Patents by Inventor Kengo Maikawa

Kengo Maikawa 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: 8716976
    Abstract: A contactless electricity-supplying device (20) includes a secondary winding (201) to which electric power is supplied from a primary winding (101), by an AC power supply (6). The impedance characteristic (Z) of Z1 in regard to the frequency has a local maximum (ZMAX) near the frequency (f0) of the fundamental wave component of aforementioned AC power supply (6); and the impedance characteristic (Z) of Z2 in regard to the frequency has the aforementioned frequency (f0) of the fundamental wave component to be between, a frequency (fMAX) that has its local maximum (ZMAX) nearest to aforementioned frequency (f0) of the fundamental wave component, and a frequency (fMIN) that has its local minimum (ZMin) nearest to the frequency (f0) of the fundamental wave component. Z1 indicates that the coupling coefficient (k) between aforementioned primary winding (101) and aforementioned secondary winding (201) is a prescribed value (0.
    Type: Grant
    Filed: May 14, 2010
    Date of Patent: May 6, 2014
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Toshihiro Kai, Kraisorn Throngnumchai, Yusuke Minagawa, Yasuaki Hayami, Kengo Maikawa
  • Publication number: 20140103871
    Abstract: A contactless electric power supply device 100 to charge a battery 28 of a vehicle includes a power transmitting circuit 101 having a power transmitting coil 12 and a charging circuit 201 having a power receiving coil 22. An electric power is transmitted from power transmitting coil 12 to power receiving coil 22 in a contactless manner. When the vehicle approaches power supply device 100, a trial power supply in which a electric power transmission through a minute electric power is carried out is executed and a power transmission efficiency from power transmitting coil 12 to power receiving coil 22 is estimated on a basis of a current flowing through power transmitting circuit 101. From this power transmission efficiency, a determination of whether power receiving coil 22 falls in a range in which battery 28 is chargeable with respect to power transmitting coil 12 is made.
    Type: Application
    Filed: May 23, 2012
    Publication date: April 17, 2014
    Inventors: Kengo Maikawa, Hiroshi Tanaka, Tomoya Imazu
  • Publication number: 20130169062
    Abstract: This contactless electricity supply device, which contactlessly performs charging of the battery (28) of a vehicle, is provided with: an electricity transmission coil (12) disposed at a road surface; and an electricity reception coil (22) disposed in the vehicle. A foreign object detection coil (13) is provided to the upper surface of the electricity transmission coil (12), and on the basis of induced voltage arising at the foreign object detection coil (13) during a trial electricity supply, foreign objects between the electricity transmission coil (12) and the electricity reception coil (22) are detected.
    Type: Application
    Filed: May 23, 2012
    Publication date: July 4, 2013
    Inventors: Kengo Maikawa, Tomoya Imazu
  • Publication number: 20120056580
    Abstract: A contactless electricity-supplying device (20) includes a secondary winding (201) to which electric power is supplied from a primary winding (101), by an AC power supply (6). The impedance characteristic (Z) of Z1 in regard to the frequency has a local maximum (ZMAX) near the frequency (f0) of the fundamental wave component of aforementioned AC power supply (6); and the impedance characteristic (Z) of Z2 in regard to the frequency has the aforementioned frequency (f0) of the fundamental wave component to be between, a frequency (fMAX) that has its local maximum (ZMAX) nearest to aforementioned frequency (f0) of the fundamental wave component, and a frequency (fMIN) that has its local minimum (ZMin) nearest to the frequency (f0) of the fundamental wave component. Z1 indicates that the coupling coefficient (k) between aforementioned primary winding (101) and aforementioned secondary winding (201) is a prescribed value (0.
    Type: Application
    Filed: May 14, 2010
    Publication date: March 8, 2012
    Inventors: Toshihiro Kai, Kraisorn Throngnumchai, Yusuke Minagawa, Yasuaki Hayami, Kengo Maikawa
  • Patent number: 7710063
    Abstract: An electric power converter, electric power conversion system and method that, without using a DC-DC converter, uses and allots the electric power of plural power sources while reducing the volume and losses. At least one phase of the motor is connected to plural power sources and generates and synthesizes pulses from output voltages of plural power sources so as to drive the multi-phase AC motor. A different phase of the motor is connected to one DC power source and generates pulses from the output voltage of the power source so as to generate a driving voltage for the multi-phase AC motor. This arrangement allows use/allotment of the power of plural power sources with a reduced number of semiconductor components.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: May 4, 2010
    Assignee: Nissan Moto Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Patent number: 7710065
    Abstract: A power conversion system includes first and second voltage sources for driving a multiple-phase AC motor and a control unit. The control unit is configured to compute first and second output voltage command values used to drive the multiple-phase AC motor based on a first output voltage command vector corresponding to the voltage source that is charged and a second output voltage command vector corresponding to the voltage source that is discharged. The first and second output voltage command vectors are determined so that a resultant vector of the first and second output voltage command vectors is coincident with a motor voltage command vector corresponding to a motor voltage command value, and a motor current command vector corresponding to the motor current command value is positioned within an included angle formed between the second output voltage command vector and a negative vector of the first output voltage command vector.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: May 4, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Sho Sato, Kantaro Yoshimoto, Kengo Maikawa, Yuki Nakajima
  • Patent number: 7659689
    Abstract: An apparatus and method for supplying a polyphase (AC) alternating current motor with driving voltages. A conversion unit is coupled to phases of the polyphase AC motor and includes a plurality of switching devices and includes, in at least one phase, a first switching device between a bus of an AC power supply and an output terminal, a second switching device between a bus of a direct current (DC) power supply and the output terminal, and a third switching device between a common bus for the AC power supply and the DC power supply and the output terminal. Driving voltages for the polyphase AC motor are generated by selecting a voltage from among voltages having potential values corresponding to the AC power supply and the DC power supply, and the selected voltage is used to operate a switch of the plurality of switching devices.
