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: 11071225
    Abstract: An integrated smart relay assembly includes a case and an electronic solid-state switch disposed inside the case and a gate driver circuit electrically connected to the electronic solid-state switch. The gate driver circuit is configured to drive the electronic solid-state switch with a predetermined gate voltage and a predetermined gate current. The relay assembly further includes a protection circuit electrically connected to the gate driver circuit. The protection circuit is configured to protect the electronic solid-state switch against over-voltage, short circuit, and overheating. The relay assembly further includes a communication interface integrated with the electronic solid-state switch. Each of the protection circuit, electronic solid-state switch, and the communication interface is disposed inside the case.
    Type: Grant
    Filed: October 17, 2019
    Date of Patent: July 20, 2021
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Publication number: 20210143811
    Abstract: A circuitry includes an electronic solid-state switch including a first power terminal and a second power terminal and a driver and switch protection system electrically connected to the electronic solid-state switch. The driver and switch protection system includes an isolated bias power circuit configured to output a direct current voltage of at least fifteen volts, a current buffer circuit electrically connected between the isolated bias power circuit and the electronic solid-state switch, and a snubber circuit electrically connected to the first power terminal and the second power terminal.
    Type: Application
    Filed: November 7, 2019
    Publication date: May 13, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Publication number: 20210135588
    Abstract: An AC electronic solid-state switch includes an electrically insulating and thermally conductive layer, a first electrically conductive trace, a second electrically conductive trace, and a plurality of semiconductor dies each electrically connected to the first electrically conductive trace and the second electrically conductive trace. Each of the plurality of semiconductor dies forms a MOSFET, IGBT or other types of electronically controllable switch. The AC electronic solid-state switch further includes a common drain conductor that is electrically connected to each drain terminal of the plurality of semiconductor dies. The AC electronic solid-state switch is configured to block between 650 volts and 1700 volts in the off-state in a first direction and a second direction, the second direction being opposite the first direction, and the AC electronic solid-state switch is configured to carry at least 500 A continuously in the on-state with a voltage drop of less than 2V.
    Type: Application
    Filed: November 5, 2019
    Publication date: May 6, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Patent number: 10998840
    Abstract: An electric drive system includes a battery pack, a power inverter module (“PIM”), an electric machine, a switching circuit, and a controller. The electric machine has three or more phase legs. The PIM has a DC-side connected to the battery pack, and an alternating current (“AC”)-side connected to the electric machine. The switching circuit includes AC switches, and for each phase leg also includes three or more winding sections each electrically connectable to or disconnectable from the battery pack and PIM via the AC switches. The controller commands a binary switching state of each respective AC switch based on the rotary speed to implement one of three different speed-based operating modes of the electric machine, and to thereby vary a conductive path from the PIM to the electric machine through one or more of the connected winding sections.
    Type: Grant
    Filed: September 13, 2019
    Date of Patent: May 4, 2021
    Assignee: GM Global Technology Operations LLC
    Inventors: Lei Hao, Chandra S. Namuduri, Rashmi Prasad
  • Publication number: 20210120693
    Abstract: An integrated smart relay assembly includes a case and an electronic solid-state switch disposed inside the case and a gate driver circuit electrically connected to the electronic solid-state switch. The gate driver circuit is configured to drive the electronic solid-state switch with a predetermined gate voltage and a predetermined gate current. The relay assembly further includes a protection circuit electrically connected to the gate driver circuit. The protection circuit is configured to protect the electronic solid-state switch against over-voltage, short circuit, and overheating. The relay assembly further includes a communication interface integrated with the electronic solid-state switch. Each of the protection circuit, electronic solid-state switch, and the communication interface is disposed inside the case.
    Type: Application
    Filed: October 17, 2019
    Publication date: April 22, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Publication number: 20210086646
    Abstract: A dual-voltage charging station system for an alternating current (“AC”) power supply and a mobile platform having a charging port includes a charge coupler, an AC-to-DC conversion stage, a cable, and a controller. The charge coupler has AC pins and direct current (“DC”) pins configured to engage with respective AC and DC receptacles of the charging port. The conversion stage is connected to the charge coupler and the AC power supply, converts the supply voltage to a DC charging voltage, and relays an appropriate AC or DC accessory voltage. The cable connects to the charge coupler such that the AC pins receive the accessory voltage and the DC pins receive the DC charging voltage. The controller simultaneously delivers the accessory voltage and the DC voltage to the mobile platform via the AC pins and the DC pins, respectively.
