Patents by Inventor Isao Kezobo

Isao Kezobo 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: 20240136915
    Abstract: A power converter includes: a multiphase inverter circuit including a plurality of switching elements; a plurality of current sensors each configured to detect a current of the inverter circuit and output a value of the current detected; a terminal voltage detector configured to detect a voltage of each terminal of a load connected to the inverter circuit and output a value of the voltage detected; a switching element drive circuit configured to control the plurality of switching elements of the inverter circuit according to a switching pattern given; a fault detector configured to detect a fault in the inverter circuit or the plurality of current sensors; and a fault identifier configured to, after the fault detector detects the fault, switch the switching pattern to be given to the switching element drive circuit according to types of faults detectable by the fault detector, and perform identification processing of identifying a type and a location of the fault in the inverter circuit or the plurality of cu
    Type: Application
    Filed: April 13, 2021
    Publication date: April 25, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroya NATSUHARA, Isao KEZOBO, Tatsuya MORI, Chiaki FUJIMOTO, Atsushi ITO, Yusuke TAKARADA
  • Patent number: 11936309
    Abstract: A permanent-magnet-synchronous electric motor control device includes: a reference voltage value calculation unit for calculating a reference voltage value; an output voltage value calculation unit for calculating an output voltage value on the basis of a voltage command; a current weakening command calculation unit for calculating a current weakening command on the basis of the reference voltage value and the output voltage value; a voltage command calculation unit for calculating the voltage command on the basis of the current weakening command; and a power converter for supplying power to a permanent-magnet-synchronous electric motor on the basis of the voltage command. The current weakening command calculation unit calculates the current weakening command in which a high-frequency component is amplified on the basis of the difference between the reference voltage value and the output voltage value.
    Type: Grant
    Filed: May 22, 2020
    Date of Patent: March 19, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuya Tsuchimoto, Tatsuya Mori, Akira Furukawa, Isao Kezobo, Genki Fujii
  • Patent number: 11936311
    Abstract: To provide a controller for motor which can reduce a torque ripple up to high frequency, without amplifying unnecessary noise and vibration. A controller for motor estimates an interlinkage flux based on the applied voltage and the detection value of current; estimates an output torque based on the detection value of current and the estimation value of interlinkage flux; extracts a pulsation component from the estimation value of output torque; calculates a voltage command correction value based on the extraction value of pulsation component; calculates a voltage command after superimposing by superimposing the voltage command correction value on the voltage command basic value; and applies voltage to winding based on the voltage command after superimposing.
    Type: Grant
    Filed: May 30, 2019
    Date of Patent: March 19, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiko Orii, Tatsuya Mori, Seiji Sawada, Kenta Kubo
  • Patent number: 11837979
    Abstract: An electric motor control device, capable of suppressing a torque ripple even when electrical characteristics on a motor have errors or variations, comprises: a fundamental electric-current instruction generator for outputting d-axis and q-axis fundamental electric-current instructions for outputting fundamental torque from the motor having saliency; a position dependency component generator for outputting a position dependency component(s) of the motor according to its rotational position; an electric current correction instruction calculator for calculating d-axis and q-axis current correction instructions from the d-axis and q-axis fundamental electric-current instructions, and the position dependency component(s); an electric current correction instruction superposition unit for generating d-axis and q-axis current instructions by performing superposition of the d-axis and q-axis current correction instructions on the d-axis and q-axis fundamental electric-current instructions; and an electric current con
    Type: Grant
    Filed: June 27, 2019
    Date of Patent: December 5, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masahiko Orii, Isao Kezobo, Tatsuya Mori, Genki Fujii
  • Patent number: 11784585
    Abstract: To provide a power converter which can distribute heat generation of the switching devices with good accuracy, even when the maximum heating phase of the positive electrode side and the maximum heating phase of the negative electrode side are different phases, and even when the maximum heating phase of the positive electrode side and the maximum heating phase of the negative electrode side changes before and after combining the offset voltage. The power converter calculates the offset voltage that makes the positive electrode side maximum heating evaluation value and the negative electrode side maximum heating evaluation value coincide with each other, in a state of controlling on/off the switching devices based on the combined AC voltage commands of the offset voltage.
