Fault arc signal detection device and method

Abstract

The invention discloses a fault arc signal detection device and method, and the device comprises a current signal sensor which is used for collecting a power supply current signal, and converting the current signal into a voltage signal; the frequency mixing module is used for moving a high-frequency band signal in the voltage signal to a specified frequency band and outputting a narrow-band signal; the second amplifier is used for amplifying the narrowband signal and outputting the amplified narrowband signal; the analog-to-digital conversion module is used for converting the amplified narrowband signal into a digital signal; and the digital judgment module is used for determining whether a fault arc exists or not according to the digital signal. By means of the scheme, the requirements for high speed and high resolution of the analog-to-digital conversion module and the requirement for the processing capacity of the digital judgment module in fault arc detection can be lowered, and higher signal processing precision can be obtained on the premise of lower cost and power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of signal detection, and in particular to a fault arc signal detection device and method. Background Art

[0002] An arc is an electrical glow discharge phenomenon that passes through an insulating medium. When an arc is not intentionally generated by people and continues to occur, it becomes a fault arc. The temperature of a fault arc is as high as over 3000 degrees Celsius, which is one of the common causes of fire in AC and DC power supply systems. For this reason, it is usually necessary to set up a fault arc detection device. The fault arc detection device is installed in the AC and DC power supply system. By collecting the power supply current waveform and analyzing its characteristics, it is determined whether there is a fault arc. When it is determined that a fault arc has occurred, the power supply current is cut off to eliminate the fault arc, or an alarm signal is issued to avoid or reduce losses.

[0003] A typical arc fault detection system structure is as follows: Figure 1 As shown, the current signal sensor 11 converts the current signal of the power supply line into a voltage signal, filters out the noise outside the processing bandwidth through the broadband filter 12, amplifies the signal through the broadband amplifier 13, and then uses the ADC (analog-to-digital converter) 14 to convert the analog voltage signal into a digital signal, and sends it to the DSP (digital signal processor) 15. The DSP 15 analyzes the spectrum of the broadband signal, extracts the arc signal characteristics, makes a judgment on whether there is a fault arc, drives the circuit breaker to cut off the fault arc, or sends an alarm signal.

[0004] The characteristics of fault arc exist in a wide frequency band, from low frequency of tens of hertz to high frequency of hundreds of megahertz. There are huge differences in the amplitude of signals of different frequencies. The signal with the largest amplitude limits the maximum gain of the amplifier, so the signal with small amplitude cannot be fully amplified. This puts forward stringent technical requirements for ADC: the conversion speed of ADC must be high enough to convert broadband signals; the resolution of ADC must be high enough to meet the conversion requirements of small signals. At the same time, ADCs that meet the above requirements are expensive and power-hungry, and also put forward high requirements on the processing power of DSP, which also increases the cost and power consumption of DSP. Summary of the invention

[0005] The embodiment of the present invention provides a fault arc signal detection device and method to reduce the high-speed and high-resolution requirements for ADC and the processing capability requirements for DSP in fault arc detection, thereby obtaining higher signal processing accuracy at a lower cost and power consumption.

[0006] To this end, the embodiment of the present invention provides the following technical solutions:

[0007] On the one hand, an embodiment of the present invention provides a fault arc signal detection device, the device comprising:

[0008] A current signal sensor, used to collect a power supply current signal and convert the current signal into a voltage signal;

[0009] A frequency mixing module, used for moving the high-frequency band signal in the voltage signal to a specified frequency band and outputting a narrow-band signal;

[0010] A second amplifier, used to amplify the narrowband signal and output the amplified narrowband signal;

[0011] An analog-to-digital conversion module, used for converting the amplified narrowband signal into a digital signal;

[0012] The digital judgment module is used to determine whether a fault arc exists according to the digital signal.

[0013] Optionally, the frequency mixing modules have multiple channels, each high-frequency band corresponds to one frequency mixing module, and each frequency mixing module uses a local oscillator signal of a different frequency to move the high-frequency band signal.

[0014] Optionally, the frequency mixing module includes:

[0015] A local oscillator signal generator, used for generating a local oscillator signal;

[0016] The single mixer is used to use the local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band and output a narrowband signal.

[0017] Optionally, the frequency mixing module includes:

[0018] A local oscillator signal generator, used for generating an orthogonal local oscillator signal;

[0019] The orthogonal mixer is used to use the orthogonal local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band, and output two narrow-band signals of an in-phase component and an orthogonal component.

