Title of Invention

DEVICES, SYSTEMS, AND METHODS FOR ADAPTIVE RF SENSING IN ARC FAULT DETECTION

Abstract Certain exemplary embodiments comprise a method, which can comprise automatically generating an output signal responsive to an input signal. The input signal can be indicative of an arc fault. The output signal can be configured to cause an electrical circuit to open. The output signal can be generated responsive to a derived signal based upon a first threshold having a first amplitude.
Full Text Devices, Systems, and Methods for Adaptive RF Sensing in Arc Fault Detection
Background
[1] United States Patent No. 5,729,145 (Blades), which is incorporated by
reference herein in its entirety, allegedly recites that "[a]rcing in an AC power
system is detected by monitoring the power waveform for wideband high-
frequency noise, and examining the detected noise for patterns of variation in
its amplitude synchronized to the power waveform. A narrowband, swept-
frequency detector and synchronous averaging may be employed to improve
discrimination of arc noise from background interference. An arcing fault
interrupter for controlling a single circuit, and a whole house monitor, for
detecting arcing anywhere in a house, are described." See Abstract.
[2] United States Patent Publication No. 20050254187 (Chu), which is
incorporated by reference herein in its entirety, allegedly recites an "apparatus
and method for event-based detection of arc faults in a circuit. At least one
sensor is arranged to sense anomaly events in an electrical signal in the circuit.
The anomaly events include distortions of the waveform of the electrical
signal. A processor identifies tne anomaly events, and generates an alarm
signal when the anomaly event?, are indicative of an arc fault. The anomaly
events may include current waveform distortions and/or voltage waveform
distortions. Waveform distortions may be measured indirectly; an impedance
may be placed in series with the circuit, so that distortions of the current
produces distortions in the voltage drop across the impedance, in which case
those voltage distortions may be anomaly events. Arc faults may be identified
by examining intervals such as individual AC cycles for anomaly events, then
determining whether at least n of a moving series of m intervals include at
least p such anomaly events. An actuator may be used to oppose any arc faults
that are detected, such as a circuit breaker to interrupt the circuit, so as to
provide arc fault protection. Existing circuits may be retrofitted with the
sensor and processor for arc fault detection, along with an actuator for arc fault
protection." See Abstract.

[3] United States Patent No. 6,459,273 (Dollar), which is incorporated by
reference herein in its entirety, allegedly recites a "sputtering arc fault detector
(10) for a system having an electrical conductor (14) carrying current to a
load. The sputtering arc fault detector includes a current monitor (64) coupled
to the conductor for generating a variable signal responsive to behavior of the
current in the conductor. A level detector (58) is coupled to the monitor and
generates a first pulse when the variable signal exceeds a first level. A step
detector (62) is coupled to the monitor and is responsive to rapid step
increases of the variable signal. The step detector generates a second pulse
when the variable signal exceeds a second level. An arc verifier (48), which is
coupled to the level detector and the step detector, combines the first and
second pulses, and generates a fault signal when the combined pulses exceed a
third level." See Abstract.
Summary
[4] Certain exemplary embodiments comprise a method, which can comprise
automatically generating an output signal responsive to an input signal. The
input signal can be indicative of an arc fault. The output signal can be
configured to cause an electrical circuit to open. The output signal can be
generated responsive to a derived signal based upon a first threshold having a
first amplitude.
Brief Description of the Drawings
[5] A wide variety of potential practical and useful embodiments will be more
readily understood through the following detailed description of certain
exemplary embodiments, with reference to the accompanying exemplary
drawings in which:
[63 BIG. 1 is a plot of signal strength waveforms generated by both an
exemplary arc fault condition and by an exemplary noise waveform;
[7] FIG. 2 is a block diagram of an exemplary embodiment of a system
2000;
[8] FIG. 3 is a flow chart of an exemplary Arc Fault Detection method
3000; and

[9] FIG. 4 is a block diagiram of an exemplary embodiment of an
information device 4000.
Definitions
[10] When the following terms are used substantively herein, the accompanying
definitions apply. These terms and definitions are presented without
prejudice, and, consistent with the application, the right to redefine these terms
during the prosecution of this application or any application claiming priority
hereto is reserved. For the purpose of interpreting a claim of any patent that
claims priority hereto, each definition (or redefined term if an original
definition was amended during the prosecution of that patent), functions as a
clear and unambiguous disavowal of the subject matter outside of that
definition.
[11] a - at least one.
[12] activity - an action, act, step, and/or process or portion thereof.
[13] adapted to - made suitable or fit for a specific use or situation.
[14] algorithm — machine instructions adapted to provide one or more
predetermined results.
[15] amplifier - a device that increases a magnitude of signals passing
through it.
[16] amplify - to increase a magnitude of a signal.
[17] amplitude - magnitude.
[18] analog - a signal formed from continuous measurement and/or input.
[19] analog to digital converter - a device configured to receive an
analog, input and generate a digital output related to the analog input.
[20] analysis - a
[21] and/or - either in conjunction with or in alternative to.
[22] apparatus - an appliance or device for a particular purpose.
[23] approximately - nearly the same as.
[24] arc fault - a discharge of electricity between two or more conductors,
the discharge associated with at least a predetermined voltage, current,
and/or power level.
[25] associate - to join, connect together, and/or relate.

[26] associated with - related to.
[27] automatically - acting or operating in a manner essentially
independent of external influence or control. For example, an
automatic light switch can rum on upon "seeing" a person in its view,
without the person manually operating the light switch.
[28] average - a value obtained by dividing a sum of a set of quantities by
the count of quantities in the set.
[29] below - less than in magnitude.
[30] between - in a separating interval.
[31] calibrate - to check, adjust, and/or determine by comparison with a
standard.
[32] can - is capable of, in at least some embodiments.
[33] cause - to produce an effect.
[34] change — to correct to a more desired value.
[35] check - to inspect and/or test.
[36] circuit - an electrically conducting pathway.
[37] circuit breaker — a device adapted to automatically open an
alternating current electrical circuit
[38] code — machine-readabl«5 instructions.
[39] comprising - including but not limited to.
[40] configure - to make suitable or fit for a specific use or situation.
[41] configured to - capable of performing a particular function.
[42] convert - to transform, adapt, and/or change.
[43] correct - to change to a more desired value.
[44] corruption - a state of being altered from a desired form,
[45] count - (n.) a number reached by counting.
[46] count - (v.) to increment, typically by one and beginning at zero.
[47] create - to bring into being.
[48] current - a flow of electrical energy.
[49] data - distinct pieces of information, usually formatted in a special or
predetermined way and/or organized to express concepts.
[50] data structure - an organization of a collection of data that allows the
data to be manipulated effectively and/or a logical relationship among

data elements that is designed to support specific data manipulation
functions. A data structure can comprise meta data to describe the
properties of the data structure. Examples of data structures can
include: array, dictionary, graph, hash, heap, linked list, matrix, object,
queue, ring, stack, tree, and/or vector.
[51] dedicate - to commit and/or give entirely to a particular use, activity,
cause, and/or entity.
[52] define — to establish the outline, form, or structure of.
[53] derive — to obtain from a source.
[54] detect — to sense, perceive, and/or identify.
[55] determine - to obtain, calculate, decide, deduce, and/or ascertain.
[56] . device - a machine, manufacture, and/or collection thereof.
[57] differential current - a difference between a first flow of electrical
charge involving a first electrical conductor and second flow of
electrical charge involving a second electrical conductor.
[58] digital - non-analog; discrete.
[59] direct current (DC) - a non-alternating electric current.
[60] duty cycle - a percentage of time that a pulse train is at a high logic
state.
[61] electrical - pertaining to electricity.
[62] electrically coupled - connected in a manner adapted to transfer
electrical energy.
[63] energy - usable power.
[64] estimate - to calculate and/or determine approximately and/or
tentatively.
[65] exceed - to be greater in magnitude than.
[66] execute - to carry out one or more machine instructions.
[67] fault - an arc fault or a ground fault.
[68] fewer — less in number compared to a reference.
[69] filter - (n.) one or more electrically coupled components configured to
remove a portion of an electrical signal.
[70] filter - (v.) to remove a portion of an electrical signal.

[71 ] frequency - a number of times of an occurrence in a predetermined
time period.
[72] from - used to indicate a source.
[73] gain - an increase or decrease in signal power, voltage, and/or current,
expressed as the ratio of output to input.
[74] generate - to create, produce, give rise to, and/or bring into existence.
[75] greater — larger in magnitude.
[76] ground fault - a shorting of an electrical device or circuit to ground.
[77] haptic - involving the human sense of kinesthetic movement and/or
the human sense of touch. Among the many potential haptic
experiences are numerous sensations, body-positional differences in
sensations, and time-based changes in sensations that are perceived at
least partially in non-visual, non-audible, and non-olfactory manners,
including the experiences of tactile touch (being touched), active
touch, grasping, pressure, friction, traction, slip, stretch, force, torque,
impact, puncture, vibration, motion, acceleration, jerk, pulse,
orientation, limb position, gravity, texture, gap, recess, viscosity, pain,
itch, moisture, temperature, thermal conductivity, and thermal
capacity.
[78] historical — from a prior time.
[79] indicate - to signify.
[80] indicative - serving to indicate.
[81] indicator — a signal for attracting attention.
[82] information device - any device capable of processing information,
such as any general purpose and/or special purpose computer, such as a
personal computer, workstation, server, minicomputer, mainframe,
supercomputer, computer terminal, laptop, wearable computer, and/or
Personal Digital Assistant (PDA), mobile terminal, Bluetooth device,
communicator, "smart" phone (such as a Treo-like device), messaging
service (e.g., Blackberry) receiver, pager, facsimile, cellular telephone,
a traditional telephone, telephonic device, a programmed
microprocessor or microcontroller and/or peripheral integrated circuit
elements, an ASIC or other integrated circuit, a hardware electronic

logic circuit such as a discrete element circuit, and/or a programmable
logic device such as a PLD, PLA, FPGA, or PAL, or the like, etc. In
general any device on which resides a finite state machine capable of
implementing at leas-: a portion of a method, structure, and/or or
graphical user interface described herein may be used as an
information device. An information device can comprise components
such as one or more network interfaces, one or more processors, one or
more memories containing instructions, and/or one or more
input/output (I/O) devices, one or more user interfaces coupled to an
I/O device, etc.
[83} initialize - to prepare something for use and/or some future event
[84] input - related to electricity entering a device.
[85] input/output (I/O) device - any sensory-oriented input and/or output
device, such as an audio, visual, haptic, olfactory, and/or taste-oriented
device, including, for example, a monitor, display, projector, overhead
display, keyboard, keypad, mouse, trackball, joystick, gamepad, wheel,
touchpad, touch panel, pointing device, microphone, speaker, video
camera, camera, scanner, printer, haptic device, vibrator, tactile
simulator, and/or tactile pad, potentially including a port to which an
I/O device can be attached or connected.
[86] kilohertz - a count of thtwsands of cycles per second.
[87] lower - lesser in magnitude in relation to something else.
[88] low pass - configured to allow sub-signals of a signal characterized by
a frequency below a predetermined maximum threshold to not be
filtered, but to filter sub-signals characterized by frequencies above Ihe
predetermined maximum threshold from the signal.
[89] machine instructions - directions adapted to cause a machine, such as
an information device, to perform one or more particular activities,
operations, or functions. The directions, which can sometimes form an
entity called a "processor", "kernel", "operating system", "program",
"application", "utility", "subroutine", "script", "macro", "file",
"project", "module", "library", "class", and/or "object", etc., can be
embodied as machine code, source code, object code, compiled code,

assembled code, interpretable code, and/or executable code, etc., in
hardware, firmware, .md/or software.
[90] machine readable medium - a physical structure from which a
machine can obtain data and/or information. Examples include a
memory, punch cards, etc.
[91] magnitude — a size or extent.
[92] manage - to direct or control.
[93] may - is allowed and/or permitted to, in at least some embodiments.
[94] measure - to determine a value of something relative to a standard.
[95] measurement - a dimension, quantification, and/or capacity, etc.
determined by observation.
[96] memory device — an apparatus capable of storing analog or digital
information, such as instructions and/or data. Examples include a non-
volatile memory, volatile memory, Random Access Memory, RAM,
Read Only Memory, ROM, flash memory, magnetic media, a hard
disk, a floppy disk, a magnetic tape, an optical media, an optical disk, a
compact disk, a CD, a digital versatile disk, a DVD, and/or a raid
array, etc. The memory device can be coupled to a processor and/or
can store instructions adapted to be executed by processor, such as
according to an embodiment disclosed herein.
[97] method - a process, procedure, and/or collection of related activities
for accomplishing something.
[98] microprocessor - an integrated circuit that comprises a central
processing unit.
[99] mix - to combine to produce a composite signal.
[100] network - a communicatively eoupled plurality of nodes. A network
can be and/or utilize an) of a wide variety of sub-networks, such as a
circuit switched, public-switched, packet switched, data, telephone,
telecommunications, video distribution, cable, terrestrial, broadcast,
satellite, broadband, corporate, global, national, regional, wide area,
backbone, packet-switched TCP/IP, Fast Ethernet, Token Ring, public
Internet, private, ATM, multi-domain, and/or multi-zone sub-network,
one or more Internet service providers, and/or one or more information

devices, such as a switch, router, and/or gateway not directly
connected to a local area network, etc.
[101] network interface - any device, system, or subsystem capable of
coupling an information device to a network. For example, a network
interface can be a telephone, cellular phone, cellular modem, telephone
data modem, fax modem, wireless transceiver, Ethernet card, cable
modem, digital subscriber line interface, bridge, hub, router, or other
similar device.
[102] obtain — to receive, iaiculate, determine, and/or compute.
[ 103] occur - to take place.
[104] operational — a state of being functional.
[105] open - to create a gap across which an electrical current is
substantially restricted from flowing.
[106] oscillating carrier -a predetermined time-varying waveform.
[ 107] output - something produced, and/or generated.
[108] outside - not within.
[109] parameter -one of a wet of measurable factors, such as an electrical
voltage value, current value, and/or frequency value.
[110] percentage — a proportion or share in relation to a whole.
[Ill] perform - to cany out.
[112] pin - an electrically conductive appendage of a microprocessor.
[113] plurality - the state of being plural and/or more than one.
[114] power supply — a source of electrical energy.
[115] potential - capable of being but not yet in existence.
[116] predetermined - established in advance.
[117] prevent — to keep an event from happening.
[118] probability - a quantitative representation of a likelihood of an
occurrence.
[119] processor - a device and/or set of machine-readable instructions for
performing one or more predetermined tasks. A processor can
comprise any one or a combination of hardware, firmware, and/or
software. A processor can-utilize mechanical, pneumatic, hydraulic,
electrical, magnetic, optical, informational, chemical, and/or biological

principles, signals, and/or inputs to perform the task(s). In certain
embodiments, a processor can act upon information by manipulating,
analyzing, modifying, converting, transmitting the information for use
by an executable procedure and/or an information device, and/or
routing the information to an output device. A processor can function
as a central processing unit, local controller, remote controller, parallel
controller, and/or distributed controller, etc. Unless stated otherwise,
the processor can be a general-purpose device, such as a
microcontroller and/or a microprocessor, such the Pentium IV series of
microprocessor manufactured by the Intel Corporation of Santa Clara,
California. In certain embodiments, the processor can be dedicated
purpose device, such as an Application Specific Integrated Circuit
(ASIC) or a Field Programmable Gate Array (FPGA) .that has been
designed to implement in its hardware and/or firmware at least a part
of an embodiment disclosed herein.
[ 120] produce — to manufacture or make.
[121] project — to calculate, estimate, or predict.
[122] provide - to furnish, supply, give, and/or make available.
[123] range — a measure of an extent of a set of values.
[124] receive - to take, get, acquire, and/or have bestowed upon.
[125] recommend - to suggest, praise, commend, and/or endorse.
[126] reference - an indicator that provides a value and/or orientation
relative to something else.
[ 127] relative — in comparison with.
[128] render - to make perceptible to a human, for example as data,
commands, text, graphics, audio, video, animation, and/or hyperlinks,
etc., such as via any visual, audio, and/or haptic means, such as via a
display, monitor, electric paper, ocular implant, cochlear implant,
speaker, etc.
[129] repeatedly - again and again; repetitively.
[ 130] request - (n.) a message asking for something.
[131] request - (v.) to express a desire for and/or ask for.