    Type: Grant
    Filed: April 18, 2018
    Date of Patent: October 10, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroya Natsuhara, Yoshihiko Kimpara, Isao Kezobo, Tatsuya Mori, Akira Furukawa
  • Publication number: 20230097479
    Abstract: A permanent-magnet-synchronous electric motor control device includes: a reference voltage value calculation unit for calculating a reference voltage value; an output voltage value calculation unit for calculating an output voltage value on the basis of a voltage command; a current weakening command calculation unit for calculating a current weakening command on the basis of the reference voltage value and the output voltage value; a voltage command calculation unit for calculating the voltage command on the basis of the current weakening command; and a power converter for supplying power to a permanent-magnet-synchronous electric motor on the basis of the voltage command. The current weakening command calculation unit calculates the current weakening command in which a high-frequency component is amplified on the basis of the difference between the reference voltage value and the output voltage value.
    Type: Application
    Filed: May 22, 2020
    Publication date: March 30, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuya TSUCHIMOTO, Tatsuya MORI, Akira FURUKAWA, Isao KEZOBO, Genki FUJII
  • Patent number: 11529993
    Abstract: To provide a motor controller and an electric power steering apparatus which can suppress torque fluctuation resulting from low detection resolution of angle, with simple calculation, even in condition where the rotational speed of motor is low. A motor controller estimates an angle error correlation value correlated with the angle detection error based on the current command value when a change frequency of the angle detection value is lower than a cutoff frequency of feedback control system which controls a rotation state; corrects the current command value or the angle detection value based on the estimation value of angle error correlation value; and changes the estimation value of angle error correlation value so that the absolute value of angle detection error increases with respect to increase in the current command value, and the absolute value of angle detection error decreases with respect to decrease in the current command value.
    Type: Grant
    Filed: November 7, 2017
    Date of Patent: December 20, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenta Tanaka, Isao Kezobo, Akira Furukawa, Seiji Sawada
  • Patent number: 11364948
    Abstract: There is provided an electric power steering device, including: a reverse steering detection unit configured to determine start of reverse steering when a magnitude of a rotational speed of a motor is equal to or smaller than a set speed, a rotational acceleration of the motor is in a direction of causing the rotational speed of the motor to become 0, and a magnitude of the rotational acceleration of the motor is equal to or larger than a set acceleration; and a current command control unit configured to output a current command for the motor based on the steering torque or the rotational speed of the motor, in which the current command control unit is configured to increase a transfer gain from input to output by the current command control unit when the reverse steering detection unit determines start of the reverse steering.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: June 21, 2022
    Assignee: Mitsubishi Electric Cornoration
    Inventors: Isao Kezobo, Kenta Tanaka, Akira Furukawa, Masaharu Tanaka, Akiyoshi Takashima
  • Publication number: 20220181998
    Abstract: An electric motor control device, capable of suppressing a torque ripple even when electrical characteristics on a motor have errors or variations, comprises: a fundamental electric-current instruction generator for outputting d-axis and q-axis fundamental electric-current instructions for outputting fundamental torque from the motor having saliency; a position dependency component generator for outputting a position dependency component(s) of the motor according to its rotational position; an electric current correction instruction calculator for calculating d-axis and q-axis current correction instructions from the d-axis and q-axis fundamental electric-current instructions, and the position dependency component(s); an electric current correction instruction superposition unit for generating d-axis and q-axis current instructions by performing superposition of the d-axis and q-axis current correction instructions on the d-axis and q-axis fundamental electric-current instructions; and an electric current con
    Type: Application
    Filed: June 27, 2019
    Publication date: June 9, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masahiko ORII, Isao KEZOBO, Tatsuya MORI, Genki FUJII
  • Publication number: 20220166356
    Abstract: To provide a controller for rotary electric machine which can suppress the increase in the switching frequency by the voltage for estimation while reducing the estimation delay of the magnetic pole position (the rotational angle). A controller for rotary electric machine turns on and off switching devices which the inverter has and applies voltage to the winding, based on a comparison result between the voltage command and the carrier wave; generates the voltage command for estimation of a preliminarily set one period on a stationary coordinate system fixed to the winding; generates the carrier wave of the same one period as the one period of the voltage command for estimation; extracts the frequency component of the one period of the voltage command for estimation from the current detection value; and estimates a rotational angle based on the frequency component.
