Abstract: The present disclosure relates to a service availability monitor for interfacing with a monitored service, determine an availability of the monitored service, log the availability of the monitored service, generate a user notification in event of interruption, and communicate the user notification. The service availability monitor may include a primary power subsystem configured to draw power from a primary power source, and a backup power subsystem configured to draw power from the primary power subsystem and provide power to the monitor when power is unavailable through the primary power subsystem. The service availability monitor may monitor an electrical power service, an Internet service a telephone service, a television service, or the like.

Abstract: The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in an electric power delivery system, the CCVT comprising a first capacitor disposed between an electrical bus and a first electrical node, and a second capacitor electrically disposed between the first electrical node and a ground connection. A resistive divider in electrical communication with a first node may generate a resistive divider electrical signal corresponding to a voltage value. An intelligent electronic device (IED) in electrical communication with the resistive divider monitors a resistive divider voltage signal. The IED detects a traveling wave based on the resistive divider voltage signal and a measurement of a primary current through an electrical bus in electrical communication with the CCVT; and analyzes the traveling wave to detect a fault on the electric power delivery system.

Abstract: The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. A current transformer is disposed between the stack of capacitors and the first ground connection. The current transformer provides an electrical signal corresponding to a current associated with the CCVT. An intelligent electronic device (IED) in electrical communication with the first current measurement device generates a voltage signal based on the electrical signal from the current transformer. The IED detects a traveling wave based on the first voltage signal; and analyzes the traveling wave to detect a fault on the electric power delivery system.

Abstract: A system for accurately determining a location of a fault in an electric power delivery system using traveling waves by compensating for dispersion of the traveling waves. The dispersion may be calculated based on a preliminary fault location determination, and the arrival times of traveling wave peaks may then be corrected using the calculated dispersion. A compensation to the traveling wave propagation speed may be made using a proportionality factor to correct for traveling wave dispersion. Dispersion correction may be a function of fault type or physical power line conditions.

Abstract: The present disclosure relates to detection of faults in an electric power system. In one embodiment, an incremental quantities subsystem may be configured to calculate a plurality of values of an operating quantity based on the plurality of time-domain representations of electrical conditions. The incremental quantities subsystem may also calculate a plurality of values of a restraining quantity based on the plurality of time-domain representations of electrical conditions. An interval during which the calculated operating quantity exceeds the calculated restraining quantity may be determined. A fault detector subsystem may be configured to declare a fault based on the calculated operating quantity exceeding the calculated restraining quantity by a security margin. A protective action subsystem configured to implement a protective action based on the declaration of the fault.

Abstract: The present disclosure relates to detection of faults in an electric power system. In one embodiment, a time-domain traveling wave differential subsystem is configured to determine at a first terminal a first index between an arrival maximum of a traveling wave generated by a fault at the first terminal and an exit maximum of the traveling wave. The traveling wave subsystem also determines a second index between an arrival maximum of the traveling wave at the second terminal and an exit maximum of the traveling wave. An operating quantity and a restraint quantity may be determined based on a magnitude of the representations of electrical conditions in the first index and the second index. A fault may be declared based on a comparison of the operating quantity and the restraint quantity. A protective action subsystem may be configured to implement a protective action based on the declaration of the fault.

Abstract: Traveling wave information from a single end of an electric power delivery system is used to determine a fault location on a power line of the electric power delivery system. Hypotheses of which of a plurality of received traveling waves represents a first reflection from the fault are evaluated. A determination of an arrival time of the first reflection from the fault is used to calculate a distance from the single end of the power line to the fault location.

Abstract: An electric power delivery system may be protected upon occurrence of a fault condition by the systems and methods disclosed herein by detecting the fault condition and signaling a protective action before the overcurrent condition reaches the protective equipment. The protective action may be an opening of a circuit breaker or engagement of a fault current limiter. The overcurrent condition may be a non-steady-state condition. The fault may be detected using traveling wave or incremental quantity techniques.

Abstract: Traveling wave information from a single end of an electric power delivery system is used to determine a fault location on a power line of the electric power delivery system. Hypotheses of which of a plurality of received traveling waves represents a first reflection from the fault are evaluated. A determination of an arrival time of the first reflection from the fault is used to calculate a distance from the single end of the power line to the fault location.

Abstract: The present disclosure pertains to systems and methods to detect faults in electric power delivery systems. In one embodiment, a data acquisition system may acquire a plurality of electric power delivery system signals from an electric power transmission line. A traveling wave system may detect a traveling wave based on the plurality of electric power delivery system signals received from the data acquisition system. The traveling wave may be analyzed using a first mode to determine a first mode arrival time and using a second mode to determine a second mode arrival time. A time difference between the first mode arrival time and the second mode arrival time may be determined. A fault location system may estimate or confirm a location of the fault based on the time difference. A protection action module may implement a protective action based on the location of the fault.

Abstract: The present disclosure pertains to systems and methods for analyzing traveling waves in an electric power delivery system. In one embodiment, a system may comprise a traveling wave identification subsystem to receive electric power system signals and identify a plurality of incident, reflected, and transmitted traveling waves. A first traveling wave may be selected from the incident and transmitted traveling waves, and a first distortion may be determined. A second traveling wave subsequent to the first traveling wave, may selected from the incident traveling waves and a second distortion may be determined. A traveling wave analysis subsystem may compare the first distortion and the second distortion and determine whether the first distortion is consistent with the second distortion. A protective action subsystem may implement a protective action based on a first determination that the first distortion is consistent with the second distortion.

