CA2672279A1 - Arc detection using discrete wavelet transforms - Google Patents
Arc detection using discrete wavelet transforms Download PDFInfo
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- CA2672279A1 CA2672279A1 CA2672279A CA2672279A CA2672279A1 CA 2672279 A1 CA2672279 A1 CA 2672279A1 CA 2672279 A CA2672279 A CA 2672279A CA 2672279 A CA2672279 A CA 2672279A CA 2672279 A1 CA2672279 A1 CA 2672279A1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
- H02H1/0015—Using arc detectors
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0092—Details of emergency protective circuit arrangements concerning the data processing means, e.g. expert systems, neural networks
Abstract
An apparatus to perform series and parallel arc fault current interruption (AFCI). The apparatus includes a resistive element (10) configured to sense a load from which a current signal is generated, a first detection unit (30) configured to output a first signal based on the current signal, and a microcontroller (80) configured to decompose at least the first signal via discrete wavelet transforms to thereby obtain discrete wavelet coefficients, and to generate a trip signal when the discrete wavelet coefficients indicate that a threshold condition for trip signal generation are satisfied.
Description
. , . . . . .. . .
ARC DETECTION USING DISCRETE WAVELET TRANSFORMS
BACKGROUND OF THE INVENTION
Aspects of the present invention are directed to electrical systems and, more particularly, to methods and systems for parallel and series arc detection in electrical systems.
BRIEF DESCRIPTION OF THE BACKGROUND
Electrical systems in residential, commercial, and industrial applications usually include a panel board for receiving electrical power from a utility source.
The power is routed through the panel board to one or more current interrupters such as, but not limited to circuit breakers, trip units, and others.
Each current interrupter distributes the power to a designated branch, where each branch supplies one or more loads with the power. The current interrupters are configured to interrupt the power to the particular branch if certain power conditions in that branch reach a predetermined set point.
For example, some current interrupters can interrupt power due to a ground fault, and are commonly known as ground fault current interrupters (GFCIs). The ground fault condition results when an imbalance of current flows between a line conductor and a neutral conductor, which could be caused by a leakage current or an arcing fault to ground.
Other current interrupters can interrupt power due to an arcing fault, and are commonly known as arc fault current interrupters (AFCls). Arcing faults are defined into two main categories, series arcs and parallel arcs. Series arcs can occur, for example, when current passes across a gap in a single conductor. Parallel arcs, on the other hand, can occur when current passes between two conductors.
Unfortunately, arcing faults may not cause a conventional circuit interrupter to trip. This is particularly true when a series arc occurs because the current sensing device is unable to distinguish between a series arc and a normal load current.
SUMMARY OF THE INVENTION
In accordance with an aspect of the invention, an apparatus to perform series and parallel arc fault current interruption (AFCI) is provided and includes a resistive element configured to sense a load from which a current signal is generated, a first detection unit configured to output a first signal based on the current signal, and a microcontro'Aer configured to decompose at least the first signal via discrete wavelet transforms to thereby obtain discrete wavelet coefficients, and to generate a trip signal when the discrete wavelet coefficients indicate that a threshold condition for trip signal generation are satisfied.
In accordance with another aspect of the invention, a method of performing series and parallel arc fault current interruption (AFCI) is provided and includes sensing a load current, sampling a signal based on the sensed load current at a high frequency, when the high frequency sampling is complete and, if a zero cross is determined to have been sampled, computing zero cross discrete wavelet coefficients, when the high frequency sampling is complete and, if the zero cross is determined to have not been sampled, computing non-zero cross discrete wavelet coefficients, and issuing a trip signal if a threshold criterion is determined to have been met based on the zero and non-zero cross discrete wavelet coefficients.
In accordance with another aspect of the invention, a method of operating a current interrupter by detecting series and parallel arcs is provided and includes sensing a load current and generating a current signal therefrom, low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions, medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients, sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region, computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof, and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a microcontroller based combination arc fault current interrupter;
FIG. 2 is a flow diagram of a trip signal issuing algorithm;
FIG. 3 is a flow diagram illustrating an interrupt handling algorithm;
FIGS. 4A and 4B are flow diagrams illustrating zero cross conlputations; and FIG. 5 is a flow diagram illustrating discrete wavelet coefficient computing algorithms.
ARC DETECTION USING DISCRETE WAVELET TRANSFORMS
BACKGROUND OF THE INVENTION
Aspects of the present invention are directed to electrical systems and, more particularly, to methods and systems for parallel and series arc detection in electrical systems.
BRIEF DESCRIPTION OF THE BACKGROUND
Electrical systems in residential, commercial, and industrial applications usually include a panel board for receiving electrical power from a utility source.
The power is routed through the panel board to one or more current interrupters such as, but not limited to circuit breakers, trip units, and others.
Each current interrupter distributes the power to a designated branch, where each branch supplies one or more loads with the power. The current interrupters are configured to interrupt the power to the particular branch if certain power conditions in that branch reach a predetermined set point.
For example, some current interrupters can interrupt power due to a ground fault, and are commonly known as ground fault current interrupters (GFCIs). The ground fault condition results when an imbalance of current flows between a line conductor and a neutral conductor, which could be caused by a leakage current or an arcing fault to ground.
Other current interrupters can interrupt power due to an arcing fault, and are commonly known as arc fault current interrupters (AFCls). Arcing faults are defined into two main categories, series arcs and parallel arcs. Series arcs can occur, for example, when current passes across a gap in a single conductor. Parallel arcs, on the other hand, can occur when current passes between two conductors.
Unfortunately, arcing faults may not cause a conventional circuit interrupter to trip. This is particularly true when a series arc occurs because the current sensing device is unable to distinguish between a series arc and a normal load current.
SUMMARY OF THE INVENTION
In accordance with an aspect of the invention, an apparatus to perform series and parallel arc fault current interruption (AFCI) is provided and includes a resistive element configured to sense a load from which a current signal is generated, a first detection unit configured to output a first signal based on the current signal, and a microcontro'Aer configured to decompose at least the first signal via discrete wavelet transforms to thereby obtain discrete wavelet coefficients, and to generate a trip signal when the discrete wavelet coefficients indicate that a threshold condition for trip signal generation are satisfied.
In accordance with another aspect of the invention, a method of performing series and parallel arc fault current interruption (AFCI) is provided and includes sensing a load current, sampling a signal based on the sensed load current at a high frequency, when the high frequency sampling is complete and, if a zero cross is determined to have been sampled, computing zero cross discrete wavelet coefficients, when the high frequency sampling is complete and, if the zero cross is determined to have not been sampled, computing non-zero cross discrete wavelet coefficients, and issuing a trip signal if a threshold criterion is determined to have been met based on the zero and non-zero cross discrete wavelet coefficients.
In accordance with another aspect of the invention, a method of operating a current interrupter by detecting series and parallel arcs is provided and includes sensing a load current and generating a current signal therefrom, low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions, medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients, sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region, computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof, and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a microcontroller based combination arc fault current interrupter;
FIG. 2 is a flow diagram of a trip signal issuing algorithm;
FIG. 3 is a flow diagram illustrating an interrupt handling algorithm;
FIGS. 4A and 4B are flow diagrams illustrating zero cross conlputations; and FIG. 5 is a flow diagram illustrating discrete wavelet coefficient computing algorithms.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, an apparatus to perform series and parallel arc fault current interruption (AFCI) is provided and includes a resistive element 10, such as a bimetal, which is configured to sense a load from which a current signal is generated.
The resistive element 10 may be formed of resistive materials that have a characteristic resistance at room temperature of 6 mOhms (milli-ohms) (at 15A) or 3 mOhms (at 20A). The resistive element 10 is electrically coupled to a signal line along which a summing amplifier 20 is disposed. The current signal, therefore, flows from the resistive element 10 and to the summing amplifier 20 along with a test signal 90 that may be outputted by a microcontroller 80, which will be described later.
While embodiments of the invention are disclosed having a bimetal as an example resistive element, it will be appreciated that the scope of the invention is not so limited and also encompasses other resistive elements suitable for the purposes disclosed herein, such as, for example, brass, bronze, copper alloy, steel, stainless steel, inconel steel and/or carbon-steel alloys.
The signal line is coupled to a series arc detection unit 30, a parallel arc detection unit 40 and a current measurement unit 50, such as a root mean square current measurement unit, a p-p current measurement unit, a Hall effect current sensor or any other suitable device. The series arc detection unit 30 is configured to output a first signal to the microcontroller 80 for use in detecting a series arc in the current signal and the parallel arc detection unit 40 is configured to output a second signal to the microcontroller 80 for use in detecting a parallel arc in the current signal.
The current measurement unit 50 is configured to output a third signal to the microcontroller 80 for use in the performance of, e.g., RMS current measurement and arc detection sample timing.
In the present context, series and parallel arcs refer to electric breakdowns of a normally nonconductive media, such as air, that produce luminous electrical discharges, such as sparks, which result from current flowing through the normally nonconductive media. Series arcs occur in series with the load current where, as an example, a current carrying line is broken. As such, series arc current can be no higher than the load current. Conversely, parallel ares occur between oppositely charged conductors, such as a circuit and a grounded element, and may be characterized by high current spikes and little or no load impedance.
The series arc detection unit 30 operates at a sampling rate of 300 kHz and filters all but those sub-signals having frequencies of about 6 kHz - 60 Hz from the current signal. To this end, the series arc detection unit 30 includes a high pass filter 31 and, optionally, first and/or second low pass filters 32 and 33 in series with one another.
Here, each of the low pass filters may include an amplifier. The parallel arc detection unit 40 operates at a sampling rate of 10 kHz and filters all but those sub-signals having frequencies of about 150-900 Hz from the current signal. To this end, the parallel arc detection unit 40 includes a low pass filter 41 and a high pass filter 42.
The current measurement unit 50 operates at a sampling rate of 10 kHz and includes a low pass filter 51.
The microcontroller 80 is configured to decompose at least one of the first and second signals as received from the series arc detection unit 30 and the parallel arc detection unit 40. The decomposition is accomplished via discrete wavelet transforms DWTs, such as mother wavelets, that are obtained from external computations and at least partly from information contained within the third signal as received from the current measurement unit 50. A result of the decomposition is the computation of discrete wavelet coefficients which are themselves employed by the microcontroller 80 in the issuance of a trip signal ST. That is, the microcontroller 80 is configured to generate a trip signal ST when the discrete wavelet coefficients indicate that one or more threshold conditions for trip signal ST generation are satisfied. Here, the threshold condition refers to a signal measurement that indicates that either a parallel or series arc occurs.
In accordance with embodiments of the invention, each DWT is a short wave of finite length that in.tegrates to zero over its period of existence. The discrete wavelet coefficients are obtained from each DWT as follows:
With reference to FIG. 1, an apparatus to perform series and parallel arc fault current interruption (AFCI) is provided and includes a resistive element 10, such as a bimetal, which is configured to sense a load from which a current signal is generated.
The resistive element 10 may be formed of resistive materials that have a characteristic resistance at room temperature of 6 mOhms (milli-ohms) (at 15A) or 3 mOhms (at 20A). The resistive element 10 is electrically coupled to a signal line along which a summing amplifier 20 is disposed. The current signal, therefore, flows from the resistive element 10 and to the summing amplifier 20 along with a test signal 90 that may be outputted by a microcontroller 80, which will be described later.
While embodiments of the invention are disclosed having a bimetal as an example resistive element, it will be appreciated that the scope of the invention is not so limited and also encompasses other resistive elements suitable for the purposes disclosed herein, such as, for example, brass, bronze, copper alloy, steel, stainless steel, inconel steel and/or carbon-steel alloys.
The signal line is coupled to a series arc detection unit 30, a parallel arc detection unit 40 and a current measurement unit 50, such as a root mean square current measurement unit, a p-p current measurement unit, a Hall effect current sensor or any other suitable device. The series arc detection unit 30 is configured to output a first signal to the microcontroller 80 for use in detecting a series arc in the current signal and the parallel arc detection unit 40 is configured to output a second signal to the microcontroller 80 for use in detecting a parallel arc in the current signal.
The current measurement unit 50 is configured to output a third signal to the microcontroller 80 for use in the performance of, e.g., RMS current measurement and arc detection sample timing.
In the present context, series and parallel arcs refer to electric breakdowns of a normally nonconductive media, such as air, that produce luminous electrical discharges, such as sparks, which result from current flowing through the normally nonconductive media. Series arcs occur in series with the load current where, as an example, a current carrying line is broken. As such, series arc current can be no higher than the load current. Conversely, parallel ares occur between oppositely charged conductors, such as a circuit and a grounded element, and may be characterized by high current spikes and little or no load impedance.
The series arc detection unit 30 operates at a sampling rate of 300 kHz and filters all but those sub-signals having frequencies of about 6 kHz - 60 Hz from the current signal. To this end, the series arc detection unit 30 includes a high pass filter 31 and, optionally, first and/or second low pass filters 32 and 33 in series with one another.
Here, each of the low pass filters may include an amplifier. The parallel arc detection unit 40 operates at a sampling rate of 10 kHz and filters all but those sub-signals having frequencies of about 150-900 Hz from the current signal. To this end, the parallel arc detection unit 40 includes a low pass filter 41 and a high pass filter 42.
The current measurement unit 50 operates at a sampling rate of 10 kHz and includes a low pass filter 51.
The microcontroller 80 is configured to decompose at least one of the first and second signals as received from the series arc detection unit 30 and the parallel arc detection unit 40. The decomposition is accomplished via discrete wavelet transforms DWTs, such as mother wavelets, that are obtained from external computations and at least partly from information contained within the third signal as received from the current measurement unit 50. A result of the decomposition is the computation of discrete wavelet coefficients which are themselves employed by the microcontroller 80 in the issuance of a trip signal ST. That is, the microcontroller 80 is configured to generate a trip signal ST when the discrete wavelet coefficients indicate that one or more threshold conditions for trip signal ST generation are satisfied. Here, the threshold condition refers to a signal measurement that indicates that either a parallel or series arc occurs.
In accordance with embodiments of the invention, each DWT is a short wave of finite length that in.tegrates to zero over its period of existence. The discrete wavelet coefficients are obtained from each DWT as follows:
x[n] f=0 ~ ~
g[n] h[n]
f=n/2- ~ f=4- n/2 ~
Levell ~[n] h[n]
DW7' coefficients f=n14 -'x12 f=0 w x/4 Level 2 DWYcoef, ficients ~[n] h[n]
f=718 - V4 f=O - 118 Level 3 DWT coefficients , where x[n] = an input signal, g[n] = a high pass digital filter from a mother wavelet, and h[n] = a low pass digital filter from the mother wavelet.
Use of the DWTs to obtain the discrete wavelet coefficients provides several advantages in current signal analysis as compared to other analytical tools, such as Fourier transforms (FT) and Fast Fourier Transforms (FFT). For example, DWTs provide a measure of a correlation between the mother wavelet and the current signal.
In addition, DWTs can infornl as to what time a particular frequency occurred, are simpler to calculate and allow for a detection of an extinguish/re-strike event, which is characteristic to parallel and series arcs, by also allowing for a search for particular frequencies/patterns at zero cross moments.
g[n] h[n]
f=n/2- ~ f=4- n/2 ~
Levell ~[n] h[n]
DW7' coefficients f=n14 -'x12 f=0 w x/4 Level 2 DWYcoef, ficients ~[n] h[n]
f=718 - V4 f=O - 118 Level 3 DWT coefficients , where x[n] = an input signal, g[n] = a high pass digital filter from a mother wavelet, and h[n] = a low pass digital filter from the mother wavelet.
Use of the DWTs to obtain the discrete wavelet coefficients provides several advantages in current signal analysis as compared to other analytical tools, such as Fourier transforms (FT) and Fast Fourier Transforms (FFT). For example, DWTs provide a measure of a correlation between the mother wavelet and the current signal.
In addition, DWTs can infornl as to what time a particular frequency occurred, are simpler to calculate and allow for a detection of an extinguish/re-strike event, which is characteristic to parallel and series arcs, by also allowing for a search for particular frequencies/patterns at zero cross moments.
Thus, when the microcontroller 80 applies DWTs to either a series arc detection or a parallel arc detection operation, the microcontroller 80 may operate by identifying a pattern or a signature that can be associated with the arcing, selecting a predetermined mother wavelet that gives a close correlation to that pattern or signature, selecting a frequency range to analyze the arcing that provides an optimized signal-to-noise ratio, selecting a portion of the waveform as the focus area and selecting the required window size that corresponds to the selected portion of the waveform.
With this in mind, it has been seen that the "Daubechiesl0" or "db10" mother wavelet is highly suitable for arc detection where the frequency range is set at 93 kHz or more, the sampling frequency is set at 300 kHz and no anti-aliasing filter is applied. Since it has also been seen that indicators of arcing lie at the zero cross points of the current signal, the zero cross points determine when sampling is triggered. Thus, a window size for the sampling frequency of 300 kHz is set as 25.3 degrees such that at least one of either the re-strike or extinguish events of an arc will be caught within the window.
Still referring to FIG. 1, the apparatus may further include an ambient temperature sensor 60 that is coupled to the microcontroller 80. The ambient temperature sensor 60 measures the ambient temperature of, at least, the resistive element 10 and outputs the measurement to the microcontroller 80. The microcontroller 80 then determines whether to compensate for any temperature changes of the resistive element 10 in the calculations mentioned above.
In addition, the apparatus may further include a push to test switch 70 including a series arc test configuration 71 and a parallel arc test configuration 72. The push to test switch 70 is coupled to the microcontroller 80 and allows an operator to test the apparatus upon installation in accordance with local and non-local regulations.
With reference now to FIGS. 2-5, a method of performing series and parallel arc fault current interruption (AFCI) will be described. As shown in FIG. 2, upon initialization of the algorithm (operation 100), which then runs continuously, during which sensing of a load current occurs, a determination is made as to whether high frequency sampling is complete or not (operation 200). Here, the high frequency sampling actually refers to medium frequency sampling relating to the performance of the series arc detection unit 30 and the high frequency sampling relating to the performance of the parallel arc detection unit 40.
Further, the high and/or medium frequency sampling occurs in accordance with the interrupt handling algorithm of FIG. 3. This algorithm starts with the receiving of a low frequency interrupt signal (operation 201), which is generated by the microcontroller 80. At this point, it is determined whether the RMS length has been sampled (operation 202) and, if it has been sampled, the RMS is computed (operation 203). Once the RMS is computed, it is used to determine how fast the apparatus needs to trip in the presence of an arcing condition. If the RMS has not yet been sampled, the zero cross is computed (operation 204).
The zero cross computations of operation 204 may be conducted in accordance with the flow diagrams of FIGS. 4A and 4B. As shown, the zero cross computations refer to Cases 0-11 that each describe an if-then-else scenario related to a previous value of the current signal, where NEGTHRESH 15, POSTHRESH = 15, NEGZERO = -3 and POSZERO = 3.
Once the zero cross is computed, whether a positive zero cross has been registered is determined (operation 205). If the positive zero cross has not been registered, delays for negative zero cross for use in zero cross sampling and non zero cross sampling are set, and the medium and/or the high frequency sampling is triggered (operation 206).
If, however, the positive zero cross has been registered, delays for positive zero cross are set for use in zero cross sampling and non zero cross sampling, the medium and/or the high frequency sampling is triggered (operation 207).
Referring back to FIG. 2, if the medium and/or the high frequency sampling is determined to not be complete, the current signal is sampled at a low frequency (operation 300) and, if the low frequency sampling is complete, a rolling average of the low frequency filtered signal is computed (operation 500).
If the medium and/or the high frequency sampling is completed and if a zero cross is determined to have been sampled, the zero cross discrete wavelet coefficients are computed from at least the rolling average (operation 410). Conversely, if the medium and/or the high frequency sampling is complete and if the zero cross is determined to have not been sampled, the non-zero cross discrete wavelet coefficients are computed from at least the rolling average (operation 420).
Here, with reference to FIG. 5, the discrete wavelet algorithm is employed in operations 410 and 420. As shown, the sampled signal is initially defined as a signal with the Outerlndex, which refers to an index for the convoluted signal, the SumCD, which is the absolute value of the sum of detailed coefficients, and the Innerlndex, which is an index of a filter in use, each being set to zero.
First, whether the OuterIndex is less than a length of the convoluted signal is determined. If the Outerlndex is not less than a length of the convoluted signal, a value of the SumCD is returned to zero. Conversely, if the Outerlndex is less than a length of the convoluted signal, values of the CDs, which are the individual detailed coefficients, are set to zero and a value of a Jumplndex is set to a value of the convoluted signal multiplied by two.
Then, whether the Innerlndex is less than a length of the filter is determined. If the Innerlndex is less than a length of the filter, the values of the CDs are set to the values of the CDs added to a value of the signal. Here, the signal value is a value of the Jumplndex added to a value of the Innerlndex multiplied by a value of the filter. This process is repeated until the Innerlndex is determined to not be less than a length of the filter. At this point, the values of the CDs are set to the absolute values of the CDs and the value of the SumCD is set to the absolute value of the SumCD added to the values of the CDs.
Lastly, with reference to FIG. 2, it is determined whether all threshold criteria have been met (operation 600) based on the zero and non-zero cross discrete wavelet coefficients. Subsequently, a trip signal is issued (operation 700) if all threshold criteria are determined to have been met. Here, the issuing of the trip signal includes comparing the summed respective energies of the discrete wavelet coefficients with threshold conditions, and determining whether the summed respective energies exceed the threshold conditions for trip signal issuance.
In accordance with another aspect of the invention, a method of operating a current interrupter by detecting series and parallel arcs is provided. The method includes sensing a load current and generating a current signal therefrom, low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions, medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients, sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region, computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof, and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies.
Here, the decomposing operation includes decomposing the medium and/or the high frequency filtered current signal using discrete wavelet transforms obtained from the low frequency filtered current signal. Further, the issuing of the trip decision includes comparing the summed respective energies of the discrete wavelet coefficients with threshold conditions, and determining whether the summed respective energies exceed the threshold conditions for trip signal issuance.
In accordance with additional aspects of the invention, a method for determining the location of the high frequency sampling window based on the previous current zero-cross and a method of incorporating a downsampling and/or a subsampling of the input signal within the convolution to reduce a number of multiplication and addition operation in a convolution calculation are provided. Here, with reference to FIG. 5, the method includes an operation of the discrete wavelet algorithm as described above.
With this in mind, it has been seen that the "Daubechiesl0" or "db10" mother wavelet is highly suitable for arc detection where the frequency range is set at 93 kHz or more, the sampling frequency is set at 300 kHz and no anti-aliasing filter is applied. Since it has also been seen that indicators of arcing lie at the zero cross points of the current signal, the zero cross points determine when sampling is triggered. Thus, a window size for the sampling frequency of 300 kHz is set as 25.3 degrees such that at least one of either the re-strike or extinguish events of an arc will be caught within the window.
Still referring to FIG. 1, the apparatus may further include an ambient temperature sensor 60 that is coupled to the microcontroller 80. The ambient temperature sensor 60 measures the ambient temperature of, at least, the resistive element 10 and outputs the measurement to the microcontroller 80. The microcontroller 80 then determines whether to compensate for any temperature changes of the resistive element 10 in the calculations mentioned above.
In addition, the apparatus may further include a push to test switch 70 including a series arc test configuration 71 and a parallel arc test configuration 72. The push to test switch 70 is coupled to the microcontroller 80 and allows an operator to test the apparatus upon installation in accordance with local and non-local regulations.
With reference now to FIGS. 2-5, a method of performing series and parallel arc fault current interruption (AFCI) will be described. As shown in FIG. 2, upon initialization of the algorithm (operation 100), which then runs continuously, during which sensing of a load current occurs, a determination is made as to whether high frequency sampling is complete or not (operation 200). Here, the high frequency sampling actually refers to medium frequency sampling relating to the performance of the series arc detection unit 30 and the high frequency sampling relating to the performance of the parallel arc detection unit 40.
Further, the high and/or medium frequency sampling occurs in accordance with the interrupt handling algorithm of FIG. 3. This algorithm starts with the receiving of a low frequency interrupt signal (operation 201), which is generated by the microcontroller 80. At this point, it is determined whether the RMS length has been sampled (operation 202) and, if it has been sampled, the RMS is computed (operation 203). Once the RMS is computed, it is used to determine how fast the apparatus needs to trip in the presence of an arcing condition. If the RMS has not yet been sampled, the zero cross is computed (operation 204).
The zero cross computations of operation 204 may be conducted in accordance with the flow diagrams of FIGS. 4A and 4B. As shown, the zero cross computations refer to Cases 0-11 that each describe an if-then-else scenario related to a previous value of the current signal, where NEGTHRESH 15, POSTHRESH = 15, NEGZERO = -3 and POSZERO = 3.
Once the zero cross is computed, whether a positive zero cross has been registered is determined (operation 205). If the positive zero cross has not been registered, delays for negative zero cross for use in zero cross sampling and non zero cross sampling are set, and the medium and/or the high frequency sampling is triggered (operation 206).
If, however, the positive zero cross has been registered, delays for positive zero cross are set for use in zero cross sampling and non zero cross sampling, the medium and/or the high frequency sampling is triggered (operation 207).
Referring back to FIG. 2, if the medium and/or the high frequency sampling is determined to not be complete, the current signal is sampled at a low frequency (operation 300) and, if the low frequency sampling is complete, a rolling average of the low frequency filtered signal is computed (operation 500).
If the medium and/or the high frequency sampling is completed and if a zero cross is determined to have been sampled, the zero cross discrete wavelet coefficients are computed from at least the rolling average (operation 410). Conversely, if the medium and/or the high frequency sampling is complete and if the zero cross is determined to have not been sampled, the non-zero cross discrete wavelet coefficients are computed from at least the rolling average (operation 420).
Here, with reference to FIG. 5, the discrete wavelet algorithm is employed in operations 410 and 420. As shown, the sampled signal is initially defined as a signal with the Outerlndex, which refers to an index for the convoluted signal, the SumCD, which is the absolute value of the sum of detailed coefficients, and the Innerlndex, which is an index of a filter in use, each being set to zero.
First, whether the OuterIndex is less than a length of the convoluted signal is determined. If the Outerlndex is not less than a length of the convoluted signal, a value of the SumCD is returned to zero. Conversely, if the Outerlndex is less than a length of the convoluted signal, values of the CDs, which are the individual detailed coefficients, are set to zero and a value of a Jumplndex is set to a value of the convoluted signal multiplied by two.
Then, whether the Innerlndex is less than a length of the filter is determined. If the Innerlndex is less than a length of the filter, the values of the CDs are set to the values of the CDs added to a value of the signal. Here, the signal value is a value of the Jumplndex added to a value of the Innerlndex multiplied by a value of the filter. This process is repeated until the Innerlndex is determined to not be less than a length of the filter. At this point, the values of the CDs are set to the absolute values of the CDs and the value of the SumCD is set to the absolute value of the SumCD added to the values of the CDs.
Lastly, with reference to FIG. 2, it is determined whether all threshold criteria have been met (operation 600) based on the zero and non-zero cross discrete wavelet coefficients. Subsequently, a trip signal is issued (operation 700) if all threshold criteria are determined to have been met. Here, the issuing of the trip signal includes comparing the summed respective energies of the discrete wavelet coefficients with threshold conditions, and determining whether the summed respective energies exceed the threshold conditions for trip signal issuance.
