A method of detecting a fault in a monitored section of an electric line. A release signal and a direction signal are generated, in the event of a fault, by a measuring unit fitted at each end of every section of the line. The direction signal is transmitted via a low-transmission-capacity line from one measuring unit to another measuring unit. Each measuring unit produces, after generating the release signal, intermediate parameters which are suitable for calculating the location of the fault. ...

A method of detecting faults on a power transmission line system includes simultaneously measuring phase current samples at each phase of each transmission terminal; calculating real and imaginary phaselets comprising partial sums of the phase current samples; for each phaselet, calculating a respective partial sum of squares of each phase current sample; calculating the sums of the real and imaginary phaselets over a variable size sliding sample window; calculating real and imaginary phasor com...

An apparatus and a method for diagnosing any abnormality in a processing equipment without the necessity of professional knowledge of a user while ensuring enhanced general-purpose usability. In the apparatus, a computer is connected to a programmable logic controller for controlling the operation of a processing equipment which repeats a predetermined sequence of a plurality of steps, while monitoring information from the processing equipment changed in accordance with the operation in the equi...

The present invention relates to a method for location of a fault utilizing unsynchronized measurements of three phase voltages and currents acquired at the line terminals without synchronization. Phasors for symmetrical components of the measured quantities are determined and used in the fault location algorithm. According to one embodiment, positive sequence phasors of post-fault quantities are used for estimation of the distance to fault and it is distinctive that such an estimation of a dist...

For the purpose of validating fault symptoms appearing at driver outputs, a symptom validation unit is provided, within a final stage, which undertakes a validation or a preliminary validation, as applicable, on the basis of a classification of symptoms. By assigning the item of validation data "invalid" to symptoms which cannot be unambiguously identified, it is possible to suppress the further consideration of the symptoms, or to initiate further diagnoses of the final stage output concerned, ...

A digital signal processor implementation of three algorithms used to detect high impedance faults. The algorithms can be wavelet based, higher order statistics based and neural network based. The algorithms are modified to process one second of data instead of ten seconds of data and a double buffered acquisition is connected to the output of the algorithms.

The faulted sections are evaluated by calculating the measuring information resulted from the faults in various positions by the previous fault simulative calculation, introducing the resulting fault simulative measuring information into a self-organizing neural network having output elements of which number being more than that of input elements to permit the self-organizing neural network to learn the classification of the simulative measuring information, preparing an evaluation rule represen...

An accurate impedance measurement method for a power system transmission line is disclosed for improving various protection functions, i.e., distance protection and/or fault location estimation. The method is less sensitive to harmonics and other transient problems introduced to power systems by series capacitance and the like, and is easily incorporated into existing protective relays. In the method, a number (n) of current and voltage samples (I.sub.k, V.sub.k) representative of values of curr...

A system that detects a motor fault includes a current sensor, a filter, and a controller. The sensor is electrically connected to the filter. A controller tunes the filter to a rotational frequency of a motor and compares a filtered signal to a predetermined value. A method that detects the motor fault condition selects an output signal conditioned by either a band pass filter or a low pass filter and compares the selected output to a predetermined value to identify a motor fault.

An imaging sensor includes a defect marker allowing an imaging device in which the imaging sensor is installed to determine which pixels in the CMOS sensor are defective. During manufacturing, the pixels in the imaging sensor are tested. Defect markers are used for defective pixels, preferably using a non-volatile marking technique. After the imaging sensor is installed in the imaging device, the imaging device reads the defect markers from the imaging sensor to determine the defective pixels. T...