Patents by Inventor Ryuji OMATA

Ryuji OMATA 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).

  • Publication number: 20190296665
    Abstract: A motor system provided with one motor and two inverters includes a first inverter control unit which changes a frequency of a first carrier wave (first carrier frequency) used for producing a switching signal fora first inverter according to an operating point of the motor; and a second inverter control unit which changes a frequency of a second carrier wave (second carrier frequency) used for producing a switching signal for a second inverter according to an operating point of the motor. The first carrier frequency has a changing characteristic depending on the first inverter control unit and the second carrier frequency has a changing characteristic depending on the second inverter control unit, and the changing characteristics are different from each other to make the first carrier frequency and the second carrier frequency differ from each other at an identical operating point.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Inventors: Kiyotaka Matsubara, Makoto Nakamura, Daigo Nobe, Ryuji Omata
  • Publication number: 20190296678
    Abstract: In a dual-inverter type of motor control apparatus which controls a synchronous motor having two or more open-end armature windings corresponding to respective phases, first and second inverter control circuits control the motor by supplying voltage commands to corresponding ones of the two inverters, with a combination of respective control methods executed by the inverter control circuits for generating the voltage commands being determined such as to provide a high speed of control response, while preventing control interference caused by effects of component characteristic disparities, such as deviations to between timings of updating the voltage commands by the two inverter control circuits.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Ryuji OMATA, Kiyotaka MATSUBARA, Makoto NAKAMURA, Daigo NOBE
  • Publication number: 20190296668
    Abstract: A control unit calculates a motor voltage vector including a corresponding excitation voltage command and a torque voltage command in response to an output request for a motor and distributes the motor voltage vector to a first inverter voltage vector and a second inverter voltage vector while maintaining the motor voltage vector obtained to control modes of operation (PWM, overmodulation, and square wave mode) of a first inverter or a second inverter. The first inverter voltage vector includes an excitation voltage command and a torque voltage command associated with an output from the first inverter, and the second inverter voltage vector includes an excitation voltage command and a torque voltage command associated with an output from the second inverter.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Inventors: Kiyotaka Matsubara, Makoto Nakamura, Daigo Nobe, Ryuji Omata
  • Publication number: 20190296677
    Abstract: An electric motor driving system controls driving of an electric motor having windings of two or more phases each having open ends by using a pair of inverters. A control unit includes a first inverter control circuit that generates a first voltage instruction output to the first inverter based on a torque instruction and a second inverter control circuit that generates a second voltage instruction output to the second inverter based on the torque instruction. At least one of the inverter control circuits includes an electric power controller that controls allocation of electrical power supplied from a pair of power supplies to the pair of inverters, respectively, by either advancing or delaying an angle of a phase of each of vectors of voltage instructions in accordance with the target electric power instruction during execution of torque feedback control.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Haruka OKA, Ryuji OMATA, Kiyotaka MATSUBARA, Makoto NAKAMURA, Daigo NOBE
  • Publication number: 20190296676
    Abstract: A control unit distributes a motor voltage vector corresponding to an output request for a motor to a first and a second inverter voltage vectors associated with outputs from a first inverter and a second inverter, and determines whether a switching condition for three-phase-on mode is satisfied. Determining that the switching condition is satisfied, the control unit switches to three-phase-on mode in which every high-side switching element or every low-side switching; element of one inverter is turned on and one end of a coil in each phase of the motor is brought into common connection, and the control unit drives the motor with an output from the other inverter. Herein, the switching condition for three-phase-on mode includes failure of one inverter and an inverter voltage vector of an output from one inverter being approximate to 0 when neither of the inverters fails.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Inventors: Kiyotaka Matsubara, Makoto Nakamura, Daigo Nobe, Ryuji Omata
  • Publication number: 20190296664
    Abstract: A control unit calculates a motor voltage vector including a corresponding excitation voltage command and a torque voltage command in response to an output request for the motor and changes a first inverter voltage vector and a second inverter voltage vector while maintaining the motor voltage vector obtained to allow distribution of the motor voltage vector at any ratio. The first inverter voltage vector includes a first excitation voltage command and a first torque voltage command associated with an output from the first inverter, and the second inverter voltage vector includes a second excitation voltage command and a second torque voltage command associated with an output from the second inverter.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Inventors: Kiyotaka Matsubara, Makoto Nakamura, Daigo Nobe, Ryuji Omata
  • Publication number: 20190296670
    Abstract: An electric motor driving apparatus controls driving of an electric motor having two or more phase windings whose ends are open by using first and second inverters. A control unit includes a first inverter control circuit and a second inverter control circuit. The first inverter control circuit generates a first voltage command as an output voltage command to the first inverter based on a torque command. The second inverter control circuit generates a second voltage command as an output voltage command to the second inverter. The control unit determines a composite voltage command based on a first voltage command vector and a second voltage command including a case, in which a pure phase difference between the first voltage command vector on a dq coordinate corresponding to the first voltage command and the second voltage command vector on the dq coordinate corresponding to the second voltage command is other than 180°.