[132] resistive current sensor - a device configured to measure an electrical
flow via a voltage drop across a resistor.
[133] resistor - a device u«ed to control current in an electric circuit by
impeding a flow of electrons.
[134] responsive - reacting to an influence and/or impetus.
[135] restart - begin again.
[136] run status - an indication of operation or non-operation.
[137] sample - to take a portion that is representative of a whole.
[ 138] select — to make a choice or selection from alternatives.
[139] sensor — a device or system adapted to detect or perceive
automatically.
[140] set - a related plurality
[141] signal — information,.such as machine instructions for activities,
encoded as automatically detectable variations in a physical variable,
such as a pneumatic, hydraulic, acoustic, fluidic, mechanical,
electrical, magnetic, optical, chemical, and/or biological variable, such
as power, energy, pressure, flowrate, viscosity, density, torque, impact,
force, voltage, current, resistance, magnetomotive force, magnetic field
intensity, magnetic field flux, magnetic flux density, reluctance,
permeability, index of refraction, optical wavelength, polarization,
reflectance, transmittancct, phase shift, concentration, and/or
temperature, etc. Depending on the context, a signal can be
synchronous, asynchronous, hard real-time, soft real-time, non-real
time, continuously generated, continuously varying, analog, discretely
generated, discretely varying, quantized, digital, continuously
measured, and/or discretely measured, etc.
[142] simulate - to create as a representation or model of another thing.
(143] single — one item.
[144] store - to place, hold, and/or retain data, typically in a memory.
[145] substantially - to a great extent or degree: •
[146] system — a collection of mechanisms, devices, data, and/or
instructions, the collection designed to perform one or more specific
functions.

[147] temperature - measure of the average kinetic energy of the molecules
in a sample of matter, expressed in terms of units or degrees designated
on a standard scale.
[148] terminate — to stop.
[ 149] time period - an interval of a defined duration.
[150] transmit - to send as a signal, provide, furnish, and/or supply.
[151] trip - (n.) an opening: of an electrical circuit that interrupts current
flow in the electrical circuit.
[1S2] trip — (v.) to open an electrical circuit; to automatically interrupt
current flow in an electrical circuit.
[153] upper - greater in magnitude in relation to something else.
[154] user - any person, process, device, program, protocol, and/or system
that uses a device.
[155] user interface - any device for rendering information to a user and/or
requesting information from the user. A user interface includes at least
one of textual, graphical, audio, video, animation, and/or haptic
elements. A textual element can be provided, for example, by a
printer, monitor, display, projector, etc. A graphical element can be
provided, for example, via a monitor, display, projector, and/or visual
indication device, such as a light, flag, beacon, etc. An audio element
can be provided, for example, via a speaker, microphone, and/or other
sound generating and/or receiving device. A video element or
animation element can be provided,, for example, via a monitor,
display, projector, and/or other visual device. A haptic element can be
provided, for example, via a very low frequency speaker, vibrator,
tactile stimulator, tactile pad, simulator, keyboard, keypad, mouse,
trackball, joystick, gamepad, wheel, touchpad, touch panel, pointing
device, and/or other haptic device, etc. A user interface can include
one or more textual elements such as, for example, one or more letters,
number, symbols, etc. A user interface can include one or more
graphical elements such as, for example, an image, photograph,
drawing, icon, window, title bar, panel, sheet, tab, drawer, matrix,
table, form, calendar, outline view, frame, dialog box, static text, text

box, list, pick list, pop-up list, pull-down list, menu, tool bar, dock,
check box, radio button, hyperlink, browser, button, control, palette,
preview panel, color wheel, dial, slider, scroll bar, cursor, status bar,
stepper, and/or progress indicator, etc. A textual and/or graphical
element can be used for selecting, programming, adjusting, changing,
specifying, etc. an appearance, background color, background style,
border style, border thickness, foreground color, font, font style, font
size, alignment, line spacing, indent, maximum data length, validation,
query, cursor type, pointer type, autosizing, position, and/or dimension,
etc. A user interface can include one or more audio elements such as,
for example, a volume control, pitch control, speed control, voice
selector, and/or one or more elements for controlling audio play, speed,
pause, fast forward, reverse, etc. A user interface can include one or
more video elements such as, for example, elements controlling video
play, speed, pause, fasi forward, reverse, zoom-in, zoom-out, rotate,
and/or tilt, etc. A user interface can include one or more animation
elements such as, for example, elements controlling animation play,
pause, fast forward, reverse, zoom-in, zoom-out, rotate, tilt, color,
intensity, speed, frequency, appearance, etc. A user interface can
include one or more haptic elements such as, for example, elements
utilizing tactile stimulus, force, pressure, vibration, motion,
displacement, temperature, etc.
[156] utilize — to put to use.
[157] value - an assigned or calculated numerical quantity.
[158] variation measure - an extent to which something changes.
[159] via — by way of and/or utilizing.
[160] voltage - a difference in electrical potential between any two
conductors of an electrical circuit.
[161] waveform — a profile, graph, and/or visual model of variations of a
signal's voltage and/or current over time.
[ 162] weight - a value indicative of importance.
[163] within - inside of.

