Patents Assigned to Schweitzer Engineering Laboratories
  • Publication number: 20130234696
    Abstract: Disclosed herein are systems and methods for regulating a voltage profile of an electric power delivery system. According to some embodiments, a system may include a remote voltage regulating device configured to regulate voltage profile by selecting among a plurality of taps on a remote transformer and an associated a remote voltage regulator controller in communication. The remote voltage regulator controller may calculate remote voltage regulation information and may transmit the remote voltage regulation information to a local voltage regulator controller. The local voltage regulator controller may be in communication with a local voltage regulating device configured to regulate the voltage profile of a local portion of the electric power delivery system by selecting among a plurality of taps on a local transformer. The local voltage regulator controller may be configured to receive the remote voltage regulation information and generate a tap change command for the local voltage regulating device.
    Type: Application
    Filed: April 22, 2013
    Publication date: September 12, 2013
    Applicant: Schweitzer Engineering Laboratories
    Inventors: Michael B. Bryson, David E. Whitehead
  • Patent number: 6744391
    Abstract: The system includes a unipolar A/D converter, which samples analog signal inputs thereto, the A/D converter being used in a protective relay for electric power systems. The unipolar A/D converter is responsive to input voltage values and current values from the power line to produce corresponding digital signals. The A/D converter has a ground pin voltage reference at least as negative as the most negative point of the input signal to be processed.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: June 1, 2004
    Assignee: Schweitzer Engineering Laboratories
    Inventors: Travis L. Mooney, Tony J. Lee, Bruce A. Hall
  • Patent number: 6525543
    Abstract: The fault identification system includes a first logic circuit which is responsive to conventional protective elements which recognize the presence of low resistance single line-to-ground faults for the A, B and C phases on a power transmission line. The first logic circuit includes a portion thereof for recognizing and providing an output indication of single line-to-ground faults, faults involving two phases and three-phase faults, in response to the occurrence of different combinations of outputs from the protective elements. A calculation circuit, when enabled, is used to determine the angular difference between the total zero sequence current and the total negative sequence current for high resistance faults when the protective elements themselves cannot identify fault conditions. The angular difference is in one of three pre-selected angular sectors.
    Type: Grant
    Filed: October 20, 2000
    Date of Patent: February 25, 2003
    Assignee: Schweitzer Engineering Laboratories
    Inventors: Jeffrey B. Roberts, Demetrios Tziouvaras
  • Patent number: 5905758
    Abstract: The fiber-optic transceiver system combines EIA-232 data with IRIG-B time code information in a time multiplexing arrangement. The combined signal is transmitted to a receiver where the time code information is decombined from the data so that the two signals are replicas of their originals. The time multiplexing is accomplished by inserting a pulse into the data stream following the occurrence of a minimum time for each data bit and the coincidence of a time code pulse.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: May 18, 1999
    Assignee: Schweitzer Engineering Laboratories
    Inventors: Edmund O. Schweiter, III, Timothy M. Minteer
  • Patent number: D492653
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: July 6, 2004
    Assignee: Schweitzer Engineering Laboratories
    Inventor: Gerald K. Hein