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).

  • Patent number: 8339076
    Abstract: An electric motor drive control apparatus includes a detection angle obtaining section that obtains the detection angle of the resolver; a correction information storage section that stores correction information for correcting the detection angle, in association with a modulation ratio that is a ratio of an effective value of a fundamental wave component of the AC voltage to the system voltage; and a detection angle correcting section that obtains the correction information from the correction information storage section, based on the modulation ratio at the time the detection angle obtaining section obtains the detection.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: December 25, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Takeshi Aoki, Subrata Saha
  • Patent number: 8281886
    Abstract: An electric motor control device includes an inverter that supplies an output of a primary-side DC power supply to an electric motor to control driving of the electric motor; a converter that includes a voltage increasing power supply device that increases a voltage of the primary-side DC power supply to supply the inverter with the increased voltage as a secondary voltage, and a regenerative power supply device that reversely supplies regenerative power from the inverter to the primary-side DC power supply; a secondary-side target voltage determination unit; a converter control unit; and an electric motor control unit.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: October 9, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Subrata Saha, Takashi Yoshida, Daisuke Ogino, Jin Izawa, Yoshinori Oono
  • Publication number: 20120249024
    Abstract: An electric motor control device includes a mode in which an inverter is controlled by a current phase of an armature current in a 2-axis orthogonal vector space, a vector being obtained by synthesizing a field and a drive current along two axes defining the vector space; a high-loss control section that, when extra power results from charging a power storage device, varies the field current in accordance with the extra power to increase the armature current while maintaining torque of an AC electric motor; and the high-loss control section varies the field current to one of a field weakening and a field intensifying side of the electric motor, which results in the higher power loss within a range in which the armature current can be output in the vector space and which is determined based on the DC power source voltage and a rotational speed of the electric motor.
    Type: Application
    Filed: March 23, 2012
    Publication date: October 4, 2012
    Applicant: AISIN AW CO., LTD.
    Inventors: Subrata SAHA, Ken IWATSUKI
  • Patent number: 8278865
    Abstract: A control device that controls a plurality of inverters respectively provided corresponding to a plurality of alternating-current electric motors so as to control the plurality of alternating-current electric motors by current feedback. The control device comprises a carrier frequency setting unit that individually selects and sets one of a plurality of carrier frequencies, each of which is a frequency of a carrier for generating switching control signals for the inverter based on a pulse width modulation method, for each of the plurality of inverters, and a switching timing table that specifies a switching timing serving as a permissible timing of switching to a different carrier frequency pair from each of a plurality of carrier frequency pairs each of which is composed of a combination of the carrier frequencies set for each of the plurality of inverters.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: October 2, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Arinori Shimada, Mitsuru Nakamura, Subrata Saha, Ken Iwatsuki
  • Patent number: 8253359
    Abstract: A control system includes an electric rotating machine; a driving circuit that is connected to a DC power supply, the driving circuit includes a frequency conversion unit configured such that, when the electric rotating machine is to be driven in a power running mode, the frequency conversion unit converts an output of the DC power supply into AC electric power, and when the electric rotating machine is to be driven in a regenerative operation mode, the frequency conversion unit converts an output of the electric rotating machine into DC electric power; and a control unit that controls the driving circuit, wherein the control unit judges whether a connection between the DC power supply and the driving circuit is being maintained, and is configured such that, when the connection is not being maintained, regenerative electric power generated by the electric rotating machine is reduced by controlling the driving circuit.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: August 28, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Kazuhiro Tanaka, Daisuke Ogino, Subrata Saha, Jin Izawa
  • Patent number: 8232753
    Abstract: A electric motor drive apparatus comprising a voltage control unit performing voltage control processing that determines alternating-current voltage command values serving as command values of the alternating-current voltages to be supplied to the alternating-current electric motor and generates switching control signals for the inverter; and a control mode selection unit selecting a synchronous control mode in which a cycle of electric angle of the alternating-current electric motor is synchronized with a switching cycle of the inverter, or an asynchronous control mode in which the cycles are not synchronized with each other. Current detection processing is performed to detect currents flowing in coils of the alternating-current electric motor in every standard calculation cycle that is set to a half of a cycle of the carrier.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: July 31, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Arinori Shimada, Mitsuru Nakamura, Subrata Saha, Ken Iwatsuki
  • Patent number: 8188702
    Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during a powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: May 29, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Takashi Yoshida, Subrata Saha, Daisuke Ogino, Jin Izawa, Yoshinori Ono
  • Patent number: 8125169
    Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: February 28, 2012
    Assignee: Aisin AW Co., Ltd.