[0020] Optionally, each narrowband signal corresponds to a second amplifier, and different second amplifiers have different amplification factors.

[0021] Optionally, the digital judgment module is specifically used to extract arc signal characteristics from the digital signal, and determine whether a fault arc exists according to the arc signal characteristics.

[0022] Optionally, the digital decision module is further configured to drive a circuit breaker to cut off the fault arc or generate an alarm when it is determined that a fault arc exists.

[0023] Optionally, the device further comprises:

[0024] A broadband filter, used for filtering out noise outside the voltage signal processing bandwidth and outputting filtering information;

[0025] The first amplifier is used to amplify the filtered signal and output the amplified voltage signal to the mixing module.

[0026] On the other hand, an embodiment of the present invention further provides a method for detecting an arc fault signal, the method comprising:

[0027] Collecting a power supply current signal and converting the current signal into a voltage signal;

[0028] Moving the high-frequency band signal in the voltage signal to a specified frequency band to obtain a narrow-band signal;

[0029] amplifying the narrowband signal to obtain an amplified narrowband signal;

[0030] Converting the amplified narrowband signal into a digital signal;

[0031] Whether an arc fault exists is determined according to the digital signal.

[0032] Optionally, moving the high-frequency band signal in the voltage signal to the designated frequency band includes: moving the high-frequency band signal in the voltage signal to the designated frequency band using a single mixer or an orthogonal mixer.

[0033] Optionally, the method further comprises: in the case where it is determined that a fault arc exists, driving a circuit breaker to cut off the fault arc, or generating an alarm.

[0034] Optionally, the method further comprises:

[0035] filtering out noise outside the voltage signal processing bandwidth to obtain a filtered signal;

[0036] amplifying the filtered signal to obtain an amplified voltage signal;

[0037] The step of moving the high-frequency band signal in the voltage signal to the designated frequency band comprises:

[0038] The high frequency band signal in the amplified voltage signal is moved to a specified frequency band.

[0039] The fault arc signal detection device and method provided by the embodiment of the present invention add a mixer to a typical fault arc detection system to move one or more high-frequency band signals to a specified frequency band to form one or more narrow-band signals. Each narrow-band signal can be amplified according to its own signal size to increase the amplification factor of the small signal, so that a low-speed, low-resolution ordinary ADC or even a simple comparator can be used to replace a high-speed, high-resolution expensive ADC to complete the conversion of each narrow-band large signal, and the same or better performance can be achieved. In addition, the processing speed requirements for the digital decision module are also reduced, and the system cost and power consumption are greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a typical schematic diagram of the structure of the fault arc detection system;

[0041] Figure 2 is a schematic diagram of a single mixer and its input and output signals;

[0042] Figure 3 is a schematic diagram of a quadrature single mixer and its input and output signals;

[0043] Figure 4 It is a structural schematic diagram of a fault arc signal detection device provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic diagram of a specific application structure of the fault arc signal detection device provided by an embodiment of the present invention;

[0045] Figure 6 is another specific application structure diagram of the fault arc signal detection device provided by an embodiment of the present invention;

[0046] Figure 7 is another specific application structure diagram of the fault arc signal detection device provided by an embodiment of the present invention;

[0047] Figure 8 This is a specific application schematic diagram of the fault arc signal detection device provided by an embodiment of the present invention;

[0048] Fig. 9 is another specific application schematic diagram of the fault arc signal detection device provided by an embodiment of the present invention;

[0049] Fig.10 It is a flow chart of a fault arc signal detection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The principle and spirit of the present invention will be described below with reference to the exemplary embodiments shown in the accompanying drawings. It should be understood that these embodiments are described only to enable those skilled in the art to better understand and implement the present invention, and are not intended to limit the scope of the present invention in any way.

[0051] In view of the problem that the existing fault arc detection system needs to use a high-speed, high-resolution ADC and a high-speed DSP to achieve practical fault arc detection performance, which makes the system cost high, the power consumption high, and the technical difficulty high, the embodiment of the present invention provides a fault arc signal detection device and method. By introducing a mixer, the high-speed, high-resolution requirements for the ADC and the processing capability requirements for the DSP are reduced, so that higher signal processing accuracy can be obtained at a lower cost and power consumption.

[0052] The following first briefly describes the mixer.

