Dc electrical circuit protection apparatus and arc detection method

A DC electrical circuit protection apparatus in a DC feed system where a plurality of DC electrical circuits are connected to a common main line, the apparatus comprising:

• a plurality of current sensors each provided in at least one of a positive or a negative electrical path in each of at least two of the plurality of DC electrical circuits;
• a plurality of arc noise absorbers which are provided one on the upstream side of each of the plurality of current sensors and which each absorb an arc noise, which occurs in one of the DC electrical circuits and flows in from the upstream side, so as not to cause the arc noise to propagate to any other DC electrical circuit;
• and
• an arc detection device which compares respective arc noise signal strengths of the DC electrical circuits from current signals detected by the plurality of current sensors, and based on the arc noise signal strengths, identifies a DC electrical circuit in which an arc has occurred from among the plurality of DC electrical circuits.

In a DC feed system in which a plurality of DC electrical circuits are connected to a common main line and which is provided with arc noise absorber which each absorb an arc noise, which has occurred in one of the DC electrical circuits, so as not to cause the arc noise to propagate to any other DC electrical circuit, wherein

• the plurality of DC electrical circuits, each of which includes a current sensor provided in one of a positive or a negative electrical path of each of the plurality of DC electrical circuits and includes the arc noise absorber which is provided on the upstream side of the current sensor and which absorbs an arc noise flowing in from the upstream side, an arc detection method comprising:
• comparing respective arc noise signal strengths of the plurality of DC electrical circuits from current signals detected by the current sensors of the DC electrical circuits, and based on the arc noise signal strengths, identifying a circuit in which an arc has occurred from among the DC electrical circuits;
• an arc noise frequency analysis which carries out a frequency analysis from the current signals detected by the current sensors;
• and
• an arc noise strength comparison which compares the signal strengths of noise frequencies analyzed in the arc noise frequency analysis step, for each of the current signals detected by the current sensors, and thus identifies an arc occurrence circuit.