    Type: Grant
    Filed: March 6, 2007
    Date of Patent: February 9, 2010
    Assignee: Nissan Motor Co., Ltd
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Patent number: 7598692
    Abstract: An electric power converter, electric power converter controlling method and electric power converting system for converting multi-phase alternating-current inputted from a generator and outputting multi-phase alternating current for controlling a drive of a motor. An input power factor commanding section outputs a command value of an input power factor according to an operating condition of the motor, and an input power factor controlling section controls the input power factor of the generator on the basis of the command value of the input power factor from the input power factor commanding section.
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: October 6, 2009
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kengo Maikawa, Kantaro Yoshimoto
  • Patent number: 7557527
    Abstract: An electrical power converter comprises a first direct current line connected to a first direct current source, a second direct current line connected to a second direct current source, an alternating current line connected to an alternating current motor, a controller, and a pulse generator. The controller determines a required torque of the alternating current motor. The controller also determines a voltage command value that substantially minimizes a copper loss of the alternating current motor while providing the required torque of the alternating current motor. The pulse generator generates an output voltage according to the voltage command value at the alternating current output.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: July 7, 2009
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Publication number: 20080258662
    Abstract: A power conversion system includes first and second voltage sources for driving a multiple-phase AC motor and a control unit. The control unit is configured to compute first and second output voltage command values used to drive the multiple-phase AC motor based on a first output voltage command vector corresponding to the voltage source that is charged and a second output voltage command vector corresponding to the voltage source that is discharged. The first and second output voltage command vectors are determined so that a resultant vector of the first and second output voltage command vectors is coincident with a motor voltage command vector corresponding to a motor voltage command value, and a motor current command vector corresponding to the motor current command value is positioned within an included angle formed between the second output voltage command vector and a negative vector of the first output voltage command vector.
    Type: Application
    Filed: October 23, 2007
    Publication date: October 23, 2008
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Sho SATO, Kantaro YOSHIMOTO, Kengo MAIKAWA, Yuki NAKAJIMA
  • Publication number: 20070216339
    Abstract: An electric power converter, electric power conversion system and method that, without using a DC-DC converter, uses and allots the electric power of plural power sources while reducing the volume and losses. At least one phase of the motor is connected to plural power sources and generates and synthesizes pulses from output voltages of plural power sources so as to drive the multi-phase AC motor. A different phase of the motor is connected to one DC power source and generates pulses from the output voltage of the power source so as to generate a driving voltage for the multi-phase AC motor. This arrangement allows use/allotment of the power of plural power sources with a reduced number of semiconductor components.
    Type: Application
    Filed: March 15, 2007
    Publication date: September 20, 2007
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Publication number: 20070216338
    Abstract: An apparatus and method for supplying a polyphase (AC) alternating current motor with driving voltages. A conversion unit is coupled to phases of the polyphase AC motor and includes a plurality of switching devices and includes, in at least one phase, a first switching device between a bus of an AC power supply and an output terminal, a second switching device between a bus of a direct current (DC) power supply and the output terminal, and a third switching device between a common bus for the AC power supply and the DC power supply and the output terminal. Driving voltages for the polyphase AC motor are generated by selecting a voltage from among voltages having potential values corresponding to the AC power supply and the DC power supply, and the selected voltage is used to operate a switch of the plurality of switching devices.
    Type: Application
    Filed: March 6, 2007
    Publication date: September 20, 2007
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Publication number: 20070159121
    Abstract: An electric power converter, electric power converter controlling method and electric power converting system for converting multi-phase alternating-current inputted from a generator and outputting multi-phase alternating current for controlling a drive of a motor. An input power factor commanding section outputs a command value of an input power factor according to an operating condition of the motor, and an input power factor controlling section controls the input power factor of the generator on the basis of the command value of the input power factor from the input power factor commanding section.
    Type: Application
    Filed: January 11, 2007
    Publication date: July 12, 2007
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Kengo Maikawa, Kantaro Yoshimoto
  • Publication number: 20060273748
    Abstract: An electrical power converter comprises a first direct current line connected to a first direct current source, a second direct current line connected to a second direct current source, an alternating current line connected to an alternating current motor, a controller, and a pulse generator. The controller determines a required torque of the alternating current motor. The controller also determines a voltage command value that substantially minimizes a copper loss of the alternating current motor while providing the required torque of the alternating current motor. The pulse generator generates an output voltage according to the voltage command value at the alternating current output.
    Type: Application
    Filed: May 31, 2006
    Publication date: December 7, 2006
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa