Patents by Inventor Shigehisa Aoyagi

Shigehisa Aoyagi 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: 20240042867
    Abstract: A motor control device connected to a power converter that performs power conversion from DC power to AC power and controls driving of an AC motor that is driven by using the AC power includes a voltage command generation unit that generates a three-phase voltage command; and a gate signal generation unit that performs pulse width modulation on the three-phase voltage command and generates a gate signal for controlling an operation of the power converter, in which the voltage command generation unit adjusts the three-phase voltage command by using a zero-phase voltage based on a power factor of the AC power in an overmodulation region in which a modulation factor according to a voltage amplitude ratio between the DC power and the AC power exceeds a predetermined threshold value, and the gate signal generation unit generates the gate signal by performing pulse width modulation on the adjusted three-phase voltage command.
    Type: Application
    Filed: September 29, 2021
    Publication date: February 8, 2024
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Kyoshiro ITAKURA, Takeshi TOKUYAMA, Takahiro ARAKI, Shigehisa AOYAGI
  • Publication number: 20230402904
    Abstract: An object of the present invention is to provide an inverter integrated motor that can effectively cool a power module of an inverter portion. An inverter portion 120 is connected to a motor portion and includes a power module 121 that converts a DC power into an AC power, a first flow path forming body 221a that is provided between a motor and the power module 121 and forms a first flow path 221, and a second flow path forming body 222a that is disposed on a side opposite a side of the first flow path forming body 221a (side of the motor 110) over the power module 121 and forms a second flow path 222. The first flow path forming body 221a and second flow path forming body 222a are formed so that a flow rate of a refrigerant F1 flowing in the first flow path forming body 221a is greater than a flow rate of a refrigerant F2 flowing in the second flow path forming body 222a.
    Type: Application
    Filed: September 9, 2021
    Publication date: December 14, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Takaki ITAYA, Noriyuki MAEKAWA, Hideaki GOTO, Shigehisa AOYAGI, Takashi HIRAO
  • Publication number: 20230395457
    Abstract: A power semiconductor device includes: a substrate in which a positive electrode wiring connected to a first conductor on a high potential side and a negative electrode wiring connected to a fourth conductor on a low potential side are provided on one surface, and an output wiring connected to a second conductor and a third conductor is provided on the other surface so as to face the positive electrode wiring and the negative electrode wiring; and a first capacitor that smooths DC power supplied to a first upper-arm circuit body and a first lower-arm circuit body. The substrate is disposed between the first upper-arm circuit body and the first lower-arm circuit body. The first capacitor is disposed between the first upper-arm circuit body and the first lower-arm circuit body, and is connected to the positive electrode wiring and the negative electrode wiring on the substrate.
    Type: Application
    Filed: September 17, 2021
    Publication date: December 7, 2023
    Inventors: Takahiro ARAKI, Takeshi TOKUYAMA, Shigehisa AOYAGI, Noriyuki MAEKAWA
  • Patent number: 11831265
    Abstract: A motor control device includes a PWM control unit, a carrier frequency setting unit, and a carrier frequency switching calculation unit. The PWM unite generates a signal to drive an inverter by pulse width modulation. The carrier frequency setting unit sets a carrier frequency used for pulse width modulation according to a number of rotations of a motor. The carrier frequency switching calculation unit calculates a frequency switching speed of the carrier frequency and is configured to perform a calculation method. The calculation method includes setting at least one of an emergency mode, a response priority mode, or a fluctuation suppression priority mode in response to various operating conditions.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: November 28, 2023
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Midori Takaoka, Takafumi Hara, Shigehisa Aoyagi, Hirokazu Matsui, Shigeyuki Nonomura
  • Publication number: 20230336040
    Abstract: A rotating electric machine includes: a rotor core (22) that has magnet insertion holes (22b) (22c); permanent magnets (21) that are inserted into the magnet insertion holes (22b) (22c); and a groove (21cc) (21dc) that is formed in at least one of a plurality of non-magnetic pole surfaces (21c) (21d) of the permanent magnet (21) so as to allow a refrigerant (101) to flow through the groove (21cc) (21dc).
