Patents by Inventor Koji Yakushi

Koji Yakushi 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: 8240148
    Abstract: The present invention provides a turbine system which can start a turbine, while controlling thermal stress generated in a turbine rotor and an expansion difference, due to thermal expansion, between a casing and the turbine rotor, to be lower than defined values, respectively. The turbine system (1) according to the present invention includes the turbine (4) having a casing (2) and the turbine rotor (3) rotatably attached to the casing (2), and a main steam pipe (5) connected to an upstream portion of the casing (2). A control valve (6) adapted for controlling a flow rate of steam discharging into the casing (2) is provided with the main steam pipe (5), and a power generator (7) is coupled with the turbine rotor (3). Additionally, a starting control system (10) is adapted for controlling the control valve (6), while obtaining an operational amount of the control valve (6).
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: August 14, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shigeru Matsumoto, Koji Yakushi, Asako Inomata, Eiji Nakagawa
  • Patent number: 7980053
    Abstract: A turbine starting controller includes: an optimum starting control unit for predicting, while taking as a variable a turbine acceleration rate/load increase rate as a directly manipulated variable, thermal stress generated in a turbine rotor over a prediction period from a current time to the future, calculating for each control cycle a manipulated variable optimum transition pattern in the prediction period which makes a turbine starting time shortest while keeping the predicted thermal stress equal to or lower than a prescribed value, and determining as an actual optimum manipulated value a value at the current time in the manipulated variable optimum transition pattern; and an rpm/load control unit to which the optimum manipulated variable from the optimum starting control unit is input, for controlling the drive of control valves.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: July 19, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Yakushi, Akimasa Nakai
  • Publication number: 20090288416
    Abstract: The present invention provides a turbine system which can start a turbine, while controlling thermal stress generated in a turbine rotor and an expansion difference, due to thermal expansion, between a casing and the turbine rotor, to be lower than defined values, respectively. The turbine system (1) according to the present invention includes the turbine (4) having a casing (2) and the turbine rotor (3) rotatably attached to the casing (2), and a main steam pipe (5) connected to an upstream portion of the casing (2). A control valve (6) adapted for controlling a flow rate of steam discharging into the casing (2) is provided with the main steam pipe (5), and a power generator (7) is coupled with the turbine rotor (3). Additionally, a starting control system (10) is adapted for controlling the control valve (6), while obtaining an operational amount of the control valve (6).
    Type: Application
    Filed: May 20, 2009
    Publication date: November 26, 2009
    Inventors: Shigeru MATSUMOTO, Koji YAKUSHI, Asako INOMATA, Eiji NAKAGAWA
  • Publication number: 20060233637
    Abstract: A turbine starting controller includes: an optimum starting control unit for predicting, while taking as a variable a turbine acceleration rate/load increase rate as a directly manipulated variable, thermal stress generated in a turbine rotor over a prediction period from a current time to the future, calculating for each control cycle a manipulated variable optimum transition pattern in the prediction period which makes a turbine starting time shortest while keeping the predicted thermal stress equal to or lower than a prescribed value, and determining as an actual optimum manipulated value a value at the current time in the manipulated variable optimum transition pattern; and an rpm/load control unit to which the optimum manipulated variable from the optimum starting control unit is input, for controlling the drive of control valves.
    Type: Application
    Filed: March 15, 2006
    Publication date: October 19, 2006
    Inventors: Koji Yakushi, Akimasa Nakai
  • Patent number: 7000893
    Abstract: A servo-valve control device for controlling servo-valve opening. The servo-valve opening follows a target by inputting signals of a servo-valve opening target value and of an actual servo-valve opening. The control device has a controller, which is constructed to receive a signal of difference between the servo-valve opening target value and the actual servo-valve opening, and to generate a servo command signal for driving the servo valve. The control device also has an extended observer, which is constructed to receive the actual valve opening signal and the servo command signal, and to estimate an input-terminal disturbance signal added on the servo valve. The control device also has a modification part, which is constructed to modify the servo command signal by subtracting the estimated input-terminal disturbance signal output from the extended observer, from the servo command signal.
    Type: Grant
    Filed: January 2, 2004
    Date of Patent: February 21, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koji Yakushi
  • Publication number: 20040193327
    Abstract: A servo-valve control device for controlling servo-valve opening. The servo-valve opening follows a target by inputting signals of a servo-valve opening target value and of an actual servo-valve opening. The control device has a controller, which is constructed to receive a signal of difference between the servo-valve opening target value and the actual servo-valve opening, and to generate a servo command signal for driving the servo valve. The control device also has an extended observer, which is constructed to receive the actual valve opening signal and the servo command signal, and to estimate an input-terminal disturbance signal added on the servo valve. The control device also has a modification part, which is constructed to modify the servo command signal by subtracting the estimated input-terminal disturbance signal output from the extended observer, from the servo command signal.
    Type: Application
    Filed: January 2, 2004
    Publication date: September 30, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Koji Yakushi