Patents by Inventor Kazuaki Tobari

Kazuaki Tobari 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: 20240097589
    Abstract: A power conversion device comprising, a power converter that outputs signal to the motor to vary the motor's output frequency, output voltage and output current and control unit that controls the power converter, the control unit is, calculating the first power from the output voltage and output current, calculating the second power from the output current, electrical circuit parameters and frequency estimates, calculating the first phase error estimate so that the first power follows the second power in the first frequency domain, calculating the second phase error estimate different from the first frequency domain in a second frequency domain, controlling the frequency estimates so that the first phase error estimate or the second phase error estimate follows the command value of the phase error estimate.
    Type: Application
    Filed: January 24, 2022
    Publication date: March 21, 2024
    Inventors: Kazuaki TOBARI, Yuta IWASE, Yoshiyuki TAGUCHI
  • Publication number: 20240079982
    Abstract: A power converter apparatus comprising: a power converter that outputs signal to the magnet motor to vary the output frequency, output voltage and output current of the magnet motor, a control unit controls the power converter, wherein the control unit calculating the gain of the magnetic flux component of the q-axis, which varies with the phase of the magnet motor, calculating the d-axis induced voltage command value based on a value of the induced voltage coefficient, frequency estimates or frequency command value, and the gain of the flux component of the q-axis.
    Type: Application
    Filed: November 10, 2021
    Publication date: March 7, 2024
    Inventors: Kazuaki TOBARI, Hironori OHASHI, Hiroshi WATANABE, Masato OHYA
  • Publication number: 20240072704
    Abstract: Motor controller device comprising a position control system that controls the position of a machine end connected to a motor, wherein the motor controller device receiving the first speed directive from the high-level controller, stored in the position control system to output a motor axis position response to the high-level controller, comprising speed controller and vibration controller in speed control system, wherein the vibration controller in speed control system comprising: a position command estimator that calculates an estimate of the location directive based on the first speed directive and the motor axis position response, a parallel vibration damping controller that extracts the frequency components that excite vibration of the machine end included in the first speed directive based on the estimated value of the location directive, and outputs the extracted frequency components.
    Type: Application
    Filed: December 14, 2021
    Publication date: February 29, 2024
    Inventors: Mitsuru MATSUBARA, Yuuri TAKANO, Yusuke UEI, Terutomo KONDO, Tetsuo YANADA, Kazuaki TOBARI
  • Patent number: 11831262
    Abstract: This motor control device receives a speed command from an upper layer system control device having a position controller, the motor control device having: a position command estimator that calculates an estimate of a position command on the basis of the speed command and a motor axis position response; and a speed command generator that generates an actual speed command on the basis of the estimate so that an end section of a machine connected to the motor does not oscillate, wherein the actual speed command is output from the speed command generator to a speed controller.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: November 28, 2023
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Mitsuru Matsubara, Kazuaki Tobari, Yuuri Takano, Yusuke Uei, Tetsuo Yanada, Hironori Ohashi
  • Patent number: 11777427
    Abstract: An estimated value of frequency of a vibration component for automatically adjusting a control unit that suppresses resonance characteristics of a machine is stably and reliably estimated without depending on the magnitude of amplitude of the vibration component and without risk of arithmetic overflow. A motor control device including an automatic adjustment device that adaptively adjusts a controller included in a motor control system based on a frequency of a vibration component superimposed on a response of the motor control system, the automatic adjustment device including a vibration extraction unit that receives the response of the motor control system and extracts the vibration component from the response of the motor control system; a notch filter unit that receives the vibration component from the vibration extraction unit; an encoding unit; a limiter unit that receives an output of the notch filter unit; an adaptive updating unit; and a unit conversion unit.