[0053] A mixer is a circuit that can move the spectrum of an input signal to a new frequency band. Its core is a circuit that implements multiplication operations and a narrowband filter circuit that follows it to extract the signal in the specified frequency band. The mixer has two input signals and one output signal. One input signal is Vin, which contains the frequency f0; the other input signal is called the local oscillator signal V L , including the frequency f L ; The center frequency of the narrowband filter is |f L +f0|or|f L -f0|; According to the center frequency of the narrowband filter, the output signal is V o , including the frequency |f L +f0|or|f L -f0|.

[0054] There are two types of mixers: single mixer and quadrature mixer. Figure 2 and Figure 3 As shown. Among them:

[0055] like Figure 2 As shown, the single mixer moves the frequency f0 portion of the input signal Vin(f0) to the frequency |f L +f0|or|f L -f0|, and filter out other frequency signals. Single mixer local oscillator signal V L (f L ) and the output signal V0(|f L +f0|) / V0(|f L -f0|) are all real signals.

[0056] like Figure 3As shown in the figure, the quadrature mixer moves the frequency f0 portion of the input signal Vin(f0) to the frequency |f L +f0|or|f L -f0|, and filters out signals of other frequencies. Unlike a single mixer, the local oscillator signal is an orthogonal complex signal V L (f L ) and V L * (f L ), the output signal is also an orthogonal complex signal V0(|f L +f0|) / V0(|f L -f0|) and V0 * (|f L +f0|) / V0 * (|f L -f0|). Using a quadrature mixer can produce a narrower signal, thereby filtering out more noise and reducing the requirements on the ADC.

[0057] To this end, the arc fault signal detection device and method provided by the embodiment of the present invention adds a mixer to a typical arc fault detection system to move one or more high-frequency band signals to a specified frequency band to form one or more narrow-band signals. Each narrow-band signal can be amplified according to its own signal size to increase the amplification factor of the small signal, so that a low-speed, low-resolution ordinary ADC can be used to complete the conversion of each narrow-band large signal, and the same or better performance can be achieved.

[0058] like Figure 4 , which is a schematic diagram of the structure of a fault arc signal detection device provided in an embodiment of the present invention.

[0059] The arc fault signal detection device comprises:

[0060] The current signal sensor 401 is used to collect the power supply current signal and convert the current signal into a voltage signal;

[0061] A frequency mixing module 402, used to move the high-frequency band signal in the voltage signal to a specified frequency band and output a narrow-band signal;

[0062] A second amplifier 403, used to amplify the narrowband signal and output the amplified narrowband signal;

[0063] The analog-to-digital conversion module 404 is used to convert the amplified narrowband signal into a digital signal, which may be a multi-bit analog-to-digital converter in the usual sense or a 1-bit analog-to-digital converter composed of a comparator;

[0064] The digital decision module 405 is used to determine whether there is an arc fault according to the digital signal.

[0065] It should be noted that, in specific applications, the digital decision module 405 can be a common DSP, a dedicated digital hardware circuit, a programmable device FPGA (Field Programmable Gate Array), or a CPU (Central Processing Unit) with strong computing power and a combination of the above devices, which is not limited in the embodiments of the present invention.

[0066] Furthermore, in another non-limiting embodiment, the fault arc signal detection device may also include: a broadband filter and a first amplifier, wherein the broadband filter is used to filter out noise outside the voltage signal processing bandwidth output by the current signal sensor 401, and output filtering information; the first amplifier is used to amplify the filtered signal and output the amplified voltage signal to the mixing module 402.

[0067] It should be noted that, in a specific application, one or more mixing modules may be provided, each high frequency band corresponding to one mixing module, each mixing module uses a local oscillator signal of a different frequency to move the high frequency band signal. Each narrowband signal corresponds to a second amplifier, and different second amplifiers may have different amplification factors.

[0068] In addition, it should be noted that the mixing module 402 may adopt a single mixer or an orthogonal mixer, which is not limited in this embodiment of the present invention.

[0069] The two fault arc signal detection devices using different mixers are described in detail below.

[0070] like Figure 5 , which is a schematic diagram of a specific application structure of the fault arc signal detection device provided in an embodiment of the present invention.

[0071] The mixing module in this embodiment includes: a local oscillator signal generator 4211 and a single mixer 4212. The local oscillator signal generator 4211 is used to generate a local oscillator signal; the single mixer 4212 is used to use the local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band and output a narrowband signal.