Abstract: The present disclosure pertains to systems and methods for monitoring traveling waves in an electric power system. In various embodiments, a data acquisition subsystem may acquire electric power system signals. A traveling wave detection subsystem may detect two or more traveling waves based on the electric power system signals and determine a location of an event triggering the traveling waves. A traveling wave security subsystem may selectively generate a restraining signal based on the location of the event as within a blocking zone. A protection action subsystem may implement a protective action when the location is outside of a blocking zone. In various embodiments, a protective action will not be implemented for traveling waves launched from known locations of switching devices operating normally. Further, protective actions may be restrained if a magnitude of a traveling wave differs from an expected value based on a pre-fault voltage.

Abstract: An intelligent electronic device (IED) may detect arrival times and/or other characteristics of traveling waves and/or reflections thereof to determine a distance to a fault location in terms of per-unit length. An IED may convert between line distances, line-of-sight distances, straight-line distances, and/or terrain-based distances. An IED may refine one or more physical line parameters used for traveling wave-based location calculations for iterative improvements in accuracy. For instance, an IED may compare reported distances to fault locations with field-verified, confirmed fault locations to refine physical line parameters used in future location calculations. Similarly, an IED may identify which of a plurality of towers corresponds to a fault location based on a mapping of towers on a per-unit scale. Confirmed fault locations may be used to update or refine the mapping to improve future tower identification relative to per-unit fault location.

Abstract: The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in an electric power delivery system, the CCVT comprising a first capacitor disposed between an electrical bus and a first electrical node, and a second capacitor electrically disposed between the first electrical node and a ground connection. A resistive divider in electrical communication with a first node may generate a resistive divider electrical signal corresponding to a voltage value. An intelligent electronic device (IED) in electrical communication with the resistive divider monitors a resistive divider voltage signal. The IED detects a traveling wave based on the resistive divider voltage signal and a measurement of a primary current through an electrical bus in electrical communication with the CCVT; and analyzes the traveling wave to detect a fault on the electric power delivery system.

Abstract: An electric power delivery system may be protected upon occurrence of a fault condition by the systems and methods disclosed herein by detecting the fault condition and signaling a protective action before the overcurrent condition reaches the protective equipment. The protective action may be an opening of a circuit breaker or engagement of a fault current limiter. The overcurrent condition may be a non-steady-state condition. The fault may be detected using traveling wave or incremental quantity techniques.

Abstract: The present disclosure relates to calculating a fault location in an electric power transmission system based on traveling waves. In one embodiment, a system consistent with the present disclosure may be configured to detect a fault in an electric power transmission system. The system may include a traveling wave detection subsystem configured to detect and measure traveling waves on a transmission line and a fault location estimation subsystem. The fault location estimation subsystem may receive from the traveling wave detection subsystem a first plurality of traveling waves on the transmission line generated during a reference event. The fault location estimation subsystem may receive from the traveling wave detection subsystem a second plurality of traveling waves generated during an unplanned event. An unmatched traveling wave in the second plurality of waves may be detected and a location of the unplanned event based on the unmatched traveling wave.

Abstract: A system for monitoring an electric power delivery system by obtaining high-frequency electric power system measurements and displaying event information is disclosed herein. The system may use the high-frequency electric power system information to detect traveling waves. The system may generate a display showing fault location on the electric power system, and timing of traveling waves received at locations on the electric power system. The display may include time on one axis and location on another axis. The display may include a waterfall display.

Abstract: Disclosed herein are systems for monitoring and protecting an electric power system using a plurality of conductor-mounted detectors (CMDs). In one embodiment, a plurality of CMDs are coupled to an electrical conductor. Each CMD may harvest power from the electrical conductor and may monitor electrical current in the conductor. When the electrical current in the conductor exceeds a fault current threshold a fault signal may be transmitted. A receiver in communication with each of the plurality of CMDs may receive the fault signal from at least one of the plurality of CMDs. A protective action may be generated and implemented to clear the fault. A portion of the electric power system affected by the fault may be determined based on identification of each of the plurality of CMDs to transmit the fault signal.

Abstract: The present disclosure relates to detection of faults in an electric power system. In one embodiment, a time-domain traveling wave directional subsystem is configured to receive a plurality of current traveling wave and a plurality of voltage traveling wave time-domain representations based on electrical conditions in the electric power delivery system. The plurality of current and voltage traveling wave time-domain representations may be compared to respective minimum thresholds. An integral may be generated based on a product of the plurality of current and voltage traveling wave time-domain representations when the current and voltage traveling wave time-domain representations exceed the minimum thresholds. A sign of the integral may reflect whether the fault is in the forward or reverse direction. A fault detector subsystem configured to declare the fault when the sign reflects that the fault is in the forward direction and the integral exceeds a security margin.

Abstract: The present disclosure relates to detection of faults in an electric power system. In one embodiment, an incremental quantities subsystem is configured to determine a forward torque, an operating torque, and a reverse torque based on the plurality of time-domain representations of electrical conditions. Each of the forward torque, the operating torque, and the reverse torque may be integrated over an interval. A fault detection subsystem may determine an occurrence of the fault based on a comparison of the operating torque to the forward torque and the reverse torque. Further, a direction of the fault may be determined based on the comparison of the forward torque, the operating torque, and the reverse torque. A fault may be declared based on the comparison and the direction. A protective action subsystem may implement a protective action based on the declaration of the fault.