Abstract: Phase selection for traveling wave fault detection systems is disclosed herein. Intelligent electronic devices (IEDs) may be used to monitor and protect electric power delivery systems by detecting and acting upon traveling waves. A phase of the electric power delivery system may be selected based on the relative polarity of the traveling waves detected. The amplitude and/or polarity of the selected phase may be compared with the amplitudes and/or polarities of the other phases to determine a fault condition. For instance, the IED may determine a single-phase-to-ground fault based on the relative polarities and magnitudes of the detected traveling waves, send a protective action to the identified faulted phase, and/or continue to monitor the system for a continuation of the event or identification of a different event, such as a three-phase fault, using incremental quantities.

Abstract: The present disclosure relates to determining locations of low-energy events on power lines. For example, an IED may receiving an input signal indicating a local electrical condition of a power line. The IED may detect traveling waves on the power line based on the local electrical condition. The IED may detect traveling waves on the power line based on the local and remote electrical conditions. The IED may determine that the traveling waves are associated with a low-energy event. The IED may determine the location of the low-energy event on the power line based at least in part on the traveling waves.

Abstract: Distance protection for electric power systems disclosed herein uses an operating signal and a sequence polarizing signal made up of a supervised sequence current and a supervised sequence voltage. The polarizing signal may be determined based on the fault type and may be weighted toward sequence currents or sequence voltages depending on the power system conditions. For phase-to-ground faults, the sequence currents may include negative-sequence and zero-sequence currents. For phase-to-phase faults, the sequence currents may include negative-sequence currents. The current portion of the sequence polarizing signal may be weighted based on detection of insufficient negative-sequence current magnitude, standing unbalance, current transformer saturation, open pole, three-phase fault, and the like. The distance elements described herein provides improved protection during real-world power system conditions and changes.

Abstract: Distance protection for electric power systems disclosed herein uses an operating signal and a sequence polarizing signal made up of a supervised sequence current and a supervised sequence voltage. The polarizing signal may be determined based on the fault type and may be weighted toward sequence currents or sequence voltages depending on the power system conditions. For phase-to-ground faults, the sequence currents may include negative-sequence and zero-sequence currents. For phase-to-phase faults, the sequence currents may include negative-sequence currents. The current portion of the sequence polarizing signal may be weighted based on detection of insufficient negative-sequence current magnitude, standing unbalance, current transformer saturation, open pole, three-phase fault, and the like. The distance elements described herein provides improved protection during real-world power system conditions and changes.

Abstract: The present disclosure pertains to detection of a broken conductor in an electric power system. In one embodiment, a broken conductor detector may be configured to be mounted to an electrical conductor and may comprise a communication subsystem configured to transmit a signal configured to indicate that the conductor is broken. A sensor may determine an operating vector. A processing subsystem may be configured to receive the operating vector from the sensor and to identify when the operating vector is outside of a range defined by a rest vector and a threshold value. In certain embodiments, the threshold may comprise a three-dimensional sphere. The processing subsystem may determine that the conductor is broken based on the operating vector remaining outside of the range for a period of time determined by the timer subsystem. A signal may be transmitted by the communication subsystem to indicate that the conductor is broken.

Abstract: The present disclosure pertains to systems and methods for detecting faults in an electric power delivery system. In one embodiment, system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions. The system may also include an incremental quantities subsystem configured to calculate an incremental current quantity and an incremental voltage quantity based on the plurality of representations. A fault detection subsystem may be configured to determine a fault type based on the incremental current quantity and the incremental voltage quantity, to select an applicable loop quantity, and to declare a fault based on the applicable loop quantity, the incremental voltage quantity, and the incremental current quantity. A protective action subsystem may implement a protective action based on the declaration of the fault.

Abstract: The present disclosure pertains to systems and methods for detecting faults in an electric power delivery system. In one embodiment, system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions. The system may also include an incremental quantities subsystem configured to calculate an incremental current quantity and an incremental voltage quantity based on the plurality of representations. A fault detection subsystem may be configured to determine a fault type based on the incremental current quantity and the incremental voltage quantity, to select an applicable loop quantity, and to declare a fault based on the applicable loop quantity, the incremental voltage quantity, and the incremental current quantity. A protective action subsystem may implement a protective action based on the declaration of the fault.

Abstract: Distance protection of electric power delivery systems are disclosed herein where a fault within a zone of protection is detected using time-domain fault detection supervised by frequency-domain fault detection. The distance fault detection may be asserted when the real or imaginary parts of the time-domain operating and polarizing quantities are both positive or both negative and an angle between the frequency domain operating and polarizing quantities is within a predetermined range. Additional security may be provided using a level check, a sign consistency check, or a disturbance detector.

