Patents by Inventor Suresh Gopalakrishnan

Suresh Gopalakrishnan 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: 20220190395
    Abstract: A battery system includes a plurality of battery modules electrically connected in series. Each of the battery modules includes: one or more battery cells; a first switch connected between a positive reference potential of the one or more battery cells and a first node; and a second switch connected between the first node and a second node, where a negative reference potential of the one or more battery cells is connected to the second node. A management module is configured to: selectively close the first switches of the battery modules while the second switches are open; and selectively close the second switch of one of the battery modules while the first switch of the one of the battery modules is open.
    Type: Application
    Filed: December 15, 2020
    Publication date: June 16, 2022
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Rashmi Prasad
  • Patent number: 11358492
    Abstract: An electrical system includes a rechargeable energy storage system (RESS) and a controller. The RESS includes first and second battery packs connected to a voltage bus, each pack having a respective plurality of battery cells and a corresponding cell balancing circuit. The RESS further includes switches that selectively connect or disconnect the packs to or from each other to achieve series and parallel modes. The controller executes a method by detecting a requested series to parallel mode transition. Responsive to a threshold imbalance being present in a state of charge or pack voltage of the packs relative to each other, the controller balances the state of charge/voltage using open/closed state control of the cell balancing circuits, and possibly a switching block having PWM-controlled switches and a circuit element. The controller may execute the requested mode transition upon balancing.
    Type: Grant
    Filed: September 4, 2018
    Date of Patent: June 14, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Yue-Yun Wang, Suresh Gopalakrishnan, Lei Hao
  • Patent number: 11351880
    Abstract: An automotive vehicle includes a vehicle-based charging unit including a receiving unit configured to receive power from a ground-based charging unit, the receiving unit including a multi-coil receiver, a first actuator operably coupled to the vehicle-based charging unit and configured to adjust a first position of the vehicle-based charging unit relative to the ground-based charging unit, and a controller configured to selectively actuate the first actuator.
    Type: Grant
    Filed: August 28, 2019
    Date of Patent: June 7, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Kausalya Singuru, Suresh Gopalakrishnan, Nikolai K. Moshchuk, David Andrés Pérez Chaparro
  • Patent number: 11356006
    Abstract: An electric machine includes a machine rotor circumscribed by a machine stator, and having a rotor shaft, rotor stack, and end cap which rotate about an axis. The end cap includes lobes equal in number to a number of pole pairs of the machine rotor. A position sensor assembly has a predetermined alignment with the machine rotor and stator. The sensor assembly includes a sensor rotor formed by the lobes and a sensor stator having a printed circuit board with conductive sine and cosine traces. Machine rotor rotation causes the sensor assembly to output an unmodulated sine and cosine signals to a controller, which then calculates a calibrated reference angle. A magnetic axis of an electrical phase of the machine is aligned with and bisects a peak of the sine trace. A direct axis of the machine rotor aligns with an edge of a lobe.
    Type: Grant
    Filed: January 28, 2020
    Date of Patent: June 7, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Suresh Gopalakrishnan, Chandra S. Namuduri, Alexandru Rajala, Thomas W. Nehl, Xiaohui Du, Edward L. Kaiser
  • Patent number: 11349475
    Abstract: Systems and methods for reallocation of electronic fuses (EFn). The method includes concurrently receiving, for a plurality (N) of EFn, respective sensor data and comparing the sensor data to respective operating ranges. An EFn that exceeds its operating range is turned off. Wherein a preprogrammed configuration of a fuse harness defines multiple (M) clusters, the method identifies, for each EFn that is within the operating range, whether the EFn is a member of a cluster of the M clusters, and other members of the cluster. The method monitors each cluster member's sensor data, with respect to preprogrammed thresholds and load current demands, to thereby categorize each EFn in each cluster as either healthy, derated, or failed. For failed EFns, a target EF in the same cluster having a reallocation potential is identified, and its fuse limits are modified in accordance with the reallocation potential.
