The invention relates to a method, a device (10) and an arrangement (1) for monitoring alternating current electric apparatuses (3), like e.g. power distribution transformers. The inventive method relies on an inductor antenna (11, 11′) suitable to detect the electromagnetic field at the frequency of the alternating current the apparatus (3) to be monitored is supplied with arranged in the vicinity of but distant to the apparatus (3) to be monitored and comprises the steps: —Detecting the electromagnetic field radiated by the electric apparatus (3) to be monitored; —Digitizing the detected electromagnetic field to obtain EMF-data; —Running a Fast-Fourier-Transformation on the digitized EMF-data to obtain FFT-transformed data; and—Monitoring the magnitudes of the FFT-transformed data at least at the frequency of the alternating current the apparatus (3) to be monitored is supplied with and its third harmonic for anomalies. The inventive device (10) and arrangement (1) are configured to perform the inventive method.

An underwater storage tank having a flexible multilayer tank containing a working liquid is provided. The flexible multilayer tank has at least one internal electrical insulating layer in contact with the working fluid, at least one external electrical insulating layer in contact with sea water, and at least one intermediate electric conductive layer sealed between the at least one internal electrical insulating layer and the at least one external electrical insulating layer. At least one first electrical connection means is connected to the at least one intermediate electric conductive layer, the least one first electrical connection means being electrically connectable to an electrical grounded measurement instrument to assess physical integrity of the flexible multilayer tank.

Provided are an electrical tree test device for a silicone rubber material for a cable accessory and a method for preparing a sample. The method includes: adding a semi-conductive silicone rubber into xylene, performing spraying on a surface of a silicone rubber insulation sample sheet, performing a curing processing, cutting the sample sheet into a high-voltage electrode with a triangular longitudinal section end, then adhering the high-voltage electrode on the surface of the silicone rubber insulation sample sheet, and performing a high temperature vulcanization to obtain a silicon rubber sample sheet; placing the silicon rubber sample sheet into a mold, injecting a high temperature vulcanizable liquid silicone rubber mixture, and performing the high temperature vulcanization, to obtain a sample; and performing cutting at a position distanced from a tip of the high-voltage electrode by 2 mm, and adhering a ground electrode of a flat plate-like structure at the cross section/

An arc detection device includes: a current detector that includes a magnetic core penetrated by first and second paths and each connecting a DC power source and a device, and detects a current flowing through each of the first and second paths and in accordance with a magnetic field generated at the magnetic core; a low impedance circuit having a lower impedance than the DC power source and the device, the low impedance circuit being connected to the first path and the second path to cause a high frequency component to bypass one of the first path or the second path; and an arc determiner that determines an occurrence of an arc based on a current detected by the current detector. In the magnetic core, a direct current flows through the first path in a direction opposite to a direction in which a direct current flows through the second path.

An apparatus and method for identifying liner holidays, with a generator having two contacts with a liner and pulsing current to a moving one of the contacts. A plurality of detected electric signals are processed to continuously generate a baseline indicative of a holiday. A holiday signal is actuated when a signal is detected which when compared to the generated baseline indicates a holiday. A plurality of electric signal types and baselines, such as current strength and voltage, may be separately detected with a holiday signal actuated when either signal type is detected which when compared to its generated baseline indicates a holiday. The moving contact may be flexible to conform to contour of the liner.

A system may include a transformer that may convert a first voltage to a second voltage, such that the second voltage is output via a conductor. The system may also include a wireless current sensor that may detect current data associated with current conducting via the conductor and a processor. The processor may receive the current data, determine one or more temperature measurements associated with the transformer based on the current data, and send a signal to a component in response to the one or more temperature measurements exceeding one or more respective threshold values.

An insulation resistance inspection system for a battery module cell pouch for inspecting an insulation resistance state of a cell pouch in the battery module configured by assembling a plurality of battery cells includes: an inspection unit bringing each of a plurality of probe modules into contact with an end surface of the cell pouch to measure an insulation resistance of the cell pouch; an interface unit connected to the inspection unit to receive a signal for the measured insulation resistance of the cell pouch; and a control unit receiving the signal for the insulation resistance of the cell pouch through the interface unit to determine whether the cell pouch is in good condition or in poor condition depending on whether the signal for the insulation resistance of the cell pouch is within a normal range that is a reference of good quality.

A system for acoustically detecting dielectric breakdown of, or partial discharge within, or on, an electrical device includes at least one electroacoustic (EA) transducer configured to detect an acoustic vibration of the electrical device, and a controller electrically connected to the at least one EA transducer. The controller is configured to receive a signal from the at least one EA transducer, and analyze the signal to determine whether the signal includes data associated with an acoustic vibration in a frequency range of dielectric breakdown and/or partial discharge of the electrical device. The applicability of such a system includes, but is not limited to, electronic parts or assembly screening, life characterization testing for materials and processes, diagnostic methods or aides, augmenting testing of components, assemblies or systems, and in service monitoring to support preventative or condition based maintenance to avert an in-service issues.

An arc detection device includes: a low-impedance circuit connected between a node on wiring connecting the positive electrode of a DC/DC converter and a plurality of DC/DC converters, extending from the positive electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters and a node on wiring connecting the negative electrode of the DC/DC converter and the plurality of DC/DC converters, extending from the negative electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters; an electric current detector that detects an electric current flowing through the low-impedance circuit; and an arc determiner that determines, on the basis of the electric current detected by the electric current detector whether an electric arc has occurred.

An arc detection device includes a voltage detector connected between a first wire and a second wire to detect a voltage between the first wire and the second wire, the first wire connecting a positive electrode of a DC/DC converter and a plurality of DC/DC converters and branching from the positive electrode of the DC power source into the plurality of DC/DC converters, the second wire connecting a negative electrode of the DC/DC converter and the plurality of DC/DC converters and branching from the negative electrode of the DC/DC converter into the plurality of DC/DC converters; and an arc determiner that determines an occurrence of an arc based on the voltage detected by the voltage detector.