Patents by Inventor Hiromichi Kawamura

Hiromichi Kawamura 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: 11394334
    Abstract: A power control method for calculating a duty command value to be used for a PWM control, generating a PWM signal corresponding to a comparison result between the duty command value and a carrier signal, and applying a PWM voltage to a load by driving an inverter based on the PWM signal. The power control method comprises obtaining a compensation amount according to a phase shift generated in the PWM voltage so as to compensate for the shift, correcting the compensation amount according to a cycle of the carrier signal, and correcting the duty command value depending on whether a strength of the carrier signal is increasing or decreasing using the corrected compensation amount.
    Type: Grant
    Filed: February 18, 2019
    Date of Patent: July 19, 2022
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Mitsuhiro Shouji, Hiromichi Kawamura, Shun Kitauchi
  • Publication number: 20220140766
    Abstract: A power control method for calculating a duty command value to be used for a PWM control, generating a PWM signal corresponding to a comparison result between the duty command value and a carrier signal, and applying a PWM voltage to a load by driving an inverter based on the PWM signal. The power control method comprises obtaining a compensation amount according to a phase shift generated in the PWM voltage so as to compensate for the shift, correcting the compensation amount according to a cycle of the carrier signal, and correcting the duty command value depending on whether a strength of the carrier signal is increasing or decreasing using the corrected compensation amount.
    Type: Application
    Filed: February 18, 2019
    Publication date: May 5, 2022
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Mitsuhiro SHOUJI, Hiromichi KAWAMURA, Shun KITAUCHI
  • Patent number: 11056993
    Abstract: A control device includes an inverter, a sensor, a controller, and a filter. The inverter supplies power to an electric motor based on a control on the electric motor. The sensor detects a current supplied from the inverter to the electric motor. The controller executes current vector control by calculating a feedback command value and a feedforward compensation value based on a torque command value, the feedback command value being indicative of a voltage value for decreasing deviation in a supply current to the electric motor, the feedforward compensation value being a value for compensating the feedback command value. The filter performs a filtering process on the feedback command value to pass a low-frequency component of the feedback command value. When the control is switched to voltage phase control, the controller initializes the voltage phase control based on the feedforward compensation value and an output from the filter.
    Type: Grant
    Filed: December 1, 2017
    Date of Patent: July 6, 2021
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Sho Ohno, Hiromichi Kawamura
  • Publication number: 20210175827
    Abstract: A control device includes an inverter, a sensor, a controller, and a filter. The inverter supplies power to an electric motor based on a control on the electric motor. The sensor detects a current supplied from the inverter to the electric motor. The controller executes current vector control by calculating a feedback command value and a feedforward compensation value based on a torque command value, the feedback command value being indicative of a voltage value for decreasing deviation in a supply current to the electric motor, the feedforward compensation value being a value for compensating the feedback command value. The filter performs a filtering process on the feedback command value to pass a low-frequency component of the feedback command value. When the control is switched to voltage phase control, the controller initializes the voltage phase control based on the feedforward compensation value and an output from the filter.
    Type: Application
    Filed: December 1, 2017
    Publication date: June 10, 2021
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Sho Ohno, Hiromichi Kawamura
  • Patent number: 10897220
    Abstract: The present invention includes: a control initiation-stop determiner which receives an initiation-stop request signal for controlling initiation and stop of a motor and information on the number of revolutions of the motor and which outputs a state signal for switching a state of a drive voltage among three states of control stop, control initiation, and control start; and a drive voltage controller which gradually increases a phase current supplied to the motor by using a PWM signal while the state signal causes the state of the drive voltage to transition from control stop to the control initiation and then to the control start.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: January 19, 2021
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi Kawamura
  • Patent number: 10715077
    Abstract: A method of controlling a motor having windings of a plurality of phases includes an estimation step of calculating a current vector norm from d-axis current and q-axis current flowing in the motor, calculating power loss from the current vector norm and the entire heat resistance of the motor, and estimating the maximum temperature of the windings of the plurality of phases based on the power loss and a transfer function having first or higher-order transfer characteristics, in the case where the motor is in a low rotation state, and a limiting step of limiting input power based on the maximum temperature estimated in the estimation step.
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: July 14, 2020
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Ken Itou, Kohei Murota, Tomoaki Mori, Naoki Takahashi, Hiromichi Kawamura
  • Patent number: 10622930
    Abstract: A motor control method of the present invention is a motor control method for controlling, by a voltage phase control, an applied voltage applied to a motor via an inverter. The control method includes: calculating a phase command value to be used for the voltage phase control by a feedforward control based on a torque command value to the motor; calculating an amplitude command value to be used for the voltage phase control, based on a drive voltage for the inverter; calculating a voltage command value to the motor based on the phase command value and the amplitude command value; and a voltage application step of applying the applied voltage from the inverter to the motor based on the voltage command value.
