The invention relates to a member (O1) for measuring a magnitude representative of a common mode voltage (V.sub.res) in an electrical network (1) or in an equipment (E), the network (1) or the equipment (E) comprising at least one first power conductor (C1) and a second power conductor (C2). The measuring member (O1) comprises a sensor formed by two resistive elements (R1, R2) which are intended to be arranged in a bridge between the two power conductors (C1, C2) and have resistance values which are identical to each other. The two resistive elements (R1, R2) are connected at a midpoint (T3). The sensor also comprises a measuring dipole (SH) connected to the midpoint (T3) and to a connection terminal intended to be electrically connected to a common conductor (Cc), of which the electrical network (1) or the equipment (E) has been equipped.

A technique and a system are used to analyze incremental quantities. The instantaneous electrical measurements associated with a loop in a multiple-phase electric power delivery system are obtained before a fault occurred on the loop and after the same fault occurred on the same loop, and differences between the instantaneous electrical measurements at different times are used to determine incremental quantities, which are used to determine a location of the fault on the loop. Multiple loops in the multiple-phase electric power delivery system are monitored to determine corresponding fault locations on each loop.

Disclosed are various embodiments for unsupervised power-line event location within a power-line network. In one embodiment, e-field measurements are received from a plurality of line-mounted sensors located on one or more power lines in the power-line network. The e-field measurements to voltage approximations. A feeder model of the power line network is constructed based at least in part on the voltage approximations. An event within the power-line network is identified. A location of the event is identified based at least in part on the feeder model.

A method for detecting an isolation fault in an electrical installation comprises: measuring an AC electrical voltage between phase conductors of an electrical load to be monitored and ground, and an electric fault current flowing between said electrical load and ground; identifying, in the measured electrical voltage, at least one first component oscillating at the predefined first frequency and one second component oscillating at the predefined second frequency; calculating an impedance of the electrical fault from the measurements and an impedance of the electrical installation from the identified first and second components; selecting a predetermined case from a predefined list; and identifying an operating condition of the electrical installation on the basis of the selected predetermined case.

Embodiments of the present disclosure may enable an electrical component within an electrical distribution equipment cabinet to be audibly monitored via an electrical fault detection device mounted on the housing of the cabinet. The electrical fault detection device may comprise a senor to detect a signal emitted from an electrical fault within the cabinet, a transducer to convert the detected signal into an electrical audio signal, and an output socket adapted for an external device that may generate an audible sound based on the detected signal. The detected sensor may be an ultrasound sensor and the detected signal may be an ultrasound emitted from the electrical fault.

A member for measuring a variable representative of a common mode voltage in an electrical network a device. The network or the device includes at least a first power conductor and a second power conductor. The measuring member has two capacitive elements which are intended to be arranged in a bridge between the two power conductors and have capacity values that are identical to each other. The two capacitive elements are connected at a midpoint. The measuring member also includes a two-terminal measurement circuit connected on the one hand to the midpoint and on the other hand to a connection terminal intended to be electrically connected to a common conductor provided in the electrical network or device.

A method identifies a location of a fault on a faulty line of an electrical power supply network having a plurality of lines, a plurality of inner nodes, and at least three outer nodes. The outer nodes each bound a line and are provided with measurement devices which are used to measure high-frequency current and/or voltage signals. To locate faults, one of the outer nodes is selected as the starting node for the search for the fault location. Starting from the starting node, paths to the other outer nodes are determined, and that those paths on which the fault location could be located are selected. A line on which the fault location could be located, in principle, is identified for each of the selected paths using the respective times at which the traveling waves arrive, and a potential fault location is determined for the respectively identified line.

A sensor device for testing electrical connections using contactless fault detection is disclosed. The sensor device includes: a surface coil comprising a plurality of concentric loops disposed at a first region located away from the electrical connections. The concentric loops generate a first magnetic field passing through the electrical connections, and the first magnetic field is equivalent to that generated by a coaxial intermediate current loop adjacent to the electrical connections based on an excitation current in the surface coil. The sensor device further includes a sensor adapted to detect a second magnetic field at a second region located away from the electrical connections, wherein variations in the detected second magnetic field provide categories of performance of the electrical connections.

A method of detecting a serial arc fault in a DC-power circuit includes injecting an RF-signal with a narrow band-width into the DC-power circuit and measuring a response signal related to the injected RF-signal in the DC-power circuit. The method further includes determining a time derivative of the response signal, analyzing the time derivative, and signaling an occurrence of a serial arc fault in the power circuit based on the results of the analysis. A system for detecting an arc fault is configured to perform a method as described before.

In the fault diagnosis method, apparatus, and computer device, the method includes acquiring line voltage values in real time according to a voltage collector connected to phase lines (S100); according to the line voltage values and preset system parameters, obtaining a voltage peak balance degree and a phase angle offset of the three-phase power grid (S200); and obtaining a fault diagnosis result according to the voltage peak balance degree and the phase angle offset (S300). In such a way, a real-time diagnosis operation of whether a three-phase power grid is balanced can be implemented only by performing on-line calculation and analysis on line voltage values, which has simple analysis operation to reduce the system complexity; and only a voltage collector is added, and no other hardware costs are required, moreover high diagnosis reliability is obtained.