Patents by Inventor Tomohiro KUTSUKI

Tomohiro KUTSUKI 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).

  • Publication number: 20220294377
    Abstract: An estimation device includes a phase current determination unit, a time difference calculation unit, and an estimation unit. The phase current determination unit performs a determination process for determining values of phase currents based on the value of the bus current detected by a bus current detection unit and states of gate pulse signals. The time difference calculation unit calculates a difference between a detection time of the bus current used in a previous determination process and a detection time of the bus current used in a present determination process. The estimation unit estimates at least one of a position and a speed of an AC motor based on the values of the phase currents determined by the phase current determination unit and the difference calculated by the time difference calculation unit.
    Type: Application
    Filed: August 23, 2019
    Publication date: September 15, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenji TAKAHASHI, Shinya TOYODOME, Mitsuo KASHIMA, Tomohiro KUTSUKI
  • Publication number: 20220294379
    Abstract: A motor drive system includes: an inverter that drives a motor; a current detector that detects and outputs the first signal that is a current value of a current flowing through the inverter; a first low-pass filter that removes a noise frequency component from the first signal and outputs a second signal that is a current value after the noise frequency component has been removed; a demagnetization current determiner that compares a demagnetization current threshold with the second signal, and outputs a demagnetization protection signal when the second signal takes a value larger than the demagnetization current threshold; and a short circuit determiner that compares a third signal with a short circuit and outputs an anomaly signal for stopping the inverter when the third signal takes a value larger than or equal to the short circuit threshold.
    Type: Application
    Filed: October 24, 2019
    Publication date: September 15, 2022
    Inventors: Tomohiro KUTSUKI, Shinji SAKAI
  • Publication number: 20220271647
    Abstract: A direct current power supply device includes a rectifier circuit that rectifies alternating current power supplied from an alternating current power supply and converts the alternating current power into direct current power, a charge storage unit that includes a function of storing a charge, a charger that charges the charge storage unit, and a heat sink. The charger includes a positive-side switching element, a negative-side switching element, a positive-side backflow prevention diode, and a negative-side backflow prevention diode. The positive-side switching element, the negative-side switching element, the positive-side backflow prevention diode, and the negative-side backflow prevention diode are discrete semiconductor elements. The negative-side backflow prevention diode is a full mold package element. The positive-side switching element, the negative-side switching element, and the positive-side backflow prevention diode are elements that are not full mold packages.
    Type: Application
    Filed: November 6, 2019
    Publication date: August 25, 2022
    Inventors: Hiroki SUZUKI, Keiichiro SHIZU, Tomohiro KUTSUKI
  • Publication number: 20220200498
    Abstract: A motor drive device: a power conversion unit; a current detection unit that detects a phase current of the alternating-current motor; a position/speed specifying unit that specifies a magnetic pole position and a rotational speed of the alternating-current motor; a d-axis current pulsation generating unit that generates a d-axis current pulsation command based on q-axis current pulsation or a q-axis current pulsation command, which being in synchronization with the q-axis current pulsation or the q-axis current pulsation command and preventing or reducing an increase or decrease in amplitude of the voltage command; and a dq-axis current control unit that generates the voltage command for controlling the phase current on the dq rotating coordinates, which rotate in synchronization with the magnetic pole position, by using the magnetic pole position, the rotational speed, the phase current, the q-axis current pulsation or the q-axis current pulsation command, and the d-axis current pulsation command.
    Type: Application
    Filed: May 20, 2019
    Publication date: June 23, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenji TAKAHASHI, Shinya TOYODOME, Mitsuo KASHIMA, Tomohiro KUTSUKI
  • Publication number: 20220149764
    Abstract: A speed estimating device for an AC motor includes: a model deviation computing unit computing a model deviation based on a voltage, a current, and an estimated angular velocity of the AC motor; a first angular velocity estimating unit computing a first estimated angular velocity based on the model deviation; a second angular velocity estimating unit computing a second estimated angular velocity differing from the first estimated angular velocity in frequency, based on the model deviation; a compensation phase computing unit computing a compensation phase based on a disturbance frequency; and an estimated angular velocity calculator computing an estimated angular velocity of the AC motor based on the first estimated angular velocity and the second estimated angular velocity. Either one of the first estimated angular velocity and the second estimated angular velocity is computed based on the compensation phase.
