Patents by Inventor Satoshi Sumita
Satoshi Sumita 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: 10658960Abstract: Disclosed are a motor control system and a motor control method that allow the balance of evaluation values in a trade-off relationship to be easily adjusted. The motor control system includes: an inverter (5) that applies AC voltage to a motor (1); a control unit (3, 4) that generates a voltage command for AC voltage in response to a control command; and a feedback unit (6, 7, 8) that applies a correction value to the control unit. The feedback unit estimates a plurality of evaluation values from a state quantity using a plurality of regression formulas, where at least one state quantity (x1, x2) of the motor is an input variable and a plurality of evaluation values (y1, y2) of the motor or a motor-driven object (2) are output variables, calculates an evaluation function with the estimated plurality of evaluation values as arguments, and generates a correction command on the basis of a calculation value resulting from the evaluation function.Type: GrantFiled: September 21, 2016Date of Patent: May 19, 2020Assignee: Hitachi, Ltd.Inventors: Satoshi Sumita, Yoshitaka Iwaji
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Patent number: 10608561Abstract: Provided is a control device of an AC motor, including: an inverter including a switching element; switching control means for controlling the switching element; and phase detection means for detecting a rotor phase of an AC motor, wherein the switching control means controls the switching element so that a voltage waveform of the inverter has half-wave symmetry in an interval of a width centering on a fundamental voltage phase of 180 degĀ±180 deg, the switching control means controls the switching element so that a harmonic voltage phase of the inverter becomes variable on the basis of a fundamental voltage-rotor phase difference which is a difference between a fundamental voltage phase and the rotor phase of the AC motor, and the switching control means controls the switching element so that a harmonic voltage amplitude of each order of the inverter is inversely proportional to the order.Type: GrantFiled: July 10, 2015Date of Patent: March 31, 2020Assignee: Hitachi, Ltd.Inventors: Satoshi Sumita, Yoshitaka Iwaji
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Patent number: 10505490Abstract: The invention is directed to omit an adjustment work of a motor control system and increase versatility.Type: GrantFiled: February 19, 2016Date of Patent: December 10, 2019Assignee: Hitachi, Ltd.Inventors: Satoshi Sumita, Yoshitaka Iwaji
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Publication number: 20190207544Abstract: Disclosed are a motor control system and a motor control method that allow the balance of evaluation values in a trade-off relationship to be easily adjusted. The motor control system includes: an inverter (5) that applies AC voltage to a motor (1); a control unit (3, 4) that generates a voltage command for AC voltage in response to a control command; and a feedback unit (6, 7, 8) that applies a correction value to the control unit. The feedback unit estimates a plurality of evaluation values from a state quantity using a plurality of regression formulas, where at least one state quantity (x1, x2) of the motor is an input variable and a plurality of evaluation values (y1, y2) of the motor or a motor-driven object (2) are output variables, calculates an evaluation function with the estimated plurality of evaluation values as arguments, and generates a correction command on the basis of a calculation value resulting from the evaluation function.Type: ApplicationFiled: September 21, 2016Publication date: July 4, 2019Inventors: Satoshi SUMITA, Yoshitaka IWAJI
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Publication number: 20190052214Abstract: The invention is directed to omit an adjustment work of a motor control system and increase versatility.Type: ApplicationFiled: February 19, 2016Publication date: February 14, 2019Inventors: Satoshi SUMITA, Yoshitaka IWAJI
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Publication number: 20180198386Abstract: Provided is a control device of an AC motor, including: an inverter including a switching element; switching control means for controlling the switching element; and phase detection means for detecting a rotor phase of an AC motor, wherein the switching control means controls the switching element so that a voltage waveform of the inverter has half-wave symmetry in an interval of a width centering on a fundamental voltage phase of 180 degĀ±180 deg, the switching control means controls the switching element so that a harmonic voltage phase of the inverter becomes variable on the basis of a fundamental voltage-rotor phase difference which is a difference between a fundamental voltage phase and the rotor phase of the AC motor, and the switching control means controls the switching element so that a harmonic voltage amplitude of each order of the inverter is inversely proportional to the order.Type: ApplicationFiled: July 10, 2015Publication date: July 12, 2018Applicant: Hitachi, Ltd.Inventors: Satoshi SUMITA, Yoshitaka IWAJI
