Patents by Inventor Takayuki FUJISAWA

Takayuki FUJISAWA 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: 11201461
    Abstract: A power system includes: a self-commutated power converter including a first arm and a second arm, each including switching elements; a first circuit breaker configured to interrupt a current flowing through a power transmission line provided between a first bus and a second bus; a first circuit breaker control unit configured to control the first circuit breaker; a converter control unit configured to stop the switching elements based on a first arm current value and a second arm current value; and a setting unit configured to set a voltage value of an AC voltage output from the power converter such that when a fault occurs in the power transmission line, the first circuit breaker is opened while the switching elements are not stopped. The converter control unit is configured to operate the switching elements such that an AC voltage with the set voltage value is output.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: December 14, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Keisuke Ishida, Takayuki Fujisawa
  • Patent number: 11165253
    Abstract: A power control system includes: a first AC/DC converter; a second AC/DC converter; a first switch connected between a first transmission line of a first power system having a first system frequency and the first AC/DC converter; a second switch connected between the first transmission line and the second AC/DC converter; a third switch connected between a second transmission line of a second power system having a second system frequency and the first AC/DC converter; a fourth switch connected between the second transmission line and the second AC/DC converter; a fifth switch connected between the first AC/DC converter and the second AC/DC converter; and a control device. When the first and second AC/DC converters are caused to operate as AC/DC converters in a BTB (Back to Back) method, the control device controls at least the fifth switch to be in a closed state.
    Type: Grant
    Filed: August 1, 2016
    Date of Patent: November 2, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takayuki Fujisawa, Keisuke Ishida
  • Publication number: 20210021129
    Abstract: A power control system includes: a first AC/DC converter; a second AC/DC converter; a first switch connected between a first transmission line of a first power system having a first system frequency and the first AC/DC converter; a second switch connected between the first transmission line and the second AC/DC converter; a third switch connected between a second transmission line of a second power system having a second system frequency and the first AC/DC converter; a fourth switch connected between the second transmission line and the second AC/DC converter; a fifth switch connected between the first AC/DC converter and the second AC/DC converter; and a control device. When the first and second AC/DC converters are caused to operate as AC/DC converters in a BTB (Back to Back) method, the control device controls at least the fifth switch to be in a closed state.
    Type: Application
    Filed: August 1, 2016
    Publication date: January 21, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takayuki FUJISAWA, Keisuke ISHIDA
  • Publication number: 20200161852
    Abstract: A power system includes: a self-commutated power converter including a first arm and a second arm, each including switching elements; a first circuit breaker configured to interrupt a current flowing through a power transmission line provided between a first bus and a second bus; a first circuit breaker control unit configured to control the first circuit breaker; a converter control unit configured to stop the switching elements based on a first arm current value and a second arm current value; and a setting unit configured to set a voltage value of an AC voltage output from the power converter such that when a fault occurs in the power transmission line, the first circuit breaker is opened while the switching elements are not stopped. The converter control unit is configured to operate the switching elements such that an AC voltage with the set voltage value is output.
    Type: Application
    Filed: June 8, 2017
    Publication date: May 21, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Keisuke ISHIDA, Takayuki FUJISAWA