Patents by Inventor Subrata Saha

Subrata Saha 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: 20170305274
    Abstract: An inverter control device that controls a rotary electric machine drive device that includes an inverter with a plurality of switching elements, where the active short circuit control is executed in a high rotational speed region, and the shut-down control is executed in a low rotational speed region, which is on a low rotational speed side with respect to the high rotational speed region, in accordance with at least a rotational speed of the rotary electric machine.
    Type: Application
    Filed: November 13, 2015
    Publication date: October 26, 2017
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Takashi YOSHIDA, Yuki SUGIYAMA, Yoichi TAJIMA, Masaya KOKUBO
  • Publication number: 20170110999
    Abstract: The magnetic pole position of a rotary electric machine is electrically derived accurately by reducing a voltage error due to a dead time while suppressing the influence on the operation efficiency of the rotary electric machine. A control device performs dead-time compensation, and performs current feedback control in a d-q-axis vector coordinate system using a magnetic pole position computed on the basis of an induced voltage produced by rotation of a rotor or on the basis of a response component to a high-frequency observation signal applied to the rotary electric machine. In the case where the rotary electric machine is controlled by deciding current commands Id*, Iq* in the d-q-axis vector coordinate system, the rotary electric machine control device controls the rotary electric machine such that the magnitude of an armature current Ia becomes equal to or more than a lower-limit current Ia_min prescribed in advance.
    Type: Application
    Filed: March 30, 2015
    Publication date: April 20, 2017
    Applicant: AISIN AW CO., LTD.
    Inventors: Arinori SHIMADA, Masashi MIYAZAKI, Subrata SAHA, Keisuke NISHIMURA, Ken IWATSUKI
  • Publication number: 20170093323
    Abstract: An inverter control device for controlling a rotating electric machine drive device that includes an inverter and a DC link capacitor, the inverter being connected to a DC power supply via a contactor, being connected to an alternating current rotating electric machine, and performing power conversion between direct current and three-phase alternating current, an arm for each alternating current phase being formed by a series circuit including an upper side switching element and a lower side switching element, and the DC link capacitor smoothing a DC link voltage, which is a DC-side voltage of the inverter, the inverter control device performing switching control on the switching elements that form the inverter.
    Type: Application
    Filed: March 26, 2015
    Publication date: March 30, 2017
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Arinori SHIMADA
  • Publication number: 20170093324
    Abstract: An inverter control device for controlling a rotating electric machine drive device that drives an alternating current rotating electric machine and includes an inverter and a DC link capacitor, the inverter being connected to a DC power supply via a contactor, being connected to the rotating electric machine, and performing power conversion between direct current and three-phase alternating current, the DC link capacitor smoothing a DC link voltage, which is a DC-side voltage of the inverter, and the inverter control device performing switching control on switching elements that form the inverter.
    Type: Application
    Filed: March 18, 2015
    Publication date: March 30, 2017
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Arinori SHIMADA
  • Patent number: 9543885
    Abstract: A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: January 10, 2017
    Assignee: AISIN AW CO., LTD.
    Inventors: Subrata Saha, Arinori Shimada
  • Patent number: 9543881
    Abstract: A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: January 10, 2017
    Assignee: AISIN AW CO., LTD.
    Inventors: Subrata Saha, Yasuhiko Kobayashi
  • Patent number: 9520809
    Abstract: A rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; an inverter control unit that controls switching of a switching element of the inverter according to a predetermined switching frequency; and an inductance control unit that switches a direct-current side inductance between a positive pole of the direct-current power supply and a positive pole of the smoothing capacitor, according to the switching frequency, between a predefined standard inductance and a high inductance that is higher than the standard inductance.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: December 13, 2016
    Assignee: AISIN AW CO., LTD.
    Inventors: Subrata Saha, Hirohisa Totani
  • Patent number: 9438153
    Abstract: A rotary electric machine control device that controls a rotary electric machine that includes a rotor in which a permanent magnet is disposed so as to provide magnetic saliency, and that performs feedback control on the rotary electric machine on the basis of a deviation between a current command and a feedback current from the rotary electric machine in a d-q-axis vector coordinate system defined by a d-axis which extends in a direction of a magnetic field produced by the permanent magnet and a q-axis which is orthogonal to the d-axis.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: September 6, 2016
    Assignee: AISIN AW CO., LTD.