In accordance with another aspect of the invention, a method of operating a current interrupter by detecting series and parallel arcs is provided. The method includes sensing a load current and generating a current signal therefrom, low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions, medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients, sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region, computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof, and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies.
Here, the decomposing operation includes decomposing the medium and/or the high frequency filtered current signal using discrete wavelet transforms obtained from the low frequency filtered current signal. Further, the issuing of the trip decision includes comparing the summed respective energies of the discrete wavelet coefficients with threshold conditions, and determining whether the summed respective energies exceed the threshold conditions for trip signal issuance.
In accordance with additional aspects of the invention, a method for determining the location of the high frequency sampling window based on the previous current zero-cross and a method of incorporating a downsampling and/or a subsampling of the input signal within the convolution to reduce a number of multiplication and addition operation in a convolution calculation are provided. Here, with reference to FIG. 5, the method includes an operation of the discrete wavelet algorithm as described above.
While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular exemplary embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
Claims (10)
1. An apparatus to perform series and parallel arc fault current interruption (AFCI), the apparatus comprising:
a resistive element (10) configured to sense a load from which a current signal is generated;
a first detection unit (30) configured to output a first signal based on the current signal; and a microcontroller (80) configured to decompose at least the first signal via discrete wavelet transforms to thereby obtain discrete wavelet coefficients, and to generate a trip signal when the discrete wavelet coefficients indicate that a threshold condition for trip signal generation are satisfied.
a resistive element (10) configured to sense a load from which a current signal is generated;
a first detection unit (30) configured to output a first signal based on the current signal; and a microcontroller (80) configured to decompose at least the first signal via discrete wavelet transforms to thereby obtain discrete wavelet coefficients, and to generate a trip signal when the discrete wavelet coefficients indicate that a threshold condition for trip signal generation are satisfied.
2. The apparatus according to claim 1, further comprising a second detection unit (40) disposed in parallel with the first detection unit (30) and configured to output a second signal based on the current signal.
3. The apparatus according to claim 1, further comprising a current measurement unit (50) disposed in parallel with the first detection unit (30) and configured to output a measurement signal, which is based on the current signal, such that the threshold condition for trip signal generation are a function of the current measurement.
4. The apparatus according to claim 2, further comprising a current measurement unit (50) disposed in parallel with the first and second detection units (30), (40) and configured to output a measurement signal, which is based on the current signal, such that the threshold condition for trip signal generation are a function of the current measurement.
5. The apparatus according to claim 1, further comprising a summing amplifier (20) operably disposed between the resistive element (10) and the first detection unit (30), wherein the microcontroller (80) is coupled to the summing amplifier (20).
6. The apparatus according to claim 1, further comprising an ambient temperature sensor (60) coupled to the microcontroller (80) by which the microcontroller (80) determines whether to compensate for temperature changes of the resistive element (10).
7. The apparatus according to claim 1, wherein the first detection unit (30) operates at a sampling rate of 300 kHz and filters all but those sub-signals having frequencies of about 6 kHz - 60 Hz from the current signal.
8. The apparatus according to claim 3, wherein the current measurement unit (50) operates at a sampling rate of 10 kHz.
9. A method of performing series and parallel arc fault current interruption (AFCI), the method comprising:
sensing a load current;
sampling a signal based on the sensed load current at a high frequency (operation 200);
when the high frequency sampling is complete and, if a zero cross is determined to have been sampled, computing zero cross discrete wavelet coefficients (operation 410);
when the high frequency sampling is complete and, if the zero cross is determined to have not been sampled, computing non-zero cross discrete wavelet coefficients (operation 420); and issuing a trip signal if a threshold criterion is determined to have been met based on the zero and non-zero cross discrete wavelet coefficients (operation 600), (operation 700).
sensing a load current;
sampling a signal based on the sensed load current at a high frequency (operation 200);
when the high frequency sampling is complete and, if a zero cross is determined to have been sampled, computing zero cross discrete wavelet coefficients (operation 410);
when the high frequency sampling is complete and, if the zero cross is determined to have not been sampled, computing non-zero cross discrete wavelet coefficients (operation 420); and issuing a trip signal if a threshold criterion is determined to have been met based on the zero and non-zero cross discrete wavelet coefficients (operation 600), (operation 700).
10. A method of operating a current interrupter by detecting series and parallel arcs, the method comprising:
sensing a load current and generating a current signal therefrom;
low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions (operation 300);
medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients (operation 200);
sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region (operation 204);
computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof (operations 410, 420); and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies (operations 600, 700).
sensing a load current and generating a current signal therefrom;
low frequency filtering the current signal and determining a fundamental frequency and a zero-cross of the low frequency filtered current signal under different load conditions (operation 300);
medium and/or high frequency filtering the current signal and decomposing the medium and/or the high frequency filtered current signal to predetermined levels to obtain discrete wavelet coefficients (operation 200);
sampling the medium and/or the high frequency filtered current signal across the zero-cross and across a pre-determined non zero-cross region (operation 204);
computing absolute values of the discrete wavelet coefficients for the sampled medium and/or the sampled high frequency current signal at the zero-cross and the non zero-cross thereof (operations 410, 420); and summing respective energies of the computed absolute values of the discrete wavelet coefficients and issuing a trip decision based on the summed respective energies (operations 600, 700).
