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: 20110089883
    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 zero 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: Application
    Filed: October 21, 2009
    Publication date: April 21, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Mohammad N. Anwar, S.M. N. Hasan, Khwaja M. Rahman, Silva Hiti, Steven E. Schulz, Sean E. Gleason
  • Patent number: 7923953
    Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. As a result, torque linearity is maintained when the electric machine operates in the field weakening region.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: April 12, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Gabriel Gallegos-Lopez, Yo Chan Son, Milun Perisic, Silva Hiti
  • Publication number: 20110068727
    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: Application
    Filed: September 24, 2009
    Publication date: March 24, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Brian A. WELCHKO, Silva HITI, Abbas RAFTARI, Jeong J. PARK, Hanne BUUR
  • Patent number: 7888905
    Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. A signal controlling the power inverter is modified utilizing a first voltage distortion compensation method if a modulation index of the signal is less than a first modulation index value. The signal is modified utilizing a second voltage distortion compensation method if the modulation index is at least equal to the first modulation index value.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: February 15, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Steven E. Schultz, Silva Hiti
  • Publication number: 20110025247
    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: Application
    Filed: July 31, 2009
    Publication date: February 3, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: PETER J. SAVAGIAN, STEVEN E. SCHULZ, SILVA HITI
  • Patent number: 7880425
    Abstract: In various embodiments, an electric motor drive system (400, FIG. 4) and a motor vehicle (1000, FIG. 10) include an inverter (404, FIG. 4) adapted to generate (604, FIG. 6), based on inverter control inputs, a number, N, of phase current waveforms (118, FIG. 1), and a phase current sampling apparatus (408, FIG. 4) having a same number, N, of current sensors (502, 503, 504, FIG. 5). Each of the current sensors is adapted to receive one of the phase current waveforms, and the current sensors are adapted simultaneously to sample the phase current waveforms and to generate digital values representing amplitudes of the phase current waveforms. The system and motor vehicle also include a controller (410, FIG. 4) adapted to receive the digital values, to perform an evaluation of the digital values, and to generate the inverter control inputs (462, FIG. 4) based on the evaluation.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: February 1, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian A. Welchko, Steven E. Schulz, Silva Hiti
  • Publication number: 20100301787
    Abstract: A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 2, 2010
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: GABRIEL GALLEGOS-LOPEZ, JAMES M. NAGASHIMA, MILUN PERISIC, SILVA HITI
  • Publication number: 20100301786
    Abstract: A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 2, 2010
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: GABRIEL GALLEGOS-LOPEZ, JAMES M. NAGASHIMA, MILUN PERISIC, SILVA HITI
  • Patent number: 7839108
    Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: November 23, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Nitinkumar R. Patel, Yo Chan Son, Silva Hiti, Steven E. Schulz
  • Patent number: 7834574
    Abstract: In various embodiments, a phase current sampling apparatus (300, 600, FIGS. 3, 6), an electric motor drive system (100, FIG. 1), and a motor vehicle (1200, FIG. 12) include switching circuitry adapted to receive first and second phase current waveforms. The switching circuitry provides the first phase current waveform during at least two offset sampling instants, and provides the second phase current waveform during a reference sampling instant. An analog-to-digital converter is adapted to sample the first phase current waveform at the offset sampling instants, and to sample the second phase current waveform at the reference sampling instant. An embodiment of a method for regulating phase current waveforms includes an analog-to-digital converter generating samples of a first phase current waveform at sampling instants that occur before and after a reference sampling instant, and generating a sample of a second phase current waveform at the reference sampling instant.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: November 16, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Stephen T. West, Brian A. Welchko, Steven E. Schulz, Silva Hiti
  • Patent number: 7800331
    Abstract: Methods and systems are provided for operating an electric motor having at least one winding coupled to first and second power supplies. A torque command for the electric motor is received. A present power reserve for the first and second power supplies is determined based at least in part on the torque command. An operating voltage for the second power supply is determined based on the present power reserve. The operating voltage for the second power supply is applied to the at least one winding. The application of the operating voltage allowing the present power reserve to flow between the first and second power supplies and the motor.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: September 21, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Sibaprasad Chakrabarti, Brian A. Welchko, Silva Hiti
  • Publication number: 20100231149
    Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. First and second voltage commands are used at the field weakening loop to generate a first adjusting current command. The first adjusting current command is then provided to the torque linearity control loop, where it is multiplied by a gain to generate an output current command, which can then be limited to generate a second adjusting current command. The second adjusting current command can then be added to a current command to generate an adjusted current command. The first adjusting current command can also be added to another current command to generate another adjusted current command. The adjusted current commands and feedback currents are then used at a synchronous current regulator to generate new first and second voltage commands.
