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).

  • Publication number: 20230378776
    Abstract: A battery system includes a battery pack configured to be selectively connected to an output terminal of the battery system and a DCFC receptacle, a first contactor that is connected between the DCFC receptacle and a first terminal of the battery pack, and a first SSR connected in series with the first contactor between the DCFC receptacle and the first terminal of the battery pack. The first SSR has an open state where current from the DCFC receptacle to the battery pack is interrupted and a dosed state where current flows from the DCFC receptacle to the battery pack, the first SSR is configured to transition from the dosed state to the open state prior to the first contactor, and current only flows from the DCFC receptacle to the battery pack when both the first contactor and the first SSR are in the closed state.
    Type: Application
    Filed: May 20, 2022
    Publication date: November 23, 2023
    Inventors: Rashmi PRASAD, Chandra S. NAMUDURI
  • Publication number: 20230365012
    Abstract: A charging system for a vehicle includes a conversion device configured to transfer an electric charge between a battery assembly of the vehicle and an energy storage system, the battery assembly having a first voltage and the energy storage system having a second voltage, the conversion device including a scalable buck-boost system having a plurality of buck-boost modules. Each buck-boost module of the plurality of buck-boost modules includes a set of switches and an inductor. The charging system also includes a controller configured to operate one or more buck-boost modules of the plurality of buck-boost modules during transfer of charge between the battery assembly and the energy storage system.
    Type: Application
    Filed: May 12, 2022
    Publication date: November 16, 2023
    Inventors: Chandra S. Namuduri, Lei Hao, Rashmi Prasad, Rasoul Hosseini, Venkata Prasad Atluri, Chengwu Duan
  • Publication number: 20230365016
    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: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan
  • Publication number: 20230364996
    Abstract: Examples described herein provide a method that includes performing an electrical degradation analysis for a power inverter. The method further includes performing a thermal degradation analysis on the power inverter. The method further includes, responsive to at least one of a result of the electrical degradation analysis being indicative of an electrical issue of the power inverter or a result of the thermal degradation analysis being indicative of a thermal issue of the power inverter, implementing a corrective action for the power inverter.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Inventors: Jiyu Zhang, Bojian Cao, Nomar S. Gonzalez Santini, Jeffrey Scott Piasecki, Tanvi Nagarale, Muhammad Hussain Alvi, Rashmi Prasad
  • Publication number: 20230369879
    Abstract: Electrical energy is transferred between an on-vehicle DC power source and an off-vehicle DC power source by controlling conduction of the phase legs of a power inverter to operatively configure the power inverter and the stator phase windings of a traction motor as a switched-mode power converter including the at least one phase winding and at least one switch of one of the phase legs.
    Type: Application
    Filed: May 13, 2022
    Publication date: November 16, 2023
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Avoki M. Omekanda
  • Publication number: 20230361771
    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: Application
    Filed: May 4, 2022
    Publication date: November 9, 2023
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Muhammad H. Alvi, Ronald O. Grover, Jr.
  • Patent number: 11810873
    Abstract: A solid-state fuse device includes a switch a gate driver connected to the switch and configured to transition the switch from a closed state to an open state when at least one of an overcurrent measurement exceeds a predetermined overcurrent threshold or a voltage drop across the switch exceeds a predetermined saturation voltage threshold.
    Type: Grant
    Filed: April 7, 2021
    Date of Patent: November 7, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Muhammad H. Alvi, Rashmi Prasad
  • Patent number: 11801770
    Abstract: A battery system includes first and second battery packs connected to positive and negative DC voltage bus rails, a contactor switch connected between the battery packs, a solid-state switch in series with the contactor switch, and a controller. The controller determines characteristic values of the switches, including a respective temperature, voltage, and current value for each. The controller also detects a predetermined electrical fault condition of the contactor switch using the characteristic values, and executes a control action in response to the electrical fault condition. The control action includes opening the semi-conductor switch to thereby interrupt a flow of current between the first and second battery packs. A mobile platform includes road wheels connected to a body, a rotary electric machine configured to power the road wheels and thereby propel the mobile platform, and the battery pack, switches, and controller.
    Type: Grant
    Filed: September 13, 2019
    Date of Patent: October 31, 2023
    Assignee: GM Global Technology Operations LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20230344293
    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: Application
    Filed: April 26, 2022
    Publication date: October 26, 2023
    Inventors: Rashmi PRASAD, Chandra S. NAMUDURI, Lei HAO, Suresh GOPALAKRISHNAN
  • Publication number: 20230299695
    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: Application
    Filed: March 21, 2022
    Publication date: September 21, 2023
    Inventors: Muhammad Hussain ALVI, Chandra S. NAMUDURI, Suresh GOPALAKRISHNAN, Chunhao J. LEE, Lei HAO, Yue-Yun WANG, Rashmi PRASAD
  • Patent number: 11765815
    Abstract: A bi-directional solid state switch includes: a first bus bar; a second bus bar; a first solid state switch implemented on a first printed circuit board (PCB), the first solid state switch including: a first control terminal; a first terminal electrically connected to the first bus bar; and a second terminal; and a second solid state switch implemented on a second PCB, the second solid state switch including: a second control terminal; a third terminal electrically connected to the second terminal of the first solid state switch; and a fourth terminal electrically connected to the second bus bar.
