Patents by Inventor Kantaro Yoshimoto

Kantaro Yoshimoto 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: 8917053
    Abstract: An electric power converter (1A) transmits and receives, via a transformer (14), electric power between alternating current power source (2) and second battery (4) or between first battery (3) and second battery. The electric power converter includes: a common bus bar (CB) for connecting the following members to primary winding (141a, 141b) of transformer (14): first electrode of alternating current power source, and first electrode of first battery; a first switch circuit (13) for selectively connecting the following members to primary winding (141a, 141b) of transformer: second electrode of alternating current power source, and second electrode of first battery; a second switch circuit (15) for connecting second battery to secondary winding (142a, 142b) of transformer; and a controller (100) for controlling the electric power of the alternating current power source, first battery and second battery by turning on and off switches of the first and second switch circuits (13, 15).
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: December 23, 2014
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Kantaro Yoshimoto
  • Publication number: 20110273136
    Abstract: An electric power converter (1A) transmits and receives, via a transformer (14), electric power between alternating current power source (2) and second battery (4) or between first battery (3) and second battery. The electric power converter includes: a common bus bar (CB) for connecting the following members to primary winding (141a, 141b) of transformer (14): first electrode of alternating current power source, and first electrode of first battery; a first switch circuit (13) for selectively connecting the following members to primary winding (141a, 141b) of transformer: second electrode of alternating current power source, and second electrode of first battery; a second switch circuit (15) for connecting second battery to secondary winding (142a, 142b) of transformer; and a controller (100) for controlling the electric power of the alternating current power source, first battery and second battery by turning on and off switches of the first and second switch circuits (13, 15).
    Type: Application
    Filed: December 15, 2009
    Publication date: November 10, 2011
    Inventor: Kantaro Yoshimoto
  • 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: 7656689
    Abstract: A control method for a power converter capable of reducing overall volume of a system and energy loss by using a plurality of power sources and distributing loads to them without a DCDC converter. The power converter has DC power sources and poles formed by connecting various poles of the DC sources. Voltage is applied to a load by switching between poles. The method includes operating a switch between poles of the first DC power source when a voltage command is lower than the electric potential of the second DC power source; and operating a switch between the poles of the second DC source when the voltage command is higher than the electric potential of the second DC source.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: February 2, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko KitaJima
  • 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: 7586768
    Abstract: An electric power conversion apparatus includes a power converter connected to at least a first DC voltage source, a second DC voltage source and an AC electric motor. A control unit controls the power converter to generate a first PWM pulse train for supplying a first output voltage pulse train from the first DC voltage source to the AC electric motor and a second PWM pulse train for supplying a second output voltage pulse train from the second DC voltage source to the load in such a manner to form a pulse continuous in time in a final output voltage at least from each pulse of the first output voltage pulse train and a subsequent pulse of the second output voltage pulse train. A current path is provided constantly from the AC electric motor to at least one of the DC voltage sources.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: September 8, 2009
    Assignee: Nissan Motor Co., Ltd.
    Inventor: 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: 20080238200
    Abstract: A control method for a power converter capable of reducing overall volume of a system and energy loss by using a plurality of power sources and distributing loads to them without a DCDC converter and a combination of a fuel cell and a battery. The power converter has DC power sources, and poles formed by connecting various poles of the DC sources. Voltage is applied to a load by switching between poles. The method includes determining conductivity for a switch between poles of said first DC power source when a voltage command is lower than the electric potential output by said second DC power source; determining conductivity for a switch between the poles of said second DC source when the voltage command is higher than the electric potential output by said second DC source; and switching the pole to be connected to said load in accordance with the determinations.
    Type: Application
    Filed: October 20, 2005
    Publication date: October 2, 2008
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima
  • 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: 20070194746
    Abstract: An electric power conversion apparatus includes a power converter connected to at least a first DC voltage source, a second DC voltage source and an AC electric motor. A control unit controls the power converter to generate a first PWM pulse train for supplying a first output voltage pulse train from the first DC voltage source to the AC electric motor and a second PWM pulse train for supplying a second output voltage pulse train from the second DC voltage source to the load in such a manner to form a pulse continuous in time in a final output voltage at least from each pulse of the first output voltage pulse train and a subsequent pulse of the second output voltage pulse train. A current path is provided constantly from the AC electric motor to at least one of the DC voltage sources.
    Type: Application
    Filed: December 20, 2006
    Publication date: August 23, 2007
    Inventor: Kantaro Yoshimoto
  • 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
  • Patent number: 7183728
    Abstract: A motor drive system includes a multi-output dc power source providing three or more output potentials, and a switching circuit including switching devices connected, respectively, with the output potentials of the multi-output power source. A controller determines a command apply voltage representing a desired voltage to be applied to the motor, and further determines a plurality of command share voltages corresponding to supply voltages of the multi-output dc power source, from the command apply voltage. The controller produces a pulsed voltage by driving the switching devices in accordance with the command share voltages.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: February 27, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yasuhiko Kitajima, 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
  • Patent number: 7122991
    Abstract: A power conversion system for converting a dc voltage to a pulsed ac voltage includes a dc voltage source providing three or more electric potentials, and a switching circuit arranged to connect one of the potentials selectively to an output terminal. A controller produces a pulsed ac output voltage at the output terminal from the potentials of the dc voltage source by controlling an on time for connecting each of the potentials to the output terminal.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: October 17, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yasuhiko Kitajima, Kantaro Yoshimoto, Masanori Yamagiwa, Ryuuta Yamaguchi, Yutaka Tajima, Yasuaki Hayami
  • Publication number: 20060091833
    Abstract: A motor drive system includes a multi-output dc power source providing three or more output potentials, and a switching circuit including switching devices connected, respectively, with the output potentials of the multi-output power source. A controller determines a command apply voltage representing a desired voltage to be applied to the motor, and further determines a plurality of command share voltages corresponding to supply voltages of the multi-output dc power source, from the command apply voltage. The controller produces a pulsed voltage by driving the switching devices in accordance with the command share voltages.
    Type: Application
    Filed: October 26, 2005
    Publication date: May 4, 2006
    Inventors: Yasuhiko Kitajima, Kantaro Yoshimoto
  • Patent number: 7034493
    Abstract: A motor control apparatus having a fundamental wave current control circuit that implements feedback control on a fundamental wave component of a motor current in a dq coordinate system rotating in synchronization with the rotation of the motor and a higher harmonic current control circuit that implements feedback control on a higher harmonic components of the motor current in a dhqh coordinate system rotating with a frequency which is an integral multiple of the frequency of the fundamental wave component of the motor current, eliminates the higher harmonic component of the motor current from the control deviation between a fundamental wave current command value and a motor current feedback value.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: April 25, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima