Schweitzer Engineering Laboratories, Inc.

Michael B Bryson

David E Whitehead

Edmund O Schweitzer, Iii

Gabriel Benmouyal

Dennis Haes

Systems and methods are provided for monitoring or protecting an electric power distribution system using protective devices that may rely on accurate time signals from a common time source. A first protective device may receive a first time signal deriving from the common time source and a second protective device may receive a second time signal deriving from the common time source. The first time signal and the second time signal may be compared; when a difference between them exceeds a defined threshold, time signal manipulation may be detected. The protective devices may modify their operation in response to or to account for the time signal manipulation.

Time signal manipulation detection using remotely managed time

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.

Voltage regulation using multiple voltage regulator controllers

Regulation of a remote load center voltage from a local location of a voltage regulator and a voltage regulator control using voltage measurements from the remote load center obtained using a metering device at the load center in communication with the voltage regulator control. The metering device may obtain remote voltage information at the load center and communicate such to the voltage regulator control using a direct communications line, a wide area network, or the like. The communications may include electrical (e.g. copper cable), light (e.g. infrared over fiber optics), radio frequency, or the like. The voltage regulator control may be configured to use local measurements and a line drop compensation algorithm in the event that the remote voltage information becomes unavailable.

Voltage regulation at a remote location using measurements from a remote metering device

The system includes a distance protective relay for power lines which includes a logic capability which is responsive to settings entered into the relay by an end user to implement the value of those settings into stored thermal model equations which emulate the temperature of the power line conductor. The logic within the relay is organized and has the capability of receiving the setting values entered by the user and to use those in the logic equations to determine the temperature of the conductor.

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Pullman, WA, United States of America

Michael B Bryson