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| US12/179,114 | 2008-07-24 | ||
| US12/179,114 US8054591B2 (en) | 2008-07-24 | 2008-07-24 | Arc detection using discrete wavelet transforms |
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| CA2672279A1 true CA2672279A1 (en) | 2010-01-24 |
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| JP (1) | JP5476060B2 (en) |
| CN (1) | CN101673930B (en) |
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Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7003435B2 (en) | 2002-10-03 | 2006-02-21 | Leviton Manufacturing Co., Inc. | Arc fault detector with circuit interrupter |
| DE102007011485A1 (en) * | 2007-03-07 | 2008-09-11 | Grünenthal GmbH | Dosage form with more difficult abuse |
| CN101910856B (en) | 2008-01-29 | 2014-06-18 | 立维腾制造有限公司 | Self testing fault circuit interrupter apparatus and method |
| US8170816B2 (en) * | 2008-12-29 | 2012-05-01 | General Electric Company | Parallel arc detection using discrete wavelet transforms |
| US8599523B1 (en) | 2011-07-29 | 2013-12-03 | Leviton Manufacturing Company, Inc. | Arc fault circuit interrupter |
| US9508612B2 (en) | 2012-03-15 | 2016-11-29 | Applied Materials, Inc. | Method to detect wafer arcing in semiconductor manufacturing equipment |
| US9366716B2 (en) | 2013-05-23 | 2016-06-14 | Pentair Thermal Management Llc | Sub-harmonic arc fault detection system and method |
| US9366713B2 (en) | 2013-05-23 | 2016-06-14 | Pentair Thermal Management Llc | Arc fault detection system and method |
| FR3007529B1 (en) * | 2013-06-21 | 2015-07-24 | Schneider Electric Ind Sas | METHOD AND DEVICE FOR DETECTING ELECTRIC ARC |
| US9759758B2 (en) | 2014-04-25 | 2017-09-12 | Leviton Manufacturing Co., Inc. | Ground fault detector |
| CN105667489B (en) * | 2014-11-21 | 2018-04-17 | 财团法人车辆研究测试中心 | Electronics fault warning method in brake and system |
| WO2016157912A1 (en) * | 2015-03-31 | 2016-10-06 | 株式会社 東芝 | Electric appliance insulation diagnosis device and insulation diagnosis method |
| US10078105B2 (en) * | 2015-09-23 | 2018-09-18 | Abb Schweiz Ag | Electrical system with arc fault detection |
| EP3386051B1 (en) * | 2017-04-04 | 2021-06-23 | ABB Schweiz AG | Electronic protection device for detecting arcing fault |
| CN107085158A (en) * | 2017-06-20 | 2017-08-22 | 浙江中科城安消防科技有限公司 | A kind of fault arc detection device and method for gathering communication |
| US11029343B2 (en) * | 2019-01-30 | 2021-06-08 | Koninklijke Fabriek Inventum B.V. | System and method for ground fault detection using hall effect sensors |
| CN109917241A (en) * | 2019-03-19 | 2019-06-21 | 德力西电气有限公司 | A kind of detection method and fault electric arc breaker of fault electric arc |
| CN110568329B (en) * | 2019-09-16 | 2020-08-18 | 珠海格力电器股份有限公司 | Arc detection method, household appliance and computer readable storage medium |
| CN111077406A (en) * | 2019-11-27 | 2020-04-28 | 西安交通大学 | Direct-current arc fault detection and positioning method based on pulse polarity characteristic distribution spectrogram |
| CN112305376B (en) * | 2020-10-28 | 2022-08-05 | 国网山东省电力公司青岛供电公司 | Low-voltage distribution line fault arc detection and identification method |
| CN112881795A (en) * | 2021-01-07 | 2021-06-01 | 国网河南省电力公司电力科学研究院 | Wavelet analysis-based power grid frequency large disturbance rapid discrimination method and system |
| CN113917294B (en) * | 2021-09-25 | 2023-10-13 | 湖北创全电气有限公司 | Intelligent self-adaptive arc detection method based on wavelet decomposition and application device thereof |
| CN113933749B (en) * | 2021-10-18 | 2023-06-16 | 广东电网有限责任公司东莞供电局 | Method, device, equipment and storage medium for detecting high-resistance ground fault of power distribution network |
Family Cites Families (117)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58169732A (en) * | 1982-03-31 | 1983-10-06 | 松下電工株式会社 | Circuit breaker |
| JPH04221496A (en) * | 1990-03-29 | 1992-08-11 | Intel Corp | Computer memory circuit mounted onto single substrate and method of finishing sequence for erasing computer memory |
| US5185684A (en) * | 1991-03-28 | 1993-02-09 | Eaton Corporation | Frequency selective arc detection |
| US5185685A (en) * | 1991-03-28 | 1993-02-09 | Eaton Corporation | Field sensing arc detection |
| US5185687A (en) * | 1991-03-28 | 1993-02-09 | Eaton Corporation | Chaos sensing arc detection |
| US5185686A (en) * | 1991-03-28 | 1993-02-09 | Eaton Corporation | Direction sensing arc detection |
| US5208542A (en) * | 1991-03-28 | 1993-05-04 | Eaton Corporation | Timing window arc detection |
| US5223795A (en) * | 1992-07-30 | 1993-06-29 | Blades Frederick K | Method and apparatus for detecting arcing in electrical connections by monitoring high frequency noise |
| US5434509A (en) * | 1992-07-30 | 1995-07-18 | Blades; Frederick K. | Method and apparatus for detecting arcing in alternating-current power systems by monitoring high-frequency noise |
| US5729145A (en) | 1992-07-30 | 1998-03-17 | Siemens Energy & Automation, Inc. | Method and apparatus for detecting arcing in AC power systems by monitoring high frequency noise |
| WO1994022031A1 (en) | 1993-03-22 | 1994-09-29 | Blades Frederick K | Electric arc detector |
| US5452223A (en) * | 1993-08-20 | 1995-09-19 | Eaton Corporation | Arc detection using current variation |
| US5659453A (en) * | 1993-10-15 | 1997-08-19 | Texas A&M University | Arc burst pattern analysis fault detection system |
| US5485093A (en) * | 1993-10-15 | 1996-01-16 | The Texas A & M University System | Randomness fault detection system |
| US5600526A (en) * | 1993-10-15 | 1997-02-04 | The Texas A & M University System | Load analysis system for fault detection |
| US5550751A (en) * | 1993-10-15 | 1996-08-27 | The Texas A & M University System | Expert system for detecting high impedance faults |
| US5578931A (en) | 1993-10-15 | 1996-11-26 | The Texas A & M University System | ARC spectral analysis system |
| US5512832A (en) * | 1993-10-15 | 1996-04-30 | The Texas A & M University System | Energy analysis fault detection system |
| US5506789A (en) * | 1993-10-15 | 1996-04-09 | The Texas A & M University System | Load extraction fault detection system |
| US5682101A (en) | 1995-03-13 | 1997-10-28 | Square D Company | Arcing fault detection system |
| US6313642B1 (en) | 1995-03-13 | 2001-11-06 | Square D Company | Apparatus and method for testing an arcing fault detection system |
| US6259996B1 (en) * | 1998-02-19 | 2001-07-10 | Square D Company | Arc fault detection system |
| US5691869A (en) | 1995-06-06 | 1997-11-25 | Eaton Corporation | Low cost apparatus for detecting arcing faults and circuit breaker incorporating same |