[0072] In a specific application, each high frequency band can be added to a single mixer 4212, and the digital decision module 405 controls the local oscillator signal generator 4211 to include the frequency f L The local oscillator signal is typically a local oscillator signal with a frequency of f L of a sinusoidal signal.

[0073] Reference Figure 5The signal coupled by the current signal sensor 401 is filtered by the broadband filter 406, amplified by the first amplifier 407, and then sent to the single mixer 4212. The single mixer 4212 filters out other signals except the specified frequency band in the input signal, outputs only the signal of the specified frequency band, and then uses the second amplifier 403 to amplify it twice. The analog-to-digital conversion module 404 only needs to convert the narrow-band large signal, and can use a low-conversion rate, low-resolution cheap ADC to achieve the performance that can be achieved by an expensive ADC with high conversion rate and high resolution in a typical circuit, or even better.

[0074] Compared with the existing arc fault detection system, the arc fault signal detection device provided in the embodiment of the present invention uses a single mixer to move the high-frequency band signal in the voltage signal coupled by the current signal sensor to the specified frequency band, and uses a low-speed, low-resolution, cheap ADC to replace the high-speed, high-resolution, expensive ADC, so as to achieve the same or better performance.

[0075] like Figure 6 , which is a schematic diagram of a specific application structure of the fault arc signal detection device provided in an embodiment of the present invention.

[0076] The frequency mixing module in this embodiment includes: a quadrature local oscillator signal generator 4221 and a quadrature mixer 4222. The quadrature local oscillator signal generator 4221 is used to generate a quadrature local oscillator signal; the quadrature mixer 4222 is used to use the quadrature local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band, and output two narrowband signals of an in-phase component and a quadrature component.

[0077] In a specific application, an orthogonal mixer 4222 may be added to each high frequency band. Figure 6 As shown, the digital decision module 405 controls the orthogonal local oscillator signal generator 4221 to generate a frequency of f L The typical orthogonal local oscillator signal is a frequency of f L The signal coupled by the current signal sensor 401 is sent to the orthogonal mixer 4222 after passing through the broadband filter 406 and the first amplifier 407. The orthogonal mixer 4222 filters out other signals except the specified frequency band in the input signal, and only outputs the signal of the specified frequency band, generating two narrow-band signals of the in-phase component and the orthogonal component, and then uses the second amplifier 403 to perform secondary amplification on the signal output by the orthogonal mixer 4222, and then sends it to the analog-to-digital conversion module 404 to convert it into a digital signal.

[0078] Figure 6 In the fault arc signal detection device of the illustrated embodiment, the signal bandwidth converted by the analog-to-digital conversion module 404 is narrower and the noise filtering is better, and a low-conversion-rate, low-resolution, and inexpensive ADC can also be used to achieve better performance.

[0079] Considering that the arc fault signal characteristics may exist in multiple frequency bands, in order to further improve the accuracy of arc fault detection, in another non-limiting embodiment, multiple mixers may be used, such as Figure 7 As shown, n mixers are set to move n high-frequency signals of different frequency bands to the same designated frequency band. The signal processing path where a mixer is located is responsible for extracting arc signals of one frequency band, and different mixers extract arc signals of different frequency bands. These mixers can be single mixers or orthogonal mixers.

[0080] During the arc fault detection process performed by the arc fault signal detection device of the above-mentioned embodiments, the digital judgment module 405 extracts arc signal characteristics from the input digital signal and determines whether there is an arc fault based on the arc signal characteristics. The specific detection method is the same as that of the prior art and will not be repeated here.

[0081] Furthermore, when determining that there is a fault arc, the digital decision module 405 drives the circuit breaker to cut off the fault arc, or issues an alarm, such as sending an alarm signal or controlling an alarm device to issue an alarm.

[0082] The fault arc signal detection device provided by the embodiment of the present invention can achieve the same or better performance by adding a mixer and using a low-speed, low-resolution cheap ADC, or even a 1-bit ADC composed of a comparator, to replace a high-speed, high-resolution expensive ADC. The mixer, local oscillator signal generator, low-frequency filter and low-frequency amplifier required in the circuit are all mature low-cost devices, which are conducive to integration and reduce system cost and power consumption.

[0083] like Figure 8 , which is a schematic diagram of a specific application of the fault arc signal detection device provided by an embodiment of the present invention.