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Patent number: 8531148Abstract: A control apparatus and a control method for an AC electric motor detect DC bus current plural times at predetermined intervals during first and second predetermined periods and multiply vectors having integrated values of detected values during respective periods as elements by an inverse matrix of a matrix having integrated values during respective periods of sine and cosine functions of output voltage phase of an inverter at the moment that detection is made as elements to thereby estimate reactive and active currents.Type: GrantFiled: June 29, 2011Date of Patent: September 10, 2013Assignee: Hitachi, Ltd.Inventors: Satoshi Sumita, Kazuaki Tobari, Daisuke Maeda, Yasuo Notohara
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Patent number: 8436563Abstract: If magnitude relations between the output terminal voltage based on a DC negative terminal of the inverter and a threshold voltage that is a fixed value are compared, polarity thereof is changed at a predetermined rotor phase. The magnitude relation, for example, is detected by an inexpensive and simple apparatus such as a level shift circuit and a NOT circuit. The rotor phase of the permanent magnet synchronous motor is inferred on the basis of changes in the magnitude relation and if it is differentiated, a rotation speed is inferred. If the inferred values of the rotor phase and rotation speed are fed back to synchronous operation or vector control, the free-running permanent magnet synchronous motor is restarted.Type: GrantFiled: June 30, 2010Date of Patent: May 7, 2013Assignee: Hitachi, Ltd.Inventors: Satoshi Sumita, Kazuaki Tobari, Shigehisa Aoyagi, Daisuke Maeda
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Publication number: 20120001581Abstract: A control apparatus and a control method for an AC electric motor detect DC bus current plural times at predetermined intervals during first and second predetermined periods and multiply vectors having integrated values of detected values during respective periods as elements by an inverse matrix of a matrix having integrated values during respective periods of sine and cosine functions of output voltage phase of an inverter at the moment that detection is made as elements to thereby estimate reactive and active currents.Type: ApplicationFiled: June 29, 2011Publication date: January 5, 2012Inventors: Satoshi SUMITA, Kazuaki Tobari, Daisuke Maeda, Yasuo Notohara
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Publication number: 20110006715Abstract: If magnitude relations between the output terminal voltage based on a DC negative terminal of the inverter and a threshold voltage that is a fixed value are compared, polarity thereof is changed at a predetermined rotor phase. The magnitude relation, for example, is detected by an inexpensive and simple apparatus such as a level shift circuit and a NOT circuit. The rotor phase of the permanent magnet synchronous motor is inferred on the basis of changes in the magnitude relation and if it is differentiated, a rotation speed is inferred. If the inferred values of the rotor phase and rotation speed are fed back to synchronous operation or vector control, the free-running permanent magnet synchronous motor is restarted.Type: ApplicationFiled: June 30, 2010Publication date: January 13, 2011Applicant: Hitachi, Ltd.Inventors: Satoshi SUMITA, Kazuaki Tobari, Shigehisa Aoyagi, Daisuke Maeda
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Publication number: 20090322262Abstract: A motor control system includes a power converter, a vector controller for controlling the power converter, an axial error estimating operation for estimating an axial error which is a deviation between the phase estimation value and phase value of the motor, and a rotational speed estimating computing unit 5 for performing control so as to equalize the estimation value to a command of the axial error, a motor constant identification computing unit. The motor constant identification computing unit identifies a motor constant with a q-axis voltage component and a rotational speed identified value or a rotational speed command to reflect the identified motor constant in the vector controller.Type: ApplicationFiled: June 24, 2009Publication date: December 31, 2009Applicant: Hitachi, Ltd.Inventors: Kazuaki Tobari, Shigehisa Aoyagi, Satoshi Sumita