Patents by Inventor Silva Hiti

Silva Hiti 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: 20140141915
    Abstract: A powertrain system includes an internal combustion engine, a first electric machine and an electro-mechanical transmission operative to transmit torque to a driveline. A method for controlling the powertrain system in the presence of a controlled neutral operation of the electro-mechanical transmission being selected includes monitoring vehicle speed, and only when the monitored vehicle speed is indicative of a low-speed zone restricting a transition from a current engine operating state.
    Type: Application
    Filed: November 16, 2012
    Publication date: May 22, 2014
    Applicant: GM Global Technology Operations LLC
    Inventors: SYED NAQI, LAWRENCE A. KAMINSKY, JY-JEN F. SAH, SHAUN C. BOWMAN, CHRISTOPHER A. LAURENT, GEORGE ROBISON, SILVA HITI, JONATHAN M. BOLENBAUGH, ALI K. NAQVI
  • Patent number: 8664901
    Abstract: Methods, systems and apparatus are provided for estimating electrical angular speed of a permanent magnet machine based on two-phase stationary reference frame feedback stator current samples, and a dimensionless gain (K) that is computed based on a sampling time (T) and machine parameters.
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: March 4, 2014
    Assignee: GM Global Technology Operations LLC
    Inventors: Milun Perisic, Yo Chan Son, Gabriel Gallegos-Lopez, Silva Hiti
  • Publication number: 20140015468
    Abstract: Embodiments of the present disclosure relate to methods, systems and apparatus for adjusting current and/or torque commands used to control operation of an asynchronous machine based on rotor flux of the asynchronous machine.
    Type: Application
    Filed: July 12, 2012
    Publication date: January 16, 2014
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Jihoon JANG, Bon Ho BAE, Silva HITI
  • Publication number: 20130278182
    Abstract: Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage commands used to control operation of a permanent magnet machine.
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: MILUN PERISIC, SILVA HITI, GABRIEL GALLEGOS-LOPEZ
  • Patent number: 8558496
    Abstract: Systems and methods are provided for monitoring current in an electric motor. An electrical system includes a (DC) interface, an electric motor, an inverter module coupled between the DC interface and the electric motor, a first current sensor between a first phase leg of the inverter module and a first phase of the electric motor to measure a first current flowing through the first phase of the electric motor, a second current sensor between the first phase leg and the DC interface to measure a second current flowing through the first phase leg, and a control module coupled to the first current sensor and the second current sensor. The control module is configured to initiate remedial action based at least in part on a difference between the first current measured by the first current sensor and the second current measured by the second current sensor.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: October 15, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Silva Hiti, Ronald W. Young, David Tang, Gregory S. Smith
  • Patent number: 8536818
    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: Grant
    Filed: April 14, 2011
    Date of Patent: September 17, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Steven E. Schulz, Mohammad N. Anwar, Michael J. Grimmer, Silva Hiti
  • Publication number: 20130207579
    Abstract: Methods, systems and apparatus are provided for estimating electrical angular speed of a permanent magnet machine based on two-phase stationary reference frame feedback stator current samples, and a dimensionless gain (K) that is computed based on a sampling time (T) and machine parameters.
    Type: Application
    Filed: February 15, 2012
    Publication date: August 15, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: MILUN PERISIC, YO CHAN SON, GABRIEL GALLEGOS-LOPEZ, SILVA HITI
  • Publication number: 20130175955
    Abstract: Methods and systems for controlling an electric motor are provided. An estimated rotor flux angular position error is generated based on estimated back electromotive force (EMF) values, and based on the estimated rotor flux angular position error, an estimated rotor flux angular position, an estimated electrical synchronous frequency and/or an estimated rotor frequency can be generated.
    Type: Application
    Filed: January 5, 2012
    Publication date: July 11, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: YO CHAN SON, LEAH DUNBAR, SILVA HITI
  • Patent number: 8463483
    Abstract: Methods and systems are provided for monitoring an electrical system of a vehicle. Data pertaining to the electrical system is obtained. Calculation modules are performed using the data to generate intermediate determinations. An aggregate calculation module is performed using each of the intermediate determinations to generate an aggregate determination pertaining to the electrical system. Redundant intermediate calculations are performed using the data to generate redundant intermediate determinations. Each of the redundant intermediate determinations is used for comparison with a respective intermediate determination.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: June 11, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Abbas Raftari, Silva Hiti, Jeong J. Park, Hanne Buur, Wei D. Wang, William R. Cawthorne
  • Patent number: 8446113
    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: Grant
    Filed: June 17, 2010
    Date of Patent: May 21, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A Welchko, Konstantin S. Majarov, Silva Hiti, Steven E. Schulz, Aniket Kothari, Nicholas Kokotovich
  • Patent number: 8390240
    Abstract: Systems and methods are provided for an automotive drive system using an absolute position sensor for field-oriented control of an induction motor. An automotive drive system comprises an induction motor having a rotor, and a position sensor coupled to the induction motor. The position sensor is configured to sense an absolute angular position of the rotor. A processor may be coupled to the position sensor and configured to determine a relative angular position of the rotor based on a difference between the absolute angular position and an initial angular position obtained when the induction motor is started. A controller may be coupled to the induction motor and the processor and configured to provide field-oriented control of the induction motor based on the relative angular position of the rotor.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: March 5, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Constantin C. Stancu, Silva Hiti, Robert T. Dawsey, Erik Hatch, Matthew D. Laba, Peter J. Savagian
  • Patent number: 8390228
    Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: March 5, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Mengwei Campbell, Bon Ho Bae, Silva Hiti, Sibaprasad Chakrabarti
  • Patent number: 8378603
    Abstract: Methods and systems for controlling an electric motor are provided. The electric motor includes at least one winding. A winding current flowing through the at least one winding is monitored. The winding current has an oscillating component and an offset component. The offset component of the winding current is isolated from the oscillating component of the winding current. The electric motor is controlled based on the offset component of the winding current.