    Type: Application
    Filed: September 23, 2019
    Publication date: March 25, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20210078442
    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: Application
    Filed: September 13, 2019
    Publication date: March 18, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20210083612
    Abstract: An electric drive system includes a battery pack, a power inverter module (“PIM”), an electric machine, a switching circuit, and a controller. The electric machine has three or more phase legs. The PIM has a DC-side connected to the battery pack, and an alternating current (“AC”)-side connected to the electric machine. The switching circuit includes AC switches, and for each phase leg also includes three or more winding sections each electrically connectable to or disconnectable from the battery pack and PIM via the AC switches. The controller commands a binary switching state of each respective AC switch based on the rotary speed to implement one of three different speed-based operating modes of the electric machine, and to thereby vary a conductive path from the PIM to the electric machine through one or more of the connected winding sections.
    Type: Application
    Filed: September 13, 2019
    Publication date: March 18, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lei Hao, Chandra S. Namuduri, Rashmi Prasad
  • Patent number: 10917030
    Abstract: An electric drive system includes a battery pack, a power inverter module (“PIM”), an electric machine, a switching circuit, and a controller. The electric machine has three or more phase legs. The PIM has a DC-side connected to the battery pack, and an alternating current (“AC”)-side connected to the electric machine. The switching circuit includes AC switches. For each phase leg the circuit also includes three or more winding sections each electrically connectable to or disconnectable from the PIM via the AC switches. The controller commands a binary switching state of each respective AC switch based on the rotary speed to implement one of four different speed-based operating modes of the electric machine, and to thereby vary a conductive path from the PIM to the electric machine through one or more of the connected winding sections.
    Type: Grant
    Filed: September 13, 2019
    Date of Patent: February 9, 2021
    Assignee: GM Global Technology Operations LLC
    Inventors: Lei Hao, Chandra S. Namuduri, Rashmi Prasad
  • Patent number: 10665398
    Abstract: A switch assembly includes a case and a direct current (DC) electronic solid-state switch coupled to the case. The case covers the DC electronic solid-state switch, and the DC electronic solid-state switch has an on-state and off-state. The DC electronic solid-state switch blocks between 650 volts and 1200 volts in a single direction in an off-state. The DC electronic solid-state switch continuously carries at least 400 amperes direct current with a voltage drop of less than one volt. The DC electronic solid-state switch also includes a plurality of semiconductor dies each forming a MOSFET. The DC electronic solid-state switch also includes a plurality of signal conductors.
    Type: Grant
    Filed: September 23, 2019
    Date of Patent: May 26, 2020
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad
  • Patent number: 10567039
    Abstract: A system and method of facilitating wireless charging of an electric vehicle (EV) include the EV performing service discovery and negotiation via a neighborhood aware network (NaN) to determine charging compatibility of a WiFi enabled charging station or another EV with the EV. The method also includes the EV requesting a reservation from the charging station or a charge from the another EV based on determining that the EV is compatible with the charging station or the another EV by broadcasting a request message that includes a packet with the request via the NaN.
    Type: Grant
    Filed: October 11, 2017
    Date of Patent: February 18, 2020
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Rashmi Prasad, Lakshmi V. Thanayankizil
  • Patent number: 10556482
    Abstract: Systems and methods are provided for thermal control using vascular channels. Vascular channels are incorporated in a network within a component. The component is a part of a manufactured environment configured for occupants. A fluid circuit is connected with the vascular channels and circulates a fluid through the component to alter a thermal state of the component.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: February 11, 2020
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Anthony M. Coppola, Rashmi Prasad, Derek F. Lahr, Fang Dai, Michelle H. Wiebenga, Ryan Gergely
  • Patent number: 10511213
    Abstract: A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux (?) is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (?). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i1) and an eddy current (i2). The magnetic flux (?) is obtained based at least partially on a third model matrix (C0), the coil current (i1) and the eddy current (i2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (?). In one example, the solenoid actuator is an injector.