Detailed Description
[164] Certain exemplary embodiments provide a method, which can comprise
automatically generating an output signal responsive to an input signal. The
input signal can be indicative of an arc fault. The output signal can be
configured to cause an electrical circuit to open. The output signal can be
generated responsive to a derived signal based upon a first threshold having a
first amplitude.
[165] Low amperage arcing in Alternating Current (AC) power systems can be
distinguished from non-arcing conditions through the measurement of
broadband Radio Frequency (RF) energy content generated by the fault. One
or more Broadband over Power Line (BPL) signals and/or noise signals can be
characterized by waveforms that can comprise similar characteristics to arc
fault generated waveforms. Noise can be conducted within an AC power
system and/or can be radiated.
[166] Certain exemplary embodiments can distinguish between and arc fault and
BPL and/or noise signals and/or waveforms. Certain exemplary embodiments
can allow an arc fault detector, based on sensing RF energy, to operate in the
presence of various broadband Radio Frequency (RF) noise sources of varying
intensities and with frequency content that includes frequencies being utilized
for arc fault detection. Additionally, multiple noise sources might be
compensated for simultaneously.
[167] Certain exemplary embodiments can be adapted to discriminate between
arcing and non-arcing conditions when environmental broadband RF noise
conditions are not assumed to be constant for all installation locations and/or
at different times at a particular location. Certain exemplary embodiments can
update certain threshold amplitudes used in the analysis of arc fault sensor
data based on a history of the sensor data. An update of threshold amplitudes
based on recent historical sensor data can provide relatively good performance
of an arc fault detection system in the presence of environmental RF noise.
Environmental noise can be assumed to be constant over short time durations.

[168] In certain exemplary embodiments, an RF signal can be obtained from an AC
branch through an RF sensor that could be an E-core shape ferrite sensor. The
signal can be mixed with an oscillating carrier. Certain exemplary
embodiments can comprise one or more algorithms adapted to determine a
relevance of broadband RF signals. The signal, once mixed with the carrier,
can be filtered and/or amplified. An energy level of the signal can be
measured, quantified, and/or represented with a corresponding received signal
strength indicator (RSSI). The RSSI signal can be a variable signal that can
represent broadband conditions (e.g., arc fault conditions), other sources of
broadband information broadcasting in an AC circuit branch, and/or
broadband environmental noise, etc.
[169] Certain exemplary embodiments can be implemented in one or more of
hardware (such as in the form of a microprocessor and/or an Application
Specific Integrated Circuit, etc.), firmware, and/or software. Certain
exemplary embodiments can comprise a mixed-signal microprocessor with
Analog-to-Digital conversion (A/D) capabilities. The microprocessor can be
selected based pn one or more characteristics of sensors and/or algorithms
associated with arc fault detection.
[170] An A/D input to the microprocessor can be driven by a variable signal that can
represent broadband RF signal strength (energy) caused potentially by an arc
fault and/or sources of RF noise. The microprocessor can execute both an
adaptive sensor algorithm as well as an arc fault detection algorithm.
[171] Certain exemplary embodiments can adjust threshold amplitudes used in
analyzing sensor data to improve the performance of a system that might
operate in differing RF noise environments. An arc fault detection algorithm
that analyzes the sensor data in ical time to determine if arcing is occurring
can use these threshold amplitudes. The threshold amplitudes can be voltage
values that can be used to determine certain characteristics of the input RSSI
signal. The adjustments can be calculated based on historical sensor data

collected over a relatively short time interval (e.g., a few seconds).
Adjustments might be made when a relatively small level of variation is
detected in historical sensor data. A relatively small level of variation can be
an indication that no arcing conditions are occurring and that detected
environmental broadband RF noise is relatively constant. When a relatively
small level of variation is detected, certain exemplary embodiments can
comprise an algorithm adapted to adjust threshold amplitudes to compensate
for changes in one or more background noise characteristics.
[172] In certain exemplary embodiments, the algorithm for adjusting one or more
threshold amplitudes can operate in parallel with a companion arc fault
detection algorithm. Certain exemplary embodiments can utilize sensor data
from the A/D converter that can also be adapted for use by other algorithms,
such as the arc fault detection algorithm. Certain exemplary embodiments
might not process all incoming data in analyzing relatively long-term trends in
historical data. In certain exemplary embodiments, the algorithm for adjusting
one or more threshold amplitudes can be adapted to execute at a
predetermined time interval. The predetermined time interval can be
approximately, in milliseconds, 150, 135.6, 99, 84.9, 77.2, 40, 33.4, 25,12,
8.2, 5, 2.2, 2, and any value or subrange therebetween. Certain exemplary
embodiments can comprise a handshaking mechanism between algorithms to
attempt to avoid changes to threshold amplitudes during analyses by other
algorithms (e.g., the arc fault detection algorithm). Thus, certain exemplary
embodiments might not update threshold amplitudes if one or more
companion algorithms signal that an analysis for potential arcing conditions is
in progress.
[173] Certain exemplary embodiments can be adapted to wait for a predetermined
time period after a handshaking signal from the companion algorithm indicates
that the companion algorithm is idle and waiting for a next potential arcing
condition. The predetermined time period can be approximately, in
milliseconds, 1000, 800.1, 625, 499, 386.1, 300, 277, 188.1,99, 50,25, and/or
any value or subrange therebetween.

