Patents by Inventor James Michael Thorne

James Michael Thorne 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: 20220231626
    Abstract: Power based self-sensing of a rotor position of an SR motor at mid to high speeds and low torque is achieved by an SR motor control system by comparing the motor power to an injection maximum power. A position current pulse is injected to a stator pole in response to the motor power being less than the injection maximum power. An actual stator current created by the position current pulse is compared to an estimated stator current, and a stored estimated rotor position in a memory is updated to a new estimated rotor position if the actual stator current is not equal to the estimated stator current.
    Type: Application
    Filed: January 21, 2021
    Publication date: July 21, 2022
    Applicant: Caterpillar Inc.
    Inventors: Jesse Ray Gerdes, James Michael Thorne, Ahmed Khalil, Jackson Wai, Sajan Abdul, Amara Ashfaq
  • Publication number: 20220200502
    Abstract: A system and method for torque compensation in a switched reluctance (SR) machine disposed on a machine is disclosed. The system may comprise a SR machine, an inverter and a controller. The controller is in operable communication with the inverter and is configured to determine a commanded main current associated with energization by a main current of a first portion of the plurality of windings for a controlling phase, and determine a commanded parasitic current associated with energization by a parasitic current of a second portion of the windings in a non-controlling phase. The controller is further configured to determine an offset current based on the commanded parasitic current, and determine a target current based on a first sum of the commanded main current and the offset current, and command the inverter to actuate the target current in the first portion of the windings during the controlling phase.
    Type: Application
    Filed: December 21, 2020
    Publication date: June 23, 2022
    Applicant: Caterpillar Inc.
    Inventors: Jesse R. Gerdes, Jackson Wai, Ahmed Khalil, James Michael Thorne, Sajan Abdul, Amara Ashfaq
  • Publication number: 20220200501
    Abstract: A work machine includes a frame, a traction system supporting the frame, a power source mounted on the frame, a switched reluctance motor, an inverter configured to control power to the motor from a power source, and a controller. The controller is configured to receive a signal indicating a desired torque and determine if the desired torque is between an upper threshold and a lower threshold. If the desired torque is between the upper threshold and the lower threshold, pulse width modulation is used to produce a PWM adjusted torque command, and the motor is commanded based on the PWM adjusted torque command. The PWM adjusted torque command is configured to cycle between the upper threshold and the lower threshold to produce the desired torque.
    Type: Application
    Filed: December 23, 2020
    Publication date: June 23, 2022
    Applicant: Caterpillar Inc.
    Inventors: Jesse R. Gerdes, Thomas M. Sopko, Carlos E. Nino Baron, Jackson Wai, Ahmed Khalil, Sajan Abdul, Amara Ashfaq, James Michael Thorne
  • Patent number: 10193475
    Abstract: A method for determining rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may include injecting a test pulse into one or more idle phases of the SR machine, determining a decoupled flux value based at least partially on a total flux value corresponding to the test pulse and a mutual flux value, and determining the rotor position based at least partially on the decoupled flux value.
    Type: Grant
    Filed: May 18, 2015
    Date of Patent: January 29, 2019
    Assignee: Caterpillar Inc.
    Inventors: Seok-hee Han, Carlos Nino Baron, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Jesse Gerdes, James Michael Thorne
  • Patent number: 10079566
    Abstract: A system and method for estimating a position and a speed of a rotor of a Switched Reluctance (SR) machine is provided. The SR machine comprises the rotor, a stator and at least one winding. The method includes generating a diagnostic pulse having a trapezoidal shape. The method further includes injecting a diagnostic pulse into the at least one winding of the SR machine. The method further includes measuring an actual stator current flowing through the at least one winding of the SR machine. The method further includes computing an estimated stator current flowing through the at least one winding using observer-based estimation technique. The estimated stator current is compared with the actual stator current to compute an error signal. At least one of the position and the speed of the rotor is estimated based on the error signal.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: September 18, 2018
    Assignee: Caterpillar Inc.
    Inventors: Ahmed Khalil, Seok-Hee Han, Jackson Wai, James Michael Thorne, Jesse Gerdes, Sangameshwar Sonth
  • Patent number: 9899946
    Abstract: A control system for a switched reluctance (SR) machine having a rotor and a stator is provided. The control system may include a converter circuit in electrical communication between the stator and a common bus, and a controller configured to monitor a bus voltage of the converter circuit and a phase current of the SR machine. The controller may be configured to determine a phase voltage based on one or more of main pulses and any diagnostic pulses, determine an estimated flux based on the phase voltage and an associated mutual voltage, determine a rotor position based at least partially on the estimated flux, and control the SR machine based on the rotor position and a desired torque.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: February 20, 2018
    Assignee: Caterpillar Inc.
