Patents by Inventor Weiqun Liu

Weiqun Liu 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: 10535997
    Abstract: A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: January 14, 2020
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Long Wu, Weiqun Liu, Xiangjian Shi
  • Publication number: 20190334348
    Abstract: A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value
    Type: Application
    Filed: April 23, 2018
    Publication date: October 31, 2019
    Applicants: NR Electric Co., Ltd, NR Engineering Co., Ltd
    Inventors: Long WU, Weiqun LIU, Xiangjian SHI
  • Patent number: 9584007
    Abstract: Embodiments of the present invention disclose a current source converter differential protection method, including: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to acquire a transient differential current and a transient restraint current; acquiring a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current.
    Type: Grant
    Filed: April 14, 2014
    Date of Patent: February 28, 2017
    Assignees: NR ELECTRIC CO., LTD., NR ENGINEERING CO., LTD.
    Inventors: Qixue Zhang, Jun Chen, Wei Yan, Xiangjian Shi, Guang Wang, Wei Yan, Weiqun Liu, Quanrong Shen
  • Publication number: 20160118877
    Abstract: Embodiments of the present invention disclose a current source converter differential protection method, including: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to acquire a transient differential current and a transient restraint current; acquiring a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current.
    Type: Application
    Filed: April 14, 2014
    Publication date: April 28, 2016
    Inventors: Qixue ZHANG, Jun CHEN, Wei YAN, Xiangjian SHI, Guang WANG, Wei YAN, Weiqun LIU, Quanrong SHEN
  • Publication number: 20130178380
    Abstract: Kits and methods of using O-rings having apertures are provided herein. O-rings are useful for incubating with a sample fluid potentially having one or more biomarkers, in order to detect the presence of the biomarkers. O-rings can be readily organized in a trackable manner prior to and during incubation with the sample fluid. O-rings can also be readily transferred and organized into one or more trackable arrays for detecting the presence of bound biomarkers and measuring the signaling product generated by bound detect molecule-linked enzymes present in a homogeneous solution with a spectrophotometer.
    Type: Application
    Filed: June 21, 2012
    Publication date: July 11, 2013
    Inventor: Weiqun Liu
  • Patent number: 8444920
    Abstract: Kits and methods of using O-rings having apertures are provided herein. O-rings are useful for incubating with a sample fluid potentially having one or more biomarkers, in order to detect the presence of the biomarkers. O-rings can be readily organized in a trackable manner prior to and during incubation with the sample fluid. O-rings can also be readily transferred and organized into one or more trackable arrays for detecting the presence of bound biomarkers and measuring the signaling product generated by bound detect molecule-linked enzymes present in a homogeneous solution with a spectrophotometer.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: May 21, 2013
    Inventor: Weiqun Liu
  • Publication number: 20110065133
    Abstract: Kits and methods of using O-rings having apertures are provided herein. O-rings are useful for incubating with a sample fluid potentially having one or more biomarkers, in order to detect the presence of the biomarkers. O-rings can be readily organized in a trackable manner prior to and during incubation with the sample fluid. O-rings can also be readily transferred and organized into one or more trackable arrays for detecting the presence of bound biomarkers and measuring the signaling product generated by bound detect molecule-linked enzymes present in a homogeneous solution with a spectrophotometer.
    Type: Application
    Filed: September 16, 2009
    Publication date: March 17, 2011
    Inventor: Weiqun Liu