Patents by Inventor Naoshi Sugawara

Naoshi Sugawara 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: 20240149705
    Abstract: The present invention prevents a failure from occurring in an electric vehicle. This electric vehicle is driven by power obtained from a power line via a collector, an energy source mounted on the electric vehicle, or using both thereof, and causes power generated, for example, during braking to be regenerated to the power line via the collector or to be consumed in a load mounted on the electric vehicle. The electric vehicle is characterized by having a function of electrically separating the collector from the power line when the voltage of the power line or a circuit voltage within the electric vehicle deviates from a predetermined range.
    Type: Application
    Filed: March 29, 2021
    Publication date: May 9, 2024
    Inventors: Hiroaki MIYATA, Naoshi SUGAWARA, Junichi YANAGITA, Kazuhiro IMAIE
  • Patent number: 8523296
    Abstract: An electric drive vehicle having an induction motor for braking or driving wheels, a motor controller for controlling the induction motor, and mechanical brakes for braking the wheels, wherein while the vehicle is in halt in a state that the mechanical breaks are not operating, the motor controller applies DC voltage or AC voltage in a frequency range of ?1 Hz to +1 Hz to the stator of the induction motor to make the induction motor generate torque for stopping the vehicle and maintain the vehicle in a halt state.
    Type: Grant
    Filed: January 26, 2007
    Date of Patent: September 3, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
  • Patent number: 7888894
    Abstract: An electric motor control system including a generator, an AC motor, a power converter for driving the AC motor using a DC output voltage of the generator, and an electric motor controller for controlling the power converter. The electric motor controller controls the power converter by predicting a change in the DC voltage.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: February 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Naoshi Sugawara, Tetsuhiro Fujimoto, Yasuhiro Kiyofuji, Keizo Shimada, Akira Kikuchi, Kazuhiro Imaie
  • Patent number: 7841434
    Abstract: In an electric drive system for a vehicle, an alternator is driven by an engine to generate electric power which is used to drive a motor to generate a driving force. During a retardation of the vehicle, the motor is operated as an alternator to convert kinetic energy to electric energy which is used to retard the vehicle. A retard resistor is provided for absorbing electric energy generated during the retardation state. The retard resistor is cooled down by an AC blower.
    Type: Grant
    Filed: May 11, 2009
    Date of Patent: November 30, 2010
    Assignees: Hitachi, Ltd., Hitachi Construction Machinery Co., Ltd.
    Inventors: Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
  • Publication number: 20090218966
    Abstract: In an electric drive system for a vehicle, an alternator is driven by an engine to generate electric power which is used to drive a motor to generate a driving force. During a retardation of the vehicle, the motor is operated as an alternator to convert kinetic energy to electric energy which is used to retard the vehicle. A retard resistor is provided for absorbing electric energy generated during the retardation state. The retard resistor is cooled down by an AC blower.
    Type: Application
    Filed: May 11, 2009
    Publication date: September 3, 2009
    Inventors: Keizo SHIMADA, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
  • Patent number: 7583036
    Abstract: In an electrically driven vehicle having a controller, the vehicle has a steering angle sensor for outputting a detected value of a steering angle of the vehicle, the controller includes a first torque order pattern along which a torque order for a first electric motor is determined and a second torque order pattern along which a torque order for a second electric motor is determined, and the first and second torque order pattern are modified on the basis of the detected value of the steering angle so that the torque order determined along the second torque order pattern is greater than the torque order determined along the first torque order pattern under the identical velocity when the vehicle turns to the left, and the torque order determined along the first torque order pattern is greater than the torque order determined along the second torque order pattern under the identical velocity when the vehicle turns to the right.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: September 1, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
  • Publication number: 20080179122
    Abstract: An electric motor control system including a generator, an AC motor, a power converter for driving the AC motor using a DC output voltage of the generator, and an electric motor controller for controlling the power converter. The electric motor controller controls the power converter by predicting a change in the DC voltage.