    Type: Application
    Filed: August 31, 2021
    Publication date: October 19, 2023
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Hideaki GOTO, Shigehisa AOYAGI, Takaki ITAYA
  • Publication number: 20230198437
    Abstract: A drive device of a synchronous motor includes a power converter that drives the synchronous motor by sequentially applying positive and negative voltages to respective phases of the synchronous motor; a current detection unit that detects a phase current; and a magnetic pole position estimation unit estimating a magnetic pole position of a rotor based on the phase current. The magnetic pole position estimation unit acquires maximum and minimum values of the phase current while the synchronous motor is stopped, calculates a first magnetic pole position from a subtracted value of an absolute value of the maximum and minimum values, calculates a second magnetic pole position from an added value of the absolute value of the maximum and minimum values, discriminates a polarity of a magnet of the rotor, and estimates an initial magnetic pole position of the rotor from the polarity and the second magnetic pole position.
    Type: Application
    Filed: February 5, 2021
    Publication date: June 22, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Hiroaki SATO, Shigehisa AOYAGI, Shigeyuki NONOMURA, Hirokazu MATSUI
  • Patent number: 11611292
    Abstract: An object of the present invention is to provide a power conversion device including a plurality of inverter circuits connected in parallel to a load, the power conversion device being capable of performing control with a smaller number of microcomputers, having high reliability, and being advantageous for miniaturization and cost reduction. Provided are: a plurality of inverter circuits connected in parallel to a load; a microcomputer which controls the plurality of inverter circuits; a plurality of signal selection units which select a drive signal of each of the plurality of inverter circuits; and a first transmission path and a second transmission path which are connected in parallel between the microcomputer and the plurality of signal selection units and transmit the drive signal of each of the plurality of inverter circuits from the microcomputer to each of the plurality of signal selection units.
    Type: Grant
    Filed: August 19, 2019
    Date of Patent: March 21, 2023
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Shigehisa Aoyagi, Toshiyuki Ajima, Kotaro Shiino
  • Patent number: 11451179
    Abstract: Disclosed are a motor control device that can accurately estimate a rotor position based on a neutral point potential even when a load increases, and a brake control device that is driven by the motor control device. The motor control device 3 includes a three-phase synchronous motor 4 including a three-phase winding, an inverter 31 connected to the three-phase winding, a control unit 6 for controlling the inverter based on a rotor position of the three-phase synchronous motor, and a rotational position estimation unit 2 for estimating a rotor position ?d based on a neutral point potential Vn of the three-phase winding. The rotational position estimation unit estimates a rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding.
    Type: Grant
    Filed: October 10, 2018
    Date of Patent: September 20, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Shigehisa Aoyagi, Hiroyuki Ota, Kenichiro Matsubara
  • Patent number: 11325641
    Abstract: An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.
    Type: Grant
    Filed: June 13, 2016
    Date of Patent: May 10, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Mitsuo Sasaki, Yoshitaka Iwaji, Shigehisa Aoyagi, Takumi Hisazumi
  • Patent number: 11290036
    Abstract: An applied voltage decision unit 510 performs in parallel, a process of determining three-phase AC commands V1u* to V1w* of a voltage applied to a motor by an inverter based on a position, of a rotor of a motor, detected by a position sensor with an output A, and a process of determining three-phase AC commands V2u* to V2w* of the voltage applied to the motor by the inverter based on a neutral point voltage VN of the motor. A PWM modulator 507 alternately outputs a PWM signal according to the three-phase AC commands V1u* to V1w* and a PWM signal according to the three-phase AC commands V2u* to V2w* to the inverter. A control device determines whether or not the position sensor with the output A has failed by comparing the position, of the rotor, detected by the position sensor with the output A with a position, of the rotor, estimated from a neutral point voltage VN of the motor.