    Type: Grant
    Filed: June 9, 2020
    Date of Patent: October 3, 2023
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Mitsuru Matsubara, Kazuaki Tobari, Yuuri Takano, Yusuke Uei, Tetsuo Yanada
  • Publication number: 20230299700
    Abstract: The present invention achieves highly accurate control characteristics by estimating an induced voltage coefficient of a magnet motor without rotary auto-tuning. A first power Pc is calculated on the basis of the output voltage and output current of the magnet motor, and a second power Pc{circumflex over (?)} is calculated on the basis of the electric circuit constant, current command, output frequency, and induced voltage coefficient of the magnet motor. The induced voltage coefficient is estimated so that the calculated first power follows the second power, and the driving of the magnet motor is controlled in accordance with the induced voltage coefficient.
    Type: Application
    Filed: June 14, 2021
    Publication date: September 21, 2023
    Inventors: Kazuaki TOBARI, Yusaku ONUMA, Takuya SUGIMOTO, Hiroshi WATANABE, Mutsuo TOKASHIKI
  • Publication number: 20230155529
    Abstract: There is provided a synchronous machine control device capable of improving the performance of a motor without complicating a control system. The synchronous machine control device controls a power converter (2) that supplies electric power to a synchronous machine (1). The synchronous machine control device includes a first magnetic flux command computation unit (21) that computes a first magnetic flux command value (?d*, ?q*) from a current command value (Id*, Iq*) of the synchronous machine (1), a magnetic flux estimation unit (23) that estimates a magnetic flux value (?dc, ?qc) of the synchronous machine (1) from a current detection value (Idc, Iqc) of the synchronous machine (1), and a voltage computation unit (19) that creates a voltage command value (Vd*, Vq*) of the power converter such that the first magnetic flux command value (?d*, ?q*) coincides with the magnetic flux value (?dc, ?qc).
    Type: Application
    Filed: December 28, 2020
    Publication date: May 18, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Shun TANIGUCHI, Kazuaki TOBARI, Noriya NAKAO, Toshiyuki AJIMA, Kenichi YOSHIDA, Kentaro MATSUO, Eigo KISHIMOTO
  • Publication number: 20230066812
    Abstract: This motor control device receives a speed command from an upper layer system control device having a position controller, the motor control device having: a position command estimator that calculates an estimate of a position command on the basis of the speed command and a motor axis position response; and a speed command generator that generates an actual speed command on the basis of the estimate so that an end section of a machine connected to the motor does not oscillate, wherein the actual speed command is output from the speed command generator to a speed controller.
    Type: Application
    Filed: December 4, 2020
    Publication date: March 2, 2023
    Inventors: Mitsuru MATSUBARA, Kazuaki TOBARI, Yuuri TAKANO, Yusuke UEI, Tetsuo YANADA, Hironori OHASHI
  • Patent number: 11575338
    Abstract: This power conversion device comprises: a power converter including a switching element; and a control unit which controls the power converter. The control unit calculates a torque electric current detection value and an excitation electric current detection value from an electric current flowing to an external device, and when an absolute value of the torque electric current detection value is greater than or equal to the excitation electric current detection value, performs control such that the excitation electric current detection value follows the torque electric current detection value.
    Type: Grant
    Filed: April 28, 2020
    Date of Patent: February 7, 2023
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kazuaki Tobari, Agnes Hadinata, Atsuhiko Nakamura, Hiroshi Watanabe, Yusaku Onuma, Takuya Sugimoto, Yoshiyuki Taguchi
  • Publication number: 20220321043
    Abstract: An estimated value of a frequency of a vibration component for automatically adjusting a control unit that suppresses resonance characteristics of a machine is estimated stably and highly reliably without depending on the magnitude of an amplitude of the vibration component and without any risk of arithmetic overflow.
    Type: Application
    Filed: June 9, 2020
    Publication date: October 6, 2022
    Inventors: Mitsuru MATSUBARA, Kazuaki TOBARI, Yuuri TAKANO, Yusuke UEI, Tetsuo YANADA
  • Patent number: 11437944
    Abstract: A power conversion device includes a harmonic voltage generation unit that superimposes dc-axis and qc-axis harmonic voltages on dc-axis and qc-axis voltage commands in accordance with a switching signal; and an inductance estimation unit that estimates dc-axis inductance and qc-axis inductance on a basis of dc-axis and qc-axis harmonic currents, amplitude values of the harmonic voltages, and the switching signal.
