Patents by Inventor Rashmi Prasad

Rashmi Prasad 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: 12034324
    Abstract: An electrified vehicle may include a plurality of electric drive units, a plurality of battery packs, a plurality of charge ports and a plurality of controllable switches. The switches may be controlled to flexibly configure power transfer into and out of the vehicle through one or more charge ports affecting one or more battery packs in parallel or individually passively or actively through inverter integrated converter charge transfer.
    Type: Grant
    Filed: October 28, 2022
    Date of Patent: July 9, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad, Minh-Khai Nguyen
  • Patent number: 12027900
    Abstract: A battery system for a vehicle includes multiple battery cells each configured to store charge for powering an electric vehicle, a high voltage bus electrically coupled with the multiple battery cells to provide power to an electric motor, and multiple cell monitoring modules each coupled with a corresponding one of the multiple battery cells, each cell monitoring module including a controller configured to monitor operation parameters of the corresponding one of the multiple battery cells. The system includes multiple DC-DC converters in a converter housing, each DC-DC converter electrically coupled with a corresponding one of the multiple battery cells outside of the converter housing, and a low voltage bus electrically connected between the multiple DC-DC converters in the converter housing and at least one vehicle electrical component outside of the converter housing. The low voltage bus is configured to provide low voltage power to at least one vehicle electrical component.
    Type: Grant
    Filed: January 13, 2023
    Date of Patent: July 2, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Mohamed Ahmed Kamel Ahmed, Chandra S. Namuduri, Jun-mo Kang
  • Patent number: 12012006
    Abstract: A battery electric system for a motor vehicle or another electrified system includes a battery pack connected to a direct current voltage bus, and having positive and negative battery terminals, a main pyrotechnic fuse (“pyro fuse”), a high-voltage (HV) component connected to the bus via an HV channel, a current sensing element connected to the HV component on the HV channel, and a control system configured to selectively disconnect the battery pack from the bus by transmitting a voltage signal to the main pyro fuse when a measured current value from the current sensor is indicative of a short-circuit fault. A channel switch may be connected to or integral with the current sensing element, and configured to disconnect the HV component from the bus by opening in response to the measured current value.
    Type: Grant
    Filed: March 11, 2022
    Date of Patent: June 18, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Rashmi Prasad, Robert J. Heydel, Andrew K. Chandler, Shubham V. Shedge, Chandra S. Namuduri, Eleni C. Pitses
  • Patent number: 12009715
    Abstract: A method includes: selectively actuating switches of an inverter module and first, second, third, and fourth switches of a motor; and charging a battery with power from a charger using at least one of first, second, and third stator windings of the motor, the battery having a first voltage and being electrically connected in parallel with the inverter module, and the charger having a second voltage that is less than the first voltage.
    Type: Grant
    Filed: April 26, 2022
    Date of Patent: June 11, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan
  • Publication number: 20240186811
    Abstract: A charging system of a vehicle includes an inverter of a propulsion system, the inverter connected to an electric motor and a battery system of the vehicle, and a switching assembly including a plurality of switches. The charging system also includes a controller configured to control the switching assembly to connect the inverter and the electric motor to a charge port of the vehicle and define a conversion circuit including one or more inverter switches and the electric motor by selectively connecting the charge port to the inverter or the electric motor and selectively connecting the battery system to the electric motor by the switching assembly. The controller is configured to operate the conversion circuit to adjust at least one of an input voltage for charging the battery system from a power source, and an output voltage for discharging the battery system to charge an external energy storage system.
    Type: Application
    Filed: December 2, 2022
    Publication date: June 6, 2024
    Inventors: Chandra S. Namuduri, Rashmi Prasad, Goro Tamai, Minh-Khai Nguyen
  • Publication number: 20240162727
    Abstract: An electric vehicle includes an electrical system and performs a method of charging the electric vehicle. The electrical system includes a first battery subpack, a second battery subpack, wherein the first battery subpack, the second battery subpack, and an electrical load of the electric vehicle are connected in parallel, and a processor. The processor is configured to control a first connection between the first battery subpack and a first charge port and a second connection between the second battery subpack and a second charge port to charge each of the first battery subpack and the second battery subpack while providing power to the electrical load.