    Inventors: Arinori Shimada, Tatsuya Okubo, Subrata Saha
  • Patent number: 9389249
    Abstract: A current detector that detects, based on output signals of N coreless current sensors, where N is a natural number of 3 or more, currents flowing in N conductors in a circuit connected so that the sum of the currents flowing in the N conductors becomes zero. The current detector has a signal-current correlation acquiring section that acquires a signal-current correlation representing a correlation between the output signals of the N coreless current sensors and the currents flowing in the N conductors. Furthermore, a current calculating section that calculates the currents flowing in the N conductors based on the output signals of all the N coreless current sensors by using the signal-current correlation.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: July 12, 2016
    Assignee: AISIN AW CO., LTD.
    Inventors: Yuya Hozumi, Keisuke Nishimura, Subrata Saha
  • Publication number: 20150365038
    Abstract: A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency.
    Type: Application
    Filed: March 26, 2014
    Publication date: December 17, 2015
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Yasuhiko KOBAYASHI
  • Publication number: 20150365040
    Abstract: A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency.
    Type: Application
    Filed: March 28, 2014
    Publication date: December 17, 2015
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Arinori SHIMADA
  • Publication number: 20150357956
    Abstract: A rotary electric machine control device that controls a rotary electric machine that includes a rotor in which a permanent magnet is disposed so as to provide magnetic saliency, and that performs feedback control on the rotary electric machine on the basis of a deviation between a current command and a feedback current from the rotary electric machine in a d-q-axis vector coordinate system defined by a d-axis which extends in a direction of a magnetic field produced by the permanent magnet and a q-axis which is orthogonal to the d-axis.
    Type: Application
    Filed: March 28, 2014
    Publication date: December 10, 2015
    Inventors: Arinori SHIMADA, Tatsuya OKUBO, Subrata SAHA
  • Publication number: 20150357960
    Abstract: A rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; an inverter control unit that controls switching of a switching element of the inverter according to a predetermined switching frequency; and an inductance control unit that switches a direct-current side inductance between a positive pole of the direct-current power supply and a positive pole of the smoothing capacitor, according to the switching frequency, between a predefined standard inductance and a high inductance that is higher than the standard inductance.
    Type: Application
    Filed: March 26, 2015
    Publication date: December 10, 2015
    Inventors: Subrata SAHA, Hirohisa TOTANI
  • Patent number: 9106174
    Abstract: An inverter control section controls the inverter by controlling an armature current in a two-axis orthogonal coordinate system that rotates in synchronization with the rotary electric machine, the armature current being a vector obtained by synthesizing a field current and a drive current extending along respective axes of the orthogonal coordinate system. If it is determined that connection between the DC power source section and the inverter is in a blocked state, the inverter control section executes zero-torque control in which the inverter is controlled such that torque regenerated by the rotary electric machine becomes zero, and executes high-loss control in which the field current is varied so as to increase the armature current while maintaining a torque command provided in the zero-torque control.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: August 11, 2015
    Assignee: AISIN AW CO., LTD.
    Inventors: Takaomi Sekiya, Subrata Saha, Mitsuru Nakamura, Arinori Shimada
  • Patent number: 9059653
    Abstract: A rotating electrical machine control device that applies a high frequency current to a rotating electrical machine including a rotor having saliency, estimates a magnetic pole direction of the rotor on the basis of a high frequency component contained in a voltage command as a response component to the high frequency current, and controls the rotating electrical machine. A high frequency superimposing section sets an estimated d-q axis rotating coordinate system, and a magnetic pole direction adjusting section sets a high frequency coordinate system having a phase difference of the high frequency current command with respect to the estimated d-q axis rotating coordinate system. A steady estimation error correcting section calculates a magnetic flux interference estimation error as an error of the estimated value of the magnetic pole direction which is caused by the d-q axis magnetic flux interference.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: June 16, 2015
    Assignee: AISIN AW CO., LTD.