| US5726577A (en) * | 1996-04-17 | 1998-03-10 | Eaton Corporation | Apparatus for detecting and responding to series arcs in AC electrical systems |
| US5835321A (en) | 1996-08-02 | 1998-11-10 | Eaton Corporation | Arc fault detection apparatus and circuit breaker incorporating same |
| AU6036798A (en) | 1997-01-24 | 1998-08-26 | Square D Company | Arcing fault detection system |
| US5839092A (en) | 1997-03-26 | 1998-11-17 | Square D Company | Arcing fault detection system using fluctuations in current peaks and waveforms |
| JPH1141793A (en) * | 1997-07-14 | 1999-02-12 | Mitsubishi Electric Corp | Exciting inrush current discriminator |
| US5815352A (en) * | 1997-09-29 | 1998-09-29 | Eaton Corporation | Arc fault detector with limiting of sensed signal to shape response characteristic and circuit breaker incoprorating same |
| US5805397A (en) * | 1997-09-29 | 1998-09-08 | Eaton Corporation | Arcing fault detector with multiple channel sensing and circuit breaker incorporating same |
| US6625550B1 (en) * | 1998-02-19 | 2003-09-23 | Square D Company | Arc fault detection for aircraft |
| US6621669B1 (en) * | 1998-02-19 | 2003-09-16 | Square D Company | Arc fault receptacle with a feed-through connection |
| US6414829B1 (en) * | 1998-02-19 | 2002-07-02 | Square D Company | Arc fault circuit interrupter |
| US5986860A (en) | 1998-02-19 | 1999-11-16 | Square D Company | Zone arc fault detection |
| US6137418A (en) * | 1998-03-05 | 2000-10-24 | Eaton Corporation | Single channel apparatus for on-line monitoring of three-phase AC motor stator electrical faults |
| US5969920A (en) | 1998-03-27 | 1999-10-19 | Eaton Corporation | Test circuit for verifying operation of an arc fault detector |
| US5982593A (en) | 1998-05-12 | 1999-11-09 | Eaton Corporation | Circuit interrupter with test actuator for ground fault and arc fault test mechanisms |
| US5933305A (en) * | 1998-06-02 | 1999-08-03 | Eaton Corporation | Arc fault detector comparing integrated interval to interval filtered load current and circuit breaker incorporating same |
| US6266219B1 (en) * | 1998-06-02 | 2001-07-24 | Pass & Seymour, Inc. | Combination ground fault and arc fault circuit interrupter |
| US6052046A (en) * | 1998-07-24 | 2000-04-18 | Eaton Corporation | Miniaturized double pole circuit breaker with arc fault and ground fault protection |
| US6128170A (en) | 1998-11-19 | 2000-10-03 | General Electric Company | Analog based first and fast second pulse removal system |
| US6459273B1 (en) | 1998-11-23 | 2002-10-01 | Siemens Energy & Automation, Inc. | Arc fault detector method |
| US6031699A (en) * | 1998-11-23 | 2000-02-29 | Siemens Energy & Automation, Inc. | Arc fault detector apparatus, means and system |
| US6373257B1 (en) * | 1998-12-09 | 2002-04-16 | Pass & Seymour, Inc. | Arc fault circuit interrupter |
| US6198611B1 (en) * | 1998-12-15 | 2001-03-06 | Pass & Seymour, Inc. | Arc fault circuit interrupter without DC supply |
| US6377055B1 (en) * | 1998-12-18 | 2002-04-23 | Pass & Seymour, Inc. | Arc fault detector device with two stage arc sensing |
| US6362628B2 (en) * | 1998-12-21 | 2002-03-26 | Pass & Seymour, Inc. | Arc fault circuit detector device detecting pulse width modulation of arc noise |
| US6239962B1 (en) * | 1999-02-09 | 2001-05-29 | General Electric Company | ARC fault circuit breaker |
| US6426632B1 (en) * | 1999-03-29 | 2002-07-30 | George A. Spencer | Method and apparatus for testing an AFCI/GFCI circuit breaker |
| US6191589B1 (en) * | 1999-03-29 | 2001-02-20 | George A. Spencer | Test circuit for an AFCI/GFCI circuit breaker |
| US6255923B1 (en) * | 1999-06-25 | 2001-07-03 | General Electric Company | Arc fault circuit breaker |
| US6232857B1 (en) * | 1999-09-16 | 2001-05-15 | General Electric Company | Arc fault circuit breaker |
| US7212640B2 (en) * | 1999-11-29 | 2007-05-01 | Bizjak Karl M | Variable attack and release system and method |
| GB0000067D0 (en) * | 2000-01-06 | 2000-02-23 | Delta Electrical Limited | Current detector and current measurement apparatus including such detector with temparature compensation |
| US6633467B2 (en) | 2000-02-03 | 2003-10-14 | Pass & Seymour, Inc. | AFCI which detects and interrupts line side arcing |
| US6388849B1 (en) * | 2000-02-14 | 2002-05-14 | Eaton Corporation | ARC fault detector responsive to average instantaneous current and step increases in current and circuit breaker incorporating same |
| US6798628B1 (en) * | 2000-11-17 | 2004-09-28 | Pass & Seymour, Inc. | Arc fault circuit detector having two arc fault detection levels |
| US6972937B1 (en) | 2000-02-17 | 2005-12-06 | Pass & Seymour, Inc. | Arc fault circuit detector having two arc fault detection levels |
| US6839208B2 (en) * | 2000-02-17 | 2005-01-04 | Pass & Seymour, Inc | Arc fault circuit interrupter recognizing arc noise burst patterns |
| US6608741B1 (en) * | 2000-03-04 | 2003-08-19 | Pass & Seymour, Inc. | Two winding resonating arc fault sensor which boosts arc fault signals while rejecting arc mimicking noise |
| US6504692B1 (en) * | 2000-04-06 | 2003-01-07 | Pass & Seymour, Inc. | AFCI device which detects upstream and downstream series and parallel ARC faults |
| USD450660S1 (en) | 2000-04-14 | 2001-11-20 | General Electric Company | Single pole arc fault circuit breaker |
| US6628487B1 (en) * | 2000-04-27 | 2003-09-30 | Pass & Seymour, Inc. | Method and apparatus for detecting upstream series arc faults |
| KR100423886B1 (en) * | 2000-05-12 | 2004-03-24 | 휴먼엘텍 주식회사 | Arc fault circuit interrupter and circuit breaker having the same |
| US6556397B2 (en) * | 2000-05-12 | 2003-04-29 | Human El-Tech, Inc. | Device and method for detecting arc fault |
| US6522509B1 (en) * | 2000-07-21 | 2003-02-18 | Eaton Corporation | Arc fault detection in ac electric power systems |
| US6678137B1 (en) * | 2000-08-04 | 2004-01-13 | General Electric Company | Temperature compensation circuit for an arc fault current interrupting circuit breaker |
| US7277822B2 (en) * | 2000-09-28 | 2007-10-02 | Blemel Kenneth G | Embedded system for diagnostics and prognostics of conduits |
| US6417671B1 (en) * | 2000-11-07 | 2002-07-09 | General Electric Company | Arc fault circuit breaker apparatus and related methods |
| US6590754B1 (en) * | 2000-11-17 | 2003-07-08 | Pass & Seymour, Inc. | AFCI with false trip prevention filter |
| US6642832B2 (en) * | 2000-12-08 | 2003-11-04 | Texas Instruments Incorporated | ARC responsive thermal circuit breaker |
| US6654219B1 (en) | 2000-12-11 | 2003-11-25 | Pass & Seymour, Inc. | Arc fault detector with diagnostic indicator |
| US6882158B2 (en) * | 2001-01-24 | 2005-04-19 | General Dynamics Ots (Aerospace) Inc. | Series arc fault diagnostic for aircraft wiring |
