Patents by Inventor Si Jian Fang

Si Jian Fang 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: 8378644
    Abstract: An active rectifier controller decouples measurements of the phase and speed of a variable frequency synchronous generator from measurements of the AC output voltage. The active rectifier controller receives position information representative of the rotor position of the VFSG independent of a load connected to the VFSG that is used to determine the phase position and speed of the VFSG. Based on measurements of the generator speed and phase, the active rectifier controller controls the active rectifier to draw AC currents in-phase with the back-electromotive force (BEMF) voltage of the VFSG.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: February 19, 2013
    Assignee: Hamilton Sundstrand Corporation
    Inventors: Waleed M. Said, Si Jian Fang
  • Publication number: 20110050184
    Abstract: An active rectifier controller decouples measurements of the phase and speed of a variable frequency synchronous generator from measurements of the AC output voltage. The active rectifier controller receives position information representative of the rotor position of the VFSG independent of a load connected to the VFSG that is used to determine the phase position and speed of the VFSG. Based on measurements of the generator speed and phase, the active rectifier controller controls the active rectifier to draw AC currents in-phase with the back-electromotive force (BEMF) voltage of the VFSG.
    Type: Application
    Filed: August 28, 2009
    Publication date: March 3, 2011
    Applicant: HAMILTON SUNDSTRAND CORPORATION
    Inventors: Waleed M. Said, Si Jian Fang
  • Patent number: 7660135
    Abstract: A universal alternating current (AC) inverter system with galvanic isolation takes an unregulated direct current (DC) input and provides a high-quality AC output that may be used in conjunction with both linear and non-linear loads. The universal AC inverter system includes a DC-DC converter for converting an unregulated DC input to a regulated DC output, and a DC-AC inverter for converting the regulated DC output to a high-quality AC output. The DC-DC converter includes a DC link isolation high frequency transformer that provides galvanic isolation between the unregulated DC input and the AC output. To avoid saturation of the transformer, the controller for the DC-DC converter employs a DC offset correction loop that prevents accumulation of DC content on the primary side of the transformer. The universal AC inverter system includes a 4-phase inverter topology that converts the regulated DC voltage provided by the DC-DC converter to an AC output.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: February 9, 2010
    Assignee: Hamilton Sundstrand Corporation
    Inventor: Si Jian Fang
  • Publication number: 20080291707
    Abstract: A universal alternating current (AC) inverter system with galvanic isolation takes an unregulated direct current (DC) input and provides a high-quality AC output that may be used in conjunction with both linear and non-linear loads. The universal AC inverter system includes a DC-DC converter for converting an unregulated DC input to a regulated DC output, and a DC-AC inverter for converting the regulated DC output to a high-quality AC output. The DC-DC converter includes a DC link isolation high frequency transformer that provides galvanic isolation between the unregulated DC input and the AC output. To avoid saturation of the transformer, the controller for the DC-DC converter employs a DC offset correction loop that prevents accumulation of DC content on the primary side of the transformer. The universal AC inverter system includes a 4-phase inverter topology that converts the regulated DC voltage provided by the DC-DC converter to an AC output.
    Type: Application
    Filed: May 23, 2007
    Publication date: November 27, 2008
    Applicant: Hamilton Sundstrand Corporation
    Inventor: Si Jian Fang