    Inventors: Arinori Shimada, Subrata Saha
  • Patent number: 9018870
    Abstract: A control device for a rotating electrical machine, which is able to reduce a tracking delay of an actual output torque and actual currents with respect to a fluctuating torque command and fluctuating current commands and to reduce steady state deviations, is obtained. The control device includes a torque current computing unit; an actual current computing unit; a current feedback control unit; and a voltage control unit that controls voltages on the basis of the two-phase voltage commands. The torque command includes a fluctuation cancellation torque command for cancelling transmission torque fluctuations transmitted from the internal combustion engine, and the current feedback control unit includes a harmonic controller that calculates the two-phase voltage commands by using a characteristic of a transfer function corresponding to a periodic function of a frequency of the transmission torque fluctuations.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: April 28, 2015
    Assignee: Aisin AW Co., Ltd.
    Inventors: Hirokazu Kobayashi, Arinori Shimada, Takeshi Aoki, Subrata Saha, Ken Iwatsuki
  • Publication number: 20140232304
    Abstract: Regenerated power fed from a rotary electric machine is immediately reduced where connection between an electric machine and a DC power source is blocked. An inverter control section controls the inverter by controlling an armature current in a two-axis orthogonal coordinate system that rotates in synchronization with the rotary electric machine, the armature current being a vector obtained by synthesizing a field current and a drive current extending along respective axes of the orthogonal coordinate system. If it is determined that connection between the DC power source section and the inverter is in a blocked state, the inverter control section executes zero-torque control in which the inverter is controlled such that torque regenerated by the rotary electric machine becomes zero, and executes high-loss control in which the field current is varied so as to increase the armature current while maintaining a torque command provided in the zero-torque control.
    Type: Application
    Filed: June 15, 2012
    Publication date: August 21, 2014
    Applicant: AISIN AW CO., LTD.
    Inventors: Takaomi Sekiya, Subrata Saha, Mitsuru Nakamura, Arinori Shimada
  • Publication number: 20140145660
    Abstract: A rotating electrical machine control device that applies a high frequency current to a rotating electrical machine including a rotor having saliency, estimates a magnetic pole direction of the rotor on the basis of a high frequency component contained in a voltage command as a response component to the high frequency current, and controls the rotating electrical machine. A high frequency superimposing section sets an estimated d-q axis rotating coordinate system, and a magnetic pole direction adjusting section sets a high frequency coordinate system having a phase difference of the high frequency current command with respect to the estimated d-q axis rotating coordinate system. A steady estimation error correcting section calculates a magnetic flux interference estimation error as an error of the estimated value of the magnetic pole direction which is caused by the d-q axis magnetic flux interference.
    Type: Application
    Filed: October 17, 2012
    Publication date: May 29, 2014
    Applicant: Aisin AW Co., Ltd.
    Inventors: Arinori Shimada, Subrata Saha
  • Publication number: 20140139203
    Abstract: A current detector that detects, based on output signals of N coreless current sensors, where N is a natural number of 3 or more, currents flowing in N conductors in a circuit connected so that the sum of the currents flowing in the N conductors becomes zero. The current detector has a signal-current correlation acquiring section that acquires a signal-current correlation representing a correlation between the output signals of the N coreless current sensors and the currents flowing in the N conductors. Furthermore, a current calculating section that calculates the currents flowing in the N conductors based on the output signals of all the N coreless current sensors by using the signal-current correlation.
    Type: Application
    Filed: October 17, 2012
    Publication date: May 22, 2014
    Applicant: AISIN AW Co., Ltd.
    Inventors: Yuya Hozumi, Keisuke Nishimura, Subrata Saha
  • Publication number: 20130307449
    Abstract: A control device for a rotating electrical machine, which is able to reduce a tracking delay of an actual output torque and actual currents with respect to a fluctuating torque command and fluctuating current commands and to reduce steady state deviations, is obtained. The control device includes a torque current computing unit; an actual current computing unit; a current feedback control unit; and a voltage control unit that controls voltages on the basis of the two-phase voltage commands. The torque command includes a fluctuation cancellation torque command for cancelling transmission torque fluctuations transmitted from the internal combustion engine, and the current feedback control unit includes a harmonic controller that calculates the two-phase voltage commands by using a characteristic of a transfer function corresponding to a periodic function of a frequency of the transmission torque fluctuations.
    Type: Application
    Filed: March 23, 2012
    Publication date: November 21, 2013
    Applicant: AISIN AW CO., LTD.
    Inventors: Hirokazu Kobayashi, Arinori Shimada, Takeshi Aoki, Subrata Saha, Ken Iwatsuki