    Type: Grant
    Filed: June 21, 2016
    Date of Patent: April 14, 2020
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi Kawamura
  • Patent number: 10541638
    Abstract: A control apparatus for controlling an electrical unit driven by AC power, the control apparatus comprising a pair of switching elements configured to convert power from a power source into AC power and supply the AC power to the electrical unit. The control apparatus comprises the steps of generating a PWM signal on the basis of the duty command value calculated by the calculation unit and a carrier signal for performing the PWM control; controlling the AC power supplied to the electrical unit by switching a connection state of the switching element on the basis of the PWM signal generated by the generating unit; determining whether the carrier signal increases or decreases; and adjusting a switching timing of the switching element by correcting the duty command value calculated by the calculation unit on the basis of whether the carrier signal is increasing or decreasing determined by the determination unit.
    Type: Grant
    Filed: April 20, 2015
    Date of Patent: January 21, 2020
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Mitsuhiro Shouji, Hiromichi Kawamura
  • Publication number: 20190341868
    Abstract: A motor control method of the present invention is a motor control method for controlling, by a voltage phase control, an applied voltage applied to a motor via an inverter. The control method includes: calculating a phase command value to be used for the voltage phase control by a feedforward control based on a torque command value to the motor; calculating an amplitude command value to be used for the voltage phase control, based on a drive voltage for the inverter; calculating a voltage command value to the motor based on the phase command value and the amplitude command value; and a voltage application step of applying the applied voltage from the inverter to the motor based on the voltage command value.
    Type: Application
    Filed: June 21, 2016
    Publication date: November 7, 2019
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi KAWAMURA
  • Publication number: 20190305713
    Abstract: A method of controlling a motor having windings of a plurality of phases includes an estimation step of calculating a current vector norm from d-axis current and q-axis current flowing in the motor, calculating power loss from the current vector norm and the entire heat resistance of the motor, and estimating the maximum temperature of the windings of the plurality of phases based on the power loss and a transfer function having first or higher-order transfer characteristics, in the case where the motor is in a low rotation state, and a limiting step of limiting input power based on the maximum temperature estimated in the estimation step.
    Type: Application
    Filed: November 1, 2016
    Publication date: October 3, 2019
    Applicant: Nissan Motor Co., Ltd.
    Inventors: Ken Itou, Kohei Murota, Tomoaki Mori, Naoki Takahashi, Hiromichi Kawamura
  • Patent number: 10199980
    Abstract: An electric power control method includes determining whether to change an operation period within which the operating is performed so as to be longer than one cycle of the carrier wave or not; reducing the switching operation of the switching elements in a first half cycle of the carrier wave; changing a slope of the carrier wave in an intermediate period between the first half cycle of the carrier wave and a last half cycle of the carrier wave in the operation period after the change to compare the carrier wave with the duty command value in magnitude; performing the switching operation of the switching elements according to a result of the comparison; and reducing the switching operation of the switching elements in the last half cycle of the carrier wave.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: February 5, 2019
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi Kawamura
  • Publication number: 20180278194
    Abstract: An electric power control method comprising: a current measuring step; a command value calculating step; an operating step; a determining step of determining whether to change an operation period within which the operating step is performed so as to be longer than one cycle of the carrier wave or not; a first reducing step of reducing the switching operation of the switching elements in a first half cycle of the carrier wave starting from a start timing of the operation period after the change during which the carrier wave monotonously changes; a comparing step of changing a slope of the carrier wave in an intermediate period between the first half cycle of the carrier wave and a last half cycle of the carrier wave in the operation period after the change to compare the carrier wave with the duty command value in the magnitude, the comparing step performing the switching operation of the switching elements according to a result of the comparison; and a second reducing step of reducing the switching operation
    Type: Application
    Filed: September 30, 2015
    Publication date: September 27, 2018
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi KAWAMURA
  • Publication number: 20180167014
    Abstract: The present invention includes: a control initiation-stop determiner which receives an initiation-stop request signal for controlling initiation and stop of a motor and information on the number of revolutions of the motor and which outputs a state signal for switching a state of a drive voltage among three states of control stop, control initiation, and control start; and a drive voltage controller which gradually increases a phase current supplied to the motor by using a PWM signal while the state signal causes the state of the drive voltage to transition from control stop to the control initiation and then to the control start.