[174] After the predetermined time period, certain exemplary embodiments can
begin collecting data to determine if a threshold amplitude update might be
desired and, if so, what the new threshold amplitudes should be.
[175] FIG. 1 is a plot of signal strength waveforms generated by both an exemplary
arc fault condition and by an exemplary noise condition. An arc fault
condition can result in a signal that can be characterized by an arc fault
waveform 1400. A noise condition can result in a signal that can be
characterized by a noise waveform 1300. Noise waveform 1300 can be
characterized by one or more gap time intervals such as first gap time interval
1500 and second gap time inteivaJ 1600. First gap time interval 1500 can be
of a distinct and measurably different duration that second gap interval 1600.
Noise waveform 1300 can be characterized by an amplitude 1350.
[176] A first threshold 1100 and/or a second threshold 1200 can be associated with
an arc fault detection circuit configured to distinguish between noise
waveform 1300 and arc fault waveform 1400. First threshold 1100 and
second threshold 1200 can be configured to be changed responsive to a
detected change in signal characteristics of the noise signal characterized by
noise waveform 1300.
[177] FIG. 2 is a block diagram of an exemplary embodiment of a system 2000,
which can comprise a circuit 2100, an alternating current through which can
be sensed and/or detected by sensor 2200. A signal from sensor 2200 can be
provided to filter 2250. Filter 2250 can be configured to derive an RSSI signal
and a load current signal from the signal from sensor 2200. Filter 2250 can be
configured to provide signals characterized by the RSSI waveform and/or the
load current waveform to information device 2300 for processing. Prior to
and/or at information device 2300, the signal can be processed and/or
sampled. At information device 2300, the resulting data can be analyzed to
identify, for example, to determine if a number of zero crossings of a
waveform during a predetermined time period is above a first predetermined

threshold, yet below a second predetermined threshold. Based on a signal
generated by information device 2300, such as in response to a determination
and/or detection of an arcing event 2600 and/or an arcing condition, and/or
detection of a hazardous arcing condition, an actuator 2400 can cause a switch
2500 to interrupt circuit 2100. Switch 2500 can be a circuit breaker, such as
an Arc Fault Circuit Interrupter (AFCI). Switch 2500 can be a device
configured to open circuit 2100 responsive to an output signal.
[178] In certain exemplary embodiments, information device 2300 can comprise a
processor, which can be configured to automatically generate an output signal
responsive to an input signal. The input signal can be indicative of an arc
fault. The output signal can be configured to cause circuit 2100 to open, such
as via opening switch 2500. The output signal can be generated responsive to
a derived signal based upon a first threshold having a first amplitude. The first
threshold can be changed from the first amplitude to a second amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period. The second amplitude for the first threshold can be based upon an
average of a predetermined count of the historical sampled values of the
measured electrical parameter.
[179] In certain exemplary embodiments, sensor 2200, filter 2250, information
device 2300, actuator 2400, and/or switch 2500 can be comprised by a circuit
breaker 2700.
[180] FIG. 3 is a flowchart of an exemplary embodiment of a method 3000. At
activity 3100, a determination can be made whether an arc fault detection
algorithm is executing. The arc fault algorithm can be any exemplary
algorithm known to one skilled in the art. If the arc fault detection algorithm
is executing, certain exemplary embodiments can avoid an update to one or
more threshold amplitudes associated with the arc fault detection algorithm.
In certain exemplary embodiments, activity 3100 can be repeated at
predetermined and/or random times during activities of method 3000. In

certain exemplary embodiments, a potential change of a threshold can be
terminated responsive to a determination that the arc fault determination
algorithm is operational.
[181] At activity 3200, a start time can be determined. For example, the start time
can be based upon an elapsed predetermined time interval since method 3000
has detected an idle status of the arc fault detection algorithm.
[182] At activity 3300, sampled values can be obtained and/or recorded. The
sampled values can be obtained from an obtained input signal. In certain
exemplary embodiments, a predetermined number of sampled values can be
obtained and/or stored. The count of sampled values can be any count, such
as, 500, 399,243, 122, 98, 76, 56,41, 24,12, 8,4, 2, and/or any value or
subrange therebetween. In certain exemplary embodiments, each of the
sampled values can be obtained at a predetermined time interval. The
predetermined time interval can be approximately, in milliseconds, 300,243.7,
199, 176, 154.3,100, 85.1,44.3, 24,12,6,4, 2, and/or any value or subrange
therebetween.
[ 183] At activity 3400, a determination can be: made of a percentage of samples
comprising values within a predetermined range. For example, all sampled
values can be compared to a predetermined limit. When the sampled values
are voltages, the predetermined limit can be approximately, in millivolts (mV).
500,422.5,350, 299.1, 187.6,100, 77.3, 50, 33.2, 25, 20, 18.1,12, 10, and/or
any value or subrange therebetween. In certain exemplary embodiments,
activity 3400 can be repeated after a predetermined amount of time has
elapsed. The predetermined amount of time can be approximately, in seconds,
50,33.1,28.8, 16.4,12, 9.9,5.4,4,2,0.9,0.5, and/or any value or subrange
therebetween.
[184] In certain exemplary embodiments, if a predetermined percentage of samples
are within a predetermined range, a decision can be made to update threshold
amplitudes. If a predetermined percentage of samples is not within the

