Patents by Inventor Steven E. Schulz

Steven E. Schulz 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: 20120271606
    Abstract: Methods and systems are provided for determining a temperature of a motor of a vehicle having an ignition when the ignition is turned on following a period of time in which the ignition had been turned off. An amount of time for which the vehicle had been turned off is determined. A motor temperature model is run using a time step to simulate the amount of time for which the vehicle had been turned off to determine an initial value of the temperature of the motor.
    Type: Application
    Filed: April 20, 2011
    Publication date: October 25, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chia-Chou YEH, Steven E. SCHULZ, Daniel J. BERRY
  • Patent number: 8288886
    Abstract: A method for avoiding electrical resonance in a vehicle having a high-voltage (HV) direct current (DC) bus shared by a first and a second power electronic converter device, such as an air conditioning compressor module (ACCM) and a traction power inverter (TPIM), includes determining an impedance characteristic of the bus, defining resonance points for the bus, selecting lower and upper switching frequency boundaries for the TPIM, and preventing the TPIM from operating within a range defined by these boundaries. A vehicle includes the first and second power electronic converter device, e.g., the APPM and the TPIM, the shared HV DC, and a controller having the algorithm set forth above, wherein the controller is adapted for avoiding electrical resonance in the HV DC bus by executing the algorithm.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: October 16, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Mohammad N. Anwar, Steven E. Schulz, Stephan N. Green, James E. Tarchinski
  • Publication number: 20120226483
    Abstract: A vehicle includes a power source, a motor, and a computing device. The power source provides electrical energy to the motor, and the motor generates rotational motion from the electrical energy received. The computing device is configured to estimate a temperature of the motor in real time based at least in part on a thermal model of the motor. The thermal model includes a plurality of nodes and at least one thermal resistance. Each node represents a region of the motor and each thermal resistance represents a heat transfer path between at least two of the nodes. A method includes solving one or more energy balance equations to determine a temperature change at each node and estimating the temperature of the motor in real time based at least in part on the temperature change at each node and at least one of the thermal resistances in the thermal model.
    Type: Application
    Filed: March 3, 2011
    Publication date: September 6, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Daniel J. Berry, Pankaj Mithal, Paul F. Turnbull, Peter J. Savagian, Chia-Chou Yeh, Steven E. Schulz
  • Patent number: 8253360
    Abstract: A vector controlled motor drive system is provided that includes a test vector and duty cycle generator module designed to receive a set of three-phase voltage command signals and designed to generate a set of pulse width modulated (PWM) waveforms. The set of PWM waveforms comprise: a first modified switching vector signal for a first motor phase that comprises at least two test pulses over three consecutive PWM cycles. The first modified switching vector signal has a first amplitude value that changes between a high amplitude value and a low amplitude value during the three consecutive PWM cycles. A number of transitions by the first modified switching vector signal between the low amplitude value and the high amplitude value over the three consecutive PWM cycles is greater than six and less than twelve.
    Type: Grant
    Filed: July 15, 2009
    Date of Patent: August 28, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Yo Chan Son, Nitinkumar R. Patel
  • Publication number: 20120203405
    Abstract: A method for monitoring an electrically-powered torque machine configured to generate torque in a hybrid powertrain system includes monitoring signal outputs of a resolver configured to monitor rotational position of the torque machine. Upon detecting a fault warning state associated with the signal outputs of the resolver, a motor torque capacity of the torque machine is derated. Upon a clearing of the fault warning state, a torque ramp-up state to increase the motor torque capacity of the torque machine is executed. Notice of an incidence of a fault associated with the signal outputs of the resolver is provided only when the motor torque capacity fails to achieve a threshold motor torque capacity within a threshold recovery time period while executing the torque ramp-up state.