[0084] This example is an example of using a single mixer in a photovoltaic DC fault arc detection system. The current signal sensor is implemented using a toroidal magnetic core coil 81. The photovoltaic DC power supply line PV+ passes through the toroidal magnetic core coil 81 to generate a high-frequency induction signal, which is first amplified after the 5KHz~15KHz broadband filter 82 removes the out-of-band noise and serves as the input signal of the single mixer 83. The narrowband filter of the single mixer 83 is implemented using a 455KHz ceramic filter 831. The local oscillator signal generator 84 generates a local oscillator signal of a specified frequency, shifts the frequency of interest in the input signal to 455KHz, and generates a narrowband signal with a bandwidth of only about 3KHz, and most of the noise has been filtered out. After secondary amplification, it can be effectively converted into a digital signal by the analog-to-digital conversion module, and further processed and judged by the digital judgment module to make a judgment on whether there is a fault arc.

[0085] like Fig. 9, which is another specific application schematic diagram of the fault arc signal detection device provided by an embodiment of the present invention.

[0086] This example is an example of using an orthogonal mixer in a low-voltage AC fault arc detection system. The current signal sensor is implemented using a low-resistance sampling resistor 91. The live wire L of the low-voltage AC power supply line generates a broadband input signal through the sampling resistor 91, and the high-frequency part of the signal is filtered out of the band by a 1MHz to 15MHz broadband filter 92 and then amplified for the first time as the input signal of the orthogonal mixer 93. The narrowband filter of the orthogonal mixer 93 is implemented by a low-pass filter 931. The orthogonal local oscillator signal generator 94 generates an orthogonal local oscillator signal of a specified frequency, shifts the frequency of interest in the input signal to zero frequency, and generates a narrowband orthogonal signal with a bandwidth of only about 10KHz after passing through the low-pass filter 931, and most of the noise has been filtered out. After secondary amplification, it can be effectively converted into a digital signal by the analog-to-digital conversion module, and further processed and judged by the digital judgment module to make a judgment on whether there is a fault arc.

[0087] There can be multiple orthogonal mixers as mentioned above, so as to shift more signals of different frequencies to zero frequency and finally convert them into digital signals.

[0088] It should be noted that Figure 8 and Fig. 9 In the example, the analog-to-digital conversion module and the digital decision module are schematically shown in a block diagram, just to make the diagram concise, and both should be understood in the same way as the corresponding modules in the previous embodiments.

[0089] Accordingly, an embodiment of the present invention further provides a method for detecting a fault arc signal, such as Fig.10 As shown, it is a flow chart of the method, comprising the following steps:

[0090] Step 1001: collect a power supply current signal and convert the current signal into a voltage signal.

[0091] Step 1002: Move the high-frequency band signal in the voltage signal to a specified frequency band to obtain a narrow-band signal.

[0092] Specifically, a single mixer or an orthogonal mixer may be used to move the high-frequency band signal in the voltage signal to a specified frequency band.

[0093] Step 1003: amplify the narrowband signal to obtain an amplified narrowband signal.

[0094] Step 1004: convert the amplified narrowband signal into a digital signal.

[0095] Step 1005: Determine whether there is an arc fault according to the digital signal.

[0096] Furthermore, in another non-limiting embodiment, the method may further include the following steps: when it is determined that a fault arc exists, driving a circuit breaker to cut off the fault arc, or generating an alarm.

[0097] Further, in another non-limiting embodiment, between the above steps 1001 and 1002, the method may further include the following steps:

[0098] filtering out noise outside the voltage signal processing bandwidth to obtain a filtered signal;

[0099] The filtered signal is amplified to obtain an amplified voltage signal.

[0100] Accordingly, in step 1002, the high-frequency band signal in the amplified voltage signal is moved to a designated frequency band.

[0101] The fault arc signal detection device and method provided by the embodiment of the present invention uses a mixer to move one or more high-frequency band signals to a specified frequency band to form one or more narrow-band signals. Each narrow-band signal can be amplified according to its signal size to increase the amplification factor of the small signal, so that the conversion of each narrow-band large signal can be completed using a low-speed, low-resolution ordinary ADC; and the processing speed requirements for the digital decision module are reduced, and the system cost and power consumption are also greatly reduced.

[0102] In a specific implementation, each module / unit included in each device or product described in the above embodiments may be a software module / unit or a hardware module / unit, or may be partly a software module / unit and partly a hardware module / unit.

