Patents by Inventor Kohei Myoen
Kohei Myoen 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).
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Patent number: 12199533Abstract: A power conversion device includes: an inverter that converts a DC voltage into an AC voltage and drives a synchronous motor; and a magnetic pole position correction unit that corrects an error in a magnetic pole position of a rotor from a rotation angle sensor of the synchronous motor. The magnetic pole position correction unit includes an actual current phase calculation unit that calculates a current phase from a current when three-phase lines are short-circuited during rotation of the synchronous motor and an ideal current phase calculation unit that calculates an ideal current phase based on a rotational speed of the rotor and a temperature of a stator, and corrects the magnetic pole position from a difference between outputs of the actual current phase calculation unit and the ideal current phase calculation unit.Type: GrantFiled: November 13, 2020Date of Patent: January 14, 2025Assignee: Hitachi Astemo, Ltd.Inventors: Kentaro Matsuo, Kohei Myoen, Kenichi Yoshida, Kazuyoshi Aizawa
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Patent number: 12199546Abstract: A motor control device controls a motor, which is driven by three-phase alternating currents and to which a magnetic pole position sensor measuring a magnetic pole position of a rotor is attached, using a detection value of a rotation angle of the motor based on a measurement result of the magnetic pole position by the magnetic pole position sensor, compares a peak-current-time rotation angle representing the detection value of the rotation angle at a peak of a current value of a target phase and a reference rotation angle representing the rotation angle at a peak of a predetermined current waveform of the target phase using any one phase of the three-phase alternating currents during a three-phase short circuit of the motor as the target phase, and corrects the detection value of the rotation angle based on a result of the comparison.Type: GrantFiled: June 10, 2021Date of Patent: January 14, 2025Assignee: HITACHI ASTEMO, LTD.Inventors: Junki Isobe, Kohei Myoen
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Publication number: 20240146222Abstract: A drive apparatus of a synchronous motor includes: a current detecting unit that detects a phase current flowing to the synchronous motor; and a magnetic pole position estimating unit that estimates a magnetic pole position of a rotor of the synchronous motor, based on the phase current detected by the current detecting unit. The magnetic pole position estimating unit includes a first peak-to-peak detector that detects a first peak-to-peak value representing a difference between a maximum value and a minimum value of the phase current, a quadrature component detector that detects a quadrature component of the phase current, and a second peak-to-peak detector that detects a second peak-to-peak value representing a difference between a maximum value and a minimum value of the quadrature component.Type: ApplicationFiled: August 31, 2021Publication date: May 2, 2024Inventors: Hiroaki SATO, Hirokazu MATSUI, Toshisada MITSUI, Kohei MYOEN
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Patent number: 11942889Abstract: A first torque calculation unit 114 calculates torque TQ_DC currently generated by a motor 106 based on a DC current DC1. A second torque calculation unit 115 calculates torque TQ_UVW currently generated by the motor 106 based on U-phase, V-phase, and W-phase currents. A torque limit calculation unit 116 calculates a torque limit TQ_LMT1 using a torque limit characteristic map measured in advance based on a current limit DC_LMT1. A torque limit correction unit 117 compares first torque TQ_DC with second torque TQ_UVW to calculate a torque variation degree KP1. Then, the torque limit TQ_LMT1 is corrected using the variation degree KP1 to calculate a torque limit TQ_LMT2. As a result, even if required torque reaches the torque limit, the DC current does not exceed the current limit, and the output of the motor can be fully utilized by approaching the current limit.Type: GrantFiled: December 12, 2019Date of Patent: March 26, 2024Assignee: Hitachi Astemo, Ltd.Inventors: Shinyu Ko, Kohei Myoen, Eigo Kishimoto
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Publication number: 20230336098Abstract: A motor control device controls a motor, which is driven by three-phase alternating currents and to which a magnetic pole position sensor measuring a magnetic pole position of a rotor is attached, using a detection value of a rotation angle of the motor based on a measurement result of the magnetic pole position by the magnetic pole position sensor, compares a peak-current-time rotation angle representing the detection value of the rotation angle at a peak of a current value of a target phase and a reference rotation angle representing the rotation angle at a peak of a predetermined current waveform of the target phase using any one phase of the three-phase alternating currents during a three-phase short circuit of the motor as the target phase, and corrects the detection value of the rotation angle based on a result of the comparison.Type: ApplicationFiled: June 10, 2021Publication date: October 19, 2023Applicant: Hitachi Astemo, Ltd.Inventors: Junki ISOBE, Kohei MYOEN
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Publication number: 20230006586Abstract: A power conversion device includes: an inverter that converts a DC voltage into an AC voltage and drives a synchronous motor; and a magnetic pole position correction unit that corrects an error in a magnetic pole position of a rotor from a rotation angle sensor of the synchronous motor. The magnetic pole position correction unit includes an actual current phase calculation unit that calculates a current phase from a current when three-phase lines are short-circuited during rotation of the synchronous motor and an ideal current phase calculation unit that calculates an ideal current phase based on a rotational speed of the rotor and a temperature of a stator, and corrects the magnetic pole position from a difference between outputs of the actual current phase calculation unit and the ideal current phase calculation unit.Type: ApplicationFiled: November 13, 2020Publication date: January 5, 2023Applicant: HITACHI ASTEMO, LTD.Inventors: Kentaro MATSUO, Kohei MYOEN, Kenichi YOSHIDA, Kazuyoshi AIZAWA
