Patents by Inventor Mahesh Krishnamurthy

Mahesh Krishnamurthy 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: 11929697
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: May 23, 2022
    Date of Patent: March 12, 2024
    Assignee: Turntide Technologies Inc.
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Patent number: 11784598
    Abstract: A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.
    Type: Grant
    Filed: February 27, 2022
    Date of Patent: October 10, 2023
    Assignee: Turntide Technologies, Inc.
    Inventors: Trevor A. Creary, Mahesh Krishnamurthy, Piyush C. Desai, Mark Johnston, Timothy Knodel
  • Publication number: 20230208336
    Abstract: A method for controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.
    Type: Application
    Filed: March 2, 2023
    Publication date: June 29, 2023
    Inventors: TREVOR CREARY, MAHESH KRISHNAMURTHY, TIM KNODEL
  • Patent number: 11682995
    Abstract: The present embodiment is a high rotor pole switched reluctance machine (HRSRM) which provides a plurality of combinations of the number of rotor poles Rn and number of stator poles Sn utilizing a numerical relationship defined by a mathematical formula, Rn=2Sn?Fp, when Sn=m×Fp, wherein Fp is the maximum number of independent flux paths in the stator when stator and rotor poles are fully aligned, and m is the number of phases. The mathematical formulation provides an improved noise performance and design flexibility to the machine. The mathematical formulation further provides a specific number of stator and rotor poles for a chosen m and Fp. The HRSRM can be designed with varying number of phases. The HRSRM provides a smoother torque profile due to a high number of strokes per revolution.
    Type: Grant
    Filed: March 7, 2022
    Date of Patent: June 20, 2023
    Assignee: Turntide Technologies, Inc.
    Inventors: Mahesh Krishnamurthy, Trevor Creary, Piyush Desai, Mark Johnston
  • Publication number: 20230107792
    Abstract: A switched reluctance machine comprising at least one rotor comprising a set of rotor poles arranged about a central axis, at least one stator positioned concentric to and radially outward from the central axis and the rotor, the stator having an outer surface and an outer surface active zone; a housing having a sleeve positioned only radially outward from the stator outer surface active zone; at least one housing endplate coupled to an end of said housing; wherein said stator has no direct connection to said housing, and wherein the number of rotor poles Rn and number of stator poles Sn utilizing a numerical relationship defined by a mathematical formula, Rn=2Sn?Fp, when Sn=m×Fp, wherein Fp is the maximum number of independent flux paths in the stator when stator and rotor poles are fully aligned, and m is the number of phases.
    Type: Application
    Filed: December 11, 2022
    Publication date: April 6, 2023
    Inventors: Piyush Desai, Tim Knodel, Bryan Knodel, Earl Fairall, Mark Johnston, Mahesh Krishnamurthy
  • Patent number: 11601081
    Abstract: A method for controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.
    Type: Grant
    Filed: November 1, 2021
    Date of Patent: March 7, 2023
    Assignee: Turntide Technologies, Inc.
    Inventors: Trevor Creary, Mahesh Krishnamurthy, Tim Knodel
  • Publication number: 20220286074
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Application
    Filed: May 23, 2022
    Publication date: September 8, 2022
    Inventors: MAHESH KRISHNAMURTHY, TREVOR CREARY
  • Publication number: 20220190765
    Abstract: A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.
    Type: Application
    Filed: February 27, 2022
    Publication date: June 16, 2022
    Inventors: Trevor A. Creary, Mahesh Krishnamurthy, Piyush C. Desai, Mark Johnston, Timothy Knodel
  • Publication number: 20220190766
    Abstract: The present embodiment is a high rotor pole switched reluctance machine (HRSRM) which provides a plurality of combinations of the number of rotor poles Rn and number of stator poles Sn utilizing a numerical relationship defined by a mathematical formula, Rn=2Sn?Fp, when Sn=m×Fp, wherein Fp is the maximum number of independent flux paths in the stator when stator and rotor poles are fully aligned, and m is the number of phases. The mathematical formulation provides an improved noise performance and design flexibility to the machine. The mathematical formulation further provides a specific number of stator and rotor poles for a chosen m and Fp. The HRSRM can be designed with varying number of phases. The HRSRM provides a smoother torque profile due to a high number of strokes per revolution.
    Type: Application
    Filed: March 7, 2022
    Publication date: June 16, 2022
    Inventors: MAHESH KRISHNAMURTHY, TREVOR CREARY, PIYUSH DESAI, MARK JOHNSTON
  • Patent number: 11342872
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: April 24, 2021
    Date of Patent: May 24, 2022
    Assignee: Turntide Technologies Inc.
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Publication number: 20220085804
    Abstract: A gate driver circuit comprises a sensor, an amplifier, a regulator, and a gate driver. The sensor is configured to sense a collector-emitter voltage and includes a first resistor and a second resistor connected in series, a high voltage diode connected between the series connected first and second resistors and a first capacitor connected parallel to the second resistor. The amplifier is configured to amplify a sensor output voltage and includes a non-inverting operational amplifier controlled by means of a plurality of resistors, a voltage follower connected to an output terminal of the non-inverting operational amplifier through a first diode and a third resistor connected across the first diode and the voltage follower. The regulator is configured to regulate a regulator output voltage based on an amplifier voltage. The gate driver is configured to connect/disconnect the regulator output voltage to the base terminal of the BJT.
