Fault sensor

Abstract

According to some embodiments, a sensor includes: a noise detector configured to receive a load current signal, limit the slew rate of the load current signal to generate an alternating current (AC) component of the load current signal, and generate a noise component of the load current signal based on the AC component and the load current signal; a multiplexer configured to select either the AC component or the noise component to generate an output; an analog-to-digital converter (ADC) configured to sample the output of the multiplexer; and a sampling control unit configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data.

Description

Cross-references to related applications

[0001] This patent application relates to commonly assigned U.S. Provisional Patent Application Serial No. 63 / 788,672, filed April 14, 2025, entitled “AC Arc Fault Detection System, Method and Apparatus”, which is incorporated herein by reference in its entirety. Background Technology

[0002] Electronic circuits, wiring, and equipment are prone to failure, such as arcing faults (e.g., AC faults, DC faults, etc.). These faults can lead to equipment damage or safety risks. Different loads exhibit different load characteristics, making the detection of some faults difficult. Summary of the Invention

[0003] This summary provides a simplified overview of selected concepts, which will be further described in the detailed description below. This summary is not intended to identify key elements or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0004] According to some embodiments, a sensor includes: a noise detector configured to receive a load current signal, limit the slew rate of the load current signal to generate an alternating current (AC) component of the load current signal, and generate a noise component of the load current signal based on the AC component and the load current signal; a multiplexer configured to select either the AC component or the noise component to generate an output; an analog-to-digital converter (ADC) configured to sample the output of the multiplexer; and a sampling control unit configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data.

[0005] According to some embodiments, a method for determining a fault includes: limiting the slew rate of a load current signal to generate an alternating current (AC) component of the load current signal; determining a noise component of the load current signal based on the AC component and the load current signal; determining a noise metric based on the noise component; determining an AC metric based on the AC component; determining an arc fault condition based on the AC metric and the noise metric; and controlling an isolation device based on the arc fault condition.

[0006] According to some embodiments, a system for determining a fault includes: means for limiting the slewing rate of a load current signal to generate an alternating current (AC) component of the load current signal; means for determining a noise component of the load current signal based on the AC component and the load current signal; means for determining a noise metric based on the noise component; means for determining an AC metric based on the AC component; means for determining an arc fault condition based on the AC metric and the noise metric; and means for controlling an isolation device based on the arc fault condition.

[0007] According to some embodiments, a sensing system includes: a noise detector configured to receive a load current signal, limit the slew rate of the load current signal to generate an alternating current (AC) component of the load current signal, and generate a noise component of the load current signal based on the AC component and the load current signal; a multiplexer configured to select at least one of the AC component or the noise component to generate an output; an analog-to-digital converter (ADC) configured to sample the output of the multiplexer; a sampling control unit configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data; and a processor configured to generate an AC metric based on the sampled AC component data, generate a noise metric based on the sampled noise component data, determine an arc fault condition based on the AC metric and the noise metric, and control an isolation device connected to a load powered by the load current signal based on the arc fault condition.

[0008] To achieve the foregoing and related objectives, the following description and accompanying drawings illustrate certain illustrative aspects and embodiments. These indicate several of a variety of ways in which one or more aspects may be employed. Other aspects, advantages, and novel features of this disclosure will become apparent when considered in conjunction with the following detailed description and drawings. Attached Figure Description

[0009] Figure 1 This is a block diagram of a detector (e.g., an arc fault detector) according to some embodiments.

[0010] Figure 2 This is a flowchart illustrating an example method for detecting faults (e.g., arc faults) according to some embodiments.

[0011] Figure 3 It is a waveform diagram illustrating the operation of a detector (e.g., an arc fault detector) according to some embodiments.

[0012] Figure 4 Exemplary embodiments of a computer-readable medium according to some embodiments are shown. Detailed Implementation

[0013] The claimed subject matter will now be described with reference to the accompanying drawings, wherein the same reference numerals are used throughout to refer to the same elements. In the following description, numerous specific details are set forth for purposes of explanation to provide a thorough understanding of the claimed subject matter. However, it may be apparent, however, that the claimed subject matter can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate the description of the claimed subject matter.

[0014] It should be understood that the following description of the embodiments should not be construed as limiting. The scope of this disclosure is not intended to be limited to the embodiments or drawings described below, which are to be regarded as illustrative only. The drawings should be regarded as schematic diagrams, and the elements shown in the drawings are not necessarily drawn to scale. Rather, the representation of the various elements makes their function and general purpose obvious to those skilled in the art.

[0015] All numerical values ​​in the specific embodiments and claims are modified by values ​​indicated by “about” or “approximately”, taking into account experimental errors and variations that would be expected by one of ordinary skill in the art.

[0016] Figure 1 This is a block diagram of a detector 100 (e.g., an arc fault detector) configured to detect alternating current (AC) faults according to some embodiments. In some embodiments, detector 100 includes: a current transformer 102 connected across an analog grounding resistor 104 to provide load isolation and generate a load current signal; a programmable gain amplifier 106 connected to the current transformer 102 to amplify the load current signal; a noise detector 108 connected to the programmable gain amplifier 106 and configured to extract a noise component of the load current signal from the AC component of the load current signal; a multiplexer 110 connected to the noise detector 108 to receive the noise component and connected to a bypass path of the noise detector 108 to receive the AC component; an analog-to-digital converter (ADC) 112 for sampling the output of the multiplexer 110 to generate a sampled arc detection signal based on the AC component and the noise component; and a sampling control unit 114 configured to control the sampling timing performed by the multiplexer 110 and the ADC 112.

[0017] In some embodiments, the ADC 112 is connected to the host system 116 to process the arc detection signal generated by the noise detector 108 and to control an isolation device 117, such as a circuit breaker or electronic fuse, connected to a load served by a load current signal (i.e., on the primary side of the current transformer 102) based on the arc fault detection. The host system 116 may include a direct memory access (DMA) unit to allow the output of the ADC 112 to be directly read into the memory of the host system 116. In some embodiments, the host system 116 includes processing units, such as one or more processors, microprocessors, data processors, coprocessors, application-specific integrated circuits (ASICs), controllers, programmable logic devices, chipsets, field-programmable gate arrays (FPGAs), application-specific instruction set processors (ASIPs), system-on-a-chip (SoCs), central processing units (CPUs) (e.g., one or more cores), microcontrollers, and / or some other type of component that interprets and / or executes instructions and / or data. The host system 116 may be implemented as hardware (e.g., a microprocessor, etc.), a combination of hardware and software (e.g., a programmable system-on-a-chip (PSoC)). TM Application-specific integrated circuits (ASICs), etc., and may include one or more memories (e.g., flash memory, DRAM, cache, etc.).

[0018] In some embodiments, the noise detector 108 includes a slew rate limiting amplifier 118 that receives a load current signal from the PGA 106 and extracts an AC component by limiting the slew rate of the output generated in response to the load current signal. The slew rate limiting amplifier 118 removes high-frequency noise from the load current signal slew rate to generate an AC component representing a noise-free input power waveform. The slew rate limiting amplifier 118 has advantages over a high-pass filter because a high-pass filter cannot remove low-order harmonics of the input power waveform below its cutoff frequency, and the slew rate limiting amplifier 118 includes fewer components, reducing cost and footprint. For example, compared to an HPF, the slew rate limiting amplifier 118 reduces the power of the 3rd and 5th line harmonics at 60 Hz by 15-20 dB. This advantage allows for iterative increases in the gain of the PGA 106, providing additional gain for arc detection at low current levels.

[0019] A slew rate limiting amplifier 118 is connected to a differential amplifier 120, which subtracts the AC component from the load current signal generated by the PGA 106 to extract a noise component. The noise component includes very low AC harmonics. A voltage divider connected to the PGA 106 to receive the load current signal includes resistors 122A and 122B connected to the non-inverting terminal of the differential amplifier 120, and is matched with a voltage divider connected to the slew rate limiting amplifier 118 and includes resistors 124A and 124B connected to the inverting terminal of the differential amplifier 120.

[0020] In some embodiments, the sampling control unit 114 measures noise at the zero-crossing point of the load current signal. A low-pass filter 126 filters the AC component, a peak detector 128 determines the peak value of the AC component, and trigger logic 130 sets the timing of the sampling interval to be consistent with the zero-crossing point.

[0021] Figure 2 This is a flowchart illustrating a method 200 for detecting faults (e.g., arc faults) according to some embodiments. Figure 3 This is a waveform and timing diagram 300 illustrating the operation of a noise detector 108 according to some embodiments. Method 200 Reference Figure 3 The diagram 300 is used for description.

