Schweitzer Engineering Laboratories, Inc.

Angelo D'Aversa

Veselin Skendzic

Sreenivas Dingari

Marcos A Donolo

Greg Rzepka

Subhash C Patel

Vinod K Yedidi

Chandrasekaran Swaminathan

James R Kesler

Jay Hartshorn

Robert I Jayne

Scott M Manson

Gabriel Benmouyal

Mark L Zeller

Gary W Scheer

Thomas Allen Stanley

Jianchun Qin

Anushka M Dissanayake

Matthew J Howell

Pallavi Kulkarni

Brian R Clark

Hamza Abubakari

Man Lung Lee

Hang Li

Balaji Janarthanan

Jyotsna Samhita Gokavarapu

Signal transducers in electrical communication with shorted leads of current transformers are used to provide monitoring and protection functions to an electric power delivery system. Differential protection is performed by comparing a predetermined threshold against a voltage signal from series-connected leads of signal transducers in electrical communication with shorted leads of current transformers. The signal transducers may be Rogowski coils. Signal transducers in communication with shorted leads may be used to improve safety and increase performance of the current transformers by decreasing susceptibility to saturation.

Differential protection using instrument transformer signal transducers

Systems, devices, and methods include protection functions in an electrical power system. A processing subsystem may include a processor. A memory subsystem may comprise a first memory section and a second memory section. A memory management subsystem may, in a first operational mode, enable memory access between the processor and the first memory section and the second memory section and, in a second operational mode, enable memory access between the processor and only the first memory section.

Isolation of protection functions in electrical power systems

Systems, devices, and methods include protection functions in an electrical power system. For example, a processing subsystem may include a processor. A memory subsystem may comprise a first memory section and a second memory section. A memory management subsystem may enable memory access only between the processor and only the first memory section to initialize the at least one protection function and, after initialization of the at least one protection function, enable memory access between the processor and the second memory section. Such a configuration may enable the protection functions as fast as possible without waiting for the functions of lesser criticality to be fully loaded and become operational.

Isolation of protection functions in electrical power systems during startup

The present disclosure relates to systems and methods for processing a stream of messages in an electric power system (EPS). In one embodiment, a system may include a configuration subsystem to receive a plurality of criteria from an operator to identify a subset of the stream of messages for real-time processing. A receiver subsystem may identify the subset of the stream of messages based on at least one criterion from the plurality of criteria. A real-time processing subsystem may receive the subset of the stream of messages from the receiver subsystem, process the stream of messages within a fixed interval of a time of receipt, and update a value based on information in the processed stream of messages. A protective action subsystem may implement a protective action based on information in the processed stream of messages.

Messaging in an electric power system

A method includes receiving electrical measurements of an input signal of a power system. The method includes determining an estimated frequency of the power system using a rate of change of phase of the power system and using zero crossings of the power system. Selection between using the rate of change of phase of the power system and using zero crossings of the power system is based on a comparison between an estimated phase angle and a measured phase angle of the power system.

Frequency measurement for load shedding and accurate magnitude calculation

A multilingual power system protection device to facilitate communications in different human languages over different communication ports is described herein. In one embodiment, an electric power system device may include communication ports configured to receive inputs in different human languages and a monitored equipment interface in communication with a component of an electric power system. The electric power system device may receive an input on one of the communication ports and may associate the input with a function implemented by the component of the electric power system. The electric power system device may further generate a response in a pre-selected human language, and may transmit the response using the communication ports.

Multilingual power system protection device

The present disclosure relates to systems and methods for detection of a failed communication link and rerouting network traffic around the failure. One embodiment of a system consistent with the present disclosure may comprise a communication subsystem in communication with the data network and configured to transmit information to a recipient. The system may also include a confirmatory signal subsystem configured to generate a confirmatory signal. The confirmatory signal may be inserted into a stream of data to be transmitted to the recipient through a first communication path. Upon detection of a disruption in the confirmatory signal, a failover subsystem configured to reroute the stream of network data to be transmitted to the recipient through a second communication path. The second communication path may comprise one or more physical connections in the network that are distinct from the first communication path.

Communication link monitoring and failover

Monitoring thermal conditions of an electric motor using current signals from power supplied to the motor is disclosed herein. The current signals may be used to calculate composite current values which may be used to calculate slip. The slip may be used to provide thermal monitoring and protection to the electric motor. Slip may be calculated using only values from the stator of the electric motor for providing thermal monitoring and protection to electric motors where rotor measurements are not available.

Electric motor thermal protection using stator current measurements

Disclosed herein are various embodiments of devices and related methods for detecting an electrical arc event using a motor management relay and for suppressing the electrical arc event. The motor management relay may incorporate an optical arc-flash sensor configured to detect an optical event. Control logic may analyze the optical event and determine whether the optical event corresponds to an electrical arc event. When an electrical arc event is detected an instruction may be issued via a control port in communication with the control logic to implement a protective action. According to various embodiments, a plurality of sensors for monitoring electrical characteristics of a motor may also be in communication with the control logic. Input from the sensors may be analyzed in order to determine whether the optical event corresponds to an electrical arc event.

Motor relay with integrated arc-flash detection

An arc flash validation unit may generate stimulus to be received by an arc flash detection unit (AFDU) and observe the response of the AFDU thereto. The response of the AFDU to the stimulus may allow for validation of the AFDU (e.g., validation that the AFDU is operating as expected). In addition, the arc flash validation unit may determine the response time of the AFDU. Different types of stimulus may be provided to the AFDU, including electro-optical (EO) stimulus (e.g., visible light), current stimulus, and the like. Results of the validation may be displayed on a human-machine interface, which may display an estimate of the total energy that would be released in an actual arc flash event. The estimate may be used to define appropriate safety parameters for the equipment monitored by the AFDU.

Validation of arc flash detection systems

Independent frequency measurement and tracking of a signal using a measurement interval where the frequency of the signal is measured and a sampling rate is calculated, and a settling interval where the frequency of the signal is not measured. The sampling rate is calculated to correspond with the frequency of the signal and updated only after the calculation of the sampling rate in the measuring interval. The signal may be a signal of an electric power system such as a voltage waveform or a current waveform. The frequency calculation may include determination of a rate of rotation of a positive-sequence phasor of the signal.

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Ambler, PA, United States of America

Angelo D'Aversa