    Type: Grant
    Filed: January 14, 2010
    Date of Patent: February 19, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: S. M. N. Hasan, Brian A. Welchko, David P. Tasky, Justin O. Nielsen, Silva Hiti
  • Patent number: 8362732
    Abstract: A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized negative sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: January 29, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Mohammad N. Anwar, S. M. N. Hasan, Khwaja M. Rahman, Silva Hiti, Steven E. Schulz, Sean E. Gleason
  • Patent number: 8359131
    Abstract: Methods and systems for operating an electric motor having a plurality of windings with an inverter having a plurality of switches coupled to a voltage source are provided. A first plurality of switching vectors is applied to the plurality of switches. The first plurality of switching vectors includes a first ratio of first magnitude switching vectors to second magnitude switching vectors. A direct current (DC) current associated with the voltage source is monitored during the applying of the first plurality of switching vectors to the plurality of switches. A second ratio of the first magnitude switching vectors to the second magnitude switching vectors is selected based on the monitoring of the DC current associated with the voltage source. A second plurality of switching vectors is applied to the plurality of switches. The second plurality of switching vectors includes the second ratio of the first magnitude switching vectors to the second magnitude switching vectors.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: January 22, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Gabriel Gallegos-Lopez, Silva Hiti, Milun Perisic
  • Patent number: 8358095
    Abstract: Method and systems for testing an electric motor are provided. A switching circuit coupled to the motor is operated in a first mode causing current to flow through the motor such that the motor is actuated with near zero torque. A magnitude of the current is repeatedly adjusted between first and second values. The current flow through the motor is monitored.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: January 22, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Peter J. Savagian, Steven E. Schulz, Silva Hiti
  • Publication number: 20130015803
    Abstract: Methods, system and apparatus are provided for reducing power loss in an electric motor drive system that includes an electric machine and an inverter module. A controller determines whether a torque command (Tcmd) is less than a minimum torque threshold (Tmin) that is required to disable the inverter module, and if so, increments a counter and determines whether the torque command (Tcmd) remains less than the minimum torque threshold (Tmin). When the torque command (Tcmd) remains less than the minimum torque threshold (Tmin), the controller checks to determine whether a current count value (n) maintained at the counter is greater than a count threshold (nth), and if so, the controller can generate a disable signal to disable switching within the inverter module.
    Type: Application
    Filed: July 14, 2011
    Publication date: January 17, 2013
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: MICHAEL ARNETT, STEVEN E. SCHULZ, BON HO BAE, SILVA HITI, RONGHUI LI
  • Patent number: 8339094
    Abstract: Methods, system and apparatus are provided for overmodulation of a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided to optimize voltage command signals that control a five-phase inverter module to increase output voltages generated by the five-phase inverter module.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: December 25, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Milun Perisic, Silva Hiti, Gabriel Gallegos-Lopez
  • Patent number: 8319458
    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: Grant
    Filed: June 17, 2010
    Date of Patent: November 27, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Silva Hiti, Steven E. Schulz, Konstantin S. Majarov, Brian A. Welchko
  • Patent number: 8278933
    Abstract: Methods and systems are provided for monitoring an automotive electrical system including an inverter having at least one switch. First and second voltage commands corresponding to respective first and second components of a commanded voltage vector on a synchronous frame of reference coordinate system are received. A plurality of duty cycles for operating the at least one switch are calculated based on the first and second voltage commands. First and second actual voltages are calculated based on the plurality of duty cycles. The first and second actual voltages correspond to respective first and second components of an actual voltage vector on the synchronous frame of reference coordinate system. An indication of a fault is generated based on the difference between the first components of the commanded voltage vector and the actual voltage vector and the difference between the second components of the commanded voltage vector and the actual voltage vector.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: October 2, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Silva Hiti, Abbas Raftari, Jeong J. Park, Hanne Buur