    Type: Grant
    Filed: October 3, 2017
    Date of Patent: December 17, 2019
    Assignee: GM Global Technology Operations LLC
    Inventors: Shifang Li, Thomas W. Nehl, Suresh Gopalakrishnan, Avoki Omekanda, Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20190357386
    Abstract: A vascular polymeric assembly is provided which includes a heat source, a polymeric substrate configured to enclose and protect at least a portion of the heat source; and a channel defined in the polymeric substrate configured to transfer a heat flow away from the heat source via a channel coolant flow.
    Type: Application
    Filed: May 16, 2018
    Publication date: November 21, 2019
    Inventors: Anthony M. Coppola, Alireza Fatemi, Rashmi Prasad
  • Patent number: 10259448
    Abstract: A hybrid vehicle propulsion includes an engine and a first electric machine, where each is configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine to provide torque to start the engine from an inactive state. A high-voltage power source is configured to power both of the first electric machine and the second electric machine over a high-voltage bus. The propulsion system further includes a controller programmed to deactivate the engine and propel the vehicle using the first electric machine in response to the vehicle being driven at a steady-state speed for a predetermined duration of time. The controller is also programmed to restart the engine using the second electric machine powered by the high-voltage power source.
    Type: Grant
    Filed: August 17, 2016
    Date of Patent: April 16, 2019
    Assignee: GM Global Technology Operations LLC
    Inventors: Norman K. Bucknor, Suresh Gopalakrishnan, Lei Hao, Derek F. Lahr, Dongxu Li, Shifang Li, Chandra S. Namuduri, Thomas W. Nehl, Avoki M. Omekanda, Rashmi Prasad, Farzad Samie, Aaron M. Sullivan
  • Publication number: 20190105995
    Abstract: A system and method of facilitating wireless charging of an electric vehicle (EV) include the EV performing service discovery and negotiation via a neighborhood aware network (NaN) to determine charging compatibility of a WiFi enabled charging station or another EV with the EV. The method also includes the EV requesting a reservation from the charging station or a charge from the another EV based on determining that the EV is compatible with the charging station or the another EV by broadcasting a request message that includes a packet with the request via the NaN.
    Type: Application
    Filed: October 11, 2017
    Publication date: April 11, 2019
    Inventors: Rashmi Prasad, Lakshmi V. Thanayankizil
  • Publication number: 20190103797
    Abstract: A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux (?) is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (?). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i1) and an eddy current (i2). The magnetic flux (?) is obtained based at least partially on a third model matrix (C0), the coil current (i1) and the eddy current (i2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (?). In one example, the solenoid actuator is an injector.
    Type: Application
    Filed: October 3, 2017
    Publication date: April 4, 2019
    Applicant: GM Global Technology Operations LLC
    Inventors: Shifang Li, Thomas W. Nehl, Suresh Gopalakrishnan, Avoki Omekanda, Rashmi Prasad, Chandra S. Namuduri
  • Publication number: 20190084370
    Abstract: Systems and methods are provided for thermal control using vascular channels. Vascular channels are incorporated in a network within a component. The component is a part of a manufactured environment configured for occupants. A fluid circuit is connected with the vascular channels and circulates a fluid through the component to alter a thermal state of the component.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 21, 2019
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Anthony M. Coppola, Rashmi Prasad, Derek F. Lahr, Fang Dai, Michelle H. Wiebenga, Ryan Gergely
  • Patent number: 10155547
    Abstract: Systems and methods are provided for heat management using vascular channels. Vascular channels are incorporated in a network within a component. The component is a part of a manufactured product and defines an exterior panel. A fluid circuit is connected with the vascular channels and circulates a fluid through the component to collect heat from the product and to dissipate heat through the exterior panel.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: December 18, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Anthony M. Coppola, Michelle H. Wiebenga, Fang Dai, Derek F. Lahr, Rashmi Prasad, Ryan Gergely
  • Patent number: 9973028
    Abstract: A charging system for use in providing power for charging a battery. The system includes a first, alternating-current-to-direct-current, stage and a second, direct-current-to-direct-current, stage. The first stage includes a single-phase diode rectifier for rectifying an input alternating-current input voltage, and a power-factor-correcting sub-circuit including a switch. The second stage includes multiple switches. The system further includes a high-frequency capacitor connected between the first stage and the second stage. The system also includes a controller connected to the switches of the first and second stages and configured to control, by way of the switches, timing of boost inductor current passing through the charging system.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: May 15, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Rashmi Prasad