Patents by Inventor Kazuto Oyama

Kazuto Oyama 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: 11222150
    Abstract: The invention is directed to modeling of heat and vibration for structures. Therefore, with a traditional model division for each component, one-to-one correspondence between the models and the components is not necessarily realized. There has been a problem in that it is difficult to divide the models. To solve the above problem, a simulation program according to the present invention includes a first model for calculating a first vehicle characteristics parameter, a second model for calculating a second vehicle characteristics parameter to transfer energy without converting the energy, and an interface model for performing conversion calculation of the first vehicle characteristics parameter and the second vehicle characteristics parameter.
    Type: Grant
    Filed: January 19, 2017
    Date of Patent: January 11, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Taizou Miyazaki, Masaru Yamasaki, Takafumi Hara, Katsuhiro Hoshino, Kazuto Oyama, Takeshi Yoshida
  • Patent number: 10873285
    Abstract: This is to reduce electromagnetic noise while reducing a calculation load of a microcomputer. An inverter drive device according to the present invention switches a first control mode, a second control mode, and a third control mode on the basis of vehicle speed information in a motor control device that controls a power converter that drives a polyphase motor by a PWM pulse signal based on a carrier signal, the first control mode being for updating a command voltage signal to the power converter only on a ridge side or a trough side of the carrier signal, the second control mode being for updating a command voltage signal to the power converter both on a ridge side and a trough side of the carrier signal, and the third control mode being for updating a command voltage signal to the power converter only once of ridge-trough-ridge or trough-ridge-trough of the carrier signal.
    Type: Grant
    Filed: November 10, 2017
    Date of Patent: December 22, 2020
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Katsuhiro Hoshino, Akihiro Ashida, Kazuto Oyama
  • Patent number: 10693410
    Abstract: A control device and a control method for a rotary electric motor, and a rotary electric motor drive system capable of reliably suppressing vibration of the rotary electric motor are provided. A rotary electric motor is controlled by PWM at a predetermined carrier frequency, and in a case where a vibration frequency in a space zero-order eigenmode of the rotary electric motor and a frequency of a frequency component of electromagnetic exciting force that generates the eigenmode overlap with each other, a value of the carrier frequency is switched from a first value to a second value different from the first value.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: June 23, 2020
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takeshi Yoshida, Takafumi Hara, Katsuhiro Hoshino, Kazuto Oyama
  • Publication number: 20190334469
    Abstract: This is to reduce electromagnetic noise while reducing a calculation load of a microcomputer. An inverter drive device according to the present invention switches a first control mode, a second control mode, and a third control mode on the basis of vehicle speed information in a motor control device that controls a power converter that drives a polyphase motor by a PWM pulse signal based on a carrier signal, the first control mode being for updating a command voltage signal to the power converter only on a ridge side or a trough side of the carrier signal, the second control mode being for updating a command voltage signal to the power converter both on a ridge side and a trough side of the carrier signal, and the third control mode being for updating a command voltage signal to the power converter only once of ridge-trough-ridge or trough-ridge-trough of the carrier signal.
    Type: Application
    Filed: November 10, 2017
    Publication date: October 31, 2019
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Katsuhiro HOSHINO, Akihiro ASHIDA, Kazuto OYAMA
  • Patent number: 10447183
    Abstract: A motor is driven while suppressing drive torque ripple generated by the motor, when any of the phases is opened during the driving of the motor. A motor drive device controls the driving of a motor in which the armature windings of respective phases are independently provided. The motor drive device is equipped with: an inverter circuit for converting the DC power supplied through DC bus lines to three-phase AC powers and respectively outputting the three-phase AC powers to the armature windings of the respective phases; and a controller for controlling the inverter circuit. When any of the phases is opened in the AC powers output from the inverter circuit, the controller adjusts the difference between the phases of the respective currents flowing through the armature windings of normal phases so that the AC powers of the other normal phases except the opened phase are compensated each other.
    Type: Grant
    Filed: June 24, 2015
    Date of Patent: October 15, 2019
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Katsuhiro Hoshino, Shingo Nishiguchi, Toshisada Mitsui, Kazuto Oyama, Hideki Miyazaki
  • Publication number: 20190222160
    Abstract: A control device and a control method for a rotary electric motor, and a rotary electric motor drive system capable of reliably suppressing vibration of the rotary electric motor are provided. A rotary electric motor is controlled by PWM at a predetermined carrier frequency, and in a case where a vibration frequency in a space zero-order eigenmode of the rotary electric motor and a frequency of a frequency component of electromagnetic exciting force that generates the eigenmode overlap with each other, a value of the carrier frequency is switched from a first value to a second value different from the first value.