    Type: Grant
    Filed: January 17, 2019
    Date of Patent: March 29, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Shigehisa Aoyagi, Takafumi Hara, Yoshitaka Sugiyama, Masaki Kashima
  • Publication number: 20220029572
    Abstract: An object of the present invention is to provide a power conversion device including a plurality of inverter circuits connected in parallel to a load, the power conversion device being capable of performing control with a smaller number of microcomputers, having high reliability, and being advantageous for miniaturization and cost reduction. Provided are: a plurality of inverter circuits connected in parallel to a load; a microcomputer which controls the plurality of inverter circuits; a plurality of signal selection units which select a drive signal of each of the plurality of inverter circuits; and a first transmission path and a second transmission path which are connected in parallel between the microcomputer and the plurality of signal selection units and transmit the drive signal of each of the plurality of inverter circuits from the microcomputer to each of the plurality of signal selection units.
    Type: Application
    Filed: August 19, 2019
    Publication date: January 27, 2022
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Shigehisa AOYAGI, Toshiyuki AJIMA, Kotaro SHIINO
  • Publication number: 20220029573
    Abstract: In Steps S54 to S55, when a change rate ??* of a torque command value to a motor 10 is equal to or greater than a predetermined value, a frequency switching speed ?fc of a carrier frequency fc is set based on the number of rotations N of the motor 10 so that a response frequency ?fc of a frequency switching speed ?fc of the carrier frequency fc becomes faster than a response frequency ?ACR of a current control unit 70. In Steps S54 and S56, when the change rate ??* of the torque command value to the motor 10 is less than a predetermined value, the frequency switching speed ?fc of the carrier frequency fc is set based on a torque command value ?* to the motor 10 and the number of rotations N of the motor 10 regardless of the response frequency ?ACR of the current control unit 70.
    Type: Application
    Filed: November 14, 2019
    Publication date: January 27, 2022
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Midori TAKAOKA, Takafumi HARA, Shigehisa AOYAGI, Hirokazu MATSUI, Shigeyuki NONOMURA
  • Patent number: 11228271
    Abstract: Provides are a control device for a three-phase synchronous motor in which a position detection accuracy of a rotor can be improved when one three-phase synchronous motor is driven by a plurality of inverters, and an electric power steering device using the same. A control device for a three-phase synchronous motor includes: a three-phase synchronous motor including a first three-phase winding and a second three-phase winding; a first inverter connected to the first three-phase winding; a second inverter connected to the second three-phase winding; a first control device that controls the first inverter on the basis of a rotor position of the three-phase synchronous motor; and a second control device that controls the second inverter on the basis of the rotor position of the three-phase synchronous motor. The first control device estimates the rotor position on a basis of a neutral point potential of the first three-phase winding and a neutral point potential of the second three-phase winding.
    Type: Grant
    Filed: July 13, 2018
    Date of Patent: January 18, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Shigehisa Aoyagi, Toshiyuki Ajima, Hiroyuki Ota, Yoshitaka Sugiyama
  • Publication number: 20210091700
    Abstract: Provides are a control device for a three-phase synchronous motor in which a position detection accuracy of a rotor can be improved when one three-phase synchronous motor is driven by a plurality of inverters, and an electric power steering device using the same. A control device for a three-phase synchronous motor includes: a three-phase synchronous motor including a first three-phase winding and a second three-phase winding; a first inverter connected to the first three-phase winding; a second inverter connected to the second three-phase winding; a first control device that controls the first inverter on the basis of a rotor position of the three-phase synchronous motor; and a second control device that controls the second inverter on the basis of the rotor position of the three-phase synchronous motor. The first control device estimates the rotor position on a basis of a neutral point potential of the first three-phase winding and a neutral point potential of the second three-phase winding.