    Type: Grant
    Filed: December 23, 2020
    Date of Patent: September 19, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Muhammad H. Alvi
  • Publication number: 20230286388
    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: Application
    Filed: March 11, 2022
    Publication date: September 14, 2023
    Applicant: 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: 11745611
    Abstract: A system for control of an electric powertrain is provided. The powertrain includes a battery configured for providing electrical energy at a first relatively higher voltage in direct current. The powertrain further includes a power inverter including a first phase circuit, a second phase circuit including first and second switches, and a third phase circuit including third and fourth switches. The powertrain further includes a motor configured for receiving alternating current electrical energy from the power inverter. The system further includes a computerized controller operating a charging cycle. The charging cycle includes deactivating the first phase circuit of the power inverter and selectively cyclically activating the first switch, the second switch, the third switch, and the fourth switch to direct electrical energy provided at a second relatively lower voltage in direct current through the motor to provide a flow of electrical energy at the first voltage to the battery.
    Type: Grant
    Filed: October 28, 2022
    Date of Patent: September 5, 2023
    Assignee: GM Global Technology Operations LLC
    Inventors: Minh-Khai Nguyen, Rashmi Prasad, Chandra S. Namuduri
  • Patent number: 11728732
    Abstract: An example electrical system is disclosed. The electrical system can include a rechargeable energy storage system (RESS) and a power inverter connected to the RESS. The power inverter can be configured to provide electrical power to an electric machine. A switch can be disposed between the plurality of machine windings and an output load. The switch is configured to transition between a closed state to allow current flow from the RESS through the inverter and the plurality of machine windings to the output load and an open state to prevent current flow to the output load.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: August 15, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Patent number: 11723168
    Abstract: A busbar assembly includes a base having a width and a length. The base has a first surface and a second surface and has a first side and a second side. A distance between the first side and the second side comprises the width, and the base defines a slot centered between approximately 75% and approximately 79% of the width.
    Type: Grant
    Filed: June 13, 2022
    Date of Patent: August 8, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Muhammad H. Alvi, Rashmi Prasad, Chandra S. Namuduri
  • Patent number: 11685266
    Abstract: A rechargeable energy storage system (RESS) includes a battery controller and battery modules, each respective module having battery cells, a cell sense board, and a semiconductor switch. The switch is connected in parallel with the cells within the respective module, and configured to conduct an electrical current during a thermal runaway propagation (TRP) event in which one or more cells is in an open-circuit state. This action bypasses the module and enables electrical components to be powered by the RESS during the TRP event. A battery electric system includes a direct current (“DC”) voltage bus, an electrical component connected thereto, the battery controller, and the RESS. A method for constructing the RESS includes connecting a respective semiconductor switch in parallel with the at least one battery cell of each respective one of the multiple battery modules, and electrically connecting the multiple battery modules together to construct the RESS.
    Type: Grant
    Filed: September 1, 2021
    Date of Patent: June 27, 2023
    Assignee: GM Global Technology Operations LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri, Robert J. Heydel, Russell K. Steele
  • Publication number: 20230168284
    Abstract: A detection system for a capacitor of a power inverter of an electric vehicle includes a protection circuit including a current sensor and a power switch having a first terminal in communication with a battery system of the electric vehicle. The protection circuit is configured to selectively generate a pulse and to sense a measured current flowing through the power switch. A voltage sensor configured to sense a measured voltage across the capacitor. A controller in communication with the voltage sensor and the protection circuit is configured to estimate a capacitance value of the capacitor based on the measured current and the measured voltage.
    Type: Application
    Filed: December 1, 2021
    Publication date: June 1, 2023
    Inventors: Muhammad Hussain Alvi, Chandra S. Namuduri, Rashmi Prasad, Renato Amorim Torres
  • Patent number: 11658474
    Abstract: Examples described herein provide a computer-implemented method that includes monitoring, using a microcontroller, an electric circuit of a vehicle, the electric comprising a battery source and a load. The battery source supplies electric power to the load. The method further includes detecting, using the microcontroller, a high current event in the electric circuit by comparing a current level of a current flowing through the electric circuit to a time-based current threshold. The method further includes responsive to detecting the high current event, controlling a gate driver to cause a switch of an electronically resettable fuse to open the electric circuit to stop the flow of the current through the electric circuit.
    Type: Grant
    Filed: September 7, 2021
    Date of Patent: May 23, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Muhammad Hussain Alvi, Rashmi Prasad
  • Patent number: 11607967
    Abstract: An example of a vehicle electrical system includes a rechargeable energy storage system (RESS) having a first voltage and a power inverter selectively 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 machine windings further include a neutral terminal separate from the polyphase terminals and configured to electrically connect to an off-board power source having a second voltage that is below the first voltage of the RESS. The power inverter is configured to cycle between first and second operational states, such that the power inverter and the electric motor steps up the first voltage to the second voltage.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: March 21, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20230073390
    Abstract: Examples described herein provide a computer-implemented method that includes monitoring, using a microcontroller, an electric circuit of a vehicle, the electric comprising a battery source and a load. The battery source supplies electric power to the load. The method further includes detecting, using the microcontroller, a high current event in the electric circuit by comparing a current level of a current flowing through the electric circuit to a time-based current threshold. The method further includes responsive to detecting the high current event, controlling a gate driver to cause a switch of an electronically resettable fuse to open the electric circuit to stop the flow of the current through the electric circuit.
    Type: Application
    Filed: September 7, 2021
    Publication date: March 9, 2023
    Inventors: Chandra S. Namuduri, Muhammad Hussain Alvi, Rashmi Prasad