Examples of operating an Intelligent Electronic Device (IED) during power swings, are described. In an example, voltage measurements for a phase is received and sampled. Root mean square (RMS) values of the voltage samples is calculated based on the voltage measurements. Delta quantities for each phase are calculated based on the RMS values. Each of the RMS values and delta quantities are associated with respective sampling instants. In response to a delta quantity being greater than a predefined threshold, a peak delta quantity is detected. A time interval between a sampling instant associated with the peak delta quantity and a sampling instant associated with a first delta quantity is determined. Based on a comparison of the time interval with a threshold time, a disturbance condition may be detected as a power swing and consequently, fault detection at the IED may be blocked.

Techniques and apparatus presented herein are directed toward monitoring an electric power delivery system to detect and locate a power generation event. A power generation event may include a tripped generator, a loss of a transmission line, or other loss of power generation. To detect the event, an analysis engine may receive and monitor input data. A detection signal may be generated based on the input data. Upon detecting the event, the analysis engine may determine a source and propagation of the event through the delivery system. Based on the source and propagation of the event, the analysis engine may determine the location of the event. The analysis engine may generate an overlay with the input data to provide the location and other information about the event to a user such that remedial action can be taken to resolve the event and restore the lost power generation.

The present disclosure relates to systems and methods for protecting against and mitigating the effects of over-excitation of elements in electric power systems. In one embodiment, a system consistent with the present disclosure may comprise a point pair subsystem to receive a plurality of point pairs that define an over-excitation curve for a piece of monitored equipment. The system may receive a plurality of measurements corresponding to electrical conditions associated with the piece of monitored equipment. A logarithmic interpolation subsystem may determine a logarithmic interpolation corresponding to one of the plurality of measurements based on the plurality of point pairs. An over-excitation detection subsystem may detect an over-excitation condition based on the logarithmic interpolation, and a protective action subsystem may implement a protective action based on the over-excitation condition.

A circuit breaker comprises a solid-state bidirectional switch, a switch control circuit, current and voltage sensors, and a processor. The solid-state bidirectional switch is connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-on state and a switched-off state. The switch control circuit control operation of the bidirectional switch. The current sensor is configured to sense a magnitude of current flowing in an electrical path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage on the electrical path and generate a voltage sense signal. The processor is configured to process the current and voltage sense signals to determine operational status information of the circuit breaker, a fault event, and power usage information of a load connected to the load output terminal.

A voltage presence determination system intended to be connected to a voltage measurement sensor for at least one phase of a high-voltage electrical network. The system comprises, for the at least one phase: a visual indicator of the presence of a voltage measured by the voltage measurement sensor, referred to as the measured voltage, a first output terminal configured to receive a first output signal, a second output terminal configured to receive a second output signal, and a plurality of linear components. The system is configured so that the first and second output terminals are functionally isolated from one another and functionally isolated from the visual indicator only by the plurality of linear components.

A microgrid control system includes: a first intelligent electronic device to detect an open/closed state of a switch coupling a microgrid and a higher-ordered system; a protection relay to disconnect a consumer from the microgrid when detecting a fault current; and a second intelligent electronic device including protection relay-controlling circuitry to apply, to the protection relay, a set value according to at least the open/closed state of the switch, wherein the protection relay detects the fault current using the set value applied by the second intelligent electronic device.

Described herein are methods and systems for estimating an originating location of a power quality event in an electrical grid. Each of a plurality of sensor devices connected to the electrical grid detects an input signal generated by electrical activity on the electrical grid, generates an output signal based upon the detected input signal, and transmits power quality data to a computing device via a communications network, where the power quality data is based upon the output signal. The computing device is configured to analyze the power quality data from at least a subset of the sensor devices to determine a power quality event occurring in the electrical grid, estimate an originating location of the power quality event based upon the power quality data, and transmit a notification to one or more remote computing devices based upon the estimated originating location of the power quality event.

A method which allows for the quick and accurate detection of faulty operating conditions and bad interconnections between and within devices in an electrical system. The method allows for the detection of arcing in wiring and components, high resistance connections, loose components, and the like. Voltage or current at each end of a conductor, or on each side of a system component, or the current through a component, may be detected and analyzed. A fault or abnormal condition is indicated when the voltage or current exceeds an expected level. Alternatively, resistance may be detected and analyzed, and a fault condition indicated when the resistance exceeds an expected level. Existing detection or computation equipment already associated with the system may be used for the detection and analysis.

A measurement device that performs a predetermined measurement task together with a plurality of other measurement devices is provided. This measurement device is provided with a sampling phase generator for generating a sampling phase for instructing a timing of sampling, and a communication unit for communicating with at least one of the plurality of other measurement devices. The communication unit transmits the sampling phase generated by the sampling phase generator to at least one of the plurality of other measurement devices. The sampling phase generator is configured to generate a third sampling phase, using an operation that is based on a generated first sampling phase and a second sampling phase received by the communication unit from at least one of the plurality of other measurement devices.

A method of detecting a fault in a device is described. The method comprises receiving an energy consumption signal for the device, the energy consumption signal indicating a varying energy consumption of the device over time during operation of the device. A basis function is selected, the basis function defining a signal pattern associated with a known fault type. A correlation between the basis function and the energy consumption signal is evaluated. Presence of an operating fault in the device is determined in dependence on the correlation, and an output is generated based on the determination.