Detection of arcing in dc electrical systems

摘要

Arcing faults in dc electric power systems are detected by apparatus which responds to a predetermined drop either in voltage across, or current drawn by, a dc load. The voltage and current drops can be measured values or scaled to the source voltage. In another arrangement, the load current is interrupted momentarily when a step decrease in current is detected. If the dc current does not return, within a predetermined margin, to the decreased value before interruption, arcing is indicated. In a third embodiment, drift of the load current following detection of a step decrease, either upward toward a short or downward toward an open circuit, is taken as an indication of arcing.