Abstract: Distance protection of electric power delivery systems are disclosed herein where a fault within a zone of protection is detected using time-domain fault detection supervised by frequency-domain fault detection. The distance fault detection may be asserted when the real or imaginary parts of the time-domain operating and polarizing quantities are both positive or both negative and an angle between the frequency domain operating and polarizing quantities is within a predetermined range. Additional security may be provided using a level check, a sign consistency check, or a disturbance detector.

Abstract: A single-ended traveling wave fault location estimation is calculated using this disclosure, and a confidence level is determined based on available independent fault location estimations. Hypothesis are calculated based on traveling wave times and values, wherein the values indicate a polarity that is the same as the first received traveling wave. Hypothesis are then compared against results of other fault location estimations, and confidence levels assigned accordingly. The fault location is then calculated and displayed based on the hypothesis and confidence levels.

Abstract: The present disclosure relates to determining locations of low-energy events on power lines. For example, an IED may receiving an input signal indicating a local electrical condition of a power line. The IED may detect traveling waves on the power line based on the local electrical condition. The IED may detect traveling waves on the power line based on the local and remote electrical conditions. The IED may determine that the traveling waves are associated with a low-energy event. The IED may determine the location of the low-energy event on the power line based at least in part on the traveling waves.

Abstract: The present disclosure pertains to systems and methods for obtaining and processing high-frequency electric power system measurements for control and monitoring of an electric power system. High-frequency measurements may be used to detect traveling waves and/or to detect faults in the electric power system. In various embodiments, a processing device may receive high-frequency electric power system measurements from each of a local location and a remote location and may process the high-frequency electric power system measurements to identify and locate a fault. The occurrence of and location of a fault and may be used to implement protective actions to remediate identified faults.

Abstract: A testing system for imposing a traveling wave signal on an electric power system signal for testing a fault detector is disclosed herein. The testing system may be configured to simulate a fault at a simulated location by controlling the timing of the traveling wave signal. The testing system may be configured to impose multiple traveling wave signals to test the accuracy of the fault location determined by the fault detector. The testing system may be configured with multiple testing apparatuses using time coordination and referenced to an intended fault instant. The testing system may be configured to supply traveling waves of different polarities to test for different fault type detection.

Abstract: The present disclosure pertains to systems and methods for supervising protective elements in electric power systems. In one embodiment, a system may be configured to selectively enable a protective action an electric power system. The system may include a data acquisition subsystem receive a plurality of representations of electrical conditions associated with at least a portion of the electric power delivery system. An incremental quantities module may calculate incremental quantities from the plurality of representations. The system may be configured to detect an event, to determine an incremental quantities value during the event, and to determine a time-varying threshold. The incremental quantities value during the event may be compared with the time-varying threshold, and a protective action module may be enabled to implement a protective action when the value of the incremental quantities value during the event exceeds the time-varying threshold.

Abstract: The present disclosure relates to a fault in an electric power delivery system. In one embodiment, a system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions associated with at least a portion of the electric power delivery system. A traveling wave detector may be configured to detect a traveling wave event based on the plurality of representations of electrical conditions. A traveling wave directional subsystem may be configured to calculate an energy value of the traveling wave event during an accumulation period based on the detection of the traveling wave by the traveling wave disturbance detector. A maximum and a minimum energy value may be determined during the accumulation period. A fault direction may be determined based on the maximum energy value and the minimum energy value. A fault detector subsystem configured to declare a fault based on the determined fault direction.

Abstract: The present disclosure pertains to detection of a broken conductor in an electric power system. In one embodiment, a broken conductor detector may be configured to be mounted to an electrical conductor and may comprise a communication subsystem configured to transmit a signal configured to indicate that the conductor is broken. A sensor may determine an operating vector. A processing subsystem may be configured to receive the operating vector from the sensor and to identify when the operating vector is outside of a range defined by a rest vector and a threshold value. In certain embodiments, the threshold may comprise a three-dimensional sphere. The processing subsystem may determine that the conductor is broken based on the operating vector remaining outside of the range for a period of time determined by the timer subsystem. A signal may be transmitted by the communication subsystem to indicate that the conductor is broken.

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: A single-ended traveling wave fault location estimation is calculated using this disclosure, and a confidence level is determined based on available independent fault location estimations. Hypothesis are calculated based on traveling wave times and values, wherein the values indicate a polarity that is the same as the first received traveling wave. Hypothesis are then compared against results of other fault location estimations, and confidence levels assigned accordingly. The fault location is then calculated and displayed based on the hypothesis and confidence levels.

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, 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.