Patents by Inventor Nobukatsu YAMAGUCHI

Nobukatsu YAMAGUCHI 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: 11606044
    Abstract: The present power conversion device includes an inverter, a step-up/down converter, a first capacitor, a second capacitor, a voltage sensor, a control device, and a backup power supply. The auxiliary device is connected between the first DC power supply and the step-up/down converter, and the control device includes an abnormality determination unit configured to determine that an abnormality has occurred when a control voltage is equal to or lower than a first threshold value, and a control unit configured to execute discharge control when the abnormality determination unit determines that the abnormality has occurred and an inter-terminal voltage measured by the voltage sensor is equal to or lower than a second threshold value.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: March 14, 2023
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Nobukatsu Yamaguchi, Yuta Nakamura, Yasuhiko Kondo
  • Patent number: 11404989
    Abstract: A power supply system (1) includes: a drive motor (M) coupled to drive wheels (W); a first inverter (23) which converts DC electric power into three-phase AC electric power; a first current sensor (23I) which generates a current detection signal according to electrical current flowing in the first inverter (23), and a system ECU (8) which executes discharge control for discharging electrical charge of a second smoothing capacitor (C2) connected to the first inverter (23), in a case of a discharge start condition being established. The system ECU (8), in a case of the drive motor (M) rotating upon starting the discharge control, executes the discharge control, after executing three-phase short-circuit control to turn ON all switching elements of an upper arm or all switching elements of a lower arm of the three-phase arm of the first inverter (23), based on the current detection signal of the sensor (23I).
    Type: Grant
    Filed: October 23, 2020
    Date of Patent: August 2, 2022
    Assignees: HONDA MOTOR CO., LTD., HITACHI ASTEMO, LTD.
    Inventors: Yasuhiko Kondo, Yuta Nakamura, Nobukatsu Yamaguchi
  • Patent number: 11362597
    Abstract: The present power control device includes an inverter, a step-up/down converter, a first capacitor, a second capacitor, and a control device. The step-up/down converter includes an upper arm and a lower arm that are switching elements, and a reactor that has a first end and a second end, the first end being connected to the first capacitor, and the second end being connected between the upper arm and the lower arm. The control device is configured to fix the lower arm in an off state and control the upper arm such that the upper arm switches at a predetermined duty ratio.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: June 14, 2022
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Nobukatsu Yamaguchi, Yuta Nakamura, Takami Suzuki
  • Publication number: 20210288604
    Abstract: A power supply system (1) includes: a drive motor (M) coupled to drive wheels (W); a first inverter (23) which converts DC electric power into three-phase AC electric power; a first current sensor (23I) which generates a current detection signal according to electrical current flowing in the first inverter (23), and a system ECU (8) which executes discharge control for discharging electrical charge of a second smoothing capacitor (C2) connected to the first inverter (23), in a case of a discharge start condition being established. The system ECU (8), in a case of the drive motor (M) rotating upon starting the discharge control, executes the discharge control, after executing three-phase short-circuit control to turn ON all switching elements of an upper arm or all switching elements of a lower arm of the three-phase arm of the first inverter (23), based on the current detection signal of the sensor (23I).
    Type: Application
    Filed: October 23, 2020
    Publication date: September 16, 2021
    Inventors: Yasuhiko KONDO, Yuta NAKAMURA, Nobukatsu YAMAGUCHI
  • Publication number: 20210104955
    Abstract: The present power conversion device includes an inverter, a step-up/down converter, a first capacitor, a second capacitor, a voltage sensor, a control device, and a backup power supply. The auxiliary device is connected between the first DC power supply and the step-up/down converter, and the control device includes an abnormality determination unit configured to determine that an abnormality has occurred when a control voltage is equal to or lower than a first threshold value, and a control unit configured to execute discharge control when the abnormality determination unit determines that the abnormality has occurred and an inter-terminal voltage measured by the voltage sensor is equal to or lower than a second threshold value.
    Type: Application
    Filed: September 30, 2020
    Publication date: April 8, 2021
    Inventors: Nobukatsu YAMAGUCHI, Yuta NAKAMURA, Yasuhiko KONDO
  • Publication number: 20210104956
    Abstract: The present power control device includes an inverter, a step-up/down converter, a first capacitor, a second capacitor, and a control device. The step-up/down converter includes an upper arm and a lower arm that are switching elements, and a reactor that has a first end and a second end, the first end being connected to the first capacitor, and the second end being connected between the upper arm and the lower arm. The control device is configured to fix the lower arm in an off state and control the upper arm such that the upper arm switches at a predetermined duty ratio.
    Type: Application
    Filed: September 30, 2020
    Publication date: April 8, 2021
    Inventors: Nobukatsu YAMAGUCHI, Yuta NAKAMURA, Takami SUZUKI
  • Patent number: 10715069
    Abstract: A discharge control device performs discharging of a capacitor, in a state in which a battery is not connected to an inverter that drives a motor, by causing electric charges accumulated in the capacitor connected to the inverter to be consumed by windings of the motor. The discharge control device performs the discharging of the capacitor by sequentially generating command values for voltages applied to a ? axis and a ? axis while causing a voltage phase in an ?? stationary coordinate system having a rotation axis of a rotor of the motor as an origin and defined by the ? axis and the ? axis orthogonal to each other to be inverted in a predefined period.
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: July 14, 2020
    Assignee: KEIHIN CORPORATION
    Inventor: Nobukatsu Yamaguchi
  • Publication number: 20190296669
    Abstract: A discharge control device performs discharging of a capacitor, in a state in which a battery is not connected to an inverter that drives a motor, by causing electric charges accumulated in the capacitor connected to the inverter to be consumed by windings of the motor. The discharge control device performs the discharging of the capacitor by sequentially generating command values for voltages applied to a ? axis and a ? axis while causing a voltage phase in an ?? stationary coordinate system having a rotation axis of a rotor of the motor as an origin and defined by the ? axis and the ? axis orthogonal to each other to be inverted in a predefined period.
    Type: Application
    Filed: March 14, 2019
    Publication date: September 26, 2019
    Inventor: Nobukatsu YAMAGUCHI