Patents by Inventor Shuichi Tachihara

Shuichi Tachihara 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: 9065368
    Abstract: In order to cause the residual magnetic flux in an induction motor to decay in a short time without an excessive current flow, an induction motor control apparatus continues an operation in which an inverter apparatus is caused to output a zero voltage to the induction motor for a predetermined time before deactivating an operation of the inverter apparatus.
    Type: Grant
    Filed: February 13, 2013
    Date of Patent: June 23, 2015
    Assignee: HITACHI, LTD.
    Inventors: Shuichi Tachihara, Tetsuo Kojima, Toyoki Asada, Yongqiang Xia
  • Patent number: 8924051
    Abstract: A control device for a railway vehicle controls an inverter device based on a direct-current link voltage Vfc between the opposite terminals of a filter capacitor. A direct-current voltage applied to the inverter device during regeneration is the sum of a voltage Vb of power storage equipment and an overhead wire voltage Vs, so that only detecting the direct-current link voltage Vfc is not enough to separate the voltage Vb of the power storage equipment and the overhead wire voltage Vs from each other. The power storage equipment can be connected in series with the inverter device, and a voltage sensor that detects the overhead wire voltage Vs is provided between a current collector device and a grounding point. The power storage equipment is controlled based on the detection result from the voltage sensor.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: December 30, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Daijiro Araki, Motomi Shimada, Shuichi Tachihara, Akira Horie, Masahiro Nagasu
  • Patent number: 8825240
    Abstract: In order to minimize a calculation load and surely obtain a maximum adhesion torque, estimated adhesion torques are always stored, an maximum value is obtained from the stored plural estimated adhesion torques immediately before slip/skid is detected when detecting the slip/skid, and the maximum value is set as a maximum adhesion torque. The maximum adhesion torque immediately before the slip/skid is detected is compared with a value of the estimated adhesion torque when the slip/skid is detected. When the calculated value exceeds a threshold value, it is determined as a condition where an adhesion coefficient drastically drops, and a suppression/return ratio of the torque is switched to a lower value than that under a condition where the adhesion coefficient does not drastically drop. The value of the torque at the time of suppression or return is set to a smaller value to surely suppress the slip/skid.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: September 2, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Watanabe, Motomi Shimada, Toshihiro Aono, Shuichi Tachihara
  • Publication number: 20130257343
    Abstract: In order to cause the residual magnetic flux in an induction motor to decay in a short time without an excessive current flow, an induction motor control apparatus continues an operation in which an inverter apparatus is caused to output a zero voltage to the induction motor for a predetermined time before deactivating an operation of the inverter apparatus.
    Type: Application
    Filed: February 13, 2013
    Publication date: October 3, 2013
    Applicant: HITACHI, LTD.
    Inventors: Shuichi TACHIHARA, Tetsuo KOJIMA, Toyoki ASADA, Yongqiang XIA
  • Publication number: 20130238176
    Abstract: In order to minimize a calculation load and surely obtain a maximum adhesion torque, estimated adhesion torques are always stored, an maximum value is obtained from the stored plural estimated adhesion torques immediately before slip/skid is detected when detecting the slip/skid, and the maximum value is set as a maximum adhesion torque. The maximum adhesion torque immediately before the slip/skid is detected is compared with a value of the estimated adhesion torque when the slip/skid is detected. When the calculated value exceeds a threshold value, it is determined as a condition where an adhesion coefficient drastically drops, and a suppression/return ratio of the torque is switched to a lower value than that under a condition where the adhesion coefficient does not drastically drop. The value of the torque at the time of suppression or return is set to a smaller value to surely suppress the slip/skid.
    Type: Application
    Filed: February 25, 2013
    Publication date: September 12, 2013
    Applicant: HITACHI, LTD.
    Inventors: Atsushi WATANABE, Motomi SHIMADA, Toshihiro AONO, Shuichi TACHIHARA
  • Publication number: 20130073125
    Abstract: A control device for a railway vehicle controls an inverter device based on a direct-current link voltage Vfc between the opposite terminals of a filter capacitor. A direct-current voltage applied to the inverter device during regeneration is the sum of a voltage Vb of power storage equipment and an overhead wire voltage Vs, so that only detecting the direct-current link voltage Vfc is not enough to separate the voltage Vb of the power storage equipment and the overhead wire voltage Vs from each other. The power storage equipment can be connected in series with the inverter device, and a voltage sensor that detects the overhead wire voltage Vs is provided between a current collector device and a grounding point. The power storage equipment is controlled based on the detection result from the voltage sensor.
    Type: Application
    Filed: May 31, 2011
    Publication date: March 21, 2013
    Inventors: Daijiro Araki, Motomi Shimada, Shuichi Tachihara, Akira Horie, Masahiro Nagasu