    Type: Application
    Filed: November 16, 2022
    Publication date: May 16, 2024
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Lei Hao, Venkata Prasad Atluri, Rashmi Prasad
  • Patent number: 11984561
    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: Grant
    Filed: December 15, 2020
    Date of Patent: May 14, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Rashmi Prasad
  • Patent number: 11984834
    Abstract: A power control system comprises a battery system including N battery packs. A plurality of contactors selectively connects N battery packs of a battery system in a first configuration supplying a first voltage level, a second configuration supplying a second voltage level, and a disconnected configuration. M power inverters connect the battery system to M electric machines, respectively. A controller is configured to determine when to transition between the first configuration and the second configuration. The controller is configured to transition between the first configuration and the second configuration by causing one of a positive torque transient and a negative torque transient to be generated by at least one of the M electric machines, transitioning the battery system from one of the first configuration and the second configuration to the disconnected configuration, and transitioning from the disconnected configuration to the other one of the first configuration and the second configuration.
    Type: Grant
    Filed: March 21, 2022
    Date of Patent: May 14, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Muhammad Hussain Alvi, Chandra S. Namuduri, Suresh Gopalakrishnan, Chunhao J. Lee, Lei Hao, Yue-Yun Wang, Rashmi Prasad
  • Publication number: 20240146075
    Abstract: An electrified vehicle may include a plurality of electric drive units, a plurality of battery packs, a plurality of charge ports and a plurality of controllable switches. The switches may be controlled to flexibly configure power transfer into and out of the vehicle through one or more charge ports affecting one or more battery packs in parallel or individually passively or actively through inverter integrated converter charge transfer.
    Type: Application
    Filed: October 28, 2022
    Publication date: May 2, 2024
    Inventors: Chandra S. Namuduri, Rashmi Prasad, Minh-Khai Nguyen
  • Patent number: 11970072
    Abstract: An example of a vehicle electrical system includes a rechargeable energy storage system (RESS) having a first voltage and a power inverter electrically connected to the RESS. The system further includes an electric motor having a plurality of machine windings with each of the machine windings including a polyphase terminal electrically connected to the power inverter. The electric motor further includes a neutral terminal separate from the polyphase terminals. The system further includes an accessory load electrically connected to the power inverter and the neutral terminal of the electric motor, with the accessory load requiring a second voltage that is below the first voltage. A current flows through the machine windings to step down the first voltage to the second voltage. The power inverter is configured to cycle between first and second operational states, such that the power inverter steps down the first voltage to the second voltage.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: April 30, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20240128782
    Abstract: A method for charging a battery pack via an offboard energy source uses an interleaved boost converter and closed-loop control. The energy source outputs a charging current via a DC charge port during a direct current fast-charging (DCFC) process. A controller detects a voltage disparity condition in which a voltage capability of the battery pack exceeds a voltage capability of the energy source. In response to this condition, a rise of the charging current over time is recorded as a current trajectory and an open-loop equivalent time constant is extracted from the current trajectory. A time constant of the PI control block is set substantially equal to the equivalent time constant. The PIM is controlled in closed-loop using proportional-integral control. The charging current is controlled in a continuous current conduction mode during the DCFC process.
    Type: Application
    Filed: October 18, 2022
    Publication date: April 18, 2024
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Patent number: 11962173
    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: April 12, 2022
    Date of Patent: April 16, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Lei Hao, Yue-Yun Wang, Suresh Gopalakrishnan, Chandra S. Namuduri, Rashmi Prasad, Madhusudan Raghavan
  • Publication number: 20240092203
    Abstract: A charging system of a vehicle includes a first conversion device of a first drive system of the vehicle, the first conversion device connected to a first electric motor. The system also includes a second conversion device of a second drive system of the vehicle, the second conversion device connected to a second electric motor. The first drive system and the second drive system are connected to a battery system of the vehicle. The system also includes a switching assembly including a plurality of switches configured to selectively connect the first electric motor and/or the second electric motor to a charge port of the vehicle, and a controller configured to control the switching assembly to define a conversion circuit that includes components of the first drive system and/or the second drive system, and control the conversion circuit to regulate an output voltage and supply power to an energy storage system.
    Type: Application
    Filed: September 20, 2022
    Publication date: March 21, 2024
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Patent number: 11912146
    Abstract: A battery charging system includes: an electric motor including stator coils; a battery; a charge port configured to receive power from charging stations by wire; first and second electrical conductors connected between the battery and the charge port; an inverter module including (a) inputs connected to receive power from the battery and (b) outputs connected to the electric motor; a third electrical conductor; and a switch configured to electrically connect and disconnect a first end of the third electrical conductor to and from the first electrical conductor, where the third electrical conductor includes a second end that is connected to at least one of the stator coils via one of the outputs of the inverter module.
