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: 12273058
    Abstract: When a difference between a first wave height value of a current flowing through a first direct-current power supply and a second wave height value of a current flowing through a second direct-current power supply is greater than or equal to a determination threshold value and the first wave height value is larger than the second wave height value, a control part in a rotating electrical machine control system determines that a first smoothing capacitor has an open-circuit failure, and when a difference between the first wave height value and the second wave height value is greater than or equal to the determination threshold value and the second wave height value is larger than the first wave height value, the control part determines that a second smoothing capacitor has an open-circuit failure.
    Type: Grant
    Filed: February 2, 2022
    Date of Patent: April 8, 2025
    Assignee: AISIN CORPORATION
    Inventor: Subrata Saha
  • Patent number: 12249937
    Abstract: A control part determines that a contactor is in an open state, based on a voltage at both ends of a smoothing capacitor and a current flowing through a direct-current power supply. In a state in which rotational speed is greater than or equal to a speed threshold value, the control part controls both inverters by shutdown control and brings both contactors into an open state. After the rotational speed reaches less than the speed threshold value, the control part controls a failure-side inverter by active short-circuit control, and drives a normal-side inverter using discharge torque of a smoothing capacitor. After eliminating an abnormal voltage state, the control part controls a normal contactor to a closed state and drives a rotating electrical machine by one of the inverters.
    Type: Grant
    Filed: February 2, 2022
    Date of Patent: March 11, 2025
    Assignee: AISIN CORPORATION
    Inventor: Subrata Saha
  • Publication number: 20250042280
    Abstract: An in-vehicle charging device that includes an AC-DC converter that converts power between AC power on the external AC power supply side and first DC power; and a DC-DC converter that converts power between the first DC power and second DC power on the DC power supply side, wherein the AC-DC converter includes a current source active rectifier having a power factor correct function, the DC-DC converter includes a chopper circuit including a reactor disposed on the AC-DC converter side and a half-bridge circuit disposed on the DC power supply side, the reactor is configured using a plurality of the coils, the half-bridge circuit is configured using the inverter, and the current source active rectifier includes a bidirectional switching device.
    Type: Application
    Filed: June 24, 2024
    Publication date: February 6, 2025
    Applicant: AISIN CORPORATION
    Inventors: Subrata SAHA, Keisuke Nakamura, Shin Taguchi
  • Publication number: 20250038675
    Abstract: An in-vehicle charging device that includes an AC-DC converter that converts power between AC power on the external AC power supply side and first DC power on the first DC power supply side, and converts power between AC power on the external AC power supply side and second DC power on the second DC power supply side, wherein the AC-DC converter is a triple active bridge circuit including: a transformer including a primary-side coil, a secondary-side first coil, and a secondary-side second coil; a primary-side bridge circuit connected to the primary-side coil; a secondary-side first bridge circuit connected to the secondary-side first coil; and a secondary-side second bridge circuit connected to the secondary-side second coil, and the primary-side bridge circuit includes a bidirectional switching device.
    Type: Application
    Filed: June 24, 2024
    Publication date: January 30, 2025
    Applicant: AISIN CORPORATION
    Inventors: Subrata SAHA, Keisuke NAKAMURA, Shin TAGUCHI
  • Publication number: 20250010740
    Abstract: An in-vehicle charging device charges a vehicle driving device DC power supply including: a rotating electrical machine including coils of multiple phases connected at a neutral point, and serving as a driving power source of a wheel; an inverter converting power between direct and alternating currents of multiple phases; and the DC power supply connected to the inverter, the in-vehicle charging device including: an AC-DC converter converts power between AC power and first DC power; an active decoupling circuit that includes the inverter, the coils of multiple phases, and an output capacitor, and generates second DC power for charging the DC power supply from the first DC power, in which a DC side terminal of the AC-DC converter and a DC side terminal of the inverter are connected without another passive component, and the output capacitor is connected between the neutral point of the coils and a DC negative electrode.
