Patents by Inventor Rajesh Nagappala

Rajesh Nagappala 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: 11967851
    Abstract: A method for adapting a usage level of a battery pack includes measuring cell sense data for each respective battery cell using a cell sense circuit, the cell sense data including a cell voltage, current, and temperature. The method includes processing the cell sense data, for each respective battery cell, through multiple battery state functions of a controller to generate numeric cell degradation values (CDVs). The battery state functions are calibrated relationships of the cell sense data to predetermined battery fault conditions. Thereafter, the method includes automatically adapting the usage level of the battery pack during operation of the battery pack, via the controller, based on the numeric CDVs. An electric powertrain system includes the battery pack, cell sense circuit, a rotary electric machine, and a controller configured to execute the above method.
    Type: Grant
    Filed: February 25, 2021
    Date of Patent: April 23, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: James C. Gibbs, Andrew M. Zettel, Calvin Goodman, Rajesh Nagappala
  • Patent number: 11858354
    Abstract: An emergency disconnect circuit for use with a high-voltage (HV) bus of a battery electric system, e.g., aboard a mobile system, includes a pyrotechnic switch and a manual switch. The pyrotechnic switch configured irreversibly opens in response to an electronic triggering signal to disconnect an HV battery pack from the HV bus in a first manner. The manual switch is arranged on a low-voltage (LV) bus in series with and between the pyrotechnic switch and an LV power supply. Transition of the manual switch from an open position to a closed position connects the LV power supply to the pyrotechnic switch. This causes the LV power supply to discharge the triggering signal to the pyrotechnic switch. When used aboard a mobile system, an electronic monitoring unit generates the triggering signal in a second manner in response to a threshold impact event.
    Type: Grant
    Filed: April 11, 2022
    Date of Patent: January 2, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Li-Pen John Ho, Calvin Goodman, Rajesh Nagappala
  • Publication number: 20230322088
    Abstract: An emergency disconnect circuit for use with a high-voltage (HV) bus of a battery electric system, e.g., aboard a mobile system, includes a pyrotechnic switch and a manual switch. The pyrotechnic switch configured irreversibly opens in response to an electronic triggering signal to disconnect an HV battery pack from the HV bus in a first manner. The manual switch is arranged on a low-voltage (LV) bus in series with and between the pyrotechnic switch and an LV power supply. Transition of the manual switch from an open position to a closed position connects the LV power supply to the pyrotechnic switch. This causes the LV power supply to discharge the triggering signal to the pyrotechnic switch. When used aboard a mobile system, an electronic monitoring unit generates the triggering signal in a second manner in response to a threshold impact event.
    Type: Application
    Filed: April 11, 2022
    Publication date: October 12, 2023
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Li-Pen John Ho, Calvin Goodman, Rajesh Nagappala
  • Publication number: 20220271552
    Abstract: A method for adapting a usage level of a battery pack includes measuring cell sense data for each respective battery cell using a cell sense circuit, the cell sense data including a cell voltage, current, and temperature. The method includes processing the cell sense data, for each respective battery cell, through multiple battery state functions of a controller to generate numeric cell degradation values (CDVs). The battery state functions are calibrated relationships of the cell sense data to predetermined battery fault conditions. Thereafter, the method includes automatically adapting the usage level of the battery pack during operation of the battery pack, via the controller, based on the numeric CDVs. An electric powertrain system includes the battery pack, cell sense circuit, a rotary electric machine, and a controller configured to execute the above method.
    Type: Application
    Filed: February 25, 2021
    Publication date: August 25, 2022
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: James C. Gibbs, Andrew M. Zettel, Calvin Goodman, Rajesh Nagappala