Arc detection using load recognition, harmonic content and broadband noise
First Claim
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1. A method of determining whether arcing is present in an electrical circuit comprising:
- sensing a change in current in said circuit and developing a corresponding input signal;
analyzing said input signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal;
analyzing a line current at a sub-harmonic level; and
processing said input signal, said output signal, and said sub-harmonic line current in a predetermined fashion and periodically determining whether an arcing fault is present in said circuit;
said processing including determining a type of load connected to said electrical circuit, based at least in part upon said input signal and said output signal.
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Abstract
A method of determining whether arcing is present in an electrical circuit includes sensing a change in current in the circuit and developing a corresponding input signal, analyzing the input signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal, and processing the input signal and the output signal in a predetermined fashion to determine whether an arcing fault is present in the circuit. The processing includes determining a type of load connected to the electrical circuit, based at least in part upon the input signal and the output signal.
232 Citations
70 Claims
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1. A method of determining whether arcing is present in an electrical circuit comprising:
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sensing a change in current in said circuit and developing a corresponding input signal; analyzing said input signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal; analyzing a line current at a sub-harmonic level; and processing said input signal, said output signal, and said sub-harmonic line current in a predetermined fashion and periodically determining whether an arcing fault is present in said circuit; said processing including determining a type of load connected to said electrical circuit, based at least in part upon said input signal and said output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 69)
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21. A system for determining whether arcing is present in an electrical circuit comprising:
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a sensor for sensing cm-rent in said circuit and developing a corresponding sensor signal; a sensor for sensing a change in the current in said circuit and developing a corresponding change in current signal; a sensor for sensing line current at a sub-harmonic level; a circuit for analyzing said sensor signal, said sub-harmonic line current, and said change in current signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal; and a controller for processing said sensor signal, said change in current signal, said sub-harmonic line current, and said output signal to determine current characteristics and a type of load connected to said electrical circuit and to determine, using said load current characteristics, the presence of broadband noise, and periodically determining whether an arcing fault is present in said circuit. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 70)
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41. A controller for a system for determining whether arcing is present in an electrical circuit in response to input signals, said input signals corresponding to a changing current in said circuit, to an analysis of a line current at a sub-harmonic level, and to the presence of broadband noise in a predetermined range of frequencies in said circuit, said controller comprising:
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a plurality of counters; means for incrementing and decrementing said plurality of counters in accordance with said input signals; means for determining a type of load connected to said electrical circuit using at least the states of one or more of said plurality of counters; and means for determining whether a fault is present using at least the states of said plurality counters. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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55. A method of determining whether arcing is present in an electrical circuit in response to input signals, said input signals corresponding to a changing current in said circuit, to an analysis of a line current at a sub-harmonic level, and to the presence of broadband noise in a predetermined range of frequencies in said circuit, said method comprising:
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incrementing and decrementing a plurality of counters in accordance with said input signals; and determining a type of load connected to said electrical circuit and whether an arcing fault is present using the states of said plurality of counters. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
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Specification