    Type: Application
    Filed: January 25, 2008
    Publication date: July 31, 2008
    Inventors: Naoshi SUGAWARA, Tetsuhiro Fujimoto, Yasuhiro Kiyofuji, Keizo Shimada, Akira Kikuchi, Kazuhiro Imaie
  • Publication number: 20080001558
    Abstract: In an electrically driven vehicle having a controller, the vehicle has a steering angle sensor for outputting a detected value of a steering angle of the vehicle, the controller includes a first torque order pattern along which a torque order for a first electric motor is determined and a second torque order pattern along which a torque order for a second electric motor is determined, and the first and second torque order pattern are modified on the basis of the detected value of the steering angle so that the torque order determined along the second torque order pattern is greater than the torque order determined along the first torque order pattern under the identical velocity when the vehicle turns to the left, and the torque order determined along the first torque order pattern is greater than the torque order determined along the second torque order pattern under the identical velocity when the vehicle turns to the right.
    Type: Application
    Filed: June 19, 2007
    Publication date: January 3, 2008
    Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
  • Patent number: 7315144
    Abstract: A motor is driven with variable frequency AC power converted from DC power, and an AC output power from the motor is converted to DC. In the conversion, an electromotive force regenerated by the motor is consumed by a plurality of resistors. When the consumption of the electromotive force is impeded in any of systems including any of the plurality of resistors, the electromotive force is consumed by the systems including the remaining resistors. Even if a system including any of the plurality of resistors fails, the electromotive force can by consumed by the other systems including the remaining resistors, thus providing a reliable rheostatic brake.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: January 1, 2008
    Assignees: Hitachi, Ltd., Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuhiro Imaie, Takashi Yagyu, Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara
  • Publication number: 20070222288
    Abstract: An electric drive vehicle having an induction motor for braking or driving wheels, a motor controller for controlling the induction motor, and mechanical brakes for braking the wheels, wherein while the vehicle is in halt in a state that the mechanical breaks are not operating, the motor controller applies DC voltage or AC voltage in a frequency range of ?1 Hz to +1 Hz to the stator of the induction motor to make the induction motor generate torque for stopping the vehicle and maintain the vehicle in a halt state.
    Type: Application
    Filed: January 26, 2007
    Publication date: September 27, 2007
    Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
  • Publication number: 20060181235
    Abstract: A motor is driven with variable frequency AC power converted from DC power, and an AC output power from the motor is converted to DC. In the conversion, an electromotive force regenerated by the motor is consumed by a plurality of resistors. When the consumption of the electromotive force is impeded in any of systems including any of the plurality of resistors, the electromotive force is consumed by the systems including the remaining resistors. Even if a system including any of the plurality of resistors fails, the electromotive force can by consumed by the other systems including the remaining resistors, thus providing a reliable rheostatic brake.
    Type: Application
    Filed: February 16, 2006
    Publication date: August 17, 2006
    Inventors: Kazuhiro Imaie, Takashi Yagyu, Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara
  • Publication number: 20060086547
    Abstract: In an electric drive system for a vehicle, an alternator is driven by an engine to generate electric power which is used to drive a motor to generate a driving force. During a retardation of the vehicle, the motor is operated as an alternator to convert kinetic energy to electric energy which is used to retard the vehicle. A retard resistor is provided for absorbing electric energy generated during the retardation state. The retard resistor is cooled down by an AC blower.
    Type: Application
    Filed: December 9, 2005
    Publication date: April 27, 2006
    Inventors: Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
  • Patent number: 6720753
    Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: April 13, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
  • Patent number: 6567282
    Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects an active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: May 20, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
  • Publication number: 20030080701
    Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.
    Type: Application
    Filed: July 10, 2002
    Publication date: May 1, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
  • Publication number: 20030081434
    Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.
    Type: Application
    Filed: March 19, 2002
    Publication date: May 1, 2003
    Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki