Patents by Inventor Masamichi Nawa

Masamichi Nawa 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: 11327116
    Abstract: A pulse pattern generation device generating a pulse pattern for controlling switching elements provided in an inverter that operates a motor, the pulse pattern generation device includes a current calculation unit that calculates a current flowing through a coil when a voltage that is applied to the motor during the operation of the motor is virtually applied to the coil of the motor, an effective current calculation unit that calculates an effective current from the current calculated by the current calculation unit, an iron loss estimation unit that estimates an iron loss which originates in a core of the motor, and a pattern generation unit that generates a pulse pattern using an evaluation function including the iron loss estimated by the iron loss estimation unit and the effective current calculated by the effective current calculation unit as evaluation items.
    Type: Grant
    Filed: April 19, 2019
    Date of Patent: May 10, 2022
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventors: Kazuki Yamane, Masamichi Nawa
  • Patent number: 11303224
    Abstract: An inverter device includes an inverter circuit that has switching elements configuring an upper arm and a lower arm of each of U, V, W-phases, a signal generator that generates signals having waveforms corresponding to signals of U, V, W-phase command voltages, a first calculation unit that calculates an effective line voltage, a second calculation unit that generates a modulation voltage every control period, and a comparison unit that compares the signals with signals of the modulation voltage every control period, and outputs signals having pulse patterns which operate the switching elements of the upper arm and the switching element of the lower arm in the inverter circuit.
    Type: Grant
    Filed: January 15, 2019
    Date of Patent: April 12, 2022
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventors: Kazuki Yamane, Masamichi Nawa
  • Publication number: 20210239761
    Abstract: A pulse pattern generation device generating a pulse pattern for controlling switching elements provided in an inverter that operates a motor, the pulse pattern generation device includes a current calculation unit that calculates a current flowing through a coil when a voltage that is applied to the motor during the operation of the motor is virtually applied to the coil of the motor, an effective current calculation unit that calculates an effective current from the current calculated by the current calculation unit, an iron loss estimation unit that estimates an iron loss which originates in a core of the motor, and a pattern generation unit that generates a pulse pattern using an evaluation function including the iron loss estimated by the iron loss estimation unit and the effective current calculated by the effective current calculation unit as evaluation items.
    Type: Application
    Filed: April 19, 2019
    Publication date: August 5, 2021
    Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventors: Kazuki YAMANE, Masamichi NAWA
  • Publication number: 20200382021
    Abstract: An inverter device includes an inverter circuit that has switching elements configuring an upper arm and a lower arm of each of U, V, W-phases, a signal generator that generates signals having waveforms corresponding to signals of U, V, W-phase command voltages, a first calculation unit that calculates an effective line voltage, a second calculation unit that generates a modulation voltage every control period, and a comparison unit that compares the signals with signals of the modulation voltage every control period, and outputs signals having pulse patterns which operate the switching elements of the upper arm and the switching element of the lower arm in the inverter circuit.
    Type: Application
    Filed: January 15, 2019
    Publication date: December 3, 2020
    Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventors: Kazuki YAMANE, Masamichi NAWA
  • Patent number: 10797631
    Abstract: This power output device is provided with: a field winding; a motor having a plurality of star-connected motor windings composed of three or more phases; a capacitor; an inverter circuit configured to perform power conversion on the power supplied from the capacitor and to supply the converted power to the motor windings; a battery connected to the field winding; and a control unit. The inverter circuit has a plurality of switching element pairs that correspond to the respective motor windings. The capacitor is connected to a positive bus bar and a negative bus bar. The field winding is connected to the positive or negative bus bar and to a neutral point of the motor. The control unit is configured to control the switching element pairs so as to charge the capacitor by boosting the voltage of the battery and to supply a direct current to the field winding.
    Type: Grant
    Filed: June 5, 2017
    Date of Patent: October 6, 2020
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi Nawa
  • Patent number: 10742154
    Abstract: This motor driving device is provided with a direct-current power supply, an inverter, and a noise filter. The noise filter is provided with: a choke coil, wherein a first winding and a second winding are wound on a common core, and the first winding is inserted into a positive electrode bus; and two capacitors connected in series between the positive electrode bus and a negative electrode bus. One end of the second winding is connected to a neutral point of a three-phase motor, and another end of the second winding is connected to a wire between the two capacitors.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: August 11, 2020
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi Nawa
  • Patent number: 10574168
    Abstract: An electrical motor device according to the present invention is provided with a control unit. The control unit is configured to adjust the ratio of transformation by adjusting the ratio between a first time period, in which all upper-arm-side switching elements are on and all lower-arm-side switching element are off, and a second time period, in which all upper-arm-side switching elements are off and all lower-arm-side switching elements are on, and to select one of a plurality of driving modes for each control cycle. The plurality of driving modes include: a dual-driving mode including the first time period and the second time period in one control cycle during electrical motor driving; and an electrical motor driving mode not including the first time period and the second time period in one control cycle during electrical motor driving.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: February 25, 2020
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi Nawa
  • Publication number: 20190165714
    Abstract: This power output device is provided with: a field winding; a motor having a plurality of star-connected motor windings composed of three or more phases; a capacitor; an inverter circuit configured to perform power conversion on the power supplied from the capacitor and to supply the converted power to the motor windings; a battery connected to the field winding; and a control unit. The inverter circuit has a plurality of switching element pairs that correspond to the respective motor windings. The capacitor is connected to a positive bus bar and a negative bus bar. The field winding is connected to the positive or negative bus bar and to a neutral point of the motor. The control unit is configured to control the switching element pairs so as to charge the capacitor by boosting the voltage of the battery and to supply a direct current to the field winding.