    Type: Application
    Filed: May 21, 2015
    Publication date: June 14, 2018
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Hiromichi KAWAMURA
  • Patent number: 9252689
    Abstract: A motor control device includes a switching element that controls a motor, a current control part that outputs a PWM signal for driving the switching element, and a setting part that sets a carrier frequency of the PWM signal. Further, a motor control part includes a torque ripple compensation part that sets a torque ripple compensation value based on a motor torque command value, the carrier frequency, and a rotation state of the motor. The current control part outputs the PWM signal based on the motor torque command value and the torque ripple compensation value.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: February 2, 2016
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yosuke Fukunaga, Hiromichi Kawamura, Kengo Fujiwara, Hideo Nakamura
  • Publication number: 20150229250
    Abstract: A motor control device includes a switching element that controls a motor, a current control part that outputs a PWM signal for driving the switching element, and a setting part that sets a carrier frequency of the PWM signal. Further, a motor control part includes a torque ripple compensation part that sets a torque ripple compensation value based on a motor torque command value, the carrier frequency, and a rotation state of the motor. The current control part outputs the PWM signal based on the motor torque command value and the torque ripple compensation value.
    Type: Application
    Filed: August 12, 2013
    Publication date: August 13, 2015
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Yosuke Fukunaga, Hiromichi Kawamura, Kengo Fujiwara, Hideo Nakamura
  • Patent number: 8976560
    Abstract: An inverter control device includes a voltage detector, a target value calculation section, an inverter control section, an abnormality detector and a voltage clamp unit. The target value calculation section calculates a target value of an alternating current output from the inverter based on a detection voltage. The inverter control section controls a switching element of the inverter based on the detection voltage and the target value. The abnormality detector detects an abnormality in the voltage detector. The voltage clamp unit holds the detection voltage, for calculating the target value, at a first assured voltage determined based on a lower limit area of an assured voltage range that assures an operation of the inverter: and holds the detection voltage, for generating the control signal, at a second (higher) assured voltage, upon detecting the abnormality in the voltage detector.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: March 10, 2015
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Toshiyuki Nakamura, Hiromichi Kawamura
  • Patent number: 8975857
    Abstract: An inverter apparatus basically includes an inverter, a rotational speed detecting component and a control component. The inverter includes a plurality of pairs of switching elements. The control component controls an on-off status of the switching elements to convert a direct current from a direct current power source into alternating current by alternately executing first and second controls when a rotational speed of a motor connected to the switching elements is larger than a prescribed rotational speed. The first control turns on the switching elements that are directly connected to a positive electrode of the power source, and turns off the switching elements that are directly connected to a negative electrode of the power source. The second control turns on the switching elements that are directly connected to the negative electrode and turns off the switching elements that are directly connected to the positive electrode.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: March 10, 2015
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Hiromichi Kawamura
  • Patent number: 8926174
    Abstract: A controller of a power converter has: an average loss calculator (202) calculating an average loss in a semiconductor device; and a partial temperature variation estimation part (204), while regarding the semiconductor device as a thermal network including at least one combination of a thermal resistance and a thermal time constant, estimating a partial temperature variation of the combination from a loss in the semiconductor device and the combination of the thermal resistance and the thermal time constant. The partial temperature variation estimation part (204) estimates an average temperature from the loss, the thermal resistance, and the thermal time constant; extracts a pulsation envelope temperature exceeding the maximum value of a pulsation temperature dependent on the average loss and the pulsation frequency; and estimates a temperature variation in the semiconductor device by adding the average temperature and the pulsation envelope temperature.
    Type: Grant
    Filed: June 3, 2011
    Date of Patent: January 6, 2015
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Hiromichi Kawamura
  • Patent number: 8922152
    Abstract: A temperature protection device basically includes a temperature detector, a temperature estimator, an overheated determining component and an overheating protection component. The temperature detector detects a temperature of a semiconductor component. The temperature estimator estimates an estimated temperature of the semiconductor component. The overheated determining component determines whether the semiconductor component is in an overheated state based on the detected temperature and the estimated temperature by using a first estimated temperature as the estimated temperature at a time point when the detected temperature has reached a first threshold temperature and a second estimated temperature that is estimated subsequent to the time point as the estimated temperature when the detected temperature has reached the first threshold temperature.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: December 30, 2014
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Hiromichi Kawamura
  • Patent number: 8631886
    Abstract: This disclosure provides a structure of an electric vehicle, which includes an engine, an electric generator for being driven by the engine, a battery for being supplied and charged with generated power at least from the electric generator, and a motor for being supplied with power from the battery to drive driving wheels. The engine, the electric generator, and a power transmission device for transmitting a motive force of the engine to the electric generator are integrally formed to constitute a power generation unit. The power generation unit is arranged inside an engine room so that at least the engine is located rearward from wheel axles of left and right front wheels.
    Type: Grant
    Filed: January 21, 2011
    Date of Patent: January 21, 2014
    Assignee: Mazda Motor Corporation
    Inventor: Hiromichi Kawamura