[0022] like Figure 3 As shown, the AC current waveform generated by the low-pass filter 126 has a roughly sinusoidal shape, represented here as a triangular waveform. At 202, a peak value is detected in the peak detector 128. The peak detector 128 generates a low output for the rising range of the AC current waveform and a high output for the falling range. The peak detector 128 identifies the zero-crossing range 302 and the periodic range 304 of the AC current waveform. The peak detector 128 generates a peak edge signal representing the positive peak value of the AC current waveform.

[0023] At 204, timing locking is implemented by trigger logic 130 to perform sampling. At 206, the noise distribution is sampled. Trigger logic 130 configures multiplexer 110 to select the output of differential amplifier 120, thereby sampling the noise component in ADC 112 during the noise sampling interval 306, which coincides with zero-crossing interval 302. At 208, a noise metric is determined. In some embodiments, host system 116 determines the noise metric.

[0024] In the example, host system 116 generates a noise averaging parameter and subtracts the noise averaging parameter from the original noise data samples to determine normalized noise samples, eliminating offset errors in the signal chain. Host system 116 can use various techniques to evaluate noise to determine a noise metric. In one technique, the absolute value of each normalized noise sample is calculated, and these values ​​are averaged to determine the ABS noise metric. In a second technique, host system 116 determines the root mean square (RMS) average of the original noise samples to determine the RMS noise metric. Host system 116 can track the ABS noise metric and the RMS noise metric over time to determine a consistent and more repeatable metric as the noise metric determined at 208.

[0025] At 210, the AC component is sampled. Trigger logic 130 configures multiplexer 110 to select the output of slew rate limiting amplifier 118, thereby sampling the AC component in ADC 112 during AC sampling interval 308, which coincides with period interval 304. At 212, the AC metric is determined. In some embodiments, host system 116 determines the AC metric.

[0026] In the example, host system 116 generates an AC mean parameter and subtracts the AC mean parameter from the original AC data sample to determine the normalized AC sample. The RMS mean of the normalized AC sample is used to determine the AC metric. The order of noise sampling and AC sampling can be reversed from the example above.

[0027] At 214, the host system 116 determines the noise ratio based on AC and noise metrics. At 216, the noise ratio is compared to a threshold. If the arc threshold is not violated, no fault condition is identified at 218; if the arc threshold is violated, an arc fault condition is identified at 220. When no arc fault is present, the average noise is low, and the noise ratio is high. When an arc is present, the average noise is significantly higher, and therefore the noise ratio is low. The arc threshold is set to a value such that the presence of an arc can be reliably detected, and the risk of false alarms is low in the absence of an arc. In some embodiments, the change in the noise ratio between the presence and absence of an arc is approximately at least twenty to one. Specific arc thresholds can be set based on individual system characteristics and balance the consequences of false or missed arc detections. In response to arc fault detection at 220, isolation device 117 is controlled at 222. The host system 116 can trip isolation device 117 to isolate the load.

[0028] Figure 4Exemplary embodiment 400 of a computer-readable medium according to some embodiments is illustrated. One or more embodiments relate to a computer-readable medium including processor-executable instructions configured to implement one or more techniques presented herein. Embodiment 400 includes a non-transitory computer-readable medium 402 (e.g., a CD-R, DVD-R, flash drive, hard disk platter, etc.) thereon encoded computer-readable data 404. The computer-readable data 404 further includes a set of processor-executable computer instructions 406, which, when executed by a computing device 408 including a reader 410 for reading the processor-executable computer instructions 406 and a processor 412 for executing the processor-executable computer instructions 406, are configured to facilitate operation according to one or more principles set forth herein. In some embodiments, the processor-executable computer instructions 406, when executed, are configured to facilitate the execution of a method 414, such as at least some of the foregoing methods. In some embodiments, the processor-executable computer instructions 406, when executed, are configured to facilitate the implementation of a system, such as some of at least one or more of the foregoing systems. Many such computer-readable media can be designed by those skilled in the art and configured to operate according to the techniques presented herein.

[0029] The term "computer-readable medium" and / or similar terms can include communication media. Communication media typically embody computer-readable instructions or other data in the form of a "modulated data signal" (e.g., a carrier wave or other transmission mechanism) and include any information transmission medium. The term "modulated data signal" can include a signal whose one or more characteristics are set or altered in a manner that encodes information in the signal.

[0030] According to some embodiments, a sensor includes: a noise detector configured to receive a load current signal, limit the slew rate of the load current signal to generate an alternating current (AC) component of the load current signal, and generate a noise component of the load current signal based on the AC component and the load current signal; a multiplexer configured to select either the AC component or the noise component to generate an output; an analog-to-digital converter (ADC) configured to sample the output of the multiplexer; and a sampling control unit configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data.

[0031] According to some embodiments, the sampling control unit includes: a peak detector configured to identify peak values ​​in the AC component; and triggering logic configured to identify a full-cycle interval and a zero-crossing interval based on the peak value, and to control the multiplexer and ADC to sample the AC component during the full-cycle interval and to sample the noise component during the zero-crossing interval.

[0032] According to some embodiments, the noise detector includes: a slew rate limiting amplifier configured to generate an AC component based on a load current signal; and a differential amplifier configured to subtract the AC component from the load current signal to generate a noise component, wherein a multiplexer is connected to the output of the slew rate limiting amplifier to receive the AC component and to the output of the differential amplifier to receive the noise component.

[0033] According to some embodiments, the sensor includes a programmable gain amplifier connected to the input of a slew rate limiting amplifier to amplify the load current signal.

[0034] According to some embodiments, the sampling control unit includes: a peak detector connected to a slew rate limiting amplifier and configured to identify peak values ​​in the AC components; and triggering logic configured to identify full-cycle intervals and zero-crossing intervals based on the peak values, and to control the multiplexer and ADC to sample the AC components during the full-cycle interval and to sample the noise components during the zero-crossing interval.

[0035] According to some embodiments, the sensor includes a low-pass filter connected between a slew rate limiting amplifier and a peak detector.

[0036] According to some embodiments, the sensor includes a processor configured to generate an AC metric based on sampled AC component data, generate a noise metric based on sampled noise component data, and determine the arc fault condition based on the AC metric and the noise metric.

[0037] According to some embodiments, the processor is configured to generate a noise metric using at least one of absolute average or root mean square average.

[0038] According to some embodiments, the processor is configured to determine an arc fault condition in response to a ratio of AC metric to noise metric that violates a threshold.

[0039] According to some embodiments, a method for determining a fault includes: limiting the slewing rate of a load current signal to generate an alternating current (AC) component of the load current signal; determining a noise component of the load current signal based on the AC component and the load current signal; determining a noise metric based on the noise component; determining an AC metric based on the AC component; determining an arc fault condition based on the AC metric and the noise metric; and controlling an isolation device based on the arc fault condition.

[0040] According to some embodiments, determining the arc fault condition includes: determining the arc fault condition based on a violation of a threshold between the AC metric and the noise metric.

[0041] According to some embodiments, determining a noise metric includes using at least one of the absolute average or the root mean square average.

[0042] According to some embodiments, the method includes: identifying a peak value in an AC component; identifying a full-cycle interval and a zero-crossing interval based on the peak value; sampling the AC component during the full-cycle interval to generate sampled AC component data; and sampling a noise component during the zero-crossing interval to generate sampled noise component data, wherein determining a noise metric includes determining a noise metric based on the sampled noise component data, and determining an AC metric includes determining an AC metric based on the sampled AC component data.

[0043] According to some embodiments, limiting the slew rate of the load current signal includes generating the AC component of the load current signal in a slew rate limiting amplifier, and determining the noise component includes subtracting the AC component from the load current signal in a differential amplifier.

[0044] According to some embodiments, a sensing system includes: a noise detector configured to receive a load current signal, limit the slew rate of the load current signal to generate an alternating current (AC) component of the load current signal, and generate a noise component of the load current signal based on the AC component and the load current signal; a multiplexer configured to select at least one of the AC component or the noise component to generate an output; an analog-to-digital converter (ADC) configured to sample the output of the multiplexer; a sampling control unit configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data; and a processor configured to generate an AC metric based on the sampled AC component data, generate a noise metric based on the sampled noise component data, determine an arc fault condition based on the AC metric and the noise metric, and control an isolation device connected to a load powered by the load current signal based on the arc fault condition.

[0045] According to some embodiments, the processor is configured to generate a noise metric using at least one of absolute average or root mean square average.

[0046] According to some embodiments, the processor is configured to determine an arc fault condition in response to a ratio of AC metric to noise metric that violates a threshold.