    Type: Application
    Filed: February 8, 2011
    Publication date: August 9, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Wei D. Wang, Bon Ho Bae, Leah Dunbar, Kevin P. Houle, William R. Cawthorne, Andrew M. Zettel, Hanne Buur, Steven E. Schulz
  • Patent number: 8212510
    Abstract: Methods and apparatus are provided for a controlling an electric motor that is at least partially disposed within a motor housing. The rotational speed and position of the electric motor are sensed, and a temperature of the electric motor is sensed. The sensor signals are converted to optical signals and are propagated in a fiber optic cable. The electric motor is controlled based, at least in part, on the propagated optical signals.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: July 3, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Jeremy B. Campbell, Jim R. Switzer, Steven E. Schulz
  • Patent number: 8212505
    Abstract: A method and system for operating an automotive electric motor having first and second components is provided. A desired frequency of vibration for the electric motor is selected. A current is caused to flow through at least one of the first and second components such that the second component moves relative to the first component. The current is modulated such that the motor vibrates at the desired frequency.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: July 3, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: James M. Nagashima, Steven E. Schulz, Yo Chan Son, Jonas Bereisa
  • Patent number: 8185342
    Abstract: Methods, system and apparatus are provided for estimating rotor angular position and angular velocity during a position sensor fault, and for verifying the accuracy or inaccuracy of a position sensor's outputs based on the estimated rotor angular position and angular velocity of the rotor following a position sensor fault.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: May 22, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Chia-Chou Yeh, Brian A. Welchko, Steven E. Schulz
  • Publication number: 20120112674
    Abstract: A method for controlling a traction power inverter module (TPIM) in a vehicle includes determining a commanded output torque of the motor using a controller. The method further includes controlling the TPIM and motor using a discontinuous pulse width modulated (DPWM) signal when the commanded output torque is less than a calibrated torque threshold. A continuous pulse width modulated (CPWM) signal is used when the commanded output torque is greater than the threshold. The method may include determining a direction of a change in the commanded output torque, and controlling the TPIM, via the controller, using the DPWM signal only when the commanded output torque drops below a predetermined hysteresis level. A vehicle includes a traction motor producing a motor torque for propelling the vehicle, an ESS, a TPIM, and a controller configured as noted above.
    Type: Application
    Filed: April 14, 2011
    Publication date: May 10, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Steven E. Schulz, Mohammad N. Anwar, Michael J. Grimmer, Silva Hiti
  • Patent number: 8165737
    Abstract: Methods and systems for controlling a power inverter in automobiles utilizing two-mode transmissions are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.
    Type: Grant
    Filed: October 24, 2007
    Date of Patent: April 24, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Stephen T. West, Brian A. Welchko, Silva Hiti
  • Publication number: 20120084039
    Abstract: A method includes detecting a first event and executing a first procedure to identify a sensor offset in response to detecting the first event. The method further includes determining, via a computing device, whether the sensor offset was measured during the execution of the first procedure, scheduling a second procedure to execute in response to detecting a second event if the sensor offset was not measured during the first procedure, and scheduling the first procedure to execute in response to detecting a subsequent occurrence of the first event if the sensor offset was measured during the first procedure.
    Type: Application
    Filed: October 1, 2010
    Publication date: April 5, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Wei D. Wang, Steven E. Schulz, Jeffrey David, Jackie L. Cui, Andrew M. Zettel, Hanne Buur
  • Patent number: 8134321
    Abstract: In a motor controller, a modified interpolation technique uses an extrapolated torque command for the upper table to improve torque linearity under certain conditions. When the torque command input is greater than the max torque limit of a first look-up table, but less than the maximum torque limit of a second, adjacent look-up table, the desired current command is computed by interpolating between the maximum torque limit of the first table and a revised torque value for the second look-up table, wherein the revised torque value is determined by extrapolating from the maximum torque limit of the first look-up table through a torque value based on the torque command input.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: March 13, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Bon Ho Bae
  • Publication number: 20120053881
    Abstract: Methods and systems are provided for assessing a vehicle transmission having a resolver. A memory is configured to store preliminary data pertaining to an error of the resolver. A processor is coupled to the memory, and is configured to determine a harmonic characteristic of the preliminary data, and to assess the vehicle transmission using the harmonic characteristic.
    Type: Application
    Filed: August 24, 2010
    Publication date: March 1, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Steven E. SCHULZ, Bon Ho BAE, Silva HITI, Min DAI, Harry J. BAUER, Samuel J. HARBIN
  • Patent number: 8100799
    Abstract: Methods and systems for driving an automobile are provided. The system includes a prime mover power source and a two-mode, compound-split, electro-mechanical transmission, including first and second motors, coupled to the prime mover power source, a power inverter coupled to the first and second motors, and a processor coupled to the first and second motors and the power inverter. The processor is configured to modify a signal controlling the power inverter utilizing a first voltage distortion compensation method if a modulation index of the signal is less than a first modulation index value and modify the signal utilizing a second voltage distortion compensation method if the modulation index is at least equal to the first modulation index value.
