Implementations of ground fault circuit interrupter (GFCI) self-test circuits may include: a current transformer coupled to a controller, a silicon controlled rectifier (SCR) test loop coupled to the controller, a ground fault test loop coupled to the controller, and a solenoid coupled to the controller. The SCR test loop may be configured to conduct an SCR self-test during a first half wave portion of a phase and the ground fault test loop may be configured to conduct a ground fault self-test during a second half wave portion of a phase. An SCR may be configured to activate the solenoid to deny power to a load upon one of the SCR self-test or the ground fault self-test being identified as failing.

A computer implemented method, a fault detection and management system and a computer program product for managing an open circuit fault on an overhead line in a power network, are provided, that include obtaining overhead line data from a sensor mounted on the overhead line, determining fault detection parameters associated with one or more nodes of the overhead line on occurrence of a predefined node condition, that is, a low voltage and a negative rate of change of line current at the one or more nodes, and generating an output based on the fault detection parameters, wherein the output indicates potential presence of an open circuit at one or more nodes.

Described herein are methods and systems for detecting electrical discharges that precede electrical fires in electrical wiring. One or more sensor devices coupled to a circuit detect one or more signal waveforms generated by electrical activity on the circuit. The sensor devices identify one or more transient signals within the one or more signal waveforms, and generate one or more transient characteristics based upon the identified transient signals. A server communicably coupled to the sensor devices receives the one or more transient characteristics. The server analyzes the one or more transient characteristics to identify one or more electrical discharge indications. The server generates one or more alert signals when one or more electrical discharge indications are identified.

The present document describes an assembly for connecting a test unit to a wiring harness or equipment to be tested, and a method for testing using the assembly. The assembly may comprise a test box unit, a generic mate-in interface, an intermediate mate-in interface and at least one specific mate-in interface. The intermediate mate-in interface comprises an input/output connector connected between the generic-to-intermediate connector and the intermediate-to-specific connector, for enabling at least one of inputting a signal into the intermediate mate-in interface and outputting a signal from the intermediate mate-in interface. The assembly is used for performing tests on the equipment using at least one of a device adapted for generating a signal and a device adapted for measuring at least one attribute of a signal or circuit which is/are connected to the input/output connector of the intermediate mate-in interface.

Disclosed is a system that reduces fault currents in a power grid, thereby reducing the risk of unintentionally igniting a fire when an object comes in proximity to a high voltage power line. The circuit comprises an isolation transformer, a neutral connection, a current compensating device, and an automatic recloser or other circuit interrupting type protection system. The isolation transformer may comprise a delta-delta or delta-zigzag transformer with a one-to-one ratio between the input and output voltages and phase angle. The current compensating device is connected to the neutral and configured to redirect a substantial portion of a fault current to ground through the isolation transformer neutral instead of the fault itself. The current compensating device may comprise an arc suppression coil tuned to match the capacitance of the three phase outputs, or an inverter.

A method for locating and clearing phase faults in a micro-grid in off-mode. The method includes determining a surveillance area of a microgrid having at least two busbars to monitor; determining all source feeders and load feeders of the surveillance area; acquiring measurement data comprising current magnitude for all source feeders and load feeders; and monitoring the at least two busbars in the surveillance area for a voltage dip in one of phase-to-phase or phase-to-neutral voltages. The method further includes, on detecting a voltage dip on the monitored busbars, determining a defect phase having a minimum phase-to-neutral voltage; and performing current analysis for the defect phase.

A method for characterizing power quality events in an electrical system includes deriving electrical measurement data for at least one first virtual meter in an electrical system from (a) electrical measurement data from or derived from energy-related signals captured by at least one first IED in the electrical system, and (b) electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system. In embodiments, the at least one first IED is installed at a first metering point in the electrical system, the at least one second IED is installed at a second metering point in the electrical system, and the at least one first virtual meter is derived or located at a third metering point in the electrical system. The derived electrical measurement data may be used to generate or update a dynamic tolerance curve associated with the third metering point.

A method and system is disclosed for identifying a location of an event in a power distribution network. The method includes receiving voltage and current flowing downstream and upstream of the distribution feeder from at least two distribution-level phasor measurement units (PMUs) installed on a distribution feeder in the power distribution network; calculating changes in forward nodal voltages along the distribution feeder using measurements from at least one PMU of the at least two distribution-level PMUs; calculating changes in backward nodal voltages along the distribution feeder using the measurements from another PMU of the at least two distribution-level PMUs; comparing the calculated changes in the forward nodal voltages to the calculated changes in the backward nodal voltages; and determining the location of the event based on the comparison of the calculated changes of the forward nodal voltages to the calculated changes backward nodal voltages.

A device, which may be embedded in a power distribution enclosure, enables analysis of the conditions of an electromechanical machine operating on a commonly supplied network with other electromechanical machines. The analysis preferably uses aggregate operating voltage and current signals supplied to or from such machines along with known changes in steady-state conditions of one or more machines to discern the discrete effect of one or more machines to the aggregate electrical signal. Such discrete effect can then be associated with the operating performance of the individual machine. And, since such voltage and current signals are normally readily available at the enclosure, wiring or any other communication means to any sensors on the electromechanical machines or devices are not necessary. The embedded device may optionally receive or transmit information to a computing or monitoring device remote from the enclosure.

High impedance fault (HIF) detection and location accuracy is provided. An HIF has random, irregular, and unsymmetrical characteristics, making such a fault difficult to detect in distribution grids via conventional relay measurements with relatively low resolution and accuracy. Embodiments disclosed herein provide a stochastic HIF monitoring and location scheme using high-resolution time-synchronized data in micro phasor measurement units (μ-PMUs) for distribution network protection. In particular, a fault detection and location process is systematically designed based on feature selections, semi-supervised learning (SSL), and probabilistic learning.