Schweitzer Engineering Laboratories, Inc.

Schweitzer Engineering Labs, Inc.

Armando Guzman-Casillas

Mangapathirao Venkata Mynam

Edmund O Schweitzer, Iii

Bogdan Zdzislaw Kasztenny

Veselin Skendzic

David E Whitehead

Gabriel Benmouyal

Normann Fischer

Luther S Anderson

Gregary C Zweigle

Jeffrey B Roberts

Marcos A Donolo

Yanfeng Gong

Tony J Lee

Jorge Fernando Calero

Yajian Tong

Stanley E Zocholl

Hector J Altuve-Ferrer

Dale S Finney

Kei Hao

Casper A Labuschagne

Daqing Hou

Matchyaraju Alla

Tracey G Windley

Satish Samineni

Bai-Lin Qin

Richard M Edge

Ping Jiang

Joseph B Mooney

Peter S LaDow

Zachary King Sheffield

Ralph W Folkers

Charles E Petras

Naiden K Spasov

Luth R S Anderson

Gabriel B Nmouyal

Taylor Joseph Blanc

Mangaoathirao Venkata Mynam

Bogdan Z Kasztenny

Edmund O Iii Schweitzer

An electronic device includes input circuitry that obtains an input signal. The electronic device includes processing circuitry that has an integrating memory dropout (IMD) timer. The IMD timer generates an extended output signal that is asserted an extended amount of time that varies based at least in part on integration of the received input signal.

Integrating memory dropout timer

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.

Phase selection for traveling wave fault detection systems

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.

Detection of low-energy events in an electric power system

Protection devices prevent damage to synchronous generators during loss-of-field events. In various embodiments, a first protective element is associated with a first protection zone to protect a generator from a loss-of-field event at full load. A second protective element is associated with a second protection zone to prevent thermal overload during underexcited operation of the generator and to protect from loss-of-filed at light load. A third protective element associated with a third protection zone limits operation of the generator within the generator's specific steady-state stability limits. A fourth protective element is associated with a fourth protection zone to provide an alarm prior to operation of the second protective element. In various embodiments, characteristics and limits of each of the protective elements are defined in the same plane (specifically, the P-Q plane) to simplify settings and allow for visualization of the element characteristics and the generator capability curve at one or more temperatures or cooling capacities.

Generator loss-of-field protection

The present disclosure relates to directionality of events on line sensors for power lines. In an embodiment, a line sensor may include phase detection circuitry that detects a feature of an operating parameter of a power line prior to an occurrence of an event. The phase detection circuitry may provide a time associated with the feature. The line sensor may include sensor circuitry that sends an activation signal. The line sensor may include a controller that, upon receiving the activation signal, measures samples of the operating parameter. The line sensor may determine a relative direction of the event based on the plurality of times detected prior to the event and the measured samples of the operating parameter.

Event direction in line sensors

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.

Fault detection in electric power delivery systems using underreach, directional, and traveling wave elements

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.

Electric power fault protection device using single-ended traveling wave fault location estimation

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.

Testing system for traveling wave fault detectors

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.

Overcurrent element in time domain

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.

Detection of an electric power system fault direction using traveling waves

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.

Time-domain line differential protection of electric power delivery systems

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.

Time-domain differential line protection of electric power delivery systems

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.

Time-domain distance line protection of electric power delivery systems

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.

Traveling wave based single end fault location

Growing community of inventors

Pullman, WA, United States of America

Armando Guzman-Casillas