A node for detecting local anomalies in an overhead power grid having at least one power line. The node includes a processing unit and a memory, wherein the node further includes: an electric field sensor configured to measure a first parameter related to an electric field around the at least one power line, and a magnetic field sensor configured to measure at least second parameter related to a magnetic field around the at least one power line. The processing unit is configured to: compare the measured first parameter and at least second parameter with historic data stored in the memory to identify local anomalies, and forward data related to the identified local anomalies to a system controller via a communication interface.

A method for determining direction of an earth fault (EF) in a feeder of a high impedance grounded power system can be performed by an Intelligent Electronic Device (IED). The method includes obtaining a measure of a first order harmonic active current component derived from residual voltage and current of the feeder when the EF occurred in the feeder, obtaining a measure of a higher order harmonic reactive current component derived from the residual voltage and current of the feeder when the EF occurred in the feeder, and determining the direction of the EF in the feeder based on a combination of the first order harmonic active current component and the higher order harmonic reactive current component.

Disclosed is a reactance-injecting module and its method of use to balance the currents among the phases of polyphase electric power transmission lines or to manage power flow among alternate paths, where the reactance-injecting module has high-speed, dedicated communication links to enable the immediate removal or reduction of injected reactance from all phases of a phase balancing cluster when a fault is detected on any one of the multiple phases. The reactance-injecting module may communicate information on a detected fault to the other reactance-injecting modules of the phase balancing cluster within 10 microseconds after the fault is detected to allow the phase balancing cluster to eliminate injected reactance from all phases within a time that is short compared to a cycle of the alternating current, such as 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.

A system and method are provided for operating a power generating asset. Accordingly, a controller detects a fault condition impacting the power generating asset. The controller then determines whether the fault condition is occurring in the power generating asset or is occurring in the power grid. When the fault condition is occurring in the power generating asset, a first response control scheme is implemented. However, when the fault condition is occurring in the power grid, a second response control scheme is implemented. The response control schemes include a first current threshold and a second current threshold respectively, with first current threshold being less than the second current threshold. Additionally, a control action is implemented in response to an approach of a current to the respective current threshold.

Systems, apparatuses, and methods are described for operating and maintaining a data network, and for detecting problems such as signal leakage. In one implementation, a computing device may determine, based on availability and location, one or more mobile devices and may cause the mobile devices to detect a wireless signal. The detected wireless signal may be identified as having leaked from a network, such as a wired network, and used to detect the source of leaks.

An apparatus includes a mechanical switch and a solid-state switch, such as a diamond switch or antiparallel-connected thyristor pair, coupled in series between an AC source and the load, such as a substation input transformer. The control circuit may be configured to connect the AC power source to the load by closing the mechanical switch and turning on the solid-state switch thereafter. The control circuit may be configured to interrupt a connection of the AC source to the load by turning off the solid-state switch and closing the mechanical switch thereafter. Operations of the switches may be coordinated with a fuse coupled in series with the solid-state switch to address different types of fault conditions.

A testing apparatus for imposing a traveling wave signal on an electric system signal for testing a fault detector is disclosed herein. The fault detector may be configured to simulate a fault at a particular location by controlling the timing of the traveling wave signal. The testing apparatus may be configured to impose multiple traveling wave signals to test the accuracy of the fault location determined by the fault detector. The testing apparatus may be configured to determine the calculation accuracy of the fault detector. The testing apparatus may impose a traveling wave signal on a signal simulating an electrical signal on an electric power delivery system. The testing apparatus may be used to test capabilities of a fault detector of detecting a fault using traveling waves or incremental quantities.

A method for fault location and isolation in a power distribution network, where the network includes a plurality of switching devices provided along a feeder, and at least one of the switching devices does not have voltage sensing capabilities. The method includes detecting an overcurrent event in the network from the fault and interrupting the overcurrent event by opening and then immediately locking out or subsequently reclosing and testing the fault. A count value is increased in each switching device that detected the overcurrent event. A message is sent from each of the switching devices that detected the overcurrent event and then detected the loss of voltage upstream to an upstream neighbor switching device. Current measurements in the messages, measured current by the devices and the counts values in the devices determine what devices are opened to isolate the fault.

A sensor system for an electric power asset includes a sensor instrument coupleable to sensors associated with the electric power asset to receive sensor signals therefrom, and an antenna connection cable coupled to the sensor instrument. The antenna connection cable includes a cable sheath and a plurality of twisted pair signal carriers contained within the cable sheath to carry sensor signals received from the electric power asset. A first subset of the plurality of twisted pair signal carriers carry antenna signals and a second separate subset of the plurality of twisted pair signal carriers carry signals for partial discharge monitoring.

A method for locating a ground fault in an IT network which has a converter with a rectifier connected to a power transmission network, a DC link and an inverter connected to an electrical machine includes measuring a common-mode voltage property of the converter or of the power transmission network and comparing the common-mode voltage property with an output voltage property of an output voltage of the inverter. When the IT network experiences a ground fault, the comparison of the common-mode voltage property with the output voltage property is used to determine whether a machine area of the IT network connected downstream of the converter, which includes the electrical machine and a connecting line between the electrical machine and the converter, causes the ground fault.