A method for detecting faults (4) in a three-phase electrical distribution network comprising determining a zero sequence current (21 C), a first phase current (21A) and a second phase current (21 B) at a location of the three-phase electrical distribution network, determining first filtered currents (22) by removing a frequency component from the determined currents corresponding to a fundamental frequency of the electrical distribution network through filtering out said frequency component, determining directions of the first filtered currents during a first time period (23), and comparing said directions (24) relatively to each other, and, if at least one of the determined directions is opposite with respect to at least one of the other two determined directions, signaling a detection of a fault (25).

The present embodiments are directed to locating electrical faults in an electrical circuit, in particular electrical faults in transmission wires of an electrical circuit. Examples of the present embodiments provide a method and apparatus for opening a switch in the electrical circuit to cause an open circuit or discontinuity at the fault; transmitting a signal to be reflected from the open circuit or discontinuity and receiving the signal reflected from the open circuit or discontinuity to determine the location of the fault. Examples are particularly suitable for high voltage systems, for example over 100V.

A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

Systems, methods, and devices of the various embodiments enable the detection and localization of power line corona discharges and/or electrical arcs by an unmanned aerial vehicle (UAV) including an array of ultraviolet (UV) point detectors.

Embodiments of the disclosure relate to detecting turn-to-turn faults in one or more windings of various objects. In one implementation, a fault detector uses a differential protection algorithm to detect a turn-to-turn fault in a winding of a three-phase shunt reactor. Various voltage and current measurements carried out upon the three-phase shunt reactor are used to calculate a difference value between a voltage-based parameter and a current-based parameter. The voltage-based parameter is indicative of a normalized negative voltage imbalance and the current-based parameter is indicative of a normalized negative current imbalance. A turn-to-turn winding fault is declared when the difference value is not equal to zero.

System and method for monitoring the condition of electricity conductor support systems, i.e. towers, in a power network distribution system employing a tower structure integrity sensor assemblage. The system allows for identifying particular portions of a structural system for maintenance attention. The tower sensors allow identification of structural failures of electricity transmission towers.

Embodiments of the disclosure relate to systems and methods for determining a fault location in a three-phase series-compensated power transmission line system by using symmetrical components-based formulas that describe various voltage and current relationships in the three-phase series-compensated power transmission lines during a fault condition. Furthermore, the systems and methods for determining the fault location in accordance with certain embodiments of the disclosure can eliminate one or more of a need to calculate an impedance value of any of the series capacitors or the series capacitor protection elements that are a part of the three-phase series-compensated power transmission line system, a need to monitor any of the series capacitor protection elements, and a need to measure a voltage drop across any of the series capacitors.

In the field of power transmission networks, particularly high voltage direct current (HVDC) power transmission networks, there is provided an electrical assembly (10). The electrical assembly (10) comprises a converter (12) that includes at least one AC terminal (14A, 14B, 14C) for connection to an AC network (16) and at least one DC terminal (18, 22) which is operatively connected to a DC power transmission medium (20, 24). The electrical assembly (10) also includes a signal injection circuit (32) which is operatively coupled with at least one DC power transmission medium (20, 24). The signal injection circuit (32) includes a signal generator (38) to selectively inject a plurality of different frequency signals into the said at least one transmission medium (20, 24). In addition the signal injection circuit (32) includes a signal analyser (42) to establish a response signature of the said at least one transmission medium (20, 24) to the plurality of different frequency injected signals. The signal injection circuit (32) also includes a control unit (46) that is programmed to detect a dielectric breakdown in the said at least one transmission medium (20, 24). More particularly the control unit (46) is programmed to control the signal generator (38) to inject a plurality of different frequency signals into the said transmission medium (20, 24), retrieve the corresponding response signature of the said transmission medium (20, 24) from the signal analyser (42), and compare the response signature to a plurality of reference signatures corresponding to dielectric breakdown and non-breakdown conditions in the said transmission medium (20, 24).

In one embodiment, an apparatus comprises an input power interface for receiving input power, a power control system for transmitting DC (Direct Current) pulse power on multiple phases over a cable to a plurality of powered devices and verifying cable operation during an off-time of pulses in the DC pulse power, and a cable interface for delivery of the DC pulse power on the multiple phases and data over the cable to the powered devices. A method for transmitting multiple phase pulse power is also disclosed herein.

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.