    Type: Application
    Filed: November 28, 2021
    Publication date: March 17, 2022
    Inventors: Alejandro Pozo Arribas, Mahesh Krishnamurthy
  • Patent number: 11277061
    Abstract: A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least two stators having a plurality of stator poles. The at least two rotors and the at least two stators are positioned about a central axis with the stator placed between the rotors. In other embodiments, the number of stators equals the number of rotors and effectively operate as a single stator and rotor. In yet another embodiment, the effective single stator and rotor type high rotor pole switched reluctance machine is realized as single stator and rotor positioned concentrically around a central axis.
    Type: Grant
    Filed: March 18, 2020
    Date of Patent: March 15, 2022
    Assignee: Turntide Technologies, Inc.
    Inventors: Mahesh Krishnamurthy, Mark Johnston, Trevor Creary, Piyush Desai
  • Patent number: 11271509
    Abstract: The present embodiment is a high rotor pole switched reluctance machine (HRSRM) which provides a plurality of combinations of the number of rotor poles Rn and number of stator poles Sn utilizing a numerical relationship defined by a mathematical formula, Rn=2Sn?Fp, when Sn=m×Fp, wherein Fp is the maximum number of independent flux paths in the stator when stator and rotor poles are fully aligned, and m is the number of phases. The mathematical formulation provides an improved noise performance and design flexibility to the machine. The mathematical formulation further provides a specific number of stator and rotor poles for a chosen m and Fp. The HRSRM can be designed with varying number of phases. The HRSRM provides a smoother torque profile due to a high number of strokes per revolution.
    Type: Grant
    Filed: July 5, 2020
    Date of Patent: March 8, 2022
    Assignee: Turntide Technologies Inc.
    Inventors: Mahesh Krishnamurthy, Trevor Creary, Piyush Desai, Mark Johnston
  • Patent number: 11264932
    Abstract: A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.
    Type: Grant
    Filed: July 31, 2020
    Date of Patent: March 1, 2022
    Assignee: Turntide Technologies Inc.
    Inventors: Trevor A. Creary, Mahesh Krishnamurthy, Piyush C. Desai, Mark Johnston, Timothy Knodel
  • Publication number: 20220060132
    Abstract: A method for controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.
    Type: Application
    Filed: November 1, 2021
    Publication date: February 24, 2022
    Inventors: TREVOR CREARY, MAHESH KRISHNAMURTHY, TIM KNODEL
  • Patent number: 11190179
    Abstract: A gate driver circuit comprises a sensor, an amplifier, a regulator and a gate driver. The sensor is configured to sense a collector-emitter voltage and includes a first resistor and a second resistor connected in series, a high voltage diode connected between the series connected first and second resistors and a first capacitor connected parallel to the second resistor. The amplifier is configured to amplify a sensor output voltage and includes a non-inverting operational amplifier controlled by means of a plurality of resistors, a voltage follower connected to an output terminal of the non-inverting operational amplifier through a first diode and a third resistor connected across the first diode and the voltage follower. The regulator is configured to regulate a regulator output voltage based on an amplifier voltage. The gate driver is configured to connect/disconnect the regulator output voltage to the base terminal of the BJT.
    Type: Grant
    Filed: July 13, 2020
    Date of Patent: November 30, 2021
    Assignee: Turntide Technologies Inc.
    Inventors: Alejandro Pozo Arribas, Mahesh Krishnamurthy
  • Patent number: 11165382
    Abstract: A method for controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.
    Type: Grant
    Filed: March 31, 2018
    Date of Patent: November 2, 2021
    Assignee: Turntide Technologies, Inc.
    Inventors: Trevor Creary, Mahesh Krishnamurthy, Tim Knodel
  • Publication number: 20210242814
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Application
    Filed: April 24, 2021
    Publication date: August 5, 2021
    Inventors: MAHESH KRISHNAMURTHY, TREVOR CREARY
  • Patent number: 11050101
    Abstract: A method and apparatus for determining and/or monitoring a thermal state of charge or melt fraction of phase change material in a battery system. The battery system includes a plurality of electrochemical cell elements, a supply of a phase change material in thermal contact with the plurality of electrochemical cell elements, and a battery management system that monitors a thermal storage capacity of the phase change material and automatically controls a power of the plurality of electrochemical cell elements as a function of the thermal storage capacity of the phase change material. The battery management system automatically adjusts a power output of the plurality of electrochemical cell elements as a function of the thermal storage capacity of the phase change material to provide a heat output within a predetermined safe temperature limit.
    Type: Grant
    Filed: January 9, 2018
    Date of Patent: June 29, 2021
    Assignee: ALL CELL TECHNOLOGIES, LLC
    Inventors: Said Al-Hallaj, Mohamad M. Salameh, Siddique Ali Khateeb Razack, Benjamin Schweitzer, Stephen Wilke, Mahesh Krishnamurthy
  • Patent number: 10992247
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: April 6, 2020
    Date of Patent: April 27, 2021
    Assignee: Turntide Technologies Inc.
    Inventors: Mahesh Krishnamurthy, Trevor Creary