Patents by Inventor Hirotaka KARAKAMA

Hirotaka KARAKAMA 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: 11837963
    Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: December 5, 2023
    Inventors: Hirotaka Karakama, Keisei Inoki, Yoichi Yano, Takahiro Uchino, Toshihiro Hanada
  • Patent number: 11621643
    Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: select a first control mode in response to determining that a command-primary frequency difference between a command frequency and a primary side frequency of the matrix converter circuitry is above a predetermined threshold, wherein the first control mode includes causing a secondary side frequency of the matrix converter circuitry to follow the command frequency; select a second control mode in response to determining that the command-primary frequency difference is below the threshold, wherein the second control mode includes maintaining a primary-secondary phase difference between a secondary side phase and a primary side phase of the matrix converter circuitry within a predetermined target range; and control the matrix converter circuitry in accordance with a selection of the first control mode or the secon
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: April 4, 2023
    Inventors: Hirotaka Karakama, Takahiro Uchino, Keisei Inoki, Masashiro Tanaka
  • Patent number: 11411507
    Abstract: A power conversion apparatus includes: matrix converter circuitry to perform power conversion between a primary side electric power and a secondary side electric power; rectifier circuitry to convert the primary side electric power to charge a capacitor; and control circuitry to: set a changeover reference voltage at a first reference voltage when the primary side voltage magnitude is a first voltage magnitude and set the changeover reference voltage at a second reference voltage when the primary side voltage magnitude is a second voltage magnitude; and select, based on the changeover reference voltage and the terminal voltage, a connection state from: a first connection state in which the rectifier circuitry is connected to the capacitor by a first route including a current limit device; and a second connection state in which the rectifier circuitry is connected to the capacitor by a second route that bypasses the current limit device.
    Type: Grant
    Filed: April 27, 2021
    Date of Patent: August 9, 2022
    Inventors: Hirotaka Karakama, Hidenori Hara, Masashiro Tanaka, Mitsugu Tajima, Yoichi Yano
  • Publication number: 20220069724
    Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.
    Type: Application
    Filed: August 30, 2021
    Publication date: March 3, 2022
    Inventors: Hirotaka KARAKAMA, Keisei INOKI, Yoichi YANO, Takahiro UCHINO, Toshihiro HANADA
  • Publication number: 20220069721
    Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: select a first control mode in response to determining that a command-primary frequency difference between a command frequency and a primary side frequency of the matrix converter circuitry is above a predetermined threshold, wherein the first control mode includes causing a secondary side frequency of the matrix converter circuitry to follow the command frequency; select a second control mode in response to determining that the command-primary frequency difference is below the threshold, wherein the second control mode includes maintaining a primary-secondary phase difference between a secondary side phase and a primary side phase of the matrix converter circuitry within a predetermined target range; and control the matrix converter circuitry in accordance with a selection of the first control mode or the secon
    Type: Application
    Filed: August 30, 2021
    Publication date: March 3, 2022
    Inventors: Hirotaka KARAKAMA, Takahiro UCHINO, Keisei INOKI, Masashiro TANAKA
  • Publication number: 20210336549
    Abstract: A power conversion apparatus includes: matrix converter circuitry to perform power conversion between a primary side electric power and a secondary side electric power; rectifier circuitry to convert the primary side electric power to charge a capacitor; and control circuitry to: set a changeover reference voltage at a first reference voltage when the primary side voltage magnitude is a first voltage magnitude and set the changeover reference voltage at a second reference voltage when the primary side voltage magnitude is a second voltage magnitude; and select, based on the changeover reference voltage and the terminal voltage, a connection state from: a first connection state in which the rectifier circuitry is connected to the capacitor by a first route including a current limit device; and a second connection state in which the rectifier circuitry is connected to the capacitor by a second route that bypasses the current limit device.
    Type: Application
    Filed: April 27, 2021
    Publication date: October 28, 2021
    Inventors: Hirotaka KARAKAMA, Hidenori HARA, Masashiro TANAKA, Mitsugu TAJIMA, Yoichi YANO