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).
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Publication number: 20240149705Abstract: 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: ApplicationFiled: March 29, 2021Publication date: May 9, 2024Inventors: Hiroaki MIYATA, Naoshi SUGAWARA, Junichi YANAGITA, Kazuhiro IMAIE
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Patent number: 8523296Abstract: 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: GrantFiled: January 26, 2007Date of Patent: September 3, 2013Assignee: Hitachi, Ltd.Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
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Patent number: 7888894Abstract: 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: GrantFiled: January 25, 2008Date of Patent: February 15, 2011Assignee: Hitachi, Ltd.Inventors: Naoshi Sugawara, Tetsuhiro Fujimoto, Yasuhiro Kiyofuji, Keizo Shimada, Akira Kikuchi, Kazuhiro Imaie
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Patent number: 7841434Abstract: 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: GrantFiled: May 11, 2009Date of Patent: November 30, 2010Assignees: Hitachi, Ltd., Hitachi Construction Machinery Co., Ltd.Inventors: Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
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Publication number: 20090218966Abstract: 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: ApplicationFiled: May 11, 2009Publication date: September 3, 2009Inventors: Keizo SHIMADA, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
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Patent number: 7583036Abstract: 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: GrantFiled: June 19, 2007Date of Patent: September 1, 2009Assignee: Hitachi, Ltd.Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
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Publication number: 20080179122Abstract: 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: ApplicationFiled: January 25, 2008Publication date: July 31, 2008Inventors: Naoshi SUGAWARA, Tetsuhiro Fujimoto, Yasuhiro Kiyofuji, Keizo Shimada, Akira Kikuchi, Kazuhiro Imaie
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Publication number: 20080001558Abstract: 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: ApplicationFiled: June 19, 2007Publication date: January 3, 2008Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
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Patent number: 7315144Abstract: 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: GrantFiled: February 16, 2006Date of Patent: January 1, 2008Assignees: Hitachi, Ltd., Hitachi Construction Machinery Co., Ltd.Inventors: Kazuhiro Imaie, Takashi Yagyu, Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara
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Publication number: 20070222288Abstract: 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: ApplicationFiled: January 26, 2007Publication date: September 27, 2007Inventors: Akira Kikuchi, Takashi Ikimi, Keizo Shimada, Naoshi Sugawara
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Publication number: 20060181235Abstract: 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: ApplicationFiled: February 16, 2006Publication date: August 17, 2006Inventors: Kazuhiro Imaie, Takashi Yagyu, Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara
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Publication number: 20060086547Abstract: 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: ApplicationFiled: December 9, 2005Publication date: April 27, 2006Inventors: Keizo Shimada, Yasuhiro Kiyofuji, Naoshi Sugawara, Kazuhiro Imaie, Shintarou Oku, Takashi Yagyu
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Patent number: 6720753Abstract: 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: GrantFiled: July 10, 2002Date of Patent: April 13, 2004Assignee: Hitachi, Ltd.Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
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Patent number: 6567282Abstract: 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: GrantFiled: March 19, 2002Date of Patent: May 20, 2003Assignee: Hitachi, Ltd.Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
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Publication number: 20030080701Abstract: 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: ApplicationFiled: July 10, 2002Publication date: May 1, 2003Applicant: Hitachi, Ltd.Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki
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Publication number: 20030081434Abstract: 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: ApplicationFiled: March 19, 2002Publication date: May 1, 2003Inventors: Akira Kikuchi, Motoo Futami, Yasuyuki Sugiura, Naoshi Sugawara, Kouichi Miyazaki