Disclosed is an intelligent on-line diagnosis method for winding deformation of power transformer. When a transformer is subjected to short-circuit shock or transportation collision, transformer windings may undergo local twisting, swelling or the like under the action of an electric power or mechanical force, which is called winding deformation and will cause a huge hidden danger to the safe operation of the power network. Commonly used diagnosis methods for winding deformation are all off-line diagnosis methods, which have the disadvantages that transformers need to be shut down and highly skilled operators are required. The present invention provide an intelligent on-line diagnosis method for winding deformation on the basis of combination of information entropy and support vector machine. By carrying out feature extraction of current and voltage signals based on permutation entropy and wavelet entropy, integrating the variation of the monitoring indicators of the power transformers in complexity, time-frequency domain and the like and automatically learning the diagnostic logic from fault features through the machine learning algorithm, intelligent diagnosis of winding deformation is realized, thereby reducing labor costs and improving diagnosis efficiency.

A method and a system for fault verification of an electronic device are provided. The electronic device includes a device to-be-verified. The method includes the following. A first power-supply voltage is applied to the electronic device until the device to-be-verified satisfies a material-failure condition. A second power-supply voltage is applied to the electronic device to determine whether the electronic device has safety risk. The first power-supply voltage is higher than the second power-supply voltage, and the safety risk is caused by material failure in the device to-be-verified. The method and the system for fault verification of an electronic device can verify safety risk caused by material failure in internal components of the electronic device.

An apparatus for checking an inductor includes a detector outputting a detection signal including information corresponding to a parallel resistance component of a checking target inductor; and a determiner receiving the detection signal and determining whether the checking target inductor is satisfactory based on a magnitude of the parallel resistance component.

Disclosed are tantalum capacitors having enhanced volumetric efficiency, effective series resistance, effective series inductance, and high frequency performance when compared to existing tantalum capacitors. Also disclosed is a screening process for tantalum capacitors to enhance reliability.

Method and system allowing more accurate detection and identification of unwanted arcing include novel processing of signal voltage representing recovered power-line current. In one implementation, arc-faults are detected based on numerical analysis where individual cycles of line voltage and current are observed and data collected during each cycle is processed to estimate likelihood of presence of arc-event within each individual cycle based on pre-defined number of arc-events occurring within pre-defined number of contiguous cycles. In another implementation, fast transient current spikes detection can be done by: computing difference values between consecutive line-current samples collected over a cycle, average of differences, and peak-to-peak value of line-current; comparing each difference value to average of difference; comparing each difference value to peak-to-peak value; and, based on calculation of composite of two comparisons, using thresholds to determine if arcing is present within processed cycle.

A partial discharge (PD) transducer that includes a PD sensor configured to sense a PD event of an electrical system. At least one light emitting device (LED) is arranged in series with the PD sensor. The LED is configured to receive the electrical sensor signal from the PD sensor and to generate a light signal in response to the electrical sensor signal.

A partial discharge (PD) detection system includes a PD sensor configured to sense a PD event of an electrical system and to generate a sensor signal in response to the PD event. An envelope generator is coupled to receive the sensor signal from the PD sensor. The envelope generator extracts an envelope signal from the sensor signal. A digitizer is configured to convert the envelope signal to a digital representation of the PD event.

Example embodiments of the invention include a powdered core bead body configured to become an inductive impedance to current signals in a power wire with high frequencies. The signals are detectable by a high frequency voltage sensor, which is configured to output an arc fault tripping indication to an arc fault tripping circuit. The bead body includes a magnetic flux-density sensing device embedded in an air cavity of the bead body, having a magnetic field sensing surface oriented substantially perpendicular to the circumferential periphery of the bead body. The bead body is configured to provide measurable magnetic flux through the magnetic flux-density sensing device, for currents in the power wire having low frequencies. The measurable magnetic flux is detectable by a low frequency magnetic flux-density sensing device, to output a low frequency current measurement for power metering devices or to determine power consumption within a protected branch.

Example embodiments of the invention include a powdered core bead body configured to become an inductive impedance to current signals with high frequencies in a power wire threaded through the powdered core bead body. The signals are detectable by a high frequency voltage sensor that is configured to output an arc fault tripping indication to an arc fault tripping circuit in response to an occurrence of high frequency current signals in the power wire.

An electrical equipment includes a first load configured for a nominal use of the equipment, at least one first metal screen, a sensor configured to measure a quantity characteristic of the first load, and a power supply conductor, wherein the first load and the at least first metal screen are linked electrically to the power supply conductor, and in that the equipment also comprises a comparator configured to compare measurements from the sensor to detect a dormant failure of the at least first metal screen.