Patents by Inventor Kan Akatsu

Kan Akatsu 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: 11811340
    Abstract: Provided is a control device for a rotating electric machine, the control device being configured to control an inverter configured to apply a voltage to each phase winding of a rotating electric machine, to thereby control, for the each phase winding, a current to be supplied to the each phase winding, the control device including a control unit configured to: calculate a voltage command value to be applied to the each phase winding so that a phase difference between harmonic components of the same order in a radial magnetic flux density and a circumferential magnetic flux density of an air gap portion between a stator core and a rotor core of the rotating electric machine becomes a phase difference target value determined in advance, and to control the inverter in accordance with the calculated voltage command value.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: November 7, 2023
    Assignees: MITSUBISHI ELECTRIC CORPORATION, SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Yoshihiro Miyama, Kan Akatsu, Yuki Sakai, Hiroki Hijikata
  • Publication number: 20220209697
    Abstract: Provided is a control device for a rotating electric machine, the control device being configured to control an inverter configured to apply a voltage to each phase winding of a rotating electric machine, to thereby control, for the each phase winding, a current to be supplied to the each phase winding, the control device including a control unit configured to: calculate a voltage command value to be applied to the each phase winding so that a phase difference between harmonic components of the same order in a radial magnetic flux density and a circumferential magnetic flux density of an air gap portion between a stator core and a rotor core of the rotating electric machine becomes a phase difference target value determined in advance, and to control the inverter in accordance with the calculated voltage command value.
    Type: Application
    Filed: April 18, 2019
    Publication date: June 30, 2022
    Applicants: Mitsubishi Electric Corporation, Shibaura Institute of Technology
    Inventors: Yoshihiro MIYAMA, Kan AKATSU, Yuki SAKAI, Hiroki HIJIKATA
  • Patent number: 10469003
    Abstract: One end of each of phase conductors wound around a stator core in a wave winding arrangement is connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch and is connected to a negative electrode terminal of the DC power supply through a second negative electrode side switch. The other end of the phase conductor is connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch and is connected to the positive electrode terminal of the DC power supply through a second positive electrode side switch. The first positive electrode side switch, the second negative electrode side switch, the first negative electrode side switch, and the second positive electrode side switch are controlled by a controller, whereby amplitude and phase of current passing through each of the phase conductors are individually controlled.
    Type: Grant
    Filed: July 27, 2015
    Date of Patent: November 5, 2019
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshihiro Miyama, Hideaki Arita, Akihiro Daikoku, Kan Akatsu, Hiroki Hijikata
  • Publication number: 20180145617
    Abstract: One end of each of phase conductors wound around a stator core in a wave winding arrangement is connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch and is connected to a negative electrode terminal of the DC power supply through a second negative electrode side switch. The other end of the phase conductor is connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch and is connected to the positive electrode terminal of the DC power supply through a second positive electrode side switch. The first positive electrode side switch, the second negative electrode side switch, the first negative electrode side switch, and the second positive electrode side switch are controlled by a controller, whereby amplitude and phase of current passing through each of the phase conductors are individually controlled.
    Type: Application
    Filed: July 27, 2015
    Publication date: May 24, 2018
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshihiro MIYAMA, Hideaki ARITA, Akihiro DAIKOKU, Kan AKATSU, Hiroki HIJIKATA
  • Patent number: 9287745
    Abstract: There is provided a single motor which performs plural driving characteristics and can expand output range thereof. Three coils are wounded around each of the stator teeth A to F, and provided to each stator tooth A to F are switches for providing a concentrated winding state by connecting the three coils in series in each stator tooth A to F, and switches for providing a distributed winding state by connecting in series the coils of any one of units through the stator teeth A to F Depending on the rotating speed, the torque or the like, the coils are changed between the concentrated winding state and the distributed winding state.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: March 15, 2016
    Assignee: SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Kan Akatsu, Hiroki Hijikata
  • Publication number: 20130307455
    Abstract: There is provided a single motor which performs plural driving characteristics and can expand output range thereof. Three coils are wounded around each of the stator teeth A to F, and provided to each stator tooth A to F are switches for providing a concentrated winding state by connecting the three coils in series in each stator tooth A to F, and switches for providing a distributed winding state by connecting in series the coils of any one of units through the stator teeth A to F Depending on the rotating speed, the torque or the like, the coils are changed between the concentrated winding state and the distributed winding state.
