Patents by Inventor Bong Su Choi

Bong Su Choi 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: 11404955
    Abstract: A method for controlling a fault of a three phase four wire interlinking converter system according to one embodiment of the present disclosure comprises obtaining a first d-q-o coordinate plane based on an internal phase angle of output voltage produced from each phase of an inverter; converting the first d-q-o coordinate plane to a second d-q-o coordinate plane based on the o-axis configured differently from the first d-q-o coordinate plane; obtaining an output voltage vector for determining a fault location by performing d-q transform on the second d-q-o coordinate plane; determining occurrence of a fault and an area related to the fault based on the output voltage vector; and in the occurrence of the fault, allocating a zero voltage vector to the area related to the fault.
    Type: Grant
    Filed: September 3, 2021
    Date of Patent: August 2, 2022
    Assignee: RESEARCH & BUSINESS FOUNDATION SUNGKYUNKWAN UNIVERSITY
    Inventors: Chung Yuen Won, Kwang Su Na, Mi Na Kim, Bong Yeon Choi, Kyoung Min Kang, Hoon Lee, Chang Gyun An, Tae Gyu Kim, Jun Sin Yi
  • Patent number: 11028711
    Abstract: According to the present invention, part of carbon dioxide heated by a heater is supplied to a dry gas seal portion of a compressor so that a device for pressurizing and heating a seal gas is not additionally required, configuration can be simplified and cost can be reduced. In addition, a seal gas flow path includes a low-temperature seal gas flow path and a high-temperature seal gas flow path so that, in an initial driving mode, carbon dioxide heated by a high-temperature portion of the heater is used as a seal gas and in a turbine-driving mode, carbon dioxide heated by a low-temperature portion of the heater is used as a seal gas and thus a more efficient operation can be performed.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: June 8, 2021
    Assignee: KOREA INSTITUTE OF ENERGY RESEARCH
    Inventors: Jun Hyun Cho, Bong Su Choi, Ho Sang Ra, Hyung Ki Shin, Jong Jae Cho, Beom Joon Lee, Chul Woo Roh, Gil Bong Lee, Young Jin Baik
  • Publication number: 20200131920
    Abstract: According to the present invention, part of carbon dioxide heated by a heater is supplied to a dry gas seal portion of a compressor so that a device for pressurizing and heating a seal gas is not additionally required, configuration can be simplified and cost can be reduced. In addition, a seal gas flow path includes a low-temperature seal gas flow path and a high-temperature seal gas flow path so that, in an initial driving mode, carbon dioxide heated by a high-temperature portion of the heater is used as a seal gas and in a turbine-driving mode, carbon dioxide heated by a low-temperature portion of the heater is used as a seal gas and thus a more efficient operation can be performed.
    Type: Application
    Filed: June 26, 2019
    Publication date: April 30, 2020
    Applicant: KOREA INSTITUTE OF ENERGY RESEARCH
    Inventors: Jun Hyun CHO, Bong Su CHOI, Ho Sang RA, Hyung Ki SHIN, Jong Jae CHO, Beom Joon LEE, Chul Woo ROH, Gil Bong LEE, Young Jin BAIK
  • Patent number: 6016218
    Abstract: An optical fiber amplifier is disclosed including: an optical line through which an optical signal is transmitted; a rare-earth-doped fiber, doped with a predetermined rare earth ion, being set on the optical line; a pumping light beam source for generating a pumping light beam having a predetermined wavelength; a first multiplexer for coupling the pumping light beam to the optical line; a second multiplexer for dividing the pumping light beam outputted from the rare-earth-doped fiber; and pumping light beam looping means for looping the pumping light beam divided by the second multiplexer back to the rare-earth-doped fiber. The residual pumping light beam outputted from the rare-earth-doped pumping light beam is looped back by the feedback loop or reflection loop, to be reprovided to the rare-earth-doped fiber through the multiplexer.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: January 18, 2000
    Assignee: Daewoo Telecom Ltd.
    Inventors: Sung Chil Jo, Bong Su Choi