The present disclosure relates to spectral analysis in wireless current sensors. For example, a wireless current sensor (WCS) includes current transformer windings that harvest electrical energy from a power line and allow the WCS to obtain current measurements of the power line. The WCS includes a processor that obtains the current measurements of the power line via the current transformer windings. The processor generates a frequency domain representation of the current on the power line using the current measurements. The processor sends a wireless signal indicating results from the frequency domain representation to an intelligent electronic device (IED) that monitors the power line to allow the TED to analyze the results for anomalies.

A method for monitoring energy-related data in an electrical system includes processing energy-related data from or derived from energy-related signals captured by at least one intelligent electronic device in the electrical system to identify at least one variation/change in the energy-related signals. The method also includes determining if the at least one identified variation/change meets a prescribed threshold or thresholds, and in response to the at least one identified variation/change meeting the prescribed threshold or thresholds, characterizing and/or quantifying the at least one identified variation/change. Information related to the characterized and/or quantified at least one identified variation/change is appended to time-series information associated with the energy-related data, and characteristics and/or quantities associated with the time-series information are evaluated to identify at least one potential load type associated with the characterized and/or quantified at least one identified variation/change.

Systems and methods for managing voltage event alarms in an electrical system are provided. In one aspect of this disclosure, a method for managing voltage event alarms in an electrical system includes processing electrical measurement data from, or derived from, energy-related signals captured by at least one intelligent electronic device (IED) to identify an anomalous voltage condition at a point of installation in the electrical system. The anomalous voltage condition may correspond, for example, to a measured IED voltage being above or greater than one or more upper alarm thresholds or below or less than one or more lower alarm thresholds. The method also includes determining if the electrical system is affected by the identified anomalous voltage condition. In response to determining that the electrical system is affected by the identified anomalous voltage condition, at least one of a plurality of criteria may be chosen to adjust at least one of the upper alarm thresholds and/or at least one of the lower alarm thresholds.

A fault interrupting switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to a transformer interface and the movable terminal is electrically coupled to a connector interface. A control rod is coupled to the movable terminal and an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. An electronics assembly electrically is coupled to the movable terminal, and includes a high voltage capacitor and an energy storage capacitor, where the high voltage capacitor provides power to operate the actuator when the vacuum interrupter is open and the energy storage capacitor provides power to the electronics assembly when the vacuum interrupter is closed.

A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first recloser connected to one end of the power line and a second recloser connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where power is provided to both ends of the power line through the first and second reclosers and one of the switching devices is a normally open switching device. The method includes detecting overcurrent by some of the switching devices, detecting loss of voltage by some of the switching devices and sending clear to close messages to some of the switching devices to open and close certain ones of the switching devices to isolate the fault.

A transformer assembly including a transformer that is part of an underground residential power distribution circuit and that provides fault isolation and restoration. The transformer assembly includes an enclosure enclosing a primary winding and a secondary winding. The transformer assembly also includes first and second switching devices mounted to a panel of the enclosure, where each switching device includes an outer housing, a transformer interface electrically coupled to the primary winding, a connector interface electrically coupled to a first connector and a vacuum interrupter having a fixed contact and a movable contact. The fixed contact is electrically coupled to the connector interface or the transformer interface and the movable terminal is electrically coupled to the other connector interface or the transformer interface.

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first end switch connected to one end of the power line and a second end switch connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where source power is provided to both ends of the power line through the first and second end switches and one of the switching devices is a normally open switching device. The method includes detecting overcurrent in the network from the fault, opening certain ones of the switching devices in response thereto, detecting loss of voltage as a result of the open switching devices and opening or closing certain ones of the switching devices to isolate the fault.

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.