    Type: Grant
    Filed: May 29, 2019
    Date of Patent: September 6, 2022
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kazuaki Tobari, Yoshitaka Iwaji, Agnes Hadinata, Yusaku Onuma, Takuya Sugimoto, Atsuhiko Nakamura, Hiroshi Watanabe, Yoshiyuki Taguchi
  • Patent number: 11424707
    Abstract: A power conversion apparatus controls a load apparatus by position sensorless vector control. The power conversion apparatus includes: a current detection unit configured to detect a current passing through the load apparatus; a current detection arithmetic unit configured to calculate a harmonic current component on a dc-axis as a control axis and a harmonic current component on a qc-axis, based on the detected current; a saliency ratio estimation unit configured to output a saliency ratio estimated value based on the harmonic current component on the dc-axis and the harmonic current component on the qc-axis; and a saliency ratio control unit configured to output a current component that increases or decreases a current command value on a d-axis of a rotor coordinate system, based on a deviation between the saliency ratio estimated value and a predetermined saliency ratio.
    Type: Grant
    Filed: December 26, 2018
    Date of Patent: August 23, 2022
    Assignee: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
    Inventors: Kazuaki Tobari, Yoshitaka Iwaji, Agnes Hadinata, Yusaku Onuma, Atsuhiko Nakamura, Takuya Sugimoto
  • Patent number: 11303236
    Abstract: An induction motor overheat monitoring method and device detects overheating of an induction motor from a detection value of a current sensor. A resistance calculation relationship data indicating a relationship between a resistance and a feature amount at the time of starting of the induction motor and a determination reference value for determining overheating are stored in advance. At each starting, a current of the induction motor is detected, a signal regarding a phase angle difference is calculated, and a feature amount of the motor is calculated from the signal regarding the phase angle difference. Further, a resistance of the induction motor is calculated by using the feature amount of the motor and the resistance calculation reference data stored in advance. Then, a temperature of the induction motor is calculated from the resistance of the induction motor, and it is determined if the motor is overheated.
    Type: Grant
    Filed: November 29, 2018
    Date of Patent: April 12, 2022
    Assignee: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
    Inventors: Guangbin Zhou, Yoshitaka Iwaji, Satoru Kaneko, Kazuaki Tobari
  • Publication number: 20220094291
    Abstract: This power conversion device comprises: a power converter including a switching element; and a control unit which controls the power converter. The control unit calculates a torque electric current detection value and an excitation electric current detection value from an electric current flowing to an external device, and when an absolute value of the torque electric current detection value is greater than or equal to the excitation electric current detection value, performs control such that the excitation electric current detection value follows the torque electric current detection value.
    Type: Application
    Filed: April 28, 2020
    Publication date: March 24, 2022
    Inventors: Kazuaki TOBARI, Agnes HADINATA, Atsuhiko NAKAMURA, Hiroshi WATANABE, Yusaku ONUMA, Takuya SUGIMOTO, Yoshiyuki TAGUCHI
  • Patent number: 11273712
    Abstract: Provided is an AC electric motor control device capable of detecting, in an AC electric motor drive device, abnormal operation of an AC electric motor or abnormal operation due to, for example, a sudden change of a load without an erroneous operation regardless of the operational state of the AC electric motor. When driving a three-phase AC electric motor by an inverter, inside a controller, an electric motor constant is calculated using at least one of the current, voltage, and rotational speed of the electric motor and the variation of the constant value is analyzed, thereby detecting abnormal operation of the electric motor or abnormal operation of a load device connected to the electric motor. In order to analyze the constant, a variation to be determined to be abnormal is preset or an abnormal value is calculated in comparison with the accumulated values of past constant changes. Alternatively, only the variation of the constant calculated in the controller is extracted to detect abnormality.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: March 15, 2022
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Yoshitaka Iwaji, Kazuaki Tobari, Yuuta Iwase, Yusaku Onuma
  • Patent number: 11239784
    Abstract: Stable current control is performed even at the time of occurrence of disturbance, while the steadily occurring current pulsation is suppressed. A motor drive device 100 includes a power conversion circuit 103 that drives an alternating-current motor 101, and a controller 102 that controls the power conversion circuit 103. The controller 102 includes a voltage command calculation unit 108, a control state judgement unit 112, and a control gain change unit 113.