    Type: Grant
    Filed: April 23, 2021
    Date of Patent: February 27, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Patent number: 11890958
    Abstract: A system in a vehicle includes a first winding section including first two or more windings and a second winding section including second two or more windings. Each of the second two or more windings corresponds to one of the first two or more windings of the first winding section. The system also includes an inverter including a high side switch and a low side switch corresponding to each of the first two or more windings. The inverter is coupled to a battery of the vehicle and boosts a voltage of a direct current (DC) charger during charging of the battery with the DC charger, converts alternating current (AC) from an AC grid to DC during charging of the battery with the AC grid, and converts DC to AC during supply of the AC grid by the battery.
    Type: Grant
    Filed: May 10, 2022
    Date of Patent: February 6, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan
  • Publication number: 20240022946
    Abstract: A slew rate controllable system for powering an electric machine. The system may include a plurality of power transistors operable for converting a direct current (DC) input into an alternating current (AC) output suitable for electrically powering the electric machine. The system may further include a gate drive system operable for controlling a slew rate associated with transitioning the power transistors between the opened and closed states.
    Type: Application
    Filed: September 28, 2023
    Publication date: January 18, 2024
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Yilun Luo, Khorshed Mohammed Alam, Eric B. Gach, Hong Nguyen, Chandra S. Namuduri, Rashmi Prasad, Junghoon Kim
  • Patent number: 11876034
    Abstract: A power module is provided and includes first stack, second stack, and third stacks of layers, a heat pipe, and at least one cold plate or heat sink. The third stack of layers is disposed between the first and second stacks of layers and includes a first semiconductor die, a second semiconductor die and a center spacer layer disposed between the first semiconductor die and the second semiconductor die. The heat pipe extends at least partially into the center spacer layer. The at least one cold plate or heat sink receives thermal energy from the first stack of layers and the second stack of layers. The first stack of layers, the second stack of layers, the third stack of layers, the heat pipe and the at least one cold plate or heat sink facilitate dual sided cooling of each of the first semiconductor die and the second semiconductor die.
    Type: Grant
    Filed: March 29, 2021
    Date of Patent: January 16, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Muhammad H. Alvi, Ming Liu, Rashmi Prasad, Anthony M. Coppola
  • Patent number: 11872906
    Abstract: An electric propulsion system includes a rotary electric machine having an output member, a rechargeable energy storage system (“RESS”) connected to the electric machine, a user interface device, and a controller. The RESS includes multiple battery modules and a switching circuit, the latter being configured, in response to electronic switching control signals, to connect the battery modules in a parallel-connected configuration or a series-connected configuration, as a selected battery configuration. The user interface device receives an operator-requested drive mode request as an electrical signal indicative of a desired drive mode of the electric propulsion system.
    Type: Grant
    Filed: May 6, 2021
    Date of Patent: January 16, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Alireza Fatemi, Thomas W. Nehl, Chandra S. Namuduri, Lei Hao, Norman K. Bucknor, Rashmi Prasad
  • Patent number: 11870433
    Abstract: An electronic solid-state switch assembly includes a base plate and a heat exchanger; an electrically insulating layer and a direct bonded substrate affixed to the base plate; a first terminal and a second terminal; a plurality of power transistors; a plurality of gate drivers; a communication interface, a current sensor, and a snubber circuit; and a controller. The plurality of gate drivers are operatively coupled to the plurality of power transistors. The plurality of power transistors are arranged in parallel on the direct bonded substrate between the first terminal and the second terminal. The plurality of power transistors are electrically connected to the first terminal and to the second terminal. The controller is in communication with the plurality of gate drivers, the current sensor, and the communication interface. The controller is configured to control, via the plurality of gate drivers, the plurality of power transistors.
    Type: Grant
    Filed: May 4, 2022
    Date of Patent: January 9, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Muhammad H. Alvi, Ronald O. Grover, Jr.
  • Patent number: 11865945
    Abstract: A rechargeable energy storage system may include a series arrangement of a plurality of batteries coupled to a first DC bus at a first DC voltage. A DC to DC converter may include a multi-input DC input stage coupled to a multi-output DC output stage. The multi-input DC input stage may include multiple distributed DC inputs, each distributed DC input being coupled to a respective one of the plurality of batteries. The multi-output DC output stage may include multiple aggregated DC outputs. At least one controllable switch may couple one or more of the multiple aggregated DC outputs to one or more other DC buses.
    Type: Grant
    Filed: June 14, 2022
    Date of Patent: January 9, 2024
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Mohamed Kamel, Chandra S. Namuduri, Rashmi Prasad, Muhammad Hussain Alvi, Lyall Kenneth Winger