Patents by Inventor Daijiro ARAKI

Daijiro ARAKI 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: 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: 8816615
    Abstract: In a drive device for a railway vehicle, in which regeneration braking force is increased by adding the output voltage of a voltage adjustment device to a DC power source voltage, operation of the current control device is started prior to the start of the power running operation or the regeneration operation of the inverter device, and the operation of the current control device is stopped later than the stopping of the power running operation or the regeneration operation of the inverter device. Thereby, the current control device is surely operated at least during the operation period of the inverter device, so that the output voltage of the voltage adjustment device is adjusted by the current control device, to thereby prevent the over-discharge of the energy storage device at the time of power running operation or the overcharge of the energy storage device at the time of regeneration operation.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: August 26, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Daijiro Araki, Motomi Shimada, Yoshihiro Miyaji, Keita Suzuki, Keishi Suzuki
  • 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
  • Publication number: 20130063055
    Abstract: In a drive device for a railway vehicle, in which regeneration braking force is increased by adding the output voltage of a voltage adjustment device to a DC power source voltage, operation of the current control device is started prior to the start of the power running operation or the regeneration operation of the inverter device, and the operation of the current control device is stopped later than the stopping of the power running operation or the regeneration operation of the inverter device. Thereby, the current control device is surely operated at least during the operation period of the inverter device, so that the output voltage of the voltage adjustment device is adjusted by the current control device, to thereby prevent the over-discharge of the energy storage device at the time of power running operation or the overcharge of the energy storage device at the time of regeneration operation.
    Type: Application
    Filed: August 10, 2012
    Publication date: March 14, 2013
    Inventors: Daijiro ARAKI, Motomi Shimada, Yoshihiro Miyaji, Keita Suzuki, Keishi Suzuki