predetermined range, a decision can be made to reset method 3000 and not
update the threshold amplitudes. The predetermined percentage can be
approximately, 98, 88.8, 75.3, 68.1, 60, 50, 45,41,1 33, 27.4, 20, and/or any
value or subrange therebetween. Thus, in certain exemplary embodiments, a
particular threshold amplitude might be changed only when a predetermined
variation measure associated with the predetermined count of historical
sampled values is below a predetermined threshold and/or magnitude.
[185] At activity 3500, an average of a predetermined count of samples can be
determined. The predetermined count of samples to be averaged can be
approximately 100, 67,50, 45, 31,17, 12, 8,4,3, and/or any value or
subrange dierebetween.
[186] At activity 3600, one or more updated threshold amplitudes can be
determined. For example, a lower threshold amplitude can be determined by
adding a first predetermined increment to the average of the predetermined
samples. The first predetermined increment can be approximately, in
millivolts, 500, 411, 345.6, 234.9, 166.6,100, 98,80.1,65, 50, 24,20, and/or
any value or subrange therebetween. An upper threshold amplitude can be
determined by adding a second predetermined increment to the average of the
predetermined samples. The second predetermined increment can be
approximately, in millivolts, 1000, 812, 677.6,480.4, 333.3,200,181,155.3,
112, 99.6, 56.0, 40, and/or any value or subrange dierebetween.
[187] At activity 3700, one or more threshold amplitudes can be updated. For
example, the threshold amplitudes determined in activity 3600 can be stored in
one or more predetermined locations for use as threshold amplitudes for the
arc fault detection algorithm.
[188] At activity 3800, the arc fault detection algorithm can execute based upon the
updated threshold amplitudes. The arc fault detection algoritfim can be
adapted to obtain an input signal from one or more input signal sensors. The
input signal can be mixed with an oscillating carrier. The mixed signal can be

filtered. The filtered signal can be amplified. An energy magnitude of the
amplified signal can be measured. The energy magnitude of the amplified
signal can be compared against one or more threshold amplitudes to determine
if additional arc fault tests should be performed. In certain exemplary
embodiments, the arc fault detection algorithm can derive and/or obtain the
RSSI signal. The RSSI signal can be analyzed to determine the presence of an
arc fault.
[189] At activity 3900, a circuit breaker can be tripped responsive to a determination
of an arc fault by the arc fauli detection algorithm. For example, an output
signal can be automatically generated responsive to an input signal. The input
signal can be indicative of an arc fault. The, output signal can be configured
to cause an electrical circuit to open (e.g.,.the circuit breaker can be tripped).
The output signal can be generated responsive to a derived signal (e.g., the
RSSI signal) based upon a fim threshold having a first amplitude. The first
threshold can be changed from the first amplitude to a second amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period. The second amplitude for the first threshold can be based upon an
average of a predetermined count of the historical sampled values of the
measured electrical parameter.
[190] The output signal can be generated responsive to the derived signal, which can
be based upon a second threshold having a third amplitude. The first threshold
can be changed from the third amplitude to a fourth amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period. The fourth amplitude for the second threshold can be based upon the
average of the predetermined count of the historical sampled values of the
measured electrical parameter.
[191] FIG. 4 is a block diagram of an exemplary embodiment of an information
device 4000, which in certain operative embodiments can comprise, for

example, information device 2300, of BIG. 2. Information device 4000 can
comprise any of numerous components, such as for example, one or more
network interfaces 4100, one or more processors 4200, one or more memories
4300 containing instructions 4400, one or more input/output (I/O) devices
4500, and/or one or more user interfaces 4600 coupled to I/O device 4500, etc.
[192} In certain exemplary embodiments, via one or more user interfaces 4600, such
as a graphical user interface, a user can view a rendering of information
related to detecting an arc fault, changing one or more threshold amplitudes
related to an arc fault detection system, and/or tripping a circuit breaker
responsive to a detected arc fault, etc.
Note
[193] Still other practical and useful embodiments will become readily apparent to
those skilled in this art from reading the above-recited detailed description and
drawings of certain exemplary embodiments. It should be understood that
numerous variations, modifications, and additional embodiments are possible,
and accordingly, all such variations, modifications, and embodiments are to be
regarded as being within the spirit and scope of this application.
[194] Thus, regardless of the content of any portion (e.g., title, field, background,
summary, abstract, drawing figure, etc.) of tfiis application, unless clearly
specified to the contrary, such as via an explicit definition, assertion, or
argument, with respect to any claim, whether of mis application and/or any
claim of any application claiming priority hereto, and whether originally
presented or otherwise:
[ 195] there is no requirement for the inclusion of any particular described or
illustrated characteristic, function, activity, or element, any particular
sequence of activities, or any particular interrelationship of elements;
[ 196] any elements can be integrated, segregated, and/or duplicated;
[197] any activity can be repeated, performed by multiple entities, and/or
performed in multiple jurisdictions; and

[198] any activity or element can be specifically excluded, the sequence of
activities can vary, and/or the i nterrelationship of elements can vary.
[199] Moreover, when any number or range is described herein, unless clearly stated
otherwise, that number or range is approximate. When any range is described
herein, unless clearly stated otherwise, that range includes all values therein
and all subranges therein. For example, if a range of 1 to 10 is described, that
range includes all values therebetween, such as for example, 1.1,2.5, 3.335,5,
6.179, 8.9999, etc., and includes all subranges therebetween, such as for
example, 1 to 3.65, 2.8 to 8.14,1.93 to 9, etc.
[200] Any information in any material (e.g., a United States patent, United States
patent application, book, article, etc.) that has been incorporated by reference
herein, is only incorporated by reference to the extent that no conflict exists
between such information and the other statements and drawings set forth
herein. In the event of such conflict, including a conflict that would render
invalid any claim herein or seeking priority hereto, then any such conflicting
information in such incorporated by reference material is specifically not
incorporated by reference hemin.
[201] Accordingly, the descriptions and drawings are to be regarded as illustrative in
nature, and not as restrictive.

