A method for classifying a partial discharge in an insulator of an electrical conductor of a medium voltage or high voltage electrical device, the method allowing a partial discharge to be classified from between at least one first class and a second class distinct from the first class. The method includes: obtaining a set of samples each corresponding to at least one partial discharge, determining a classification model by automatic learning based on at least one statistical quantity of the samples of the set, acquiring a new sample corresponding to at least one partial discharge, and determining the class of the partial discharge associated with the new sample acquired using the classification model.

A load test device includes: a resistor unit that includes a plurality of resistors that receive supplied power and a wall (holding frame) that holds opposite ends of each of the plurality of resistors; and an insulating cap that is attached to a portion of a terminal of the resistor that protrudes from the wall. The cap is composed of a material that is deformed by heat. When a temperature of the terminal becomes equal to or higher than a first temperature, the cap is deformed by heat and detached from the terminal.

Methods and locating systems for determining an insulation fault location on an electric conductor of a subsea supply line are provided. By applying electric voltage on the electric conductor, an electrochemical reaction takes place at an insulation fault location between the metallic conductor material and the seawater, said electrochemical reaction forming gas, which in turn is connected to developing noise. Sonic sensors capture the sonic waves produced thereby within and without of the subsea supply line and evaluate the measuring signals in order to determine the insulation fault location. Alternatively or additionally to capturing noise, the gas-bubble image patterns occurring at the insulation fault location are optically captured and consulted in order to determine the insulation fault location.

A partial discharge determination method and apparatus, and a partial discharge determination system capable of indicating how much margin is left before dielectric breakdown, in a lighting impulse withstand voltage test, and a power device for which whether partial discharge is caused is determined by them, and a method for manufacturing a power device including the partial discharge determination method. A low-pass filter receives an acoustic signal resulting from application of an impulse voltage and acquired by an acoustic emission sensor, and removes an electromagnetic noise superimposed on the acoustic signal. A mechanical oscillation removal unit removes a mechanical oscillation component of a device under test, from the acoustic signal resulting from application of the impulse voltage which is a high voltage, based on the mechanical oscillation component acquired in advance and included in the acoustic signal resulting from application of the impulse voltage which is a low voltage.

An electrical device (10, 13), in particular a power transformer (13), a shunt reactor, or an on-load tap changer (10), comprises a housing (101, 131) that is filled or fillable with insulation oil (11, 11′); and a sensor (12) that comprises a piezo element (16) in the housing (101, 131) on a level with a minimum fill level (19, 19′) of the insulation oil (11, 11′); and an evaluation device (18) that is connected to the piezo element (16); wherein the evaluation device (18) is formed such that it can induce an oscillation of the piezo element (16);
and it can determine the fill level from a measurement of a characteristic of the oscillation, in particular the half-life period of the amplitude of the oscillation.

Systems, methods, and apparatus for corona detection using audio data are provided. In one example embodiment, the method includes obtaining, by one or more computing devices, audio data indicative of audio associated with an electrical system for at least one time interval. The method includes partitioning, by the one or more computing devices, the audio data for the time interval into a plurality of time windows. The method includes determining, by the one or more computing devices, a signal indicative of a presence of corona based at least in part on audio data collected within an identified time window of the plurality of time windows relative to audio data collected for a remainder of the time interval.

The invention concerns a method and a system for detecting an electric arc in an electrical installation (7) equipped with at least one sensor (5) capable of detecting temporal acoustic signals produced by the electrical installation (7), said method being characterised in that it comprises a device for analysis (3) configured to analyse any temporal acoustic signal (5) coming from said one or more sensors (5) by associating with said acoustic signal a corresponding parsimony measurement (m) whose value indicates whether the acoustic signal is an electrical arc signature or not.

The invention relates to a DC electrical power supply source including a protective housing and electrical energy storage devices disposed in the protective housing. The storage devices are connected electrically in series by way of interconnection elements. There is an acoustic sensor configured to measure ultrasounds and a filling medium disposed in the housing. The filling medium exhibits a homogeneous acoustic impedance and forms a continuous acoustic link between the interconnection elements and the acoustic sensor.

The transformer fault detection apparatus includes an integrated sensor unit for sensing signals through a plurality of sensors located on each of upper and lower drain valves in a transformer. A first possible discharge area calculation unit calculates a first possible discharge area estimated to be a location of a partial discharge source of the transformer, based on arrival times of signals sensed by different sensors located on the upper drain valve. A second possible discharge area calculation unit calculates a second possible discharge area estimated to be the location of the partial discharge source, based on arrival times of signals sensed by different sensors located on the lower drain valve. A final possible discharge area calculation unit calculates a final possible discharge area, based on an overlapping area between the first and second possible discharge areas.

The present disclosure provides a method for detecting an electrical discharge in an electrical apparatus. The method includes sensing an electromagnetic wave using an electrical sensor and generating an electric signal for a predetermined time period, sensing an acoustic wave using an acoustic sensor and generating an acoustic signal for the predetermined time period. The acoustic sensor is associated with at least one compartment of the electrical apparatus. Electrical data is generated based on a quasi-periodic characteristic of electric peak sequences of the electrical signal. Acoustic data is generated based on a quasi-periodic characteristic of acoustic peak sequences of the acoustic signal, wherein the electrical data is combined with the acoustic data to provide an operation status of the at least one compartment.