[0047] According to some embodiments, the sensing system includes an isolation device connected to the load.

[0048] According to some embodiments, the sampling control unit includes: a peak detector configured to identify peak values ​​in the AC component; and triggering logic configured to identify a full-cycle interval and a zero-crossing interval based on the peak value, and to control the multiplexer and ADC to sample the AC component during the full-cycle interval and to sample the noise component during the zero-crossing interval.

[0049] According to some embodiments, the noise detector includes: a slew rate limiting amplifier configured to generate an AC component based on a load current signal; and a differential amplifier configured to subtract the AC component from the load current signal to generate a noise component, wherein a multiplexer is connected to the output of the slew rate limiting amplifier to receive the AC component and to the output of the differential amplifier to receive the noise component.

[0050] This document provides various operations according to embodiments. In one embodiment, one or more of the described operations may constitute computer-readable instructions stored on one or more computer-readable media that, when executed by a computing device, would cause the computing device to perform the described operations. The order in which some or all of the operations are described should not be construed as implying that these operations must be sequentially related. Alternative orders will be understood by those skilled in the art who benefit from this description. Furthermore, it will be understood that not all operations must be present in every embodiment provided herein. And, it will be understood that not all operations are necessary in some embodiments.

[0051] Any aspect or design described herein as an "example" is not necessarily to be construed as superior to other aspects or designs. Rather, the term "example" is used to present one possible aspect and / or implementation that may be relevant to the techniques presented herein. Such examples are not essential to these techniques and are not intended to be limiting. Various embodiments of these techniques may include such examples, either alone or in combination with other features, and / or the examples shown may be modified and / or omitted.

[0052] The term "or" as used in this application is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise stated or clear from the context, "X adopts A or B" is intended to mean any natural inclusive arrangement. That is, if X adopts A; X adopts B; or X adopts both A and B, then "X adopts A or B" is satisfied in any of the foregoing cases. Furthermore, unless otherwise stated or clear from the context to the singular form, the articles "a" and "an" as used in this application and the appended claims are generally interpreted as "one or more". And, unless otherwise stated, "first", "second", etc., are not intended to imply temporal, spatial, or sequential aspects. Rather, such terms are used only as identifiers, names, etc., of features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B, or two different or two identical elements or the same element.

[0053] Furthermore, while this disclosure has been shown and described with respect to one or more embodiments, equivalent changes and modifications will occur to those skilled in the art upon reading and understanding of this specification and the accompanying drawings. This disclosure includes all such modifications and changes and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the aforementioned components (e.g., elements, resources, etc.), unless otherwise stated, the terminology used to describe such components is intended to correspond to any component that performs a specified function of the component (e.g., functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary embodiments shown herein. Furthermore, while a particular feature of this disclosure may be relevant only to one disclosure in several embodiments, such features may be combined with one or more other features of other embodiments, which may be desirable and advantageous for any given or particular application. Moreover, with respect to the use of the terms “comprising,” “having,” “having,” “with,” or variations thereof in the detailed description or claims, these terms are intended to be inclusive in a manner similar to the term “comprising.”

Claims

1. A sensor, comprising: A noise detector is configured as follows: Receive load current signal; Limit the slew rate of the load current signal to generate the AC component of the load current signal; as well as The noise component of the load current signal is generated based on the AC component and the load current signal; A multiplexer configured to select either the AC component or the noise component to generate an output; An analog-to-digital converter (ADC) is configured to sample the output of the multiplexer; as well as A sampling control unit is configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data.

2. The sensor according to claim 1, wherein, The sampling control unit includes: A peak detector, configured to identify peak values ​​in the AC components; and The triggering logic is configured as follows: Based on the aforementioned peak value, the entire period interval and the zero-crossing interval are identified; and The multiplexer and the ADC are controlled to sample the AC component during the full cycle interval and the noise component during the zero-crossing interval.

3. The sensor according to claim 1, wherein, The noise detector includes: A slew rate limiting amplifier configured to generate the AC component based on the load current signal; and A differential amplifier is configured to subtract the AC component from the load current signal to generate the noise component, wherein: The multiplexer is connected to the output of the slew rate limiting amplifier to receive the AC component, and to the output of the differential amplifier to receive the noise component.