    Type: Application
    Filed: January 27, 2012
    Publication date: November 21, 2013
    Applicant: SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Kan Akatsu, Hiroki Hijikata
  • Patent number: 7795772
    Abstract: A motor is basically provided with a stator, a rotor, a low permeability layer and a current control device. The stator includes a magnetic stator core and a stator winding. The rotor includes a rotor core and a plurality of permanent magnets arranged to form N and S poles of the rotor. The low permeability layer has a lower magnetic permeability than the rotor core and extends between each of the N and S poles in a direction generally parallel to the magnetic flux paths of the permanent magnets such that the permanent magnets and the low permeability are arranged to obstruct the magnetic flux between the N and S poles to provide a forward salient pole characteristic. The current control device produces a current whose phase is shifted such that the magnetic flux of the permanent magnets intensifies.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: September 14, 2010
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Publication number: 20080290753
    Abstract: A motor is basically provided with a stator, a rotor, a low permeability layer and a current control device. The stator includes a magnetic stator core and a stator winding. The rotor includes a rotor core and a plurality of permanent magnets arranged to form N and S poles of the rotor. The low permeability layer has a lower magnetic permeability than the rotor core and extends between each of the N and S poles in a direction generally parallel to the magnetic flux paths of the permanent magnets such that the permanent magnets and the low permeability are arranged to obstruct the magnetic flux between the N and S poles to provide a forward salient pole characteristic. The current control device produces a current whose phase is shifted such that the magnetic flux of the permanent magnets intensifies.
    Type: Application
    Filed: May 16, 2008
    Publication date: November 27, 2008
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Minoru ARIMITSU, Kan AKATSU
  • Patent number: 7405504
    Abstract: A rotor for a rotary electric machine includes a rotor core made of magnetic material, and being in the form of a disk, and a plurality of magnet sets each including a pair of permanent magnets whose polarities are identical to each other. The magnet sets are arranged circumferentially in the rotor core so that the polarities of the magnet sets change alternately. The rotor core includes nonmagnetic portions each formed between adjacent two of the magnet sets.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: July 29, 2008
    Assignees: Nissan Motor Co., Ltd., National University Corporation Tokyo University of Agriculture and Technology
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Patent number: 7388309
    Abstract: A rotary electric machine includes a rotor including a plurality of magnet sections arranged along a rotational direction of the rotor so that polarities of the magnet sections change alternately, and a stator including armature coils, and being disposed to confront the rotor across an air gap. Permanent magnet flux which is not linked with one of the air gap and the armature coils is higher than permanent magnet flux which is linked with the air gap and the armature coils in a no-load state.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: June 17, 2008
    Assignee: Nissna Motor Co., Ltd.
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Patent number: 7138742
    Abstract: In a rotating machine, a plurality of laminated electromagnetic steel sheets constitutes at least one of a stator and a rotor and a plurality of permanent joining portions to unit each of the laminated electromagnetic steel sheets to form a corresponding one of the stator and the rotor, the plurality of permanent joining portions being set to be located at positions at which an integration value of a magnetic flux density with respect to a plane enclosed with the permanent joining portions is always zeroed.
    Type: Grant
    Filed: July 21, 2004
    Date of Patent: November 21, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Publication number: 20060055267
    Abstract: A rotor for a rotary electric machine includes a rotor core made of magnetic material, and being in the form of a disk, and a plurality of magnet sets each including a pair of permanent magnets whose polarities are identical to each other. The magnet sets are arranged circumferentially in the rotor core so that the polarities of the magnet sets change alternately. The rotor core includes nonmagnetic portions each formed between adjacent two of the magnet sets.
    Type: Application
    Filed: September 13, 2005
    Publication date: March 16, 2006
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Publication number: 20060055268
    Abstract: A rotary electric machine includes a rotor including a plurality of magnet sections arranged along a rotational direction of the rotor so that polarities of the magnet sections change alternately, and a stator including armature coils, and being disposed to confront the rotor across an air gap. Permanent magnet flux which is not linked with one of the air gap and the armature coils is higher than permanent magnet flux which is linked with the air gap and the armature coils in a no-load state.