    Type: Grant
    Filed: August 17, 2021
    Date of Patent: May 31, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lyall Kenneth Winger, James Morrison, Suresh Gopalakrishnan, Chandra S. Namuduri
  • Publication number: 20220158574
    Abstract: An apparatus for heating a DC battery in a vehicle including an electric motor. The apparatus comprises an AC generating module coupled to the battery and the electric motor that generates three AC phases. The first, second, and third AC phases are applied to first, second, and third windings of the electric motor, respectively. The first, second, and third AC phases create zero torque in the electric motor because the first AC phase amplitude is equal to the sum of the second and third AC phase amplitudes and the second and third AC phases are 180 degrees out of phase with the first AC phase. The AC generating module creates a heating alternating current in the DC battery.
    Type: Application
    Filed: November 17, 2020
    Publication date: May 19, 2022
    Inventors: Lei Hao, Neeraj S. Shidore, Suresh Gopalakrishnan, Chandra S. Namuduri, Venkatesh Gopalakrishnan
  • Patent number: 11336101
    Abstract: A system for use with a direct current fast-charging (DCFC) station includes a controller and battery system. The battery system includes first and second battery packs, and first, second, and third switches. The switches have ON/OFF conductive states commanded by the controller to connect the battery packs in a parallel-connected (P-connected) or series-connected (S-connected) configuration. An electric powertrain with one or more electric machines is powered via the battery system. First and second charge ports of the system are connectable to the station via a corresponding charging cable. The first charge port receives a low or high charging voltage from the station. The second charge port receives a low charging voltage. When the station can supply the high charging voltage to the first charge port, the controller establishes the S-connected configuration via the switches, and thereafter charges the battery system solely via the first charge port.
    Type: Grant
    Filed: February 3, 2020
    Date of Patent: May 17, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Lei Hao, Yue-Yun Wang, Suresh Gopalakrishnan, Chandra S. Namuduri, Rashmi Prasad, Madhusudan Raghavan
  • Patent number: 11327901
    Abstract: A modular dynamically allocated capacity storage system (MODACS) is provided and includes a housing and a control module. The housing includes source terminals, switches, cells, and sensing module. The source terminals supplying power at a first voltage potential to a first plurality of loads and power at a second voltage potential to a second plurality of loads. The cells are configured to supply power to each of the source terminals based on states of the switches. The sensing modules are configured to determine parameters of each of the cells and generate corresponding status signals. The control module is configured to receive a power request signal, and based on the power request signal and the parameters of each of the cells, determine a connected configuration for the cells relative to each other and the plurality of source terminals and set states of the switches according to the connected configuration.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: May 10, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Suresh Gopalakrishnan, Chandra S. Namuduri, Lyall K. Winger, Dave G. Rich
  • Publication number: 20220136475
    Abstract: An energy storage system (ESS) for a vehicle propulsion system includes a first battery electrically coupled to a first voltage bus, a second battery electrically coupled to a second voltage bus, and a bidirectional DC/DC power converter electrically coupled to the voltage buses. A starter for cranking an engine is electrically coupled to the first voltage bus. A controller executes computer code stored in memory. The computer code is configured to operate the converter in a boost mode to transfer power from the second voltage bus to the first voltage bus, in response to the controller determining that: a power capability of the first battery is below a power demand on the first voltage bus; a state of charge of the first battery is below a state of charge threshold; or a temperature of the first battery is below a temperature threshold.
    Type: Application
    Filed: October 30, 2020
    Publication date: May 5, 2022
    Inventors: Venkatesh Gopalakrishnan, Chandra S. Namuduri, Suresh Gopalakrishnan, Dongxu Li, Chunhao J. Lee, Neeraj S. Shidore, Norman K. Bucknor
  • Publication number: 20220102769
    Abstract: A method for preconditioning a battery pack at cold ambient temperatures is disclosed. The battery pack includes one or more battery cells. The method includes the steps of determining a desired rate of temperature rise for a battery cell, determining a desired cell current based on the desired rate of temperature rise, and determining a desired pack current based on the desired cell current and the battery pack configuration. The method further includes using a controller to control a current generation device to provide the desired pack current to the battery pack, wherein the current generation device generates an alternating current.
