METHOD AND DEVICE FOR PROTECTION AGAINST INTERNAL ARCING FAULTS IN AN ELECTRICAL DISTRIBUTION SYSTEM, AND ELECTRICAL CABINET COMPRISING SUCH A DEVICE

摘要

This method comprises the steps of:-detect any light beam from 300nm to 430nm inside the distribution system and, in case of presence of this beam, generate a signal indicative of the presence of an internal arc inside the system,analyzing the characteristics of the aforesaid light beam from the aforementioned signal and, if these characteristics satisfy the conditions required to characterize an internal arc fault, send an internal arc fault signal then,in the presence of an internal arc fault, attenuate its effects in the distribution system. This method is characterized in that, between the above-mentioned detection step and the analysis step, the visible-type part and the infra-red-type part of this bundle are eliminated, these parts being able to come from the ionised gases. ejected by the exhausts of a low-voltage circuit breaker cutting a short-circuit current. The protection device P for carrying out this method comprises a light detector (1) associated with current measurement sensors (6), and protection means (3) comprising a main circuit breaker (4), a short circuit breaker circuit-breaker (7) and a relay (5).