| 摘要 |
A method for the early detection of faults in an electric supply system, comprising the steps of continuously checking the existence of RF transients on the electric supply system line, transforming detected transients whose amplitude is above a predetermined level, into a sequence of pulses, analyzing the temporal spacing between pulses to identify those which are due to dimmers, and disregarding them, identifying short-noisy states structures in said sequence, states whose duration is shorter than a period T-ARC, determining short-noisy states where the current amplitudes before and after said states are different, and disregarding these states considered to be caused by normal switching operations, regarding each of the remaining short-noisy states as a faulty event and accumulating such events in a first register, identifying separately long-noisy states in said sequence, states whose duration is longer than a period T-ARC, ascribing a number of arcing events to each long-noisy state proportional to its duration, and accumulating these numbers in a second register; and summing the values in said first and second registers, and if the sum exceeds a predetermined value N-ALARM, within a predetermined period, activating an alarm and/or a current breaker.
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