    Type: Application
    Filed: September 30, 2020
    Publication date: March 31, 2022
    Inventors: Neeraj S. Shidore, Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan, Meixian Wang, Venkatesh Gopalakrishnan
  • Patent number: 11254223
    Abstract: An electric propulsion system includes a battery pack and a DC-DC converter. The converter has a bypass switch and semiconductor switches. A traction power inverter module (“TPIM”) rectifies a DC bus voltage on the voltage bus to produce an AC bus voltage. An electric machine is connected to the TPIM and energized via the AC bus voltage. A controller calculates required output power from the converter based on a requested operating mode, and speed and torque of the electric machine. When the output power exceeds a threshold, the bypass switch closes to bypass the converter. When the output power is less than the threshold, the controller uses a minimum loss voltage from a loss map as a target control voltage of the converter to optimize efficiency of the electric propulsion system.
    Type: Grant
    Filed: November 6, 2019
    Date of Patent: February 22, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan, Chengwu Duan, Norman K. Bucknor
  • Publication number: 20220032803
    Abstract: A charging system of an electrical automobile vehicle includes a converter unit and a first energy storage system of within a first automobile vehicle. A charging cable is releasably connected from the first energy storage system to a charging station or is releasably connected to a second energy storage system of a second automobile vehicle. A vehicle charging controller is connected to the converter unit and programmed to communicate with the charging station and to the second energy storage system. A plurality of low-loss switching devices of the converter unit are selectively operated by signals from the vehicle charging controller to position the plurality of low-loss switching devices in an on-state (ON) or an off-state (OFF) to control charging the first energy storage system from the charging station or charging the second energy storage system from the first energy storage system.
    Type: Application
    Filed: July 31, 2020
    Publication date: February 3, 2022
    Inventors: Lei Hao, Venkata Prasad Atluri, Chandra S. Namuduri, Suresh Gopalakrishnan
  • Patent number: 11235678
    Abstract: A charging system of an electrical automobile vehicle includes a converter unit and a first energy storage system of within a first automobile vehicle. A charging cable is releasably connected from the first energy storage system to a charging station or is releasably connected to a second energy storage system of a second automobile vehicle. A vehicle charging controller is connected to the converter unit and programmed to communicate with the charging station and to the second energy storage system. A plurality of low-loss switching devices of the converter unit are selectively operated by signals from the vehicle charging controller to position the plurality of low-loss switching devices in an on-state (ON) or an off-state (OFF) to control charging the first energy storage system from the charging station or charging the second energy storage system from the first energy storage system.
    Type: Grant
    Filed: July 31, 2020
    Date of Patent: February 1, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lei Hao, Venkata Prasad Atluri, Chandra S. Namuduri, Suresh Gopalakrishnan
  • Patent number: 11233407
    Abstract: A battery includes: a first terminal; a second terminal; a plurality of individually housed batteries; a plurality of switches configured to connect ones of the individually housed batteries to and from ones of the first and second terminals; and a switch control module configured to: at a frequency, vary a voltage applied to a gate of one of the switches, the one of the switches configured to connect at least one of the individually housed batteries to one of the first and second terminals; and diagnose whether a fault is present in the one of the switches based on a voltage across the one of the switches.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: January 25, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lyall K. Winger, Dave G. Rich, Suresh Gopalakrishnan, Chandra S. Namuduri
  • Patent number: 11220172
    Abstract: A vehicle powertrain includes a first power-source configured to generate a first power-source torque and a multiple speed-ratio transmission configured to transmit the first power-source torque to power the vehicle. The powertrain also includes a fluid coupling having a fluid pump shaft operatively connected to the first power-source and a turbine shaft operatively connected to the multi-speed transmission. The fluid coupling is configured to multiply the first power-source torque, and transfer the multiplied first power-source torque to the multiple speed-ratio transmission. The powertrain additionally includes a second power-source configured to generate a second power-source torque and a first torque transfer system configured to connect the second power-source to the first power-source. The powertrain further includes a second torque transfer system configured to connect the second power-source to the multi-speed transmission. A motor vehicle having such a powertrain is also envisioned.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: January 11, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Neeraj S. Shidore, Derek F. Lahr, Lei Hao, Madhusudan Raghavan, Suresh Gopalakrishnan
  • Publication number: 20210402887
    Abstract: A method of controlling fast charging of at least one battery pack within a high voltage electrical propulsion system includes identifying an operating condition, wherein the operating condition is one of charging mode and propulsion mode, and, when the electrical system is in charging mode, initiating charging of the at least one battery pack, terminating charging of the at least one battery pack and connecting the at least one battery pack to power components of the electrical propulsion system when there is a request to terminate charging of the at least one battery pack, and terminating charging of the at least one battery pack and connecting the at least one battery pack to power components of the electrical propulsion system when there is no request to terminate charging of the at least one battery pack and the charging of the at least one battery pack is complete.