    Type: Application
    Filed: February 7, 2019
    Publication date: September 26, 2019
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Ryuji OMATA, Yuri MURATA, Makoto NAKAMURA, Kiyotaka MATSUBARA, Daigo NOBE
  • Publication number: 20190296663
    Abstract: In a so-called dual power source and dual inverter system, in which a pair of first and second inverters controls and drives a motor that includes multiple windings of phases each having open ends based on electric power supplied from a pair of power supplies, a motor driving system capable of appropriately allocating the electric power supplied from the pair of power supplies to the pair of inverters is provided. The motor driving system includes a pair of first and second inverter control circuits to generate a pair of first and second voltage instructions supplied to the first and second inverters based on a torque command, respectively. One of the first and second inverter control circuits includes a power controller that controls sharing of the electric power supplied from the first and second power supplies in accordance with a target electric power instruction.
    Type: Application
    Filed: March 21, 2019
    Publication date: September 26, 2019
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Haruka OKA, Ryuji OMATA, Kiyotaka MATSUBARA, Makoto NAKAMURA, Daigo NOBE
  • Patent number: 9903931
    Abstract: In a diagnostic device, a determiner determines whether a rotational speed of an AC motor is within a low rotational-speed range in which its rotational speed is approximately zero. An input-voltage estimate calculator calculates, as an input-voltage estimate, an estimate of an input voltage to an inverter when it is determined that the rotational speed of the AC motor is within the low rotational-speed range. A malfunction determiner performs a diagnostic task. The diagnostic task calculates an absolute value of a difference between an input-voltage measurement value measured by an input voltage sensor and the input-voltage estimate. The diagnostic task determines whether the absolute value of the difference is higher than a predetermined voltage threshold. The diagnostic task determines that there is a malfunction in the input voltage sensor upon determining that the absolute value of the difference is higher than the predetermined voltage threshold.
    Type: Grant
    Filed: November 10, 2016
    Date of Patent: February 27, 2018
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Yuri Murata
  • Patent number: 9819293
    Abstract: A voltage sensor abnormality diagnosis apparatus is applied to a motor controller operating switching of inverter by a switching signal for complementary on and off and diagnoses abnormality of input voltage sensor. An input voltage estimated value calculation section calculates input voltage estimated value by multiplying voltage command amplitude deviation by conversion coefficient, the voltage command amplitude deviation being obtained by subtracting theoretical voltage command amplitude, which is amplitude of theoretical voltage command calculated by using a motor model expression, from a control voltage command amplitude, which is an amplitude of a control voltage command calculated by feedback control and has been corrected by the dead time correction amount. An abnormality determination section determines that the input voltage sensor is abnormal if an absolute value of a difference between an input voltage sensor value and the input voltage estimated value is larger than a voltage threshold value.
    Type: Grant
    Filed: November 10, 2016
    Date of Patent: November 14, 2017
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Yuri Murata
  • Publication number: 20170163195
    Abstract: A voltage sensor abnormality diagnosis apparatus is applied to a motor controller operating switching of inverter by a switching signal for complementary on and off and diagnoses abnormality of input voltage sensor. An input voltage estimated value calculation section calculates input voltage estimated value by multiplying voltage command amplitude deviation by conversion coefficient, the voltage command amplitude deviation being obtained by subtracting theoretical voltage command amplitude, which is amplitude of theoretical voltage command calculated by using a motor model expression, from a control voltage command amplitude, which is an amplitude of a control voltage command calculated by feedback control and has been corrected by the dead time correction amount. An abnormality determination section determines that the input voltage sensor is abnormal if an absolute value of a difference between an input voltage sensor value and the input voltage estimated value is larger than a voltage threshold value.
    Type: Application
    Filed: November 10, 2016
    Publication date: June 8, 2017
    Applicant: DENSO CORPORATION
    Inventors: Ryuji OMATA, Yuri MURATA
  • Publication number: 20170131379
    Abstract: In a diagnostic device, a determiner determines whether a rotational speed of an AC motor is within a low rotational-speed range in which its rotational speed is approximately zero. An input-voltage estimate calculator calculates, as an input-voltage estimate, an estimate of an input voltage to an inverter when it is determined that the rotational speed of the AC motor is within the low rotational-speed range. A malfunction determiner performs a diagnostic task. The diagnostic task calculates an absolute value of a difference between an input-voltage measurement value measured by an input voltage sensor and the input-voltage estimate. The diagnostic task determines whether the absolute value of the difference is higher than a predetermined voltage threshold. The diagnostic task determines that there is a malfunction in the input voltage sensor upon determining that the absolute value of the difference is higher than the predetermined voltage threshold.