What is claimed is:
1. A method comprising:
automatically generating an output signal responsive to an input signal,
said input signal indicative of an arc fault, said output signal configured to
cause an electrical circuit to open, said output signal generated responsive to a
derived signal based upon a first threshold having a first amplitude, said first
threshold changed from said first amplitude to a second amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period, said second amplitude for said first threshold based upon an average of
a predetermined count of said historical sampled values of said measured
electrical parameter.
2. The method of claim 1, further comprising:
terminating a potential change of said first threshold responsive to a
determination that an arc fault determination algorithm is operational.
3. The method of claim 1, further comprising:
obtaining said input signal.
4. The method of claim 1, further comprising:
mixing said input signal with an oscillating carrier.
5. The method of claim 1, further comprising:
mixing said input signal with an oscillating carrier; and
filtering said mixed signal.
6. The method of claim 1, further comprising:
mixing said input signal with an oscillating carrier;
filtering said mixed signal; and
amplifying said filtered signal.

7. The method of claim 1, further comprising:
mixing said input signal with an oscillating carrier;
filtering said mixed signal;
amplifying said filtered signal; and
measuring an energy magnitude of said amplified signal.
8. The method of claim 1, further comprising:
obtaining said derived signal.
9. The method of claim 1, further comprising:
changing said first threshold only when a predetermined variation measure
associated with said predetermined count of historical sampled values is below
a second threshold.
10. The method of claim 1, further comprising:
restarting an activity configured to change said first threshold after a
predetermined time period.
11. The method of claim 1, further comprising:
storing each of said historical sampled values of said measured electrical
parameter.
12. The method of claim 1, further comprising:
checking a sampled value of said measured electrical parameter to
determine if said sampled values is within said predetermined range.
13. The method of claim 1, further comprising:
automatically changing a second threshold, having a third amplitude, said
second threshold changed from said third amplitude to a fourth amplitude if
said predetermined percentage of historical sampled values of said measured
electrical parameter are within said predetermined range during said
predetermined time period, said fourth amplitude for said second threshold

based upon said average of said predetermined count of said historical
sampled values of said measured electrical parameter.
14. The method of claim 1, wherein said second amplitude is determined by
adding a predetermined voltage value to a sampled average of said
predetermined count of historical sampled values of said measured electrical
parameter.
15. A signal comprising machine instructions for activities comprising:
automatically generating an output signal responsive to an input signal,
said input signal indicative of an arc fault, said output signal configured to
cause an electrical circuit to open, said output signal generated responsive to a
derived signal based upon a first threshold having a first amplitude, said first
threshold changed from said first amplitude to a second amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period, said second amplitude for said first threshold based upon an average of
a predetermined count of said historical sampled values of said measured
electrical parameter.
16. A machine-readable medium comprising machine instructions for activities
comprising:
automatically generating an output signal responsive to an input signal,
said input signal indicative of an arc fault, said output signal configured to
cause an electrical circuit to open, said output signal generated responsive to a
derived signal based upon a first threshold having a first amplitude, said first
threshold changed from said first amplitude to a second amplitude if a
predetermined percentage of historical sampled values of a measured electrical
parameter are within a predetermined range during a predetermined time
period, said second amplitude for said first threshold based upon an average of
a predetermined count of said historical sampled values of said measured
electrical parameter.

17. A system comprising:
a processor configured to:
automatically generating an output signal responsive to an input signal,
said input signal indicative of an arc fault, said output signal configured to
cause an electrical circuit to open, said output signal generated responsive
to a derived signal based upon a first threshold having a first amplitude,
said first threshold changed from said first amplitude to a second
amplitude if a predetermined percentage of historical sampled values of a
measured electrical parameter are within a predetermined range during a
predetermined time period, said second amplitude for said first threshold
based upon an average of a predetermined count of said historical sampled
values of said measured electrical parameter.
18. The system of claim 17, further comprising:
a device configured to open said electrical circuit responsive to said output
signal.
19. The system of claim 17, further comprising:
a circuit breaker comprising said processor.

Certain exemplary embodiments comprise a method, which can comprise automatically generating an output signal responsive to an input signal. The input signal can be indicative of an arc fault. The output signal can be configured to cause an electrical circuit to open. The output signal can be generated responsive to a derived signal
based upon a first threshold having a first amplitude.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=kIfg594Ez+w1NUvbMPzcwA==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 272852
Indian Patent Application Number 10/KOLNP/2009
PG Journal Number 19/2016
Publication Date 06-May-2016
Grant Date 28-Apr-2016
Date of Filing 01-Jan-2009
Name of Patentee SIEMENS INDUSTRY, INC.
Applicant Address 3333 OLD MILTON PARKWAY, ALPHARETTA, GEORGIA GA 30005-4437,
Inventors:
# Inventor's Name Inventor's Address
1 HENSON, JEREMY 4637 ANGIER AVE., DURHAM, NORTH CAROLINA 27703
2 RESTREPO, CARLOS 600 BRICKWORKS CIRCLE, # 6309 ATLANTA, GEORGIA 30307,
PCT International Classification Number H02H 1/00
PCT International Application Number PCT/US2007/014003
PCT International Filing date 2007-06-13
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/460,372 2006-07-27 U.S.A.