    Type: Application
    Filed: July 12, 2017
    Publication date: July 18, 2019
    Inventors: Takeshi YOSHIDA, Takafumi HARA, Katsuhiro HOSHINO, Kazuto OYAMA
  • Publication number: 20190102491
    Abstract: The invention is directed to modeling of heat and vibration for structures. Therefore, with a traditional model division for each component, one-to-one correspondence between the models and the components is not necessarily realized. There has been a problem in that it is difficult to divide the models. To solve the above problem, a simulation program according to the present invention includes a first model for calculating a first vehicle characteristics parameter, a second model for calculating a second vehicle characteristics parameter to transfer energy without converting the energy, and an interface model for performing conversion calculation of the first vehicle characteristics parameter and the second vehicle characteristics parameter.
    Type: Application
    Filed: January 19, 2017
    Publication date: April 4, 2019
    Inventors: Taizou MIYAZAKI, Masaru YAMASAKI, Takafumi HARA, Katsuhiro HOSHINO, Kazuto OYAMA, Takeshi YOSHIDA
  • Patent number: 10090790
    Abstract: The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: October 2, 2018
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Hirokazu Sambonsuge, Kohei Myoen, Kazuto Oyama
  • Publication number: 20170331401
    Abstract: The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced.
    Type: Application
    Filed: October 21, 2015
    Publication date: November 16, 2017
    Inventors: Hirokazu SAMBONSUGE, Kohei MYOEN, Kazuto OYAMA
  • Patent number: 9694688
    Abstract: In order to provide an electric vehicle drive system capable of promoting improvement in stability of vehicle traveling when stopping a regeneration operation during operation of a regeneration cooperative brake, the electric vehicle drive system, a battery control unit 310, upon detecting that a battery state is an unchargeable state during control of the regeneration cooperative brake, diagnoses whether a battery 300 is chargeable, and upon deciding to be unchargeable from a result of diagnosis, outputs a Fail signal. Then, a rotating electrical machine control unit 210, upon receiving a Fail prediction signal while the regeneration cooperative brake is being controlled, executes loss increase control for increasing an internal loss of a rotating electrical machine 900 and reducing regenerative electric power by a regenerative brake while maintaining torque of the rotating electrical machine 900 at regenerative torque corresponding to regenerative brake force.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: July 4, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Kazuto Oyama, Hideki Miyazaki, Katsuhiro Hoshino
  • Publication number: 20170133958
    Abstract: The purpose of the present invention is to continue to drive a motor while suppressing drive torque ripple generated by the motor, when any of the phases is opened during the driving of the motor. A motor drive device controls the driving of a motor in which the armature windings of respective phases are independently provided. The motor drive device is equipped with: an inverter circuit for converting the DC power supplied through DC bus lines to three-phase AC powers and respectively outputting the three-phase AC powers to the armature windings of the respective phases; and a controller for controlling the inverter circuit. When any of the phases is opened in the AC powers output from the inverter circuit, the controller adjusts the difference between the phases of the respective currents flowing through the armature windings of normal phases so that the AC powers of the other normal phases except the opened phase are compensated each other.
    Type: Application
    Filed: June 24, 2015
    Publication date: May 11, 2017
    Inventors: Katsuhiro HOSHINO, Shingo NISHIGUCHI, Toshisada MITSUI, Kazuto OYAMA, Hideki MIYAZAKI
  • Publication number: 20150340934
    Abstract: An inverter device is configured such that a pull-out direction for a direct current cable to be connected an external power source is adjustable without modifying the shape of a motor and the shape of the inverter device body, thereby reducing the packaging volume including the direct current cable. To this end, a DC bus bar 96 that connects a smoothing capacitor 90 to semiconductor modules 500a to 500c is provided with two pairs of positive and negative terminals 92a, 94a, 92b, and 94b to be connected to an external power source 30. The positive and negative terminals 92a and 94a and the positive and negative terminals 92b and 94b respectively project from different side surfaces of an inverter housing 110.
    Type: Application
    Filed: October 21, 2013
    Publication date: November 26, 2015
    Inventors: Kosuke SUZUKI, Hideki MIYAZAKI, Tetsuya KAWASHIMA, Kazuto OYAMA
  • Publication number: 20150258897
    Abstract: In order to prevent cell batteries from reaching a regeneration inhibiting voltage in an initial period of regeneration braking and to ensure that a large amount of regeneration can be secured even if characteristics of cell batteries are varied, when a vehicle braking request is received (S2-2), a first limit of regeneration power (S2-8) for which the amount of regeneration is relatively small is performed, and while regeneration control is being performed, information about the cell batteries such as voltage across terminals is acquired from a battery monitoring device to identify a cell battery of which the voltage across terminals becomes the highest among the multiple cell batteries. After the determination is completed (S2-5), the process proceeds to a second regeneration control (S2-9).