    Type: Grant
    Filed: September 12, 2007
    Date of Patent: January 24, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Steven E. Schulz, Silva Hiti
  • Publication number: 20110309779
    Abstract: Methods and systems for operating an inverter coupled to an electric motor are provided. The inverter has a plurality of high switches and a plurality of low switches coupled to the electric motor. An event indicative of deceleration of the electric motor is detected. The inverter is alternated between a first mode of operation and a second mode of operation during the deceleration of the electric motor. In the first mode of operation, each of the plurality of high switches is activated and each of the plurality of low switches is deactivated. In the second mode of operation, each of the plurality of low switches is activated and each of the plurality of high switches is deactivated.
    Type: Application
    Filed: June 17, 2010
    Publication date: December 22, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Silva Hiti, Steven E. Schulz, Konstantin S. Majarov, Brian A. Welchko
  • Publication number: 20110309777
    Abstract: Methods and systems for operating an inverter having a plurality of high switches and a plurality of low switches coupled to an electric motor are provided. An event indicative of deceleration of the electric motor is detected. The inverter is alternated between a first mode of operation and a second mode of operation during the deceleration of the electric motor. In the first mode of operation, each of the plurality of high switches is activated and each of the plurality of low switches is deactivated or each of the plurality of low switches is activated and each of the plurality of high switches is deactivated. In the second mode of operation, each of the plurality of high switches is deactivated and each of the plurality of low switches is deactivated.
    Type: Application
    Filed: June 17, 2010
    Publication date: December 22, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Brian A. Welchko, Konstantin S. Majarov, Silva Hiti, Steven E. Schulz, Aniket Kothari, Nicholas Kokotovich
  • Patent number: 8062170
    Abstract: Temperature of an electric drive is regulated to prevent undesirable thermal effects. Temperature conditions of the electric drive system are monitored and torque of the electric drive system is limited based on the temperature conditions.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: November 22, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Stephen T. West, Wei D. Wang, Brian A Welchko, Steven E. Schulz, Peter E. Wu
  • Publication number: 20110279074
    Abstract: An electric motor system includes an electric motor comprising a stator with windings and a rotor configured to operate at a motor speed; a cooling system comprising coolant configured to cool the rotor and the stator, the coolant having a coolant flow rate and a coolant temperature; an inverter module coupled to the electric motor and configured to provide current to the windings based on inverter control signals; a current regulated torque controller coupled to the inverter module and configured to generate the inverter control signals in response to a derated torque command; and a temperature estimation controller coupled to the current regulated torque controller and configured to generate the derated torque command based on an initial torque command and an estimated stator winding temperature. The temperature estimation controller is configured to estimate the estimated stator winding temperature based on the motor speed and the coolant flow rate.
    Type: Application
    Filed: May 12, 2010
    Publication date: November 17, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: CHIA-CHOU YEH, STEVEN E. SCHULZ
  • Patent number: 8054084
    Abstract: Systems and methods are provided for identifying a fault condition in stator windings in an electric motor. A method comprises applying a first signal at a first electrical angle to the stator windings and measuring a second signal from the stator windings in response to the first signal. The method further comprises determining a measured response for the electric motor at the first electrical angle based on the second signal and obtaining a nominal response for the electric motor at the first electrical angle. A fault condition is identified when a magnitude of the difference between the measured response and the nominal response is greater than a threshold value.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: November 8, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Khwaja M. Rahman, Chia-Chou Yeh
  • Publication number: 20110231040
    Abstract: A method for controlling an inverter coupled to an electric motor for a vehicle includes generating a discontinuous PWM signal for the inverter when a torque of the electric motor and a speed of the electric motor are substantially zero, and when at least one predetermined vehicle condition is met.
    Type: Application
    Filed: March 17, 2010
    Publication date: September 22, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Steven E. Schulz, Goro Tamai, Lan Wang, Karl Andrew Sime, Silva Hiti, Brian A. Welchko