4. The sensor according to claim 3, comprising: A programmable gain amplifier is connected to the input of the slew rate limiting amplifier to amplify the load current signal.

5. The sensor according to claim 3, wherein, The sampling control unit includes: A peak detector, connected to the slew rate limiting amplifier and configured to identify peak values ​​in the AC component; and The triggering logic is configured as follows: Based on the aforementioned peak value, the full-cycle interval and zero-crossing interval are identified; and The multiplexer and the ADC are controlled to sample the AC component during the full cycle interval and the noise component during the zero-crossing interval.

6. The sensor according to claim 5, comprising: A low-pass filter is connected between the slew rate limiting amplifier and the peak detector.

7. The sensor according to claim 1, comprising: The processor is configured as follows: An AC metric is generated based on the sampled AC component data; A noise metric is generated based on the sampled noise component data; as well as The arc fault condition is determined based on the AC metric and the noise metric.

8. The sensor according to claim 7, wherein: The processor is configured to generate the noise metric using at least one of the absolute average or the root mean square average.

9. The sensor according to claim 7, wherein: The processor is configured to determine the arc fault condition in response to a violation of a threshold in the ratio of the AC metric and the noise metric.

10. A method for determining a fault, comprising: Limit the slew rate of the load current signal to generate the AC component of the load current signal; The noise component of the load current signal is determined based on the AC component and the load current signal; The noise metric is determined based on the noise components; The AC metric is determined based on the AC components; The arc fault condition is determined based on the AC metric and the noise metric. as well as Control the isolation device based on the arc fault condition.

11. The method of claim 10, wherein: Determining the arc fault condition includes: The arc fault condition is determined based on the ratio of the AC metric and the noise metric violating a threshold.

12. The method according to claim 10, wherein: Determining the noise metric involves using at least one of the absolute average or the root mean square average.

13. The method of claim 10, comprising: Identify the peak values ​​in the AC components; Based on the aforementioned peak values, the entire cycle range and zero-crossing range are identified; The AC components are sampled during the entire period to generate sampled AC component data; as well as The noise component is sampled during the zero-crossing interval to generate sampled noise component data, wherein: Determining the noise metric includes determining the noise metric based on the sampled noise component data; as well as Determining the AC metric involves determining the AC metric based on the sampled AC component data.

14. The method of claim 10, wherein: Limiting the slew rate of the load current signal includes: The AC component of the load current signal is generated in the slew rate limiting amplifier; and Determining the noise components includes: The AC component is subtracted from the load current signal in the differential amplifier.

15. A sensing system, comprising: A noise detector is configured as follows: Receive load current signal; Limit the slew rate of the load current signal to generate the AC component of the load current signal; as well as The noise component of the load current signal is generated based on the AC component and the load current signal; A multiplexer configured to select at least one of the AC component or the noise component to generate an output; An analog-to-digital converter (ADC) is configured to sample the output of the multiplexer; A sampling control unit is configured to control the multiplexer and the ADC to generate sampled AC component data and sampled noise component data; as well as The processor is configured as follows: An AC metric is generated based on the sampled AC component data; A noise metric is generated based on the sampled noise component data; The arc fault condition is determined based on the AC metric and the noise metric. as well as An isolation device is controlled based on the arc fault condition, and the isolation device is connected to a load powered by the load current signal.

16. The sensing system according to claim 15, wherein: The processor is configured to generate the noise metric using at least one of the absolute average or the root mean square average.

17. The sensing system according to claim 15, wherein: The processor is configured to determine the arc fault condition in response to a violation of a threshold in the ratio of the AC metric and the noise metric.

18. The sensing system of claim 15, comprising: The isolation device connected to the load.

19. The sensing system according to claim 15, wherein, The sampling control unit includes: A peak detector, configured to identify peak values ​​in the AC components; and The triggering logic is configured as follows: Based on the aforementioned peak value, the full-cycle interval and zero-crossing interval are identified; and The multiplexer and the ADC are controlled to sample the AC component during the full cycle interval and the noise component during the zero-crossing interval.

20. The sensing system according to claim 15, wherein, The noise detector includes: A slew rate limiting amplifier configured to generate the AC component based on the load current signal; and A differential amplifier is configured to subtract the AC component from the load current signal to generate the noise component, wherein: The multiplexer is connected to the output of the slew rate limiting amplifier to receive the AC component, and to the output of the differential amplifier to receive the noise component.

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