    Type: Application
    Filed: June 27, 2024
    Publication date: January 9, 2025
    Applicants: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata SAHA, Keisuke NAKAMURA, Shin TAGUCHI, Takashi KOSAKA, Hiroaki MATSUMORI
  • Publication number: 20250010739
    Abstract: An in-vehicle charging device that includes a first circuit configured to include the excitation circuit and convert power between AC power on an external AC power supply side and first DC power; and a second circuit configured to include the inverter, the multi-phase stator coils, and an output capacitor, and generate second DC power for charging the DC power supply from the first DC power, wherein the output capacitor is connected between the neutral point of the multi-phase stator coils and a DC negative electrode.
    Type: Application
    Filed: June 20, 2024
    Publication date: January 9, 2025
    Applicant: AISIN CORPORATION
    Inventors: Subrata SAHA, Keisuke NAKAMURA, Shin TAGUCHI
  • Patent number: 11979104
    Abstract: A rotary electric machine control apparatus (1) suitably controls two inverters (10) connected to associated ends of open windings (8). The rotary electric machine control apparatus (1) performs target control involving: controlling a first one of the inverters (10), which is selected from a first inverter (11) and a second inverter (12), by rectangular wave control; and controlling a second one of the inverters (10) by special pulse width modulation control that is one type of pulse width modulation control. The special pulse width modulation control is a control method to produce a switching pattern (Su2+) that is based on a difference between a switching pattern resulting from the pulse width modulation control and a switching pattern (Su1+) resulting from the rectangular wave control when a target voltage is to be generated in the open windings (8).
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: May 7, 2024
    Assignees: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata Saha, Hiroki Iwai, Takashi Kosaka, Hiroaki Matsumori
  • Patent number: 11955907
    Abstract: A rotating electrical machine control system (100) whose control target is an alternating-current rotating electrical machine (80) including M coil sets (8) includes M inverters (50) each including a plurality of switching elements (5) and connected to a direct-current power supply (41) and one of the coil sets (8) to convert electric power between a direct current and alternating currents of N phases; M current sensors (6) each provided for each coil set (8) to detect an alternating current of each phase flowing through the coil set (8); and an inverter control device (30) that generates switching control signals (S) for controlling the plurality of switching elements (5). The inverter control device (30) performs current feedback control of the rotating electrical machine (80) using all detection values for each of N phases obtained by the M current sensors (6), to generate the switching control signals (S) common to the M inverters (50).
    Type: Grant
    Filed: March 26, 2020
    Date of Patent: April 9, 2024
    Assignee: AISIN CORPORATION
    Inventors: Subrata Saha, Shoji Nagata
  • Publication number: 20240088816
    Abstract: A rotating electrical machine control device shifts a control system to synchronous five-pulse control when an operating point crosses a second boundary from a state in which asynchronous pulse-width modulation control is being executed, and shifts the control system to the asynchronous pulse-width modulation control when the operating point crosses a first boundary from a state in which the synchronous five-pulse control is being executed. The first boundary is set such that the number of switching pulses per unit rotational speed by the synchronous five-pulse control immediately before the operating point crosses the first boundary is smaller than the number of the switching pulses per unit rotational speed by the asynchronous pulse-width modulation control immediately after the operating point crosses the first boundary.
    Type: Application
    Filed: February 8, 2022
    Publication date: March 14, 2024
    Applicants: AISIN CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Subrata SAHA, Keisuke NISHIMURA, Kyohei KAWAMURA
  • Patent number: 11909342
    Abstract: Two inverters (10) provided at respective both ends of open-end windings (8) are appropriately controlled. As control regions (R) of a rotating electrical machine (80), a first speed region (VR1) and a second speed region (VR2) in which the rotational speed of the rotating electrical machine (80) is higher than in the first speed region (VR1) for the same torque are set, and in the second speed region (VR2), a rotating electrical machine control device (1) controls both inverters (10), a first inverter (11) and a second inverter (12), by mixed pulse width modulation control in which control is performed such that a plurality of pulses with different patterns are outputted during a first period (T1) which is a half cycle of electrical angle, and an inactive state continues during a second period (T2) which is the other half cycle.