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Patent number: 11290044Abstract: Provided is a motor control device capable of suppressing a sudden change in torque due to spike noise. A control device (motor control device) continues motor control using dq-axis current command values Id* and Iq* (current command values) or dq-axis detection current values real_Id and real_Iq before detecting a noise state (detection current values before a current supplied to a motor suddenly changes) instead of dq-axis detection current values real_Id and real_Iq (latest detection current values) when the current changes suddenly.Type: GrantFiled: January 24, 2019Date of Patent: March 29, 2022Assignee: HITACHI ASTEMO LTD.Inventors: Atsushi Komuro, Kohei Myoen
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Publication number: 20220077795Abstract: A first torque calculation unit 114 calculates torque TQ_DC currently generated by a motor 106 based on a DC current DC1. A second torque calculation unit 115 calculates torque TQ_UVW currently generated by the motor 106 based on U-phase, V-phase, and W-phase currents. A torque limit calculation unit 116 calculates a torque limit TQ_LMT1 using a torque limit characteristic map measured in advance based on a current limit DC_LMT1. A torque limit correction unit 117 compares first torque TQ_DC with second torque TQ_UVW to calculate a torque variation degree KP1. Then, the torque limit TQ_LMT1 is corrected using the variation degree KP1 to calculate a torque limit TQ_LMT2. As a result, even if required torque reaches the torque limit, the DC current does not exceed the current limit, and the output of the motor can be fully utilized by approaching the current limit.Type: ApplicationFiled: December 12, 2019Publication date: March 10, 2022Applicant: Hitachi Astemo, Ltd.Inventors: Shinyu KO, Kohei MYOEN, Eigo KISHIMOTO
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Patent number: 11196377Abstract: 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: GrantFiled: November 28, 2018Date of Patent: December 7, 2021Assignee: HITACHI ASTEMO, LTD.Inventors: Midori Takaoka, Junki Isobe, Kohei Myoen, Toshiyuki Ajima, Kazuaki Tobari, Yoshitaka Iwaji
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Patent number: 11001148Abstract: To appropriately limit a current output from an inverter to a motor according to a state of a cooling mechanism that cools the motor and the inverter. A motor control unit includes a current command unit configured to calculate current command values (Id*, Iq*) for determining a current to be output to a motor on the basis of an input torque command, a motor lock determination unit configured to determine whether the motor is in a locked state on the basis of a motor rotation speed Nrpm indicating a rotation state of the motor, and a torque command limitation unit configured to limit the current to be output to the motor by limiting the torque command on the basis of a cooling water temperature Tc indicating a state of the cooling mechanism in a case where the motor lock determination unit determines that the motor is in the locked state.Type: GrantFiled: January 18, 2018Date of Patent: May 11, 2021Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Hirokazu Matsui, Atsushi Komuro, Kohei Myoen
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Publication number: 20200389117Abstract: 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: ApplicationFiled: November 28, 2018Publication date: December 10, 2020Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Midori TAKAOKA, Junki ISOBE, Kohei MYOEN, Toshiyuki AJIMA, Kazuaki TOBARI, Yoshitaka IWAJI
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Publication number: 20200389107Abstract: Provided is a motor control device capable of suppressing a sudden change in torque due to spike noise. A control device (motor control device) continues motor control using dq-axis current command values Id* and Iq* (current command values) or dq-axis detection current values real_Id and real_Iq before detecting a noise state (detection current values before a current supplied to a motor suddenly changes) instead of dq-axis detection current values real_Id and real_Iq (latest detection current values) when the current changes suddenly.Type: ApplicationFiled: January 24, 2019Publication date: December 10, 2020Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Atsushi KOMURO, Kohei MYOEN
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Publication number: 20200021220Abstract: To appropriately limit a current output from an inverter to a motor according to a state of a cooling mechanism that cools the motor and the inverter. A motor control unit includes a current command unit configured to calculate current command values (Id*, Iq*) for determining a current to be output to a motor on the basis of an input torque command, a motor lock determination unit configured to determine whether the motor is in a locked state on the basis of a motor rotation speed Nrpm indicating a rotation state of the motor, and a torque command limitation unit configured to limit the current to be output to the motor by limiting the torque command on the basis of a cooling water temperature Tc indicating a state of the cooling mechanism in a case where the motor lock determination unit determines that the motor is in the locked state.Type: ApplicationFiled: January 18, 2018Publication date: January 16, 2020Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Hirokazu MATSUI, Atsushi KOMURO, Kohei MYOEN
