Patents by Inventor Tadashi Koshizuka

Tadashi Koshizuka 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).

  • Patent number: 10074971
    Abstract: According to one embodiment, an excitation inrush current suppressing apparatus comprising: bus voltage measurement equipment which measures each phase voltage of the single-phase AC-side bus; transformer voltage measurement equipment which measures a single-phase-side voltage of the transformer; phase detector which detects a cutoff phase when opening the circuit breaker by monitoring each phase voltage measured by the bus voltage measurement equipment and the single-phase-side voltage measured by the transformer voltage measurement equipment, holds the detected cutoff phase, and outputs the same phase as the held cutoff phase; and close command output device which closes the circuit breaker by the same voltage phase as the cutoff phase output from the phase detector.
    Type: Grant
    Filed: January 12, 2015
    Date of Patent: September 11, 2018
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kei Kawasaki, Tadashi Koshizuka, Shiro Maruyama, Minoru Saito, Noriyuki Nagayama
  • Patent number: 10032582
    Abstract: A pair of fixed arc electrodes are arranged facing each other within a sealed container that is filled with arc-extinguishing gas 1. There are provided: a compression puffer chamber for accumulating pressurized gas that is obtained by elevating the pressure of the arc-extinguishing gas; and an insulated nozzle that directs the pressurized gas towards the arc discharge from the compression puffer chamber. A buffer chamber is provided, in which hot exhaust gas generated by the heat of the arc discharge is temporarily accumulated. A pressurized gas through-flow space is provided, communicating with the compression puffer chamber. In the pressurized gas through-flow space, an opening/closing section prevents inflow of hot exhaust gas by assuming a closed condition during the earlier half of the current interruption period, and in the latter half of the current interruption period the opening/closing section 41 is opened to allow flow of pressurized gas.
    Type: Grant
    Filed: March 23, 2015
    Date of Patent: July 24, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiyuki Uchii, Takeshi Shinkai, Takanori Iijima, Tadashi Mori, Tadashi Koshizuka, Norimitsu Kato, Hiroshi Furuta
  • Patent number: 9704664
    Abstract: 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° from the detected phase.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: July 11, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadashi Koshizuka, Shiro Maruyama, Minoru Saito, Hiroyuki Maehara, Koji Suzuki
  • Patent number: 9659727
    Abstract: A switch capable of easily accomplishing current cutoff roles required for a high-voltage switch, and which has a short breaking time. The switch includes pressure housings filled with an insulative medium, a plurality of contactors each including a contact, a plurality of operation units actuating the contacts, an insulative spacer dividing the interiors of the pressure housings into the same number of internal spaces as the number of contacts, and an electrode passing completely through the insulative spacer and fastened to the insulative spacer. The contactor is provided one by one for each internal space, and all contacts are electrically connected in series via the electrode, and the operation units actuate the corresponding contacts, respectively.
    Type: Grant
    Filed: July 9, 2014
    Date of Patent: May 23, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhisa Kanaya, Yoshiaki Ohda, Tadashi Koshizuka, Masayuki Sato, Yuki Matsui
  • Patent number: 9583934
    Abstract: According to one embodiment, an excitation inrush current suppression device for suppressing excitation inrush currents flowing through a breaker of the three-phase collective operation type for opening and closing connection is configured to measure a three-phase AC voltage of the power supply bus bar to calculate prospective magnetic fluxes of the transformer, and to measure a three-phase AC voltage on the transformer side to calculate residual magnetic fluxes of the transformer after shutoff, so as to set the breaker closed when polarities of the prospective magnetic fluxes respectively agree with polarities of the residual magnetic fluxes in all of the phases respectively.
