Pullman, WA, United States

Schweitzer Engineering Laboratories

www.selinc.com/
Pullman, WA, United States

Schweitzer Engineering Laboratories, Inc. designs, manufactures, and supports products and services ranging from generator and transmission protection to distribution automation and control systems. Founded in 1982 by Edmund O. Schweitzer III, SEL shipped the world's first digital protective relay. Presently, the company designs and manufactures embedded system products for protecting, monitoring, control, and metering of electric power systems. E. O. Schweitzer Manufacturing, a manufacturer of fault indicators and sensors started by Edmund O. Schweitzer, Jr. in 1949, became a division of SEL in 2005. Wikipedia.

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Patent
Schweitzer Engineering Laboratories | Date: 2017-03-29

Electrical power machines are monitored according to the disclosure herein using time stamped mechanical conditions and electrical conditions. The mechanical conditions may include rotational position, calculated and time stamped rotational frequency, valve position, temperature, or vibration. The time stamped electrical conditions may include electrical power system frequency, electrical power machine field data, electrical power machine terminal information such as voltage and current, and the like. Electrical and mechanical time-stamped electrical power machine data from different machines that may be local or remote from each other may be compared for monitoring the machines.


Patent
Schweitzer Engineering Laboratories | Date: 2017-01-17

This disclosure relates to various embodiments of lockout relay devices. In one embodiment, a lockout relay device may transition between a closed position and a lockout position in response to an action of a deck device. The lockout relay may further be configured to transition from the lockout position to the closed position only in response to one of a manual adjustment and a reset operation. A manual actuator may permit a manual transition of the lockout relay device from the closed position to the lockout position and from the lockout position to the closed position. The lockout relay device may remain in the lockout position until the occurrence of one of a manual adjustment and a reset operation.


Patent
Schweitzer Engineering Laboratories | Date: 2017-01-26

The present disclosure provides systems and methods for identifying and reporting failures of an analog to digital (A/D) conversion system. The systems and methods may detect and report a problem of input circuitry of an A/D converter and/or an A/D converter itself. For example, an identifiable characteristic can be introduced into the input signal provided to an A/D converter. The A/D converter may output a digital value that includes the identifiable characteristic of the A/D converter input. A monitoring system may determine and/or report a change in, or a failure of, the A/D converter or input circuitry thereto, based on the identification, non-existence of, or variation in the identifiable characteristic in the digital output.


Patent
Schweitzer Engineering Laboratories | Date: 2017-08-16

The time signal verification and distribution device disclosed herein verifies and distributes a time signal to consuming devices. The device determines a time quality status of a first and second time signal, calculates a difference between a first and a second time signal, and compares the difference to a predetermined threshold. Based on the time quality status and the comparison, the time signal verification and distribution device distributes a time signal to a plurality of time signal consuming devices. Exceeding the predetermined threshold may indicate a spoofing attack or other problem with the time signals.


Patent
Schweitzer Engineering Laboratories | Date: 2017-04-26

The present application discloses detecting manipulation of GNSS signals using a second time source. If two or more GNSS constellation signals are being detected, the phase error between the GNSS constellation signals may be monitored. When the phase error drifts, then manipulation is determined. The integrity of a GNSS constellation signal may be monitored using an internal time source such as a crystal oscillator by monitoring a slope of the free running counter at the detected rising edges of a pulse-per-second signal from the GNSS constellation. If more than two GNSS constellations are monitored, a voting scheme may be used to determine the manipulated GNSS constellation.


The present disclosure pertains to systems and methods for detecting faults 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. A traveling wave differential subsystem may be configured to determine operating quantities and restraint quantities from the plurality of representations of electrical conditions. An incremental quantities subsystem configured to calculate an incremental current quantity and an incremental voltage quantity. A fault detector subsystem may be configured to declare a fault based on a comparison of the operating quantity and the restraint quantity. The 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. A protective action subsystem may implement a protective action based on the declaration of the fault.


Patent
Schweitzer Engineering Laboratories | Date: 2017-04-19

Systems and methods are disclosed that provide for managing transient assets used in connection with an access-controlled area of a distribution site of an electric power delivery system. In some embodiments, one or more users entering and access-controlled area may be identified via physical access control credentials provided to an associated access control system. Transient assets brought within an access-controlled area may be detected via one or more wired and/or wireless communication channels and may be associated with the one or more identified users located within the access-controlled area.


Patent
Schweitzer Engineering Laboratories | Date: 2016-09-19

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.


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.


Patent
Schweitzer Engineering Laboratories | Date: 2017-01-23

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.

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