    Type: Application
    Filed: September 25, 2013
    Publication date: September 17, 2015
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Takashi Okada, Hideki Miyazaki, Kazuto Oyama, Takao Kojima
  • Publication number: 20150202966
    Abstract: In order to provide an electric vehicle drive system capable of promoting improvement in stability of vehicle traveling when stopping a regeneration operation during operation of a regeneration cooperative brake, the electric vehicle drive system, a battery control unit 310, upon detecting that a battery state is an unchargeable state during control of the regeneration cooperative brake, diagnoses whether a battery 300 is chargeable, and upon deciding to be unchargeable from a result of diagnosis, outputs a Fail signal. Then, a rotating electrical machine control unit 210, upon receiving a Fail prediction signal while the regeneration cooperative brake is being controlled, executes loss increase control for increasing an internal loss of a rotating electrical machine 900 and reducing regenerative electric power by a regenerative brake while maintaining torque of the rotating electrical machine 900 at regenerative torque corresponding to regenerative brake force.
    Type: Application
    Filed: July 24, 2013
    Publication date: July 23, 2015
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Kazuto Oyama, Hideki Miyazaki, Katsuhiro Hoshino
  • Publication number: 20140306563
    Abstract: Disclosed is a mechanical-electrical integrated electric drive system capable of returning common mode current from a rotary electric machine's side to a virtual neutral point of a power-conversion device inside the electric drive system, where the system comprises a rotary electric machine that includes a rotor, a stator having a stator core including armature windings, and a housing holding the stator and having AC terminals of the armature windings arranged thereon; a power conversion device that is fixed to the periphery of the housing and includes an inverter circuit and AC bus bars connecting the inverter circuit with the AC terminals; conductor rings that are arranged in contact with the stator core to collect common mode current deriving from stray capacitance of the stator; and a connection wire that connects the conductor bar to a virtual neutral point on the DC input side of the inverter circuit.
    Type: Application
    Filed: November 5, 2012
    Publication date: October 16, 2014
    Inventors: Kazuto Oyama, Kosuke Suzuki, Hideki Miyazaki, Katsuhiro Hoshino
  • Publication number: 20130066501
    Abstract: It is desirable to enhance efficiency of a power conversion device in both of a case where a motor generator which is an electric rotating machine is operated as a motor and a case where the motor generator is operated as a generator by performing regeneration braking. At the time of performing regeneration braking, strength of regeneration braking can be controlled by making an inverter circuit conductive in response to a predetermined phase of an AC output which the inverter circuit generates and by controlling a conduction width. Due to such a control, the number of times of switching a semiconductor element which constitutes the inverter circuit can be reduced thus suppressing heat generation of the semiconductor element and also the efficiency of the power conversion device can be enhanced. Further, the enhancement of efficiency of the power conversion device can be realized also in a motor operation and hence, it is also possible to enhance efficiency with respect to the traveling of a vehicle.
    Type: Application
    Filed: April 28, 2010
    Publication date: March 14, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Kazuto Oyama, Hideki Miyazaki, Kimihisa Furukawa, Toshisada Mitsui, Shingo Nishiguchi, Akinori Kamiya
  • Publication number: 20090179510
    Abstract: A rotating electrical machine main body 40 includes a rotor 4 having a fan, a stator 1, and housings 2, 3. An inverter unit 30 includes a case 14 and a plurality of switching semiconductor devices 15. The rotating electrical machine main body 40 and the inverter unit 30 are coupled with each other when the case 14 is connected to the housing 3. A cooling air circulated by rotation of a fan 12a cools the inverter unit 30 before flowing into the housing. Part of the case 14 is disposed between the rotating electrical machine main body 40 and the switching semiconductor devices 15, preventing thermal radiation radiated (or irradiated) from the rotating electrical machine main body 40 from reaching the switching semiconductor devices 15.
    Type: Application
    Filed: December 5, 2008
    Publication date: July 16, 2009
    Applicant: Hitachi, LTD.
    Inventors: Kenichi Yoshida, Tokihito Suwa, Kazuto Oyama, Hisaya Shimizu, Yosuke Umesaki
  • Publication number: 20080224560
    Abstract: To provide an electric machine capable of being improved in both fabricability and reliability, and a process for manufacturing the machine.
    Type: Application
    Filed: January 22, 2008
    Publication date: September 18, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Kenichi YOSHIDA, Kazuto Oyama, Hisaya Shimizu, Yosuke Umesaki
  • Publication number: 20060177202
    Abstract: With regard to an optical disk video camera using an optical disk as a recording medium, the optical disk video camera is made smaller in size by changing a position of a battery which supplies power. In order to allow the optical disk video camera to be downsized, the battery which supplies power is arranged so that a part of the battery and a perpendicular projection plane of the optical disk overlap one another.
    Type: Application
    Filed: August 3, 2005
    Publication date: August 10, 2006
    Applicant: Hitachi, Ltd.
    Inventor: Kazuto Oyama
  • Patent number: D517107
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: March 14, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kojima, Yoshihiro Iwama, Minoru Ikeda, Kazuto Oyama