    Type: Grant
    Filed: January 24, 2014
    Date of Patent: February 28, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kei Kawasaki, Tadashi Koshizuka, Shiro Maruyama, Minoru Saito, Noriyuki Nagayama
  • Patent number: 9515479
    Abstract: 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.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: December 6, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadashi Koshizuka, Shiro Maruyama, Hiroyuki Maehara, Yoshimasa Sato
  • Patent number: 9508514
    Abstract: An electromagnetic rebound mechanism unit and a magnetic latch unit are fixedly installed between a switchgear and a spring drive unit by virtue of a rebound fixing member and a fixing yoke. The electromagnetic rebound mechanism unit includes a rebound coil fixedly secured to the rebound fixing member, a reinforcing plate fixedly secured to a movable shaft and a rebound ring fixedly secured to the reinforcing plate. The magnetic latch unit includes a permanent magnet fixedly secured to the rebound fixing member, a latch ring fixedly secured to the permanent magnet and a movable yoke fixedly secured to the movable shaft. The spring drive unit includes a support frame, a spring retaining plate, a circuit-opening spring, a damper unit, and first and second electromagnetic solenoids.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: November 29, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Ohda, Tadashi Koshizuka, Kazuhisa Kanaya, Masayuki Ando
  • Patent number: 9502189
    Abstract: According to an embodiment, when a transformer that is connected to a first power supply through a first breaker as well as to a second power supply through a second breaker is detected to be disconnected from the power supplies, a specific phase of the three phases of the first breaker is closed to suppress an excitation inrush current, based on calculated residual magnetic fluxes and a voltage of the first power supply, and thereafter, the remaining two phases are closed. Based on the calculated residual magnetic fluxes and a voltage of the second power supply, a specific phase of the three phases of the second breaker is closed to suppress an excitation inrush current, and thereafter, the remaining two phases are closed.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: November 22, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shiro Maruyama, Minoru Saito, Tadashi Koshizuka, Tomohiko Mitani
  • Patent number: 9490627
    Abstract: 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.
    Type: Grant
    Filed: December 3, 2014
    Date of Patent: November 8, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadashi Koshizuka, Shiro Maruyama, Minoru Saito, Hiroyuki Maehara, Koji Suzuki
  • Patent number: 9425615
    Abstract: 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.
    Type: Grant
    Filed: September 17, 2013
    Date of Patent: August 23, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadashi Koshizuka, Minoru Saito, Shiro Maruyama, Hiroyuki Maehara, Yoshimasa Sato
  • Publication number: 20160225557
    Abstract: A switch capable of easily accomplishing current cutoff roles required for a high-voltage switch, and which has a short breaking time. The switch includes pressure housings filled with an insulative medium, a plurality of contactors each including a contact, a plurality of operation units actuating the contacts, an insulative spacer dividing the interiors of the pressure housings into the same number of internal spaces as the number of contacts, and an electrode passing completely through the insulative spacer and fastened to the insulative spacer. The contactor is provided one by one for each internal space, and all contacts are electrically connected in series via the electrode, and the operation units actuate the corresponding contacts, respectively.
    Type: Application
    Filed: July 9, 2014
    Publication date: August 4, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazuhisa KANAYA, Yoshiaki OHDA, Tadashi KOSHIZUKA, Masayuki SATO, Yuki MATSUI
  • Patent number: 9385525
    Abstract: 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.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: July 5, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadashi Koshizuka, Minoru Saito, Shiro Maruyama, Hiroyuki Maehara, Koji Suzuki
  • Publication number: 20160156175
    Abstract: A current-limiting reactor that is capable of decreasing an increase rate of a fault current without increasing a handling energy by a surge absorber of a DC breaker provided in a DC system. A current-limiting reactor apparatus includes a reactor connected in series with a DC breaker, a surge absorber connected in parallel with the reactor, and a switch connected in series with the surge absorber. The switch is loaded before the DC breaker cuts off a current and after a fault occurs in a power system.
    Type: Application
    Filed: March 26, 2014
    Publication date: June 2, 2016
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadashi KOSHIZUKA, Yoshiaki OHDA, Masayuki SATO, Yuki MATSUI
  • Publication number: 20160099123
    Abstract: An electromagnetic rebound mechanism unit and a magnetic latch unit are fixedly installed between a switchgear and a spring drive unit by virtue of a rebound fixing member and a fixing yoke. The electromagnetic rebound mechanism unit includes a rebound coil fixedly secured to the rebound fixing member, a reinforcing plate fixedly secured to a movable shaft and a rebound ring fixedly secured to the reinforcing plate. The magnetic latch unit includes a permanent magnet fixedly secured to the rebound fixing member, a latch ring fixedly secured to the permanent magnet and a movable yoke fixedly secured to the movable shaft. The spring drive unit includes a support frame, a spring retaining plate, a circuit-opening spring, a damper unit, and first and second electromagnetic solenoids.
    Type: Application
    Filed: December 14, 2015
    Publication date: April 7, 2016
    Inventors: Yoshiaki Ohda, Tadashi Koshizuka, Kazuhisa Kanaya, Masayuki Ando
  • Patent number: 9291686
    Abstract: A residual magnetic flux estimation device 1 includes a DC power-source control device 11 which controls a DC power source 300 to apply a DC voltage across two terminals of a ? connection that is a secondary winding or a tertiary winding, a voltage measuring device 12 which measures a terminal voltage at the primary side of a three-phase transformer 200, a computing device 13 that 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 device 14 that 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.
