Patents by Inventor Tianjun Fu

Tianjun Fu 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: 9698722
    Abstract: A temperature estimation module estimates each junction temperature of a corresponding semiconductor device, among a plurality of semiconductor devices, for each phase of an inverter. The temperature estimation module or the data processing system determines a hottest device with a highest junction temperature among the semiconductor devices. A thermal adjustment module or data processing system determines if the highest junction temperature parameter is less than maximum junction temperature parameter for the respective semiconductor device or deciding whether or not to adjust a duty cycle of the semiconductor devices.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: July 4, 2017
    Assignee: DEERE & COMPANY
    Inventors: David M. Loken, Long Wu, Tianjun Fu, Robert B. Shaw, Neal D. Clements
  • Publication number: 20160373047
    Abstract: A temperature estimation module estimates each junction temperature of a corresponding semiconductor device, among a plurality of semiconductor devices, for each phase of an inverter. The temperature estimation module or the data processing system determines a hottest device with a highest junction temperature among the semiconductor devices. A thermal adjustment module or data processing system determines if the highest junction temperature parameter is less than maximum junction temperature parameter for the respective semiconductor device or deciding whether or not to adjust a duty cycle of the semiconductor devices.
    Type: Application
    Filed: August 27, 2015
    Publication date: December 22, 2016
    Inventors: David M. Loken, Long Wu, Tianjun Fu, Robert B. Shaw, Neal D. Clements
  • Publication number: 20160276971
    Abstract: In one example embodiment, a method includes determining a first adjustment value for a slip frequency of a rotor in an induction motor, determining a second adjustment value for an inductance of the induction motor and tuning the slip frequency of the rotor and the inductance of the induction motor based on the first adjustment value and the second adjustment value, respectively.
    Type: Application
    Filed: March 16, 2015
    Publication date: September 22, 2016
    Inventors: Lav THYAGARAJAN, Long WU, Tianjun FU
  • Patent number: 9071186
    Abstract: In one example embodiment, a device for controlling an alternating current (AC) machine is disclosed. The device includes a processor configured to determine a plurality of instantaneous voltages corresponding to a plurality of phase voltages of an inverter, the inverter driving the AC machine. The processor is further configured to determine an actual line-to-line voltage of the inverter based on the plurality of instantaneous voltages. The processor is further configured to determine a terminal voltage feedback for controlling the AC machine, based on the determined actual line-to-line voltage and a terminal voltage threshold.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: June 30, 2015
    Assignee: Deere & Company
    Inventors: Long Wu, Tianjun Fu, Chris J. Tremel
  • Publication number: 20140306637
    Abstract: In one example embodiment, a device for controlling an alternating current (AC) machine is disclosed. The device includes a processor configured to determine a plurality of instantaneous voltages corresponding to a plurality of phase voltages of an inverter, the inverter driving the AC machine. The processor is further configured to determine an actual line-to-line voltage of the inverter based on the plurality of instantaneous voltages. The processor is further configured to determine a terminal voltage feedback for controlling the AC machine, based on the determined actual line-to-line voltage and a terminal voltage threshold.
    Type: Application
    Filed: April 12, 2013
    Publication date: October 16, 2014
    Applicant: DEERE & COMPANY
    Inventors: Long WU, Tianjun FU, Chris J. TREMEL
  • Patent number: 8410737
    Abstract: Embodiments of the present invention provide a device and method for generating initial operating points for controlling an interior permanent magnet (IPM) machine. The method includes loading an inductance lookup table, first calculating a maximum torque per Ampere (MTPA) trajectory for a first threshold speed based on machine parameters of the IPM machine, second calculating a truncated voltage limit ellipse with monotonically increasing torque for a first speed based on the machine parameters, if the first speed is higher than the first threshold speed, determining an operating trajectory at the first speed based on at least one of the calculated MTPA trajectory and the calculated truncated voltage limit ellipse, and generating an Id,Iq map that maps an Id value and an Iq value to each torque command of a plurality of torque commands for the first speed based on the determined operating trajectory.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: April 2, 2013
    Assignee: Deere & Company
    Inventors: Long Wu, Srujan Kusumba, Zimin W. Vilar, Tianjun Fu, Robert Shaw
  • Publication number: 20120217916
    Abstract: Embodiments of the present invention provide a device and method for generating initial operating points for controlling an interior permanent magnet (IPM) machine. The method includes loading an inductance lookup table, first calculating a maximum torque per Ampere (MTPA) trajectory for a first threshold speed based on machine parameters of the IPM machine, second calculating a truncated voltage limit ellipse with monotonically increasing torque for a first speed based on the machine parameters, if the first speed is higher than the first threshold speed, determining an operating trajectory at the first speed based on at least one of the calculated MTPA trajectory and the calculated truncated voltage limit ellipse, and generating an Id,Iq map that maps an Id value and an Iq value to each torque command of a plurality of torque commands for the first speed based on the determined operating trajectory.
    Type: Application
    Filed: February 28, 2011
    Publication date: August 30, 2012
    Applicant: DEERE & COMPANY
    Inventors: Long Wu, Srujan Kusumba, Zimin W. Vilar, Tianjun Fu, Robert Shaw