    Type: Application
    Filed: November 10, 2016
    Publication date: May 11, 2017
    Applicant: DENSO CORPORATION
    Inventors: Ryuji OMATA, Yuri MURATA
  • Patent number: 9590551
    Abstract: A control apparatus includes an inverter for driving a three-phase AC motor when connected to a DC power source, a smoothing capacitor interposed between the DC power source and an input side of the inverter and connected in parallel to the DC power source, a current sensor for detecting a current of one phase of the motor, and a controller for controlling the motor through the inverter. The controller performs a discharge process to discharge the capacitor, when the DC power source is disconnected from the capacitor. The controller calculates a d-axis voltage command reference value based on d-axis and q-axis current command values. The controller sets a q-axis voltage command reference value to zero. The controller generates d-axis and q-axis voltage command values by correcting at least the d-axis voltage command reference value and outputs the d-axis and q-axis voltage command values to the inverter.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: March 7, 2017
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takeshi Itoh, Hirofumi Kako
  • Patent number: 9473059
    Abstract: A control apparatus controls an AC motor by detecting current passing through one phase. The apparatus includes an upper controller which includes a torque command calculation section, and a torque monitoring section monitoring torque to determine whether the torque is within a range, and a lower controller which controls current supply to an inverter based on a torque command value to control the motor, and which acquires information on a current-supply state and a rotation state of the motor and transmits information on a control state to the upper controller. At least one of the controllers estimates a current estimate value of an estimated phase or a d-q axis current estimate value based on a current detection value of the one phase and an electrical angle, and calculates information for monitoring torque based on the current estimate value. The torque monitoring section monitors the torque based on the information.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: October 18, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada
  • Patent number: 9431935
    Abstract: A control device of a three-phase AC motor includes: an inverter that drives the AC motor; a current sensor that senses a current flowing in a sensor phase of the AC motor as a sensor phase current; and a controller that switches on and off a switching element of the inverter to control a current flowing through the AC motor. The controller includes: a current estimation device that estimates d-axis and q-axis current estimated values based on the sensor phase current and an electric angle of the AC motor; and a zero-crossing interpolation device that interpolates a command value relating to a voltage of the AC motor when the sensor phase current is in a zero cross range, which includes a zero point. When the sensor phase current is in the zero cross range, the zero-crossing interpolation device interpolates the command value with a continuous variable value.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: August 30, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada
  • Patent number: 9419554
    Abstract: A control device of a three-phase AC motor includes: an inverter for driving the motor; a current sensor for sensing a sensor phase current of the motor; and a controller for controlling the motor. The controller includes: a current estimation device for estimating d-axis and q-axis current estimated values based on the sensor phase current and an electric angle of the motor; and a zero-crossing interpolation device for interpolating the d-axis and q-axis current estimated values by fixing the d-axis and q-axis current estimated values when the sensor phase current is in a zero cross range, which includes a zero point, so that the sensor phase current crosses the zero point, and for outputting interpolated d-axis and q-axis current estimated values as fixed d-axis and q-axis values, which are used for a feedback control relating to current flowing through the motor.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: August 16, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada
  • Patent number: 9331627
    Abstract: According to a control apparatus for an AC motor, a switching section selects a two-phase control current value as a current fixing value, when a first current detection value of a first phase of the AC motor and a second current detection value of a second phase of the AC motor are normal. The switching section selects an one-phase control current value, which is calculated based on a normal phase current detection value, which is a value of a normal phase and is one of the first and second current detection values, as the current fixing value, when an abnormality is detected in part of the first and second current detection values, and a predetermined period has elapsed from the detection of the abnormality.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: May 3, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada
  • Patent number: 9318982
    Abstract: According to a control apparatus for an AC motor, a switching section selects a two-phase control current value as a current fixing value, when a first current detection value of a first phase of the AC motor and a second current detection value of a second phase of the AC motor are normal. The switching section selects an one-phase control current value, which is calculated based on a normal phase current detection value, which is a value of the normal phase and is one of the first and the second current detection values, as the current fixing value, when it is determined that the current supplied to the AC motor has been stabilized after an abnormality is detected in part of the first and second detection values.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: April 19, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada
  • Patent number: 9276517
    Abstract: A control device of a three phase AC motor includes: an inverter for driving the motor; a current sensor for sensing current in a sensor phase of the motor; and a controller for switching multiple switching elements in the inverter to control the current of the motor. The controller includes: a revolution number calculation device for calculating the revolution number of the motor; a three-phase voltage command operation device for operating three phase voltage commands to be applied to the motor based on a current command and an electric angle; and a current concentration determination device for determining whether a current concentration is caused based on the three phase voltage commands when the revolution number is not more than a predetermined revolution number. In the current concentration, current not less than a predetermined threshold value flows continuously for a predetermined period in one or more phases of the inverter.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: March 1, 2016
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takeshi Itoh, Hirofumi Kako
  • Patent number: 9209723
    Abstract: A control device of a three-phase AC motor includes: an inverter; a current sensor for a sensor phase current; and a controller switching a switching element of each phase of the inverter and having a current estimation device, which calculates a sensor-phase-standard current phase according to ? and ? axis currents and a current estimated value of another phase. The current estimation device calculates the ? axis current at every switching and intermediate timings, calculates a first differential value of the ? axis current at every switch timing, calculates the ? axis current according to the first differential value, calculates a second differential value of the ? axis current at every intermediate timing, and calculates the ? axis current according to the second differential value. The intermediate timing is set to have an unequal interval between two adjacent switch timings.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: December 8, 2015
    Assignee: DENSO CORPORATION
    Inventors: Ryuji Omata, Takahumi Oowada