    Inventors: Daisuke Ogino, Takashi Yoshida, Subrata Saha, Jin Izawa, Norio Tomiya
  • Publication number: 20120032620
    Abstract: A control device that controls for an electric motor drive device including a DC/AC conversion section that converts a DC voltage into an AC voltage to supply the AC voltage to an AC electric motor. The control device is configured with a computation cycle setting section that sets a computation cycle of the control signal generation section to a first cycle, which is N times (N is an integer of 1 or more) a reference computation cycle that is set to half a carrier cycle, and that sets a computation cycle of the voltage command value determination section to a second cycle, which is M times (M is an integer of 2 or more) the first cycle, in the case where the control mode determined by the control mode determination section is the pulse width modulation control mode.
    Type: Application
    Filed: June 28, 2011
    Publication date: February 9, 2012
    Applicant: AISIN AW CO., LTD.
    Inventors: Arinori SHIMADA, Subrata SAHA, Ken IWATSUKI
  • Patent number: 8057090
    Abstract: A device and related method for mixing a powdered component and a liquid component with minimal user interaction are described. A powdered component and a liquid component are separately fed into a mixing chamber. The powdered component may be released into the liquid component by removing a barrier. Alternatively, the two components are drawn into the mixing chamber from respective sources by a vacuum. The mixture is sonicated at precise vibrational frequencies to control the physical properties of the final blended content. A piston-like device is used to remove the blended content from the mixing chamber.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: November 15, 2011
    Inventors: Subrata Saha, Pamela Saha
  • Publication number: 20110241584
    Abstract: Disclosed is a control device capable of ending strong field control based on a voltage index, such as a modulation factor. A voltage waveform control unit performs PWM control when a voltage index indicating the magnitude of voltage command values with respect to a DC voltage is less than a predetermined square wave threshold value, and performs square wave control when the voltage index is equal to or greater than the threshold. A field adjusting unit performs strong field control on the condition that the voltage index is equal to or greater than a predetermined strong field threshold value less than the square wave threshold value. A mode control unit ends the strong field control when a rotational speed is less than a rotational speed threshold value determined on the basis of a target torque and the DC voltage.
    Type: Application
    Filed: February 2, 2011
    Publication date: October 6, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Peng HE, Subrata SAHA, Ken IWATSUKI
  • Publication number: 20110241583
    Abstract: Disclosed is a control device capable of ending strong field control in a structure that performs strong field control and square wave control on the basis of a voltage index, such as a modulation factor. A voltage waveform control unit performs PWM control when a voltage index is less than a threshold, and performs square wave control when the voltage index is equal to or greater than the threshold value. A field adjusting unit performs strong field control when the voltage index is equal to or greater than a predetermined strong field threshold value less than the square wave threshold value. A mode control unit ends the strong field control when a field adjustment command value is equal to or greater than an adjustment command threshold value determined on the basis of a target torque and a voltage/speed ratio in a direction in which field flux is strengthened.
    Type: Application
    Filed: February 1, 2011
    Publication date: October 6, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Peng HE, Subrata SAHA, Ken IWATSUKI
  • Publication number: 20110234135
    Abstract: A motor control device that has a high-frequency component, and a DC bias component that has a magnitude which causes a motor to be magnetically saturated and take on a certain value over a predetermined period, and is positively and negatively symmetrical are impressed as an observation command on a d-axis current command. The polarity of the magnetic pole of a permanent magnet is identified based on a relationship of large and small magnitudes between a first amplitude, which is attained during a period during which a DC bias component takes on a positive certain value, among amplitudes of a high- frequency component contained in a d-axis response voltage computed based on a feedback current respondent to the observation command, and a second amplitude attained during a period during which the DC bias component takes on a negative certain value.
    Type: Application
    Filed: February 1, 2011
    Publication date: September 29, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Koichi KATO, Keisuke NISHIMURA, Zhiqian CHEN, Subrata SAHA
  • Publication number: 20110127933
    Abstract: A control device that controls an electric motor drive device is configured with a current control portion that determines a voltage command value, a voltage control portion that generates a switching control signal, and a current control period determining portion. The control device is also configured with a voltage control period determining portion that determines a voltage control period, and a control period setting portion. In the control device, the current control period determining portion determines, according to a target torque, the current control period as a value that increases continuously or stepwise as the target torque decreases. Furthermore, the voltage control period determining portion determines, according to a rotating speed, the voltage control period as a value that increases continuously or stepwise as the rotating speed decreases.