| US6777953B2 (en) * | 2001-01-24 | 2004-08-17 | General Dynamics (Otc) Aerospace, Inc. | Parallel arc fault diagnostic for aircraft wiring |
| US6703842B2 (en) * | 2001-01-25 | 2004-03-09 | Matsushita Electric Works, Ltd. | Method for discriminating abnormal current including arc current in AC load circuit and apparatus for executing the same |
| WO2002073805A1 (en) * | 2001-03-14 | 2002-09-19 | Koninklijke Philips Electronics N.V. | A current mode device and a communication arrangement comprising current mode devices |
| US6542056B2 (en) * | 2001-04-30 | 2003-04-01 | Eaton Corporation | Circuit breaker having a movable and illuminable arc fault indicator |
| US6522228B2 (en) * | 2001-04-30 | 2003-02-18 | Eaton Corporation | Circuit breaker including an arc fault trip actuator having an indicator latch and a trip latch |
| US6876203B2 (en) * | 2001-06-11 | 2005-04-05 | Frederick K. Blades | Parallel insulation fault detection system |
| US7136265B2 (en) | 2001-10-17 | 2006-11-14 | Square D Company | Load recognition and series arc detection using bandpass filter signatures |
| US7068480B2 (en) * | 2001-10-17 | 2006-06-27 | Square D Company | Arc detection using load recognition, harmonic content and broadband noise |
| US7151656B2 (en) * | 2001-10-17 | 2006-12-19 | Square D Company | Arc fault circuit interrupter system |
| GB2381607A (en) | 2001-11-01 | 2003-05-07 | Matthew James Johnson | Serila-parallel correlator architecture |
| US6999289B2 (en) * | 2001-11-09 | 2006-02-14 | Pass & Seymour, Inc. | Arc fault circuit interrupter which detects the cessation of arcs of an arc fault |
| US20030098982A1 (en) * | 2001-11-28 | 2003-05-29 | Jds Uniphase Corporation | Truncated series-based resonant cavity interferometer |
| US6545574B1 (en) * | 2001-12-17 | 2003-04-08 | General Electric Company | Arc fault circuit breaker |
| US6736944B2 (en) * | 2002-04-12 | 2004-05-18 | Schneider Automation Inc. | Apparatus and method for arc detection |
| US6707651B2 (en) * | 2002-06-03 | 2004-03-16 | Eaton Corporation | ARC fault or ground fault or ARC fault/ground fault trip signal generator and trip unit employing the same |
| US6720872B1 (en) * | 2002-07-16 | 2004-04-13 | Eaton Corporation | Ground fault/arc fault circuit interrupter and method of testing the same with a test button and a reset button |
| JP2004082406A (en) * | 2002-08-23 | 2004-03-18 | Tdk Corp | Optical recording medium |
| US7106069B2 (en) | 2002-11-15 | 2006-09-12 | Human El-Tech, Inc. | Apparatus for detecting arc fault |
| KR100487929B1 (en) * | 2002-11-15 | 2005-05-27 | 서창전기통신 주식회사 | Device for Detecting Arc Fault |
| US20040100274A1 (en) * | 2002-11-22 | 2004-05-27 | Siemens Energy & Automation, Inc. | Arc fault tester |
| US6980407B2 (en) | 2002-12-09 | 2005-12-27 | Texas Instrument Incorporated | Arc detection apparatus and method |
| US6927597B2 (en) * | 2002-12-20 | 2005-08-09 | General Electric Company | Direct current machine monitoring system and method |
| US7010438B2 (en) * | 2002-12-23 | 2006-03-07 | Power Measurement Ltd. | Integrated circuit with power monitoring/control and device incorporating same |
| US6833713B2 (en) * | 2003-01-31 | 2004-12-21 | Delphi Technologies, Inc. | Smart wire harness for an electrical circuit |
| EP1593072A2 (en) * | 2003-02-07 | 2005-11-09 | Power Measurement Ltd | A method and system for calculating and distributing utility costs |
| US7009406B2 (en) * | 2003-04-24 | 2006-03-07 | Delphi Technologies, Inc. | Arc fault detector and method |
| US7069116B2 (en) * | 2004-02-02 | 2006-06-27 | Abb Inc. | High impedance fault detection |
| US7062388B2 (en) * | 2004-03-18 | 2006-06-13 | General Electric Company | Series arc detection |
| US7721069B2 (en) * | 2004-07-13 | 2010-05-18 | 3Plus1 Technology, Inc | Low power, high performance, heterogeneous, scalable processor architecture |
| US7148696B2 (en) * | 2005-01-12 | 2006-12-12 | Eaton Corporation | Electrical switching apparatus and method including fault detection employing acoustic signature |
| US7391218B2 (en) * | 2005-03-11 | 2008-06-24 | Honeywell International Inc. | Method and apparatus for generalized arc fault detection |
| US7362553B2 (en) * | 2005-06-08 | 2008-04-22 | Eaton Corporation | Arc fault circuit interrupter and method for inhibiting series arc protection based on dimmer phase angle |
| US7672739B2 (en) | 2005-08-11 | 2010-03-02 | University Of South Florida | System for multiresolution analysis assisted reinforcement learning approach to run-by-run control |
| US7253637B2 (en) * | 2005-09-13 | 2007-08-07 | Square D Company | Arc fault circuit interrupter system |
| EP1924861A2 (en) | 2005-09-15 | 2008-05-28 | Honeywell International Inc. | Arc fault detection and confirmation using voltage and current analysis |
| US7359168B2 (en) * | 2005-10-18 | 2008-04-15 | Eaton Corporation | Arc fault circuit interrupter and method for disabling series arc protection during current transients |
| US7403129B2 (en) * | 2006-05-10 | 2008-07-22 | Eaton Corporation | Electrical switching apparatus and method employing acoustic and current signals to distinguish between parallel and series arc faults |
| US7368918B2 (en) * | 2006-07-27 | 2008-05-06 | Siemens Energy & Automation | Devices, systems, and methods for adaptive RF sensing in arc fault detection |
| US7463465B2 (en) * | 2006-12-28 | 2008-12-09 | General Electric Company | Series arc fault current interrupters and methods |
| US7558033B2 (en) * | 2007-02-27 | 2009-07-07 | Eaton Corporation | Arc fault circuit interrupter and method of parallel and series arc fault detection |
| US7969156B2 (en) | 2007-03-30 | 2011-06-28 | Liebert Corporation | Method and apparatus for monitoring a load |
| CN201051651Y (en) * | 2007-06-18 | 2008-04-23 | 邢刚 | A failure arc protection breaker |
| US20090040666A1 (en) * | 2007-08-07 | 2009-02-12 | Elms Robert T | Circuit interrupter including test circuit |
| US7865321B2 (en) * | 2007-10-01 | 2011-01-04 | The Texas A&M University System | Arcing event detection |
-
2008
- 2008-07-24 US US12/179,114 patent/US8054591B2/en active Active
-
2009
- 2009-07-16 CA CA2672279A patent/CA2672279A1/en not_active Abandoned
- 2009-07-22 JP JP2009170658A patent/JP5476060B2/en active Active
- 2009-07-24 CN CN200910160133.4A patent/CN101673930B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN101673930A (en) | 2010-03-17 |
| US20100020451A1 (en) | 2010-01-28 |
| US8054591B2 (en) | 2011-11-08 |
| JP5476060B2 (en) | 2014-04-23 |
| JP2010045026A (en) | 2010-02-25 |
| CN101673930B (en) | 2014-11-05 |
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