    Type: Application
    Filed: June 29, 2020
    Publication date: December 30, 2021
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas W. Nehl
  • Patent number: 11199169
    Abstract: An electric starter system for an internal combustion includes a pinion gear, a pinion solenoid coupled to the pinion gear, a starter motor that is selectively connectable to the flywheel of the engine via the pinion gear, and a controller in communication with the pinion solenoid and the starter motor. In response to an engine auto-stop signal, the controller is configured to translate the pinion gear into contact with the flywheel and the motor, and cause rotation of the engine crankshaft to a predetermined crank angle. In response to an engine auto-start signal, the controller is configured to command delivery of motor torque from the starter motor, through the pinion gear, and to the flywheel for a duration sufficient for starting the engine.
    Type: Grant
    Filed: April 21, 2021
    Date of Patent: December 14, 2021
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Pranjal Sharma
  • Patent number: 11133680
    Abstract: System and method of dynamically balancing a rechargeable energy storage assembly having two or more respective units, a respective switch for each of the respective units and at least one sensor. The system includes a controller configured to control operation of the respective switch. The respective switch is configured to enable a respective circuit connection to the respective units when in an ON state and disable the respective circuit connection when in an OFF state. The respective units are characterized by a respective state of charge obtained based in part on the at least one sensor. A controller is configured to selectively employ at least one of a plurality of charging modes to charge one or more of the respective units, through operation of the respective switch. The plurality of charging modes includes a rest charging mode, a rapid initial charging mode and a rapid final charging mode.
    Type: Grant
    Filed: January 8, 2019
    Date of Patent: September 28, 2021
    Assignee: GM Global Technology Operations LLC
    Inventors: Yue-Yun Wang, Lei Hao, Suresh Gopalakrishnan
  • Publication number: 20210239449
    Abstract: An electric powertrain includes a sensor-controller interface, an inverter-controller electrically connected to the battery pack, and an electric machine connected to the inverter-controller and having a rotor with an angular position. The rotor powers a driven load at a torque and/or speed level controlled by the inverter-controller in response to position signals indicative of the angular position. A rotary position sensor is operatively connected to the rotor to generate and output the position signals. The sensor derives the position signals from unmodulated sine and cosine signals, and communicates the position signals and a binary sensor state of health (SOH) to the inverter-controller over the interface. The inverter-controller also decodes the position signals and the binary sensor SOH to generate decoded control data, and controls the torque and/or speed level using the decoded control data.
    Type: Application
    Filed: January 30, 2020
    Publication date: August 5, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Suresh Gopalakrishnan, Shuqing Zeng, Chandra S. Namuduri
  • Publication number: 20210242691
    Abstract: A system for use with a direct current fast-charging (DCFC) station includes a controller and battery system. The battery system includes first and second battery packs, and first, second, and third switches. The switches have ON/OFF conductive states commanded by the controller to connect the battery packs in a parallel-connected (P-connected) or series-connected (S-connected) configuration. An electric powertrain with one or more electric machines is powered via the battery system. First and second charge ports of the system are connectable to the station via a corresponding charging cable. The first charge port receives a low or high charging voltage from the station. The second charge port receives a low charging voltage. When the station can supply the high charging voltage to the first charge port, the controller establishes the S-connected configuration via the switches, and thereafter charges the battery system solely via the first charge port.
    Type: Application
    Filed: February 3, 2020
    Publication date: August 5, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lei Hao, Yue-Yun Wang, Suresh Gopalakrishnan, Chandra S. Namuduri, Rashmi Prasad, Madhusudan Raghavan