    Type: Application
    Filed: October 22, 2010
    Publication date: June 2, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Arinori SHIMADA, Subrata SAHA, Ken IWATSUKI
  • Patent number: 7928686
    Abstract: An electric motor control device includes a direct current power source; an inverter interposed between an electric motor and the direct current power source, the inverter device controlling an exchange of electric power therebetween; an inverter control unit that generates PWM pulses having a duty ratio corresponding to voltage command signals and sends the PWM pulses to the inverter in order to switch the inverter; a frequency changing unit that changes a carrier frequency of the PWM pulses generated by the inverter control unit in a manner corresponding to a frequency control signal; and a motor control unit.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: April 19, 2011
    Assignee: Aisin AW Co., Ltd.
    Inventors: Subrata Saha, Isao Fujiwara, Keisuke Nishimura, Kazuma Hasegawa, Yoshinori Oono, Seiichi Kinugasa
  • Publication number: 20110080131
    Abstract: A control device that controls a plurality of inverters respectively provided corresponding to a plurality of alternating-current electric motors so as to control the plurality of alternating-current electric motors by current feedback. The control device comprises a carrier frequency setting unit that individually selects and sets one of a plurality of carrier frequencies, each of which is a frequency of a carrier for generating switching control signals for the inverter based on a pulse width modulation method, for each of the plurality of inverters, and a switching timing table that specifies a switching timing serving as a permissible timing of switching to a different carrier frequency pair from each of a plurality of carrier frequency pairs each of which is composed of a combination of the carrier frequencies set for each of the plurality of inverters.
    Type: Application
    Filed: August 31, 2010
    Publication date: April 7, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Arinori SHIMADA, Mitsuru Nakamura, Subrata Saha, Ken Iwatsuki
  • Publication number: 20110080125
    Abstract: A electric motor drive apparatus comprising a voltage control unit performing voltage control processing that determines alternating-current voltage command values serving as command values of the alternating-current voltages to be supplied to the alternating-current electric motor and generates switching control signals for the inverter; and a control mode selection unit selecting a synchronous control mode in which a cycle of electric angle of the alternating-current electric motor is synchronized with a switching cycle of the inverter, or an asynchronous control mode in which the cycles are not synchronized with each other. Current detection processing is performed to detect currents flowing in coils of the alternating-current electric motor in every standard calculation cycle that is set to a half of a cycle of the carrier.
    Type: Application
    Filed: August 31, 2010
    Publication date: April 7, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Arinori SHIMADA, Mitsuru Nakamura, Subrata Saha, Ken Iwatsuki
  • Publication number: 20110074320
    Abstract: A control device that controls an electric motor drive device. The control device is configured with a first voltage control section that derives a modulation rate representing a ratio of an effective value of the voltage command values to the DC voltage and a voltage command phase. A second voltage control section generates a control signal for controlling the DC/AC conversion section on the basis of the modulation rate, the voltage command phase, and a magnetic pole position representing a rotational angle of a rotator of the AC electric motor. A computation cycle of the first voltage control section is set to be longer than a computation cycle of the second voltage control section.
    Type: Application
    Filed: August 12, 2010
    Publication date: March 31, 2011
    Applicant: AISIN AW CO., LTD.
    Inventors: Mitsuru NAKAMURA, Arinori Shimada, Subrata Saha, Ken Iwatsuki, Zhiqian Chen
  • Publication number: 20100327786
    Abstract: An electric motor drive control apparatus includes a detection angle obtaining section that obtains the detection angle of the resolver; a correction information storage section that stores correction information for correcting the detection angle, in association with a modulation ratio that is a ratio of an effective value of a fundamental wave component of the AC voltage to the system voltage; and a detection angle correcting section that obtains the correction information from the correction information storage section, based on the modulation ratio at the time the detection angle obtaining section obtains the detection.
    Type: Application
    Filed: May 10, 2010
    Publication date: December 30, 2010
    Applicant: AISIN AW CO., LTD.
    Inventors: Takeshi Aoki, Subrata Saha
  • Publication number: 20100201293
    Abstract: A rotary electric machine control system includes a battery electric power calculation unit for calculating battery electric power that is supplied from the battery; a torque limitation unit for limiting an output torque of the rotary electric machine; and a battery electric power abrupt variation estimation unit for estimating that the battery electric power is in an abrupt variation state in which the battery electric power is varying abruptly on the basis of at least one of a variation rate of the battery electric power and a variation rate of a rotational speed of the rotary electric machine.
    Type: Application
    Filed: December 1, 2008
    Publication date: August 12, 2010
    Applicant: AISIN AW CO., LTD.
    Inventors: Takashi Yoshida, Subrata Saha, Daisuke Ogino, Jin Izawa