a DC voltage applied between the converter and the inverter and corresponding to each phase of the three-phase AC load is output from the converter for each phase of the electric power system.Type: GrantFiled: October 18, 2013Date of Patent: March 15, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta Hasegawa, Yosuke Nakazawa, Kentaro Suzuki, Katsuhisa Inagaki, Teruyuki Ishizuki
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Publication number: 20150229120Abstract: According to one embodiment, an over-voltage prevention device is provided between a secondary-winding side of a wound-rotor induction machine and a frequency converter configured to excite the secondary-winding side of the wound-rotor induction machine through a three-phase excitation power supply line. The over-voltage prevention device includes a first short-circuit device having a function of short-circuiting between phases of the excitation power supply line, and a second short-circuit device having a function of short-circuiting between phases of the excitation power supply line with a short-circuit impedance greater than a short-circuit impedance of the first short-circuit device.Type: ApplicationFiled: February 6, 2015Publication date: August 13, 2015Inventors: Yutaro KITAMORI, Takahisa Kageyama, Teruyuki Ishizuki, Takashi Fujita
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Publication number: 20150214870Abstract: According to one embodiment, an over-voltage prevention device includes a first short-circuit device provided between a secondary side of a wound-rotor induction machine and a frequency converter configured to excite the secondary side by a three-phase AC current and having a function of short-circuiting between phases of the three-phase AC current, resistors each connected between the first short-circuit device and the frequency converter for each phase, and second short-circuit devices connected respectively to the resistors in parallel and having a function of short-circuiting between the frequency converter and the secondary side of the wound-rotor induction machine.Type: ApplicationFiled: January 26, 2015Publication date: July 30, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Ryuta HASEGAWA, Teruyuki ISHIZUKI, Takashi FUJITA, Takahisa KAGEYAMA, Yutaro KITAMORI, Sho SATO
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Patent number: 9077268Abstract: In one embodiment, there is provided a controller that performs control to supply driving electricity to a secondary winding of a variable-speed generator-motor from a secondary exciter and thereby start the variable-speed generator-motor from a standstill state in a variable-speed pumped storage system. The controller performs control to complete a start-up by the driving electricity from the secondary exciter and connect the variable-speed generator-motor in parallel with an electric power system, in a state where a rotating speed of the variable-speed generator-motor is lower than a lower limit speed of a variable-speed operation range.Type: GrantFiled: April 26, 2012Date of Patent: July 7, 2015Assignee: Kabushiki Kaisha ToshibaInventor: Teruyuki Ishizuki
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Publication number: 20150002106Abstract: According to one embodiment, there is provided a generator excitation apparatus including a plurality of first power converters and a second power converter. The plurality of first power converters are electrically connected to windings of respective phases of rotors of a wound rotor type induction generator in which the windings of the rotors of the respective phases are electrically independent, and are configured to bidirectionally convert DC and AC. The second power converter is configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase DC power supply. The DC sides of the first power converters are electrically connected together to a DC side of the second power converter.Type: ApplicationFiled: June 25, 2014Publication date: January 1, 2015Inventors: Katsuhisa INAGAKI, Kentaro SUZUKI, Ryuta HASEGAWA, Teruyuki ISHIZUKI, Kiyoshi KUSUNOKI
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CONTROL SYSTEM OF VARIABLE SPEED PUMPED STORAGE HYDROPOWER SYSTEM AND METHOD OF CONTROLLING THE SAME
Publication number: 20140197638Abstract: In one embodiment, a control system of a variable speed pumped storage hydropower system includes an optimization processing unit configured to calculate a flow rate adjusting valve opening demand value and a first command value, a speed control unit configured to generate a secondary current active power component command value of a secondary excitation device based on the first command value, a mechanical (pump-turbine) output compensation unit configured to calculate a compensation value of the opening of the flow rate adjusting valve and/or a compensation value of the generator-motor output, and an output control unit configured to generate a flow rate adjusting valve opening command value based on the generator-motor output command value, the flow rate adjusting valve opening demand value, the compensation value calculated by the mechanical output compensation unit, and the output detection value of the generator-motor.Type: ApplicationFiled: December 20, 2013Publication date: July 17, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Kiyoshi KUSUNOKI, Yuichi Shiozaki, Teruyuki Ishizuki, Tadahiro Yanagisawa -
Publication number: 20140119068Abstract: In one embodiment, an electric power converting device includes a converter which converts a three-phase AC voltage output from a three-phase AC power source, into a DC voltage of each phase of a three-phase AC load, and an inverter which converts the DC voltage converted by the converter, into a single-phase AC voltage of each phase of the three-phase AC load. The converter includes for each phase of an electric power system a circuit which consists of a plurality of switching elements connected in series. The electric power converting device controls on/off of a switching element corresponding to one of phases of the electric power system in the converter such that a voltage which reduces fluctuation of a DC voltage applied between the converter and the inverter and corresponding to each phase of the three-phase AC load is output from the converter for each phase of the electric power system.Type: ApplicationFiled: October 18, 2013Publication date: May 1, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Ryuta HASEGAWA, Yosuke Nakazawa, Kentaro Suzuki, Katsuhisa Inagaki, Teruyuki Ishizuki
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Publication number: 20120274289Abstract: In one embodiment, there is provided a controller that performs control to supply driving electricity to a secondary winding of a variable-speed generator-motor from a secondary exciter and thereby start the variable-speed generator-motor from a standstill state in a variable-speed pumped storage system. The controller performs control to complete a start-up by the driving electricity from the secondary exciter and connect the variable-speed generator-motor in parallel with an electric power system, in a state where a rotating speed of the variable-speed generator-motor is lower than a lower limit speed of a variable-speed operation range.Type: ApplicationFiled: April 26, 2012Publication date: November 1, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Teruyuki ISHIZUKI