Patents by Inventor Mitsujiro Sawamura

Mitsujiro Sawamura 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: 20060049795
    Abstract: It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.
    Type: Application
    Filed: July 2, 2003
    Publication date: March 9, 2006
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventors: Hideaki Iura, Kazuhiro Nonaka, Yuichi Terazono, Yoichi Yamamoto, Satoshi Sueshima, Katsushi Terazono, Mitsujiro Sawamura
  • Publication number: 20060049787
    Abstract: It is an object of the invention to provide an apparatus for estimating a magnetic pole position of a motor in which the amplitudes of high-frequency currents can be adjusted. In the invention, a controlling apparatus for driving a motor (1-1) by a voltage source PWM inverter (1-2), and controlling a torque and speed, or torque, speed, and position of the motor has: means for switching over first means for producing an arbitrary phase difference in PWM carrier signals between respective two phases such as UV, VW, or WU of three or UVW phases, and second means for causing the phase difference between two phases such as V, VW, or WU of three or UVW phases to become zero; means for extracting high-frequency currents in a same frequency band as carrier signals generated by it, from estimated currents; and means (1-4) for estimating a magnetic pole position by using the extracted high-frequency currents.
    Type: Application
    Filed: September 25, 2003
    Publication date: March 9, 2006
    Inventors: Kozo Ide, Mitsujiro Sawamura, Mengesha Wogari, Jun Oyama
  • Patent number: 4916376
    Abstract: An inverter driving method for has an arrangement polyphase induction motor, for altering a plurality of winding connections of the motor and a storage arrangement for a plurality of motor control constant groups preset corresponding to the respective winding connections so as to perform optimal vector control. When the classification of the winding connection is selected, one set of motor control constant groups corresponding to the winding connection is read out of the storage arrangement and applied to a control unit of the induction motor as control constants.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: April 10, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Tuneo Kume, Toshihiro Sawa, Masanobu Miyazato, Mitsujiro Sawamura, Michihiko Zenke