Patents by Inventor Daqing Hou

Daqing Hou 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).

  • System for detection of transients from a coupling capacitor voltage transformer used in a protective relay
    Patent number: 5703745
    Abstract: The voltage and current conditions on a power transmission line are monitored to determine the coincidence of a low voltage condition and a lack of a high current condition. The coincidence of those two conditions is indicative of a CCVT transient, and the tripping action from zone 1 distance elements is delayed for a period of 1.375 cycles. The tripping delay is supervised by a fault impedance determination, which, if a threshold is exceeded, the remaining portion of the time delay is eliminated, so that a trip is allowed if the time delay period has not expired.
    Type: Grant
    Filed: October 20, 1995
    Date of Patent: December 30, 1997
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Jeffrey B. Roberts, Daqing Hou