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: February 20, 2024
    Assignees: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata Saha, Hiroki Iwai, Takashi Kosaka, Hiroaki Matsumori, Naoto Saito, Yoshinobu Ito, Isao Fujiwara
  • Publication number: 20230387846
    Abstract: When a difference between a first wave height value of a current flowing through a first direct-current power supply and a second wave height value of a current flowing through a second direct-current power supply is greater than or equal to a determination threshold value and the first wave height value is larger than the second wave height value, a control part in a rotating electrical machine control system determines that a first smoothing capacitor has an open-circuit failure, and when a difference between the first wave height value and the second wave height value is greater than or equal to the determination threshold value and the second wave height value is larger than the first wave height value, the control part determines that a second smoothing capacitor has an open-circuit failure.
    Type: Application
    Filed: February 2, 2022
    Publication date: November 30, 2023
    Applicant: AISIN CORPORATION
    Inventor: Subrata SAHA
  • Publication number: 20230378896
    Abstract: A control part determines that a contactor is in an open state, based on a voltage at both ends of a smoothing capacitor and a current flowing through a direct-current power supply. In a state in which rotational speed is greater than or equal to a speed threshold value, the control part controls both inverters by shutdown control and brings both contactors into an open state. After the rotational speed reaches less than the speed threshold value, the control part controls a failure-side inverter by active short-circuit control, and drives a normal-side inverter using discharge torque of a smoothing capacitor. After eliminating an abnormal voltage state, the control part controls a normal contactor to a closed state and drives a rotating electrical machine by one of the inverters.
    Type: Application
    Filed: February 2, 2022
    Publication date: November 23, 2023
    Applicant: AISIN CORPORATION
    Inventor: Subrata SAHA
  • Publication number: 20230378838
    Abstract: A slot-housed portion disposed on a radially inner side includes a first conductor portion and a second conductor portion having a higher electrical resistance per unit length than the first conductor portion, and has a higher electrical resistance per unit length than a slot-housed portion disposed on a radially outer side.
    Type: Application
    Filed: November 10, 2021
    Publication date: November 23, 2023
    Applicant: AISIN CORPORATION
    Inventors: Subrata SAHA, Kiyotaka KOGA, Takashi MOMIKI, Tokihito NAGAE, Masaki OTOMORI, Teppei TSUDA
  • Publication number: 20230261604
    Abstract: In a first control state, it is determined which one of a first failure pattern (FP1) and a second failure pattern (FP2) is a failure pattern (FT), and in a second control state, it is determined which one of a first lower-stage-side failure pattern (LF1) and a second lower-stage-side failure pattern (LF2) is a lower-stage-side failure pattern (LF), and it is determined which one of a set of upper-stage-side arms of a first inverter (11), a set of lower-stage-side arms of the first inverter (12), a set of upper-stage-side arms of a second inverter (12), and a set of lower-stage-side arms of the second inverter (12) is failure-side arms, based on a result of the determination in the first control state and a result of the determination in the second control state.
    Type: Application
    Filed: March 26, 2021
    Publication date: August 17, 2023
    Applicants: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata SAHA, Hiroki IWAI, Takashi KOSAKA, Hiroaki MATSUMORI
  • Patent number: 11705850
    Abstract: A rotating electrical machine control system that controls an alternating-current rotating electrical machine having two coil sets of an N phase arranged on the same stator core includes a first inverter, a second inverter, and an inverter control device that individually controls the two inverters such that currents of different phases flow through the two coil sets. The inverter control device stops the second inverter and performs switching control of the first inverter to convert electric power between a direct current and an alternating current of an N phase, or performs switching control of the two inverters to convert electric power between a direct current and alternating currents of 2N phases. Switching devices included in the first inverter have a shorter transition time between an off state and an on state and smaller switching loss than switching devices included in the second inverter.
    Type: Grant
    Filed: June 17, 2020
    Date of Patent: July 18, 2023
    Assignee: AISIN CORPORATION
    Inventors: Subrata Saha, Isao Fujiwara
  • Patent number: 11603928
    Abstract: A vehicle drive device (1) is disclosed that includes a shift detent mechanism (90); an actuator (74) that generates drive power for allowing the shift detent mechanism to operate; a sensor (135) that generates sensor information indicating an amount of operation of the shift detent mechanism; a control part (153) that controls the actuator; and a clutch (30) that is synchronized with operation of the shift detent mechanism, and when the control part changes a state of the clutch, the control part performs feedback control of the actuator based on a relationship between a target value for an amount of operation of the shift detent mechanism and the sensor information, and before completing the change in the state of the clutch, the feedback control ends and operation of the actuator stops.