    Type: Application
    Filed: July 13, 2018
    Publication date: March 25, 2021
    Inventors: Takafumi HARA, Shigehisa AOYAGI, Toshiyuki AJIMA, Hiroyuki OTA, Yoshitaka SUGIYAMA
  • Patent number: 10924048
    Abstract: An inverter control device including at least first and second inverters includes: a current detector that detects a current flowing through a main circuit of the first inverter; a current controller that generates a voltage command value of the first inverter on the basis of a detected current and a current command; and a voltage command predictor that generates a voltage command value of the second inverter on the basis of a variation of the voltage command value of the first inverter.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: February 16, 2021
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Hiroshi Tamura, Hiroshi Aoyagi, Tomishige Yatsugi, Shigehisa Aoyagi
  • Publication number: 20200412284
    Abstract: An applied voltage decision unit 510 performs in parallel, a process of determining three-phase AC commands V1u* to V1w* of a voltage applied to a motor by an inverter based on a position, of a rotor of a motor, detected by a position sensor with an output A, and a process of determining three-phase AC commands V2u* to V2w* of the voltage applied to the motor by the inverter based on a neutral point voltage VN of the motor. A PWM modulator 507 alternately outputs a PWM signal according to the three-phase AC commands V1u* to V1w* and a PWM signal according to the three-phase AC commands V2u* to V2w* to the inverter. A control device determines whether or not the position sensor with the output A has failed by comparing the position, of the rotor, detected by the position sensor with the output A with a position, of the rotor, estimated from a neutral point voltage VN of the motor.
    Type: Application
    Filed: January 17, 2019
    Publication date: December 31, 2020
    Inventors: Shigehisa AOYAGI, Takafumi HARA, Yoshitaka SUGIYAMA, Masaki KASHIMA
  • Publication number: 20200280278
    Abstract: An inverter control device including at least first and second inverters includes: a current detector that detects a current flowing through a main circuit of the first inverter; a current controller that generates a voltage command value of the first inverter on the basis of a detected current and a current command; and a voltage command predictor that generates a voltage command value of the second inverter on the basis of a variation of the voltage command value of the first inverter.
    Type: Application
    Filed: November 22, 2016
    Publication date: September 3, 2020
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Hiroshi TAMURA, Hiroshi AOYAGI, Tomishige YATSUGI, Shigehisa AOYAGI
  • Patent number: 10745045
    Abstract: A power steering device includes a steering mechanism, an electric motor for applying a steering assist force to the steering mechanism, and a first motor rotational position sensor for sensing as an actual axis phase a rotational position of a rotor of the electric motor. A control device is configured to: receive input of a signal of first actual axis phase outputted from the first motor rotational position sensor; receive input of a signal of value of electric current flowing through the electric motor; estimate as a control phase a phase of an induced voltage occurring in the electric motor, based on the signal of value of electric current; and determine whether or not the first motor rotational position sensor is abnormal, based on a difference between the first actual axis phase and the control phase.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: August 18, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi, Shigehisa Aoyagi
  • Publication number: 20200244203
    Abstract: Disclosed are a motor control device that can accurately estimate a rotor position based on a neutral point potential even when a load increases, and a brake control device that is driven by the motor control device. The motor control device 3 includes a three-phase synchronous motor 4 including a three-phase winding, an inverter 31 connected to the three-phase winding, a control unit 6 for controlling the inverter based on a rotor position of the three-phase synchronous motor, and a rotational position estimation unit 2 for estimating a rotor position ?d based on a neutral point potential Vn of the three-phase winding. The rotational position estimation unit estimates a rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding.
    Type: Application
    Filed: October 10, 2018
    Publication date: July 30, 2020
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Shigehisa AOYAGI, Hiroyuki OTA, Kenichiro MATSUBARA
  • Patent number: 10700627
    Abstract: To control an inverter in the event of an arm failure of a power converter, fluctuation in an output torque is suppressed, and reduction of a total output caused by the failure is suppressed by distributing an output into a plurality of inverters. A power converter for driving a redundant motor having a pair of first and second independent coils, includes: a first inverter circuit connected to the first coil; a second inverter circuit, independent from the first inverter circuit, connected to the second coil; and a first phase relay provided between the first inverter circuit and the first coil. When any one of a plurality of arms of the first inverter circuit fails, the first phase relay shuts off conduction between the failed arm and the first coil, and the redundant motor is driven by operating the second inverter circuit and the remaining arms of the first inverter circuit.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: June 30, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Shigehisa Aoyagi, Tomonobu Koseki