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: February 1, 2022
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Noriya Nakao, Kazuaki Tobari, Fumikazu Takahashi, Shingo Nishiguchi
  • Patent number: 11196377
    Abstract: In a motor drive device 120, a phase compensation amount calculation unit 110 calculates a phase compensation amount ?? for compensating a voltage phase ?v* when a control mode is switched in a control selection unit 90. The control selection unit 90 outputs the three-phase voltage command Vuvw* according to any one of the plurality of control modes based on the modulation factor Kh*, the voltage phase ?v*, and the phase compensation amount ??. A PWM control unit 100 outputs gate signals Gun, Gup, Gvn, Gvp, Gwn, and Gwv based on the three-phase voltage command Vuvw* and a rotor position ?d. The inverter 20 has a plurality of switching elements, and controls the plurality of switching elements based on gate signals Gun, Gup, Gvn, Gyp, Gwn, and Gwv to drive the AC motor 10.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: December 7, 2021
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Midori Takaoka, Junki Isobe, Kohei Myoen, Toshiyuki Ajima, Kazuaki Tobari, Yoshitaka Iwaji
  • Publication number: 20210328537
    Abstract: Provided is an AC electric motor control device capable of detecting, in an AC electric motor drive device, abnormal operation of an AC electric motor or abnormal operation due to, for example, a sudden change of a load without an erroneous operation regardless of the operational state of the AC electric motor. When driving a three-phase AC electric motor by an inverter, inside a controller, an electric motor constant is calculated using at least one of the current, voltage, and rotational speed of the electric motor and the variation of the constant value is analyzed, thereby detecting abnormal operation of the electric motor or abnormal operation of a load device connected to the electric motor. In order to analyze the constant, a variation to be determined to be abnormal is preset or an abnormal value is calculated in comparison with the accumulated values of past constant changes. Alternatively, only the variation of the constant calculated in the controller is extracted to detect abnormality.
    Type: Application
    Filed: February 13, 2018
    Publication date: October 21, 2021
    Inventors: Yoshitaka IWAJI, Kazuaki TOBARI, Yuuta IWASE, Yusaku ONUMA
  • Publication number: 20210273591
    Abstract: A power conversion device includes a harmonic voltage generation unit that superimposes dc-axis and qc-axis harmonic voltages on dc-axis and qc-axis voltage commands in accordance with a switching signal; and an inductance estimation unit that estimates dc-axis inductance and qc-axis inductance on a basis of dc-axis and qc-axis harmonic currents, amplitude values of the harmonic voltages, and the switching signal.
    Type: Application
    Filed: May 29, 2019
    Publication date: September 2, 2021
    Inventors: Kazuaki TOBARI, Yoshitaka IWAJI, Agnes HADINATA, Yusaku ONUMA, Takuya SUGIMOTO, Atsuhiko NAKAMURA, Hiroshi WATANABE, Yoshiyuki TAGUCHI
  • Publication number: 20210257946
    Abstract: Stable current control is performed even at the time of occurrence of disturbance, while the steadily occurring current pulsation is suppressed. A motor drive device 100 includes a power conversion circuit 103 that drives an alternating-current motor 101, and a controller 102 that controls the power conversion circuit 103. The controller 102 includes a voltage command calculation unit 108, a control state judgement unit 112, and a control gain change unit 113.
    Type: Application
    Filed: March 14, 2019
    Publication date: August 19, 2021
    Applicant: HitachiI Automotive Systems, Ltd.
    Inventors: Noriya NAKAO, Kazuaki TOBARI, Fumikazu TAKAHASHI, Shingo NISHIGUCHI