    Type: Application
    Filed: June 4, 2019
    Publication date: May 26, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Jun KITAGAWA, Tatsuya MORI, Isao KEZOBO, Seiji SAWADA, Kenta KUBO
  • Patent number: 11338844
    Abstract: An electric power steering apparatus includes a high-frequency compensation unit that outputs a high-frequency compensation signal obtained by filtering the high-frequency components of an assist torque command signal and multiplying the filtered high-frequency components by a gain; a corrected steering torque signal obtained by negatively or positively feeding back the high-frequency compensation signal to a steering torque signal is inputted to an assist torque command calculation unit; the assist torque command calculation unit outputs the assist torque command signal in accordance with the corrected steering torque signal.
    Type: Grant
    Filed: May 24, 2016
    Date of Patent: May 24, 2022
    Assignee: Mitsubishi Electric Cornoration
    Inventors: Isao Kezobo, Kenta Tanaka, Masaharu Tanaka, Akiyoshi Takashima
  • Publication number: 20220103102
    Abstract: To provide a controller for motor which can reduce a torque ripple up to high frequency, without amplifying unnecessary noise and vibration. A controller for motor estimates an interlinkage flux based on the applied voltage and the detection value of current; estimates an output torque based on the detection value of current and the estimation value of interlinkage flux; extracts a pulsation component from the estimation value of output torque; calculates a voltage command correction value based on the extraction value of pulsation component; calculates a voltage command after superimposing by superimposing the voltage command correction value on the voltage command basic value; and applies voltage to winding based on the voltage command after superimposing.
    Type: Application
    Filed: May 30, 2019
    Publication date: March 31, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao KEZOBO, Masahiko ORII, Tatsuya MORI, Seiji SAWADA, Kenta KUBO
  • Publication number: 20220073129
    Abstract: An angle detector including; a magnet being mounted on a rotation axle and that has a first track magnetized in P pole-pairs and second track magnetized in Q pole-pairs, a first hole device group that senses magnetic flux from the first track, a second hole device group that senses magnetic flux from the second track, a first detection unit that outputs an M-step absolute angular signal through division of one electric-angle rotation into M sections, a second detection unit that outputs an N-step relative angular signal through division of each of the M divided sections into N sections, an angle calculation unit that divides the one electric-angle rotation into [M×N] sections and calculates an [M×N]-step electric angular signal, based on the absolute angular signal and the relative angular signal, and an angle correction unit that outputs a correction angle supplemented so as to smooth the electric angular signal.
    Type: Application
    Filed: July 9, 2019
    Publication date: March 10, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuya TSUCHIMOTO, Tatsuya MORI, Isao KEZOBO, Satoru AKUTSU, Isao SONODA, Genki FUJII
  • Patent number: 11237021
    Abstract: Provided are a failure determination device and method for a rotating machine control device, which are capable of detecting failure of a sensor configured to detect a rotational position of a rotating machine while the rotating machine is in operation. A rotation angle estimator calculates a rotation angle estimation value. A relationship between the rotation angle estimation value (?est), and a first angle detection value (?1) and a second angle detection value (?2), which are obtained from output signals of angle sensors configured to detect a rotational position of a rotating machine, is monitored while the rotating machine is in operation. In this manner, failure of the angle sensors, which are configured to detect the rotational position of the rotating machine, can be always detected even while the rotating machine is in operation.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: February 1, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Isao Kezobo, Munenori Yamamoto, Akira Furukawa
  • Patent number: 11155294
    Abstract: An electric power steering apparatus includes: a torque sensor configured to detect a steering torque of a driver; a motor configured to assist in a steering force of the driver; a rotation angle estimation unit configured to estimate a rotation angle of the motor to output an estimated angle; a correction signal calculation unit configured to calculate a correction signal based on the steering torque; a frequency separation unit configured to separate the estimated angle into a first frequency component and a second frequency component; an estimated angle correction unit configured to calculate, as a control angle, a value obtained by adding a second-frequency-component corrected signal, which is obtained by correcting the second frequency component based on the correction signal, to the first frequency component; and an electric power supply unit configured to supply electric power to the motor based on the control angle.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: October 26, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuya Tsuchimoto, Isao Kezobo, Yuji Takatsuka, Akira Furukawa
