Systems and methods for arc fault detection
First Claim
1. An electrical fault detection device, comprising:
- a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal, the high frequency sensor adapted to allow passage of high frequency signals and reject low frequency signals;
a series arc-detection circuit coupled to the high-frequency sensor and including;
a high-frequency module configured to identify and reject one or more narrowband portions of the high frequency component and identify a broadband portion of the high frequency component;
a detection module configured to;
rectify the sinusoidal electrical power signal;
store a fault count value representing a propensity of the high-frequency component to be an arc fault;
adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and
generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and
a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line.
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Accused Products
Abstract
In accordance with one aspect the present disclosure is directed toward a method for detecting arc faults on a power line. The method may include monitoring power signals associated with a power line and filtering the power signals to produce a high frequency signal and a low frequency signal. A mask signal may generated based on the low frequency signal, and the high frequency signal may be analyzed to extract a broadband portion of the high frequency signal. A fault counter may be incremented if the magnitude of the broadband portion is approximately greater than a first threshold level. A fault counter may be decremented if the magnitude of the broadband portion is approximately less than the first threshold level. A trip signal is provided to a switching device associated with the power line if the fault counter exceeds a predetermined fault limit.
50 Citations
39 Claims
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1. An electrical fault detection device, comprising:
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a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal, the high frequency sensor adapted to allow passage of high frequency signals and reject low frequency signals; a series arc-detection circuit coupled to the high-frequency sensor and including; a high-frequency module configured to identify and reject one or more narrowband portions of the high frequency component and identify a broadband portion of the high frequency component; a detection module configured to; rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An electrical fault detection device, comprising:
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a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including; a high-frequency module configured to identify a broadband portion of the high frequency component; a detection module configured to; rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line wherein the detection device is further configured to; determine a dynamic range of the broadband portion; and decrease the fault count value if the dynamic range of the broadband portion does not exceed a threshold dynamic range.
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12. An electrical fault detection device, comprising:
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a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including; a high-frequency module configured to identify a broadband portion of the high frequency component; a detection module configured to; rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line wherein the detection module is configured to establish a zero-crossing time period representing the time period that the amplitude of the rectified sinusoidal electrical power signal is below a threshold level, and wherein the detection module is further configured to; decrease the fault count value at a first rate while the quarter-cycle amplitude at the end of the zero-crossing time period does not exceed a first amplitude threshold. - View Dependent Claims (13, 14, 15, 16, 17)
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18. An electrical fault detection device, comprising:
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a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including; a high-frequency module configured to identify a broadband portion of the high frequency component; a detection module configured to; rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line wherein the detection module is configured to establish a zero-crossing time period representing the time period that the amplitude of the rectified sinusoidal electrical power signal is below a threshold level, and wherein the detection module is further configured to; detect a number of instances that the quarter-cycle amplitude and the non-quarter-cycle amplitude collectively cross a first amplitude threshold after the zero-crossing time period; and decrease the fault count value by a first rate if the number of instances exceeds a first threshold crossing limit. - View Dependent Claims (19, 20)
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21. An electronic circuit for detecting series arcing conditions in a sinusoidal electrical signal, comprising:
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a rectifier configured to obtain the absolute value of the sinusoidal electrical signal; a superheterodyne receiver configured to extract a broadband component from the rectified sinusoidal signal; a counter coupled to the receiver and configured to change a fault count value, the fault count value representing a propensity of the sinusoidal signal to include a series arcing condition, the change occurring at multiple rates based on one or more of a quarter-cycle amplitude of the broadband component during the quarter cycle following a zero crossing of the rectified sinusoidal signal, a non-quarter-cycle amplitude of the broadband component after the quarter cycle, and a rate-of-change of the amplitude of the broadband component; and a comparator coupled to counter for generating a series-arc trip signal when fault exceeds a fault count threshold. - View Dependent Claims (22, 23, 24)
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25. A method for electrical fault detection comprising:
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detecting a high-frequency component of a sinusoidal electrical power signal; identifying a broadband portion of the high-frequency component; storing a fault count value representing a propensity of the high-frequency component be an arc fault; adjusting the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of the amplitude of broadband portion during power signal, the amplitude of the broadband portion after the rising quarter cycle, and a rate of change of the amplitude of the broadband portion, wherein the at least one characteristic corresponds with a weighted adjustment factor, the weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; generating a trip signal if the fault count value exceeds a fault count threshold; and providing the trip signal to a trip circuit for opening the electrical distribution line in response to the trip signal.
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26. An electrical fault detection device, comprising:
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a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including; a high-frequency module configured to identify a broadband portion of the high frequency component; a detection module configured to; rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on at least one characteristic of the broadband portion, the at least one characteristic including one or more of a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the at least one characteristic has a respective weighted adjustment factor defining an amount by which the fault count value is adjusted upon detection of the at least one characteristic; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line wherein the series arc detection circuit configured to; provide a test command signal to an RF noise generator, the RF noise generator configured to generate a high-frequency broadband noise signal and deliver the high frequency broadband noise signal to an input of the high-frequency sensor in response to the test command signal; and generate a test failure trip signal if adjustment of the fault count value in response to the high-frequency broadband noise signal is inconsistent with predetermined adjustment characteristics. - View Dependent Claims (27, 28, 29, 30, 31, 32)
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33. A method for testing an electrical fault detection device having a microprocessor and analog processing circuitry, the analog processing circuitry configured to detect a high-frequency component of a sinusoidal electrical power signal, identify a broadband portion of the high frequency component, and generate digital signals indicative of at least one characteristic of the broadband portion,
the microprocessor configured to store a fault count value representing a propensity of the high-frequency component to be an arc fault, adjust the fault count value based on the at least one characteristic of the broadband portion, and generate a trip signal if the fault count exceeds a fault threshold, the method comprising: -
providing a test command signal to an RF generator, the RF generator configured to generate, in response to the test command signal, a high-frequency broadband noise signal and deliver the high-frequency broadband noise signal to an input of the analog processing circuitry; monitoring, by the microprocessor, the high-frequency broadband noise signal to determine whether the digital signals generated by the analog processing circuitry are consistent with the high-frequency broadband noise signal; and generating a test failure trip signal if the digital signals generated by the analog processing circuitry are not consistent with the high-frequency broadband noise signal. - View Dependent Claims (34, 35, 36, 37, 38, 39)
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Specification