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.

The wide application of power electronic components in power systems with renewable energy sources has changed the fault characteristics of conventional power systems, resulting in the performance degradation of conventional protections. To solve these problems, a novel principle of pilot protection based on structural similarity and square error criteria is provided. The structural similarity criterion utilizes the difference of fault characteristics between renewable sources and synchronous generators to identify internal faults, and the square error criterion is used to solve abnormal calculation of the conventional similarity based protection. Compared with conventional differential protections, the disclosed protection shows excellent performance in speed and reliability during various faults.

The present disclosure relates to systems and methods of detecting discharge events on power lines. For example, a system may include an acoustic sensor that detects a sound wave emitted from a power line. The system may include a radio frequency (RF) sensor that detects a radio wave emitted from the power line. The system may include electrical sensor circuitry that detects an electrical parameter of power being delivered on the power line. The system may include a processor that determines that a discharge event has occurred based on the sound wave, the radio wave, and the electrical characteristic. The system may provide an output signal indicating that the partial discharge event has occurred.

A method for analyzing effects of electrical perturbations on equipment in an electrical system includes processing energy-related signals from at least one intelligent electronic device in the electrical system to identify an electrical perturbation in the electrical system. An end time of the electrical perturbation may be determined, and electrical measurement data from prior to, during and/or after the end time of the electrical perturbation may be analyzed to identify and quantify the effects of the electrical perturbation on equipment in the electrical system. The effects may include, for example, equipment restarts/re-energizations due to the electrical perturbation. One or more actions may be taken or performed to reduce the effects of the electrical perturbation and extend the life of the equipment. The actions may include, for example, at least one of communicating the equipment restarts/re-energizations and controlling at least one component in the electrical system.

Systems and methods for facilitating selected communications among primary protection relays using a supervisory system with a configurable input/output (IO) map. Primary protection relays may obtain signals from equipment associated with an electric power delivery system and provide primary protection without need for communication. The primary protection relays may communicate a unique identifier as well as signal values, states, and commands to the supervisory system. The supervisory system may route specifically identified communications among primary protection relays in accordance with a configurable IO map by transmitting selected portions of the communications on a port associated with the receiving primary protection relay. The primary protection relays may perform secondary protection and other operations using the communicated information.

A system for controlling a power distribution network providing power using a plurality of phases comprises an electronic processor and memory storing instructions that, when executed by the electronic processor, cause the system to receive a loss of voltage fault indication associated with a fault in the power distribution network. The electronic processor identifies a first subset of the plurality of phases associated with the loss of voltage fault indication and a second subset of the plurality of phases not associated with the loss of voltage fault indication. The first and second subsets each include at least one member. The electronic processor identifies a downstream isolation device downstream of the fault. The electronic processor sends an open command to the downstream isolation device for each phase in the first subset. The electronic processor sends a close command to a tie-in isolation device downstream of the downstream isolation device.