    Type: Grant
    Filed: July 22, 2011
    Date of Patent: March 22, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Keisuke Udagawa, Tadashi Koshizuka, Minoru Saitoh, Yoshimasa Sato, Hiroyuki Maehara
  • Patent number: 9197057
    Abstract: According to one embodiment, there is provided a magnetizing inrush current suppression apparatus including an interrupting phase detection unit that detects a phase when the transformer that converts a three-phase alternating-current voltage to a single-phase alternating-current voltage is disconnected, a single-phase alternating-current voltage measurement unit that measures the single-phase alternating-current voltage on the power system side of the circuit breaker, and a closing unit that closes the circuit breaker in the detected phase, based on the measured single-phase alternating-current voltage.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: November 24, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Keisuke Udagawa, Tadashi Koshizuka, Shiro Maruyama, Minoru Saitoh, Noriyuki Nagayama
  • Publication number: 20150206683
    Abstract: Provided is a switchgear which is capable of easily accomplishing an interruption task required in a high-voltage-purpose switchgear and which is short in the interruption time. The switchgear includes a pressure container 1 and 2 filled with an insulating medium, a plurality of contact point units 7 and 9, an insulation spacer 3 configured to divide the inside of the pressure containers 1 and 2 into the same number of internal spaces 101 and 102 as the number of the contact point units, and a spacer electrode 6 extending through the insulation spacer 3 and fixed to the insulation spacer 3. The contact point units 7 and 9 include contact points and an operating unit 29 for operating the contact points. The contact point units 7 and 9 are installed in the internal spaces 101 and 102, one in each space.
    Type: Application
    Filed: March 31, 2015
    Publication date: July 23, 2015
    Inventors: Yoshiaki Ohda, Tadashi Koshizuka, Masayuki Sato, Kasuhisa Kanaya, Yuki Matsui
  • Publication number: 20150194280
    Abstract: A pair of fixed arc electrodes are arranged facing each other within a sealed container that is filled with arc-extinguishing gas 1. There are provided: a compression puffer chamber for accumulating pressurized gas that is obtained by elevating the pressure of the arc-extinguishing gas; and an insulated nozzle that directs the pressurized gas towards the arc discharge from the compression puffer chamber. A buffer chamber is provided, in which hot exhaust gas generated by the heat of the arc discharge is temporarily accumulated. A pressurized gas through-flow space is provided, communicating with the compression puffer chamber. In the pressurized gas through-flow space, an opening/closing section prevents inflow of hot exhaust gas by assuming a closed condition during the earlier half of the current interruption period, and in the latter half of the current interruption period the opening/closing section 41 is opened to allow flow of pressurized gas.
    Type: Application
    Filed: March 23, 2015
    Publication date: July 9, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshiyuki UCHII, Takeshi SHINKAI, Takanori IIJIMA, Tadashi MORI, Tadashi KOSHIZUKA, Norimitsu KATO, Hiroshi FURUTA
  • Publication number: 20150171626
    Abstract: Current measurement means inputs single-phase current that is output from current measurement equipment and calculates (current measurement step) the current flowing in the ganged three-phase operation breaker when the ganged three-phase operation breaker interrupts the inductive load. Based on the measurement results of this current measurement equipment, phase detection means detects (phase detection step) a first interrupting phase selected from the three phases of the ganged three-phase operation breaker and the current interrupted point of this first interrupting phase.
    Type: Application
    Filed: February 25, 2015
    Publication date: June 18, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tadashi KOSHIZUKA, Shiro MARUYAMA, Minoru SAITO, Hiroyuki MATSUOKA
  • Publication number: 20150124357
    Abstract: According to one embodiment, an excitation inrush current suppressing apparatus comprising: bus voltage measurement equipment which measures each phase voltage of the single-phase AC-side bus; transformer voltage measurement equipment which measures a single-phase-side voltage of the transformer; phase detector which detects a cutoff phase when opening the circuit breaker by monitoring each phase voltage measured by the bus voltage measurement equipment and the single-phase-side voltage measured by the transformer voltage measurement equipment, holds the detected cutoff phase, and outputs the same phase as the held cutoff phase; and close command output device which closes the circuit breaker by the same voltage phase as the cutoff phase output from the phase detector.
    Type: Application
    Filed: January 12, 2015
    Publication date: May 7, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kei Kawasaki, Tadashi Koshizuka, Shiro Maruyama, Minoru Saito, Noriyuki Nagayama