[0103] For example, for each device or product applied to or integrated in a chip, each module / unit contained therein may be implemented in the form of hardware such as circuits, or at least some of the modules / units may be implemented in the form of software programs, which run on a processor integrated inside the chip, and the remaining (if any) modules / units may be implemented in the form of hardware such as circuits; for each device or product applied to or integrated in a chip module, each module / unit contained therein may be implemented in the form of hardware such as circuits, and different modules / units may be located in the same component (such as a chip, circuit module, etc.) or different components of the chip module, or at least some of the modules / units may be implemented in the form of software programs. The element can be implemented in the form of a software program, which runs on a processor integrated inside the chip module, and the remaining (if any) modules / units can be implemented in the form of hardware such as circuits; for various devices and products applied to or integrated in the terminal, the various modules / units contained therein can be implemented in the form of hardware such as circuits, and different modules / units can be located in the same component (for example, chip, circuit module, etc.) or in different components in the terminal, or, at least some modules / units can be implemented in the form of a software program, which runs on a processor integrated inside the terminal, and the remaining (if any) modules / units can be implemented in the form of hardware such as circuits.

[0104] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A fault arc signal detection device, characterized in that: The device comprises: A current signal sensor, used to collect a power supply current signal and convert the current signal into a voltage signal; A frequency mixing module, used for moving the high-frequency band signal in the voltage signal to a specified frequency band and outputting a narrow-band signal; A second amplifier, used to amplify the narrowband signal and output the amplified narrowband signal; An analog-to-digital conversion module, used for converting the amplified narrowband signal into a digital signal; The digital judgment module is used to determine whether a fault arc exists according to the digital signal.

2. The arc fault signal detection device according to claim 1, characterized in that: The frequency mixing modules have multiple channels, each high frequency band corresponds to one frequency mixing module, and each frequency mixing module uses a local oscillator signal of a different frequency to transfer the high frequency band signal.

3. The arc fault signal detection device according to claim 2, characterized in that: The mixing module comprises: A local oscillator signal generator, used for generating a local oscillator signal; The single mixer is used to use the local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band and output a narrowband signal.

4. The arc fault signal detection device according to claim 2, characterized in that: The mixing module comprises: A local oscillator signal generator, used for generating an orthogonal local oscillator signal; The orthogonal mixer is used to use the orthogonal local oscillator signal to move the high-frequency band signal in the voltage signal to a specified frequency band, and output two narrow-band signals of an in-phase component and an orthogonal component.

5. The arc fault signal detection device according to claim 1, characterized in that: Each narrowband signal corresponds to a second amplifier, and different second amplifiers have different amplification factors.

6. The arc fault signal detection device according to claim 1, characterized in that: The digital judgment module is specifically used to extract arc signal characteristics from the digital signal, and determine whether a fault arc exists according to the arc signal characteristics.

7. The arc fault signal detection device according to claim 1, characterized in that: The digital judgment module is also used to drive the circuit breaker to cut off the fault arc or issue an alarm when it is determined that there is a fault arc.

8. The arc fault signal detection device according to any one of claims 1 to 7, characterized in that: The device also includes: A broadband filter, used for filtering out noise outside the voltage signal processing bandwidth and outputting filtering information; The first amplifier is used to amplify the filtered signal and output the amplified voltage signal to the mixing module.

9. A method for detecting arc fault signals, characterized in that: The method comprises: Collecting a power supply current signal and converting the current signal into a voltage signal; Moving the high-frequency band signal in the voltage signal to a specified frequency band to obtain a narrow-band signal; amplifying the narrowband signal to obtain an amplified narrowband signal; Converting the amplified narrowband signal into a digital signal; Whether an arc fault exists is determined according to the digital signal.

10. The arc fault signal detection method according to claim 9, characterized in that: Moving the high frequency band signal in the voltage signal to the specified frequency band includes: A single mixer or a quadrature mixer is used to move the high-frequency band signal in the voltage signal to a specified frequency band.

11. The arc fault signal detection method according to claim 9, characterized in that: The method further comprises: When it is determined that there is a fault arc, the circuit breaker is driven to cut off the fault arc, or an alarm is issued.

12. The arc fault signal detection method according to any one of claims 9 to 11, characterized in that: The method further comprises: Filtering out the noise outside the voltage signal processing bandwidth to obtain a filtered signal; amplifying the filtered signal to obtain an amplified voltage signal; The step of moving the high-frequency band signal in the voltage signal to the designated frequency band comprises: The high frequency band signal in the amplified voltage signal is moved to a specified frequency band.

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