| 摘要 |
A direct current (DC) arc fault detector (4) includes a first current sensor (10) sensing an alternating current (AC) component of current flowing in a DC power circuit; a second current sensor (12) sensing a DC component of the current; and a bandpass filter (14) filtering the sensed AC component. A demodulating logarithmic amplifier (16) includes an input (18) of the filtered AC component (15), and an output (20). An integrator or minimum detector (22) includes an input (24) connected to the amplifier output, and an output (26). A processor (28) repetitively inputs (64) and then resets (66) the integrator or minimum detector output, and determines (70;82;94) an arc when, for a predetermined time: the sensed DC component being greater than a first predetermined value, and a present value of the integrator or minimum detector output being greater than or different from a previous value of such output by more than a second predetermined value, or the present value being greater than a third predetermined value. |