    Type: Application
    Filed: September 15, 2005
    Publication date: March 16, 2006
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Patent number: 6977496
    Abstract: In a coaxial multiplex position detecting apparatus for a rotating machine, a stator includes stator pieces, each stator piece individually being split in a circumferential direction of the stator, an exciting current winding, and a detection winding, the exciting current winding and the detection winding being wound on the respective stator pieces, and a plurality of rotors are disposed on outside and inside positions of the stator in a radial direction of the stator, the respective rotors having convex and recess portions in accordance with the number of poles that the respective rotors have and having different numbers of poles according to the inside and outside positions of the rotors from each other, revolution positions of the respective rotors being determined according to an output signal of the detection winding of the stator.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: December 20, 2005
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kan Akatsu, Masaki Nakano
  • Patent number: 6952069
    Abstract: An electric rotating machine including inner and outer rotors coaxially disposed and driven by a compound current, and a stator disposed between the rotors. Each of the rotors includes a plurality of permanent magnets circumferentially arranged. The stator includes a stator core and a coil to which the compound current is applied. The stator core includes a plurality of circumferentially arranged stator pieces with the coils. The stator pieces have a same shape and are formed by plates laminated in axial alignment with each other. Each stator piece includes inner and outer yokes disposed radially inside and outside, respectively, and a coil area defined between the yokes. The stator pieces adjacent to one another include a first air gap circumferentially formed between the adjacent outer yokes, a second air gap circumferentially formed between the adjacent inner yokes and mutual contact portions circumferentially contacted at the inner yokes.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: October 4, 2005
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kan Akatsu, Sachiko Taguchi
  • Patent number: 6879125
    Abstract: In control apparatus and method for at least one electrical rotating machine, two rotors are disposed in the electrical rotating machine on the same axis of rotation and being driven independently of each other by means of a generated compound current and are associated with at least one stator and a position of at least one of the rotors is controlled in such a manner that a maximum value of the compound current is reduced as low as possible.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: April 12, 2005
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Kan Akatsu
  • Publication number: 20050052091
    Abstract: In a rotating machine, a plurality of laminated electromagnetic steel sheets constitutes at least one of a stator and a rotor and a plurality of permanent joining portions to unit each of the laminated electromagnetic steel sheets to form a corresponding one of the stator and the rotor, the plurality of permanent joining portions being set to be located at positions at which an integration value of a magnetic flux density with respect to a plane enclosed with the permanent joining portions is always zeroed.
    Type: Application
    Filed: July 21, 2004
    Publication date: March 10, 2005
    Inventors: Minoru Arimitsu, Kan Akatsu
  • Patent number: 6815857
    Abstract: In an electrical rotating machine, two rotors are provided, each rotor has a plurality of permanent magnets along its peripheral direction thereof, arranged coaxially with the other rotor, and is driven by means of a compound current supplied to stator coils and a single stator has a plurality of stator coils through which the compound current is caused to flow, one of the rotors exhibiting a forward saliency characteristic and the other rotor exhibits a reverse saliency characteristic.
    Type: Grant
    Filed: November 3, 2003
    Date of Patent: November 9, 2004
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Kan Akatsu
  • Publication number: 20040130229
    Abstract: An electric rotating machine including inner and outer rotors coaxially disposed and driven by a compound current, and a stator disposed between the rotors. Each of the rotors includes a plurality of permanent magnets circumferentially arranged. The stator includes a stator core and a coil to which the compound current is applied. The stator core includes a plurality of circumferentially arranged stator pieces with the coils. The stator pieces have a same shape and are formed by plates laminated in axial alignment with each other. Each stator piece includes inner and outer yokes disposed radially inside and outside, respectively, and a coil area defined between the yokes. The stator pieces adjacent to one another include a first air gap circumferentially formed between the adjacent outer yokes, a second air gap circumferentially formed between the adjacent inner yokes and mutual contact portions circumferentially contacted at the inner yokes.
    Type: Application
    Filed: October 28, 2003
    Publication date: July 8, 2004
    Inventors: Kan Akatsu, Sachiko Taguchi
  • Publication number: 20040119373
    Abstract: In an electrical rotating machine, two rotors are provided, each rotor has a plurality of permanent magnets along its peripheral direction thereof, arranged coaxially with the other rotor, and is driven by means of a compound current supplied to stator coils and a single stator has a plurality of stator coils through which the compound current is caused to flow, one of the rotors exhibiting a forward saliency characteristic and the other rotor exhibits a reverse saliency characteristic.
    Type: Application
    Filed: November 3, 2003
    Publication date: June 24, 2004
    Inventor: Kan Akatsu