    Type: Application
    Filed: June 5, 2017
    Publication date: May 30, 2019
    Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi NAWA
  • Publication number: 20190123675
    Abstract: This motor driving device is provided with a direct-current power supply, an inverter, and a noise filter. The noise filter is provided with: a choke coil, wherein a first winding and a second winding are wound on a common core, and the first winding is inserted into a positive electrode bus; and two capacitors connected in series between the positive electrode bus and a negative electrode bus. One end of the second winding is connected to a neutral point of a three-phase motor, and another end of the second winding is connected to a wire between the two capacitors.
    Type: Application
    Filed: March 31, 2017
    Publication date: April 25, 2019
    Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi NAWA
  • Publication number: 20190115863
    Abstract: An electrical motor device according to the present invention is provided with a control unit. The control unit is configured to adjust the ratio of transformation by adjusting the ratio between a first time period, in which all upper-arm-side switching elements are on and all lower-arm-side switching element are off, and a second time period, in which all upper-arm-side switching elements are off and all lower-arm-side switching elements are on, and to select one of a plurality of driving modes for each control cycle. The plurality of driving modes include: a dual-driving mode including the first time period and the second time period in one control cycle during electrical motor driving; and an electrical motor driving mode not including the first time period and the second time period in one control cycle during electrical motor driving.
    Type: Application
    Filed: March 31, 2017
    Publication date: April 18, 2019
    Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Masamichi NAWA
  • Patent number: 9667169
    Abstract: A power conversion apparatus includes a power conversion element; a capacitor; a control circuit that outputs a control signal to control operation of the power conversion element at the time of driving a load; a discharge control unit that outputs a discharge control signal to control operation of the power conversion element at the time of discharging the capacitor; a power supply circuit that generates a power supply voltage, on the basis of a voltage between both ends of the capacitor; and a driver unit that outputs a driving signal to operate the power conversion element, on the basis of the control signal or the discharge control signal. The power conversion element is operated according to the discharge control signal, a current is flown from the capacitor to the load through the power conversion element, and the capacitor is discharged.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: May 30, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Masamichi Nawa, Takayuki Itsuji
  • Publication number: 20140239870
    Abstract: A power conversion apparatus includes a power conversion element; a capacitor; a control circuit that outputs a control signal to control operation of the power conversion element at the time of driving a load; a discharge control unit that outputs a discharge control signal to control operation of the power conversion element at the time of discharging the capacitor; a power supply circuit that generates a power supply voltage, on the basis of a voltage between both ends of the capacitor; and a driver unit that outputs a driving signal to operate the power conversion element, on the basis of the control signal or the discharge control signal. The power conversion element is operated according to the discharge control signal, a current is flown from the capacitor to the load through the power conversion element, and the capacitor is discharged.
    Type: Application
    Filed: November 15, 2012
    Publication date: August 28, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Masamichi Nawa, Takayuki Itsuji
  • Patent number: 7541769
    Abstract: An electric power converter which has improved accuracy in compensation of a dead time. A motor driving system employing the electric power converter is also provided. A power module includes a plurality of switching devices connected in series and converts DC power to AC power. A control circuit produces a voltage command value in accordance with a control command inputted from the exterior, and produces gate signals to drive the switching devices of the power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation. A dead time compensation logic circuit calculates a final dead time compensation voltage based on a change rate of the voltage command value, a gain (dead time compensation voltage value), and a polarity of a current, the gain being calculated from a DC voltage value supplied to the electric power converter, a dead time, and a switching frequency.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: June 2, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Masamichi Nawa, Takefumi Sawada
  • Publication number: 20070176575
    Abstract: An electric power converter which has improved accuracy in compensation of a dead time. A motor driving system employing the electric power converter is also provided. A power module includes a plurality of switching devices connected in series and converts DC power to AC power. A control circuit produces a voltage command value in accordance with a control command inputted from the exterior, and produces gate signals to drive the switching devices of the power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation. A dead time compensation logic circuit calculates a final dead time compensation voltage based on a change rate of the voltage command value, a gain (dead time compensation voltage value), and a polarity of a current, the gain being calculated from a DC voltage value supplied to the electric power converter, a dead time, and a switching frequency.
    Type: Application
    Filed: January 18, 2007
    Publication date: August 2, 2007
    Applicant: Hitachi, Ltd.
    Inventors: Masamichi Nawa, Takefumi Sawada