    Type: Application
    Filed: March 22, 2019
    Publication date: May 12, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuriko TAKEDA, Kenji TAKAHASHI, Shinya TOYODOME, Mitsuo KASHIMA, Tomohiro KUTSUKI
  • Publication number: 20220140736
    Abstract: A DC power supply device includes: a rectifier circuit; a reactor connected at one end to one output terminal of the rectifier circuit; a charging unit including a first and second switching element connected in series between another end of the reactor and another output terminal of the rectifier circuit, the charging unit configured to charge a first and second capacitor connected in series between output terminals to which a load is connected; and a control unit that controls the charging unit. The control unit sets, based on the timing at which the zero-crossing occurs, a dead time in which both the and second switching element are off, and when states of the first and second switching element at a time of occurrence of the zero-crossing match a predetermined set of states, reverses the states of the first switching element and the second switching element.
    Type: Application
    Filed: April 12, 2019
    Publication date: May 5, 2022
    Inventors: Hiroki SUZUKI, Keiichiro SHIZU, Tomohiro KUTSUKI
  • Patent number: 11031895
    Abstract: A motor drive system can detect a misconnection. A motor drive system for driving a motor including a plurality of stator windings includes: an inverter that converts a DC voltage supplied from a DC voltage source into an AC voltage and applies the AC voltage to the motor; a connection switching device that is disposed between the inverter and the motor and can switch a connection state of the stator windings; and a controller that performs abnormality determination on a connection state of the connection switching device on the basis of a current value of a current flowing in each of the stator windings.
    Type: Grant
    Filed: July 7, 2017
    Date of Patent: June 8, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tomohiro Kutsuki, Keiichiro Shizu, Kazunori Hatakeyama, Takashi Yamakawa, Takayuki Kato
  • Patent number: 10734900
    Abstract: A converter device includes a rectifier circuit to rectify an AC voltage output from an AC power supply, a booster circuit including a plurality of reactors, a plurality of switching elements, and a plurality of backflow prevention elements to boost an output voltage of the rectifier circuit, a smoothing capacitor to smooth an output voltage of the booster circuit, a bus-current detection circuit to detect a value of a current that flows between the rectifier circuit and the booster circuit, a first filter circuit having a first filter time constant, a second filter circuit having a second filter time constant shorter than the first filter time constant, and a control unit to control an operation of the switching elements as a current value detected by the bus-current detection circuit is input to the control unit via the first filter circuit and the second filter circuit.
    Type: Grant
    Filed: December 28, 2016
    Date of Patent: August 4, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akito Tanaka, Satoru Ichiki, Tomohiro Kutsuki, Daisuke Suzuki, Akira Sakai
  • Patent number: 10696141
    Abstract: A synchronous motor control device includes: a DC power supply; an inverter main circuit; a three-phase synchronous motor; and an inverter control unit that outputs a PWM signal used to control the inverter main circuit. The inverter control unit includes: a PWM signal generation unit; a start-up control unit that outputs a start-up voltage command value to the PWM signal generation unit at the time of start-up; a steady state control unit that calculates a steady state voltage command value in a steady state and outputs the value to the PWM signal generation unit; and a steady state control parameter initial value calculation unit that outputs an initial value of a control parameter to the steady state control unit such that an output voltage vector from the inverter main circuit to the three-phase synchronous motor is consistent before and after switching from the start-up to the steady state.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: June 30, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Mitsuo Kashima, Tomohiro Kutsuki, Tomomi Higashikawa, Akiyoshi Muramatsu
  • Patent number: 10693377
    Abstract: The converter device includes a rectification circuit that receives, as an input, AC power from an AC power supply, and performs full-wave rectification on the AC power received, a booster circuit that boosts an output voltage from the rectification circuit, a smoothing capacitor that smooths an output voltage from the booster circuit, and outputs a voltage smoothed, to the load, and a controller that controls the booster circuit. The booster circuit includes a plurality of booster sections each of which includes a reactor, a switching element, and a reverse-blocking diode. The controller maintains, in an ON state, the switching element included in at least one of the plurality of booster sections for a predetermined time period to determine the presence or absence of a fault of the booster section.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: June 23, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tomohiro Kutsuki, Akira Sakai, Daisuke Suzuki, Satoru Ichiki, Akito Tanaka
  • Publication number: 20200169207
    Abstract: A motor drive system can detect a misconnection. A motor drive system for driving a motor including a plurality of stator windings includes: an inverter that converts a DC voltage supplied from a DC voltage source into an AC voltage and applies the AC voltage to the motor; a connection switching device that is disposed between the inverter and the motor and can switch a connection state of the stator windings; and a controller that performs abnormality determination on a connection state of the connection switching device on the basis of a current value of a current flowing in each of the stator windings.