    Type: Application
    Filed: May 24, 2010
    Publication date: September 16, 2010
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: GABRIEL GALLEGOS-LOPEZ, YO CHAN SON, MILUN PERISIC, SILVA HITI
  • Patent number: 7774148
    Abstract: In an embodiment of a method, the method includes measuring currents and voltages that are coupled to a motor that includes an internal permanent magnet and determining a reactive power in response to the measured currents and voltages. The method further includes estimating a first flux orthogonal to an axis of the internal permanent motor and estimating a second flux aligned with the axis of the internal permanent motor. Additionally, the method includes estimating a torque in response to the measured currents and the first and second fluxes.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: August 10, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Brian A Welchko, Silva Hiti, Steven E. Schulz
  • Patent number: 7768220
    Abstract: Methods and systems are provided for reducing torque ripple in an electric motor. A method comprises receiving a torque command and determining a cancellation current command based on the torque command. The method further comprises generating a harmonic cancellation command based on the cancellation current command, wherein the harmonic cancellation command compensates for a phase shift and an attenuation introduced by a current regulated control module coupled to an inverter coupled to the electric motor. The method further comprises providing the harmonic cancellation command to the current regulated control module, wherein the current regulated control module is configured to control the inverter in response to the harmonic cancellation command and the torque command.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: August 3, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Steven E. Schulz, Goro Tamai, Silva Hiti
  • Patent number: 7759886
    Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an IPM machine. The systems and methods adjust the q-axis and the d-axis components of the stator current commands of the IPM machine using a flux weakening and a torque linearity control loop respectively. Thereby, torque linearity is maintained during the field weakening region of operation of the IPM machine.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: July 20, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Gabriel Gallegos-Lopez, Yo Chan Son, Milun Perisic, Silva Hiti
  • Patent number: 7755319
    Abstract: Apparatus, systems, and methods are provided for reducing voltage source inverter losses. One apparatus includes a sensor couplable to the motor and configured to sense an operating frequency of the motor and an amount of torque produced by the motor. The apparatus also includes a controller coupled to the sensor, the controller configured to determine a zero vector modulation (ZVM) based on the sensed frequency and torque. A system includes means for sensing a threshold output frequency of the motor and means for sensing a threshold torque of the motor. The system also includes means for determining a ZVM for the inverter based on the sensed threshold frequency and threshold torque. One method includes sensing that a motor is operating below a threshold frequency and is producing torque above a threshold torque amount. The method also includes determining a ZVM for the inverter based on the sensed frequency and torque.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: July 13, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Silva Hiti, Steven E. Schulz, Brian A Welchko
  • Patent number: 7755313
    Abstract: According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux ?*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.
    Type: Grant
    Filed: September 12, 2007
    Date of Patent: July 13, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Yo Chan Son, Gabriel Gallegos-Lopez, Silva Hiti, Michael Milani, Milun Perisic
  • Patent number: 7723946
    Abstract: Method and system are provided for controlling an alternating current (AC) motor via an inverter. The method includes selecting a pulse sequencing method based on a modulation index of the inverter, and providing a voltage to the AC motor based on the pulse sequencing method. The system includes an inverter having a modulation index (Mi) and a controller coupled to the inverter. The controller selects a pulse sequencing method based on Mi and produces a signal based on the pulse sequencing method. The inverter includes a switch network producing a voltage in response to the signal, and the voltage drives the AC motor.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: May 25, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Brian A Welchko, Steven E. Schulz, Silva Hiti
  • Patent number: 7719138
    Abstract: Systems and methods are disclosed for a two-source series inverter. The systems and methods combine operation of a first voltage source and a second voltage source in series powering a novel voltage combining arrangement and a conventional inverter via a switch configuration to power a load. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: May 18, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Gabriel Gallegos-Lopez, Milun Perisic, George John, Gregory S. Smith, Silva Hiti
  • Patent number: RE42200
    Abstract: An apparatus includes a multi-phase inverter, a fault detector to indicate a detection of a fault, a sensor to provide a speed signal indicative of whether a speed of a PM motor is greater than a transition speed, and a controller. The controller is operable to apply either an open-circuit response or a short-circuit response to the multi-phase inverter. The open-circuit response is applied when the speed of the PM motor is greater less than the transition speed and a fault is detected. The short-circuit response is applied when the speed of the PM motor is less greater than the transition speed and the fault is detected. The transition speed is either a fixed predetermined speed or an adjusted predetermined speed.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: March 8, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Brian Welchko, Jonathan B. Huse, Silva Hiti, Brendan M. Conlon, Constantin C. Stancu, Khwaja M. Rahman, David Tang, William R. Cawthorne