    Type: Grant
    Filed: March 19, 2020
    Date of Patent: March 14, 2023
    Assignee: AISIN CORPORATION
    Inventors: Yasuyuki Sato, Subrata Saha, Hideki Kakisako, Shotaro Kondo, Junichiro Ohtsubo
  • Publication number: 20230028358
    Abstract: Two inverters (10) provided at respective both ends of open-end windings (8) are appropriately controlled. As control regions (R) of a rotating electrical machine (80), a first speed region (VR1) and a second speed region (VR2) in which the rotational speed of the rotating electrical machine (80) is higher than in the first speed region (VR1) for the same torque are set, and in the second speed region (VR2), a rotating electrical machine control device (1) controls both inverters (10), a first inverter (11) and a second inverter (12), by mixed pulse width modulation control in which control is performed such that a plurality of pulses with different patterns are outputted during a first period (T1) which is a half cycle of electrical angle, and an inactive state continues during a second period (T2) which is the other half cycle.
    Type: Application
    Filed: September 29, 2020
    Publication date: January 26, 2023
    Applicants: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata SAHA, Hiroki IWAI, Takashi KOSAKA, Hiroak MATSUMORI, Naoto SAITO, Yoshinobu ITO, Isao FUJIWARA
  • Publication number: 20230006594
    Abstract: A rotary electric machine control apparatus (1) suitably controls two inverters (10) connected to associated ends of open windings (8). The rotary electric machine control apparatus (1) performs target control involving: controlling a first one of the inverters (10), which is selected from a first inverter (11) and a second inverter (12), by rectangular wave control; and controlling a second one of the inverters (10) by special pulse width modulation control that is one type of pulse width modulation control. The special pulse width modulation control is a control method to produce a switching pattern (Su2+) that is based on a difference between a switching pattern resulting from the pulse width modulation control and a switching pattern (Su1+) resulting from the rectangular wave control when a target voltage is to be generated in the open windings (8).
    Type: Application
    Filed: September 29, 2020
    Publication date: January 5, 2023
    Applicants: AISIN CORPORATION, NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Subrata SAHA, Hiroki IWAI, Takashi KOSAKA, Hiroaki MATSUMORI
  • Patent number: 11456686
    Abstract: Two inverters provided at respective both ends of open-end windings are appropriately controlled. A rotating electrical machine control device (1) that can control a first inverter (11) and a second inverter (12) by a plurality of control schemes, respectively, the control schemes differing from each other in at least one of a switching pattern and a switching frequency and being independent of each other, has a control mode in which the first inverter (11) and the second inverter (12) are controlled by the same control scheme in a first speed region (VR1) in which the rotational speed of a rotating electrical machine (80), and the first inverter (11) and the second inverter (12) are controlled by different control schemes in a second speed region (VR2) in which the rotational speed of the rotating electrical machine (80) is higher than in the first speed region (VR1).
    Type: Grant
    Filed: August 30, 2019
    Date of Patent: September 27, 2022
    Assignee: AISIN CORPORATION
    Inventors: Subrata Saha, Isao Fujiwara
  • Publication number: 20220200508
    Abstract: A rotating electrical machine control system that controls an alternating-current rotating electrical machine having two coil sets of an N phase arranged on the same stator core includes a first inverter, a second inverter, and an inverter control device that individually controls the two inverters such that currents of different phases flow through the two coil sets. The inverter control device stops the second inverter and performs switching control of the first inverter to convert electric power between a direct current and an alternating current of an N phase, or performs switching control of the two inverters to convert electric power between a direct current and alternating currents of 2N phases. Switching devices included in the first inverter have a shorter transition time between an off state and an on state and smaller switching loss than switching devices included in the second inverter.
    Type: Application
    Filed: June 17, 2020
    Publication date: June 23, 2022
    Applicant: AISIN CORPORATION
    Inventors: Subrata SAHA, Isao FUJIWARA