    Inventors: Seok-hee Han, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Sangameshwar Sonth, Jesse Gerdes, James Michael Thorne
  • Patent number: 9800192
    Abstract: A control system for a multi-phase switched reluctance (SR) machine, having at least two phases, is disclosed. The control system may include a converter circuit and a controller. The controller may include a phase voltage estimator module configured to determine a first phase voltage and a second phase voltage associated with a second phase second phase for the SR machine. The controller may further include a flux estimator module configured to determine first and second estimated fluxes, the first estimated flux associated with the first phase and based on the first phase voltage and an associated first mutual voltage and the second estimated flux the second estimated flux associated with the second phase and based on the second phase voltage and an associated second mutual voltage, and a position observer module configured to determine a rotor position based at least partially on the first estimated flux, the second mutual flux.
    Type: Grant
    Filed: April 7, 2016
    Date of Patent: October 24, 2017
    Assignee: Caterpillar Inc.
    Inventors: Seok-hee Han, Jackson Wai, Ahmed Khalil, Jesse Gerdes, James Michael Thorne, Sangameshwar Sonth
  • Publication number: 20170294858
    Abstract: A control system for a multi-phase switched reluctance (SR) machine, having at least two phases, is disclosed. The control system may include a converter circuit and a controller. The controller may include a phase voltage estimator module configured to determine a first phase voltage and a second phase voltage associated with a second phase second phase for the SR machine. The controller may further include a flux estimator module configured to determine first and second estimated fluxes, the first estimated flux associated with the first phase and based on the first phase voltage and an associated first mutual voltage and the second estimated flux the second estimated flux associated with the second phase and based on the second phase voltage and an associated second mutual voltage, and a position observer module configured to determine a rotor position based at least partially on the first estimated flux, the second mutual flux.
    Type: Application
    Filed: April 7, 2016
    Publication date: October 12, 2017
    Applicant: Caterpillar Inc.
    Inventors: Seok-hee Han, Jackson Wai, Ahmed Khalil, Jesse Gerdes, James Michael Thorne, Sangameshwar Sonth
  • Publication number: 20170229992
    Abstract: A control system for a switched reluctance (SR) machine having a rotor and a stator is provided. The control system may include a converter circuit in electrical communication between the stator and a common bus, and a controller configured to monitor a bus voltage of the converter circuit and a phase current of the SR machine. The controller may be configured to determine a phase voltage based on one or more of main pulses and any diagnostic pulses, determine an estimated flux based on the phase voltage and an associated mutual voltage, determine a rotor position based at least partially on the estimated flux, and control the SR machine based on the rotor position and a desired torque.
    Type: Application
    Filed: February 10, 2016
    Publication date: August 10, 2017
    Applicant: Caterpillar Inc.
    Inventors: Seok-hee Han, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Sangameshwar Sonth, Jesse Gerdes, James Michael Thorne
  • Publication number: 20170126156
    Abstract: A method for determining rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may include injecting a test pulse into one or more idle phases of the SR machine, determining a decoupled flux value based at least partially on a total flux value corresponding to the test pulse and a mutual flux value, and determining the rotor position based at least partially on the decoupled flux value.
    Type: Application
    Filed: May 18, 2015
    Publication date: May 4, 2017
    Applicant: Caterpillar Inc.
    Inventors: Seok-hee Han, Carlos Nino Baron, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Jesse Gerdes, James Michael Thorne
  • Publication number: 20150381087
    Abstract: A method for determining rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may include injecting a test pulse into one or more idle phases of the SR machine, determining a decoupled flux value based at least partially on a total flux value corresponding to the test pulse and a mutual flux value, and determining the rotor position based at least partially on the decoupled flux value.
    Type: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: Seok-hee Han, Carlos Nino Baron, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Jesse Gerdes, James Michael Thorne
  • Patent number: 8901869
    Abstract: A method of controlling speed of an electric machine having a rotor and a stator is provided. The method may comprise the steps of monitoring a desired speed and a measured speed of the rotor, generating a torque command based on the desired speed and the measured speed, and controlling phase current to the stator based on a hybrid closed loop analysis of the torque command, the measured speed and an estimated position of the rotor. The estimated rotor position may be derived at least partially from the desired speed.
    Type: Grant
    Filed: July 31, 2012
    Date of Patent: December 2, 2014
    Assignee: Caterpillar Inc.
    Inventors: Jackson Wai, Jesse Gerdes, James Michael Thorne
  • Publication number: 20140035505
    Abstract: A method of controlling speed of an electric machine having a rotor and a stator is provided. The method may comprise the steps of monitoring a desired speed and a measured speed of the rotor, generating a torque command based on the desired speed and the measured speed, and controlling phase current to the stator based on a hybrid closed loop analysis of the torque command, the measured speed and an estimated position of the rotor. The estimated rotor position may be derived at least partially from the desired speed.
    Type: Application
    Filed: July 31, 2012
    Publication date: February 6, 2014
    Applicant: CATERPILLAR, INC.
    Inventors: Jackson Wai, Jesse Gerdes, James Michael Thorne