  • Patent number: 11150075
    Abstract: An angle detection device including: an angle sensor AGSE outputting first and second sine wave signals SINWS1, SINWS2 having phases that are different from each other by 90 degrees in accordance with rotation of a detection target; an angle calculator calculating an angle signal corresponding to a rotation angle of the detection target based on SINWS1 and SINWS2; and an angle sensor AGSE abnormality determiner ASAD determining an abnormality of AGSE based on SINWS1 and SINWS2. The ASAD includes: an amplitude signal calculator calculating an amplitude signal MALS based on a square root of a sum of squares of SINWS1 and SINWS2; a first angle signal ANGS1 calculation processor calculating ANGS1 based on SINWS1 and MALS; a second angle signal ANGS2 calculation processor calculating ANGS2 based on SINWS2 and MALS; and an abnormality determination processor determining the abnormality of AGSE based on an error between ANGS1 and ANGS2.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: October 19, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Isao Kezobo, Munenori Yamamoto, Akira Furukawa
  • Patent number: 11152881
    Abstract: A control device includes: a first power converter applying a voltage to a first winding; a second power converter applying a voltage to a second winding; a first power supply circuit supplying power to the first power converter; a second power supply circuit supplying power to the second power converter; a current command calculator; a first current controller; and a second current controller. The second power supply circuit supplies power at a voltage higher than a voltage of the first power supply circuit. The current command calculator calculates a first voltage usage state, which is an indicator value correlated with a magnitude of the output voltage of the first power converter with respect to a power supply voltage output at a time of supply of power by the first power supply circuit, and calculates the second current command based on the first voltage usage state.
    Type: Grant
    Filed: March 13, 2018
    Date of Patent: October 19, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuya Tsuchimoto, Isao Kezobo, Akira Furukawa
  • Patent number: 11130518
    Abstract: When a voltage application command is outputted to a three-phase winding of one system, a d-axis proportionality constant and a q-axis proportionality constant are set with Ld and Lq, respectively, as parameters; when voltage application commands are outputted to three-phase windings of two systems, a d-axis proportionality constant and a q-axis proportionality constant are set with [Ld+Md] and [Lq+Mq], respectively, as parameters.
    Type: Grant
    Filed: November 14, 2016
    Date of Patent: September 28, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa, Isao Kezobo
  • Patent number: 11063544
    Abstract: An inverter device includes: an inverter, a power supply current detection sensor, a phase current detection sensor, a three-phase voltage command calculator, and an inverter on/off signal generation unit. The phase current detection sensor detects a phase current in one phase of the inverter. The inverter on/off signal generation unit generates on/off signals based on the phase voltage commands. The three-phase voltage command calculator uses the power supply current and the phase current detected by the power supply current detection sensor and the phase current detection sensor, respectively, so as to calculate phase voltage commands directed to the inverter, and at a center time point of a period in which an upper arm switching element corresponding to one phase out of two phases for which the phase current detection sensor is not provided is on, and lower arm switching elements corresponding to the other two phases are on.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: July 13, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa, Isao Kezobo
  • Patent number: 11014601
    Abstract: An electric power steering apparatus including: a steering torque detector to detect a steering torque of a driver; a motor to assist a steering force of the driver; an estimated speed calculator to calculate an estimated speed, which is an estimated value of a rotation speed of the motor; an estimated speed corrector to correct the estimated speed based on the steering torque; an estimated angle calculator to calculate an estimated angle of the motor by integrating the estimated speed after the correction; and an electric power supply to supply electric power to the motor based on the estimated angle, wherein the estimated speed corrector corrects the estimated speed when a determination signal, which is based on a value obtained by removing a frequency component of steering of the driver from a derivative of the steering torque, the steering torque, and the estimated speed have the same signs.
    Type: Grant
    Filed: May 18, 2017
    Date of Patent: May 25, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuya Tsuchimoto, Isao Kezobo, Akira Furukawa, Yuji Takatsuka