    Type: Application
    Filed: July 7, 2017
    Publication date: May 28, 2020
    Inventors: Tomohiro KUTSUKI, Keiichiro SHIZU, Kazunori HATAKEYAMA, Takashi YAMAKAWA, Takayuki KATO
  • Patent number: 10476423
    Abstract: A synchronous motor control device includes a voltage detector, a current detector, an inverter main circuit, and an inverter control unit. The inverter control unit includes: a phase current reproduction unit that reproduces a direct current into phase currents flowing to a permanent magnet synchronous motor; a current coordinate transformation unit that transforms the reproduced phase current into current on a control coordinate axis of a rotating coordinate system; a current control unit that calculates a voltage command value of the permanent magnet synchronous motor in such a manner that the current on the control coordinate axis equals a specific value; and a limiter unit that limits the value of the voltage command value.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: November 12, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Mitsuo Kashima, Tomohiro Kutsuki, Tomomi Higashikawa, Akiyoshi Muramatsu
  • Publication number: 20190312510
    Abstract: A converter device includes a rectifier circuit to rectify an AC voltage output from an AC power supply, a booster circuit including a plurality of reactors, a plurality of switching elements, and a plurality of backflow prevention elements to boost an output voltage of the rectifier circuit, a smoothing capacitor to smooth an output voltage of the booster circuit, a bus-current detection circuit to detect a value of a current that flows between the rectifier circuit and the booster circuit, a first filter circuit having a first filter time constant, a second filter circuit having a second filter time constant shorter than the first filter time constant, and a control unit to control an operation of the switching elements as a current value detected by the bus-current detection circuit is input to the control unit via the first filter circuit and the second filter circuit.
    Type: Application
    Filed: December 28, 2016
    Publication date: October 10, 2019
    Inventors: Akito TANAKA, Satoru ICHIKI, Tomohiro KUTSUKI, Daisuke SUZUKI, Akira SAKAI
  • Publication number: 20190173384
    Abstract: The converter device includes a rectification circuit that receives, as an input, AC power from an AC power supply, and performs full-wave rectification on the AC power received, a booster circuit that boosts an output voltage from the rectification circuit, a smoothing capacitor that smooths an output voltage from the booster circuit, and outputs a voltage smoothed, to the load, and a controller that controls the booster circuit. The booster circuit includes a plurality of booster sections each of which includes a reactor, a switching element, and a reverse-blocking diode. The controller maintains, in an ON state, the switching element included in at least one of the plurality of booster sections for a predetermined time period to determine the presence or absence of a fault of the booster section.
    Type: Application
    Filed: February 24, 2016
    Publication date: June 6, 2019
    Inventors: Tomohiro KUTSUKI, Akira SAKAI, Daisuke SUZUKI, Satoru ICHIKI, Akito TANAKA
  • Publication number: 20180208023
    Abstract: A synchronous motor control device includes: a DC power supply; an inverter main circuit; a three-phase synchronous motor; and an inverter control unit that outputs a PWM signal used to control the inverter main circuit. The inverter control unit includes: a PWM signal generation unit; a start-up control unit that outputs a start-up voltage command value to the PWM signal generation unit at the time of start-up; a steady state control unit that calculates a steady state voltage command value in a steady state and outputs the value to the PWM signal generation unit; and a steady state control parameter initial value calculation unit that outputs an initial value of a control parameter to the steady state control unit such that an output voltage vector from the inverter main circuit to the three-phase synchronous motor is consistent before and after switching from the start-up to the steady state.
    Type: Application
    Filed: August 4, 2015
    Publication date: July 26, 2018
    Inventors: Mitsuo KASHIMA, Tomohiro KUTSUKI, Tomomi HIGASHIKAWA, Akiyoshi MURAMATSU
  • Publication number: 20180131308
    Abstract: A synchronous motor control device includes a voltage detector, a current detector, an inverter main circuit, and an inverter control unit. The inverter control unit includes: a phase current reproduction unit that reproduces a direct current into phase currents flowing to a permanent magnet synchronous motor; a current coordinate transformation unit that transforms the reproduced phase current into current on a control coordinate axis of a rotating coordinate system; a current control unit that calculates a voltage command value of the permanent magnet synchronous motor in such a manner that the current on the control coordinate axis equals a specific value; and a limiter unit that limits the value of the voltage command value.
    Type: Application
    Filed: August 4, 2015
    Publication date: May 10, 2018
    Inventors: Mitsuo KASHIMA, Tomohiro KUTSUKI, Tomomi HIGASHIKAWA, Akiyoshi MURAMATSU