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Patent number: 10090790Abstract: The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced.Type: GrantFiled: October 21, 2015Date of Patent: October 2, 2018Assignee: Hitachi Automotive Systems, Ltd.Inventors: Hirokazu Sambonsuge, Kohei Myoen, Kazuto Oyama
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Patent number: 10027270Abstract: To provide a motor control device capable of properly compensating the fluctuation in inverter output voltage during a dead time. The motor control device is for an inverter including switching elements composing upper and lower arms to convert a direct-current voltage to an alternating-current voltage and apply the alternating-current voltage to a motor thereby controlling a current of the motor to be a current target value, the motor control device including a dead time compensation unit that compensates fluctuation in inverter output voltage during a dead time with each switching between the upper and lower arms by a dead time compensation voltage, wherein the dead time compensation unit acquires an input parameter that determines a polarity of motor current during the dead time in a half-cycle of a fundamental wave of the motor current, and varies the dead time compensation voltage according to magnitude of the input parameter.Type: GrantFiled: January 15, 2016Date of Patent: July 17, 2018Assignee: Hitachi Automotive Systems, Ltd.Inventors: Kohei Myoen, Yusuke Kogure
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Publication number: 20180019697Abstract: To provide a motor control device capable of properly compensating the fluctuation in inverter output voltage during a dead time. The motor control device is for an inverter including switching elements composing upper and lower arms to convert a direct-current voltage to an alternating-current voltage and apply the alternating-current voltage to a motor thereby controlling a current of the motor to be a current target value, the motor control device including a dead time compensation unit that compensates fluctuation in inverter output voltage during a dead time with each switching between the upper and lower arms by a dead time compensation voltage, wherein the dead time compensation unit acquires an input parameter that determines a polarity of motor current during the dead time in a half-cycle of a fundamental wave of the motor current, and varies the dead time compensation voltage according to magnitude of the input parameter.Type: ApplicationFiled: January 15, 2016Publication date: January 18, 2018Inventors: Kohei MYOEN, Yusuke KOGURE
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Publication number: 20170331401Abstract: The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced.Type: ApplicationFiled: October 21, 2015Publication date: November 16, 2017Inventors: Hirokazu SAMBONSUGE, Kohei MYOEN, Kazuto OYAMA
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Patent number: 9819299Abstract: Provided are an inverter device deterring PWM voltage error even if high inverter output frequencies are used for overmodulation driving and an electric vehicle equipped with the inverter device. In an angular section where the output voltage from an inverter device is linearly approximated with the zero cross point as the center thereof, a PWM generator in the inverter device changes either the time interval between the centers of PWM ON pulses or the time interval between the centers of PWM OFF pulses depending on the inverter operation state. An electric vehicle is equipped with the inverter device, which drives a motor.Type: GrantFiled: May 21, 2014Date of Patent: November 14, 2017Assignee: Hitachi Automotive Systems, Ltd.Inventors: Toshiyuki Ajima, Kimihisa Furukawa, Kohei Myoen, Hiroyuki Yamada
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Patent number: 9791299Abstract: A diagnostic device capable of accurately diagnosing the soundness of a resolver circuit is provided. A shifter receives excitation signal and excitation signal; shifts the level of excitation signal, excitation signal, or both; and performs level shifting such that a period of time that starts with one of two times in which, in the vicinity of the peak value of excitation signal, excitation signal and excitation signal are at the same value and ends with the other of the two times is less than a prescribed threshold. A trigger generation circuit generates a trigger during said period of time. A control unit determines whether there is an abnormality in the resolver circuit on the basis of the trigger.Type: GrantFiled: January 31, 2014Date of Patent: October 17, 2017Assignee: Hitachi Automotive Systems, Ltd.Inventors: Kosei Goto, Satoru Shigeta, Atsushi Okabe, Kohei Myoen, Yuuichirou Takamune
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Patent number: 9455655Abstract: A motor control system can suppress production costs, suppress the occurrence of unexpected excessive torque, and continue system operation as much as possible even when the diagnosis results of a monitoring device are abnormal. A computation device computes a voltage command value indicating the voltage to impose on a motor. Based on the voltage command value, the computation device generates a control signal that controls a drive device. When the diagnosis results of the monitoring device are normal, the computation device computes the voltage command value so that the absolute value of the detection value of current flowing to the motor is no greater than a second threshold, and when the diagnosis results of the monitoring device are abnormal, the computation device computes the voltage command value so that this absolute value is no greater than a third threshold that is smaller than the second threshold.Type: GrantFiled: December 18, 2013Date of Patent: September 27, 2016Assignee: Hitachi Automotive Systems, Ltd.Inventors: Kohei Myoen, Atsushi Komuro