Direct-current arc detection device, detection method and photovoltaic system

Abstract

The invention relates to the technical field of electronic power, in particular to a direct-current arc detection device and method and a photovoltaic system, the direct-current arc detection device comprises a current acquisition module, a program-controlled filtering module and a control module, and the current acquisition module is used for acquiring a current signal on a branch between the output side of a photovoltaic panel and the input side of an inverter; the program-controlled filtering module is used for filtering the current signal based on the filtering parameter; the control module is used for adjusting the filtering parameters and analyzing the filtered current signal to judge whether a direct-current arc fault exists or not, and the control module is further used for controlling the inverter to be disconnected from the photovoltaic panel when it is judged that the direct-current arc fault exists. The direct-current arc detection device can realize intelligent direct-current arc detection and is low in false alarm rate.

Description

Technical Field

[0001] The present application relates to the field of electronic power technology, and in particular to a DC arc detection device, a detection method, and a photovoltaic system. Background Art

[0002] In a photovoltaic energy storage system, DC-side arc faults are likely to cause fires, so the detection of DC arcs is very important. Traditional arc detection generally uses fixed filtering parameters and static threshold judgment, which has problems such as insufficient suppression of inverter switching noise and sensitivity to environmental electromagnetic interference, resulting in low arc detection sensitivity and high false alarm rate under complex working conditions. Different models of photovoltaic inverters need to customize filter parameters, resulting in a long on-site commissioning period, increased operation and maintenance costs, and a lack of remote maintenance means. Existing solutions generally have problems such as high power consumption of the detection circuit and inability to effectively collect fault data for model optimization. In addition, traditional arc circuit breakers rely on external power supply, consuming energy continuously in the fault-free state, which does not meet the energy efficiency requirements of photovoltaic systems.

[0003] Currently, there is no intelligent DC arc current detection solution with a low false alarm rate that can be applied to different models of inverters. Summary of the Invention

[0004] In view of this, the embodiments of the present application provide a DC arc detection device, a detection method, and a photovoltaic system, which solve the technical problem that the existing DC arc detection cannot adjust the filtering parameters in real time and dynamically.

[0005] In the first aspect of the embodiments of the present application, a DC arc detection device is provided. The DC arc detection device includes: a current acquisition module for acquiring a current signal on a branch between the output side of a photovoltaic panel and the input side of an inverter; a programmable filtering module for filtering the current signal based on filtering parameters; a control module for adjusting the filtering parameters and analyzing the filtered current signal to determine whether there is a DC arc fault. The control module is further configured to control the inverter to disconnect from the photovoltaic panel when it is determined that there is a DC arc fault.

[0006] In one of the embodiments, the programmable filtering module includes a band-pass filtering unit, a buffer unit, and a parameter adjustment unit connected in sequence; The band-pass filtering unit is used to limit the frequency of the input current signal; the buffer unit is used to maintain the integrity of the current signal, and the parameter adjustment unit is used to filter the current signal according to the filtering parameters generated by the control module.

[0007] In one embodiment, the parameter adjustment unit includes a filter chip, and the filter chip cooperates with the band-pass filtering unit to form a second-order band-pass filter.

[0008] In one embodiment, the filter chip is configured to change the center frequency of the second-order band-pass filter based on the first control signal and the clock signal of the control module, and adjust the quality factor of the second-order band-pass filter based on the second control signal of the control module.

[0009] In one embodiment, the filter chip includes a signal input pin, a signal output pin, a plurality of control signal pins, and a clock pin; The signal input pin is used to access the current signal, and the signal output pin is used to output the current signal; Some of the control signal pins are used to access the first control signal, and some of the control signal pins are used to access the second control signal; The clock signal pin includes a first clock signal pin and a second clock signal pin. After the first clock signal pin and the second clock signal pin are short-circuited, they are connected to the control module for accessing the clock signal.

[0010] In one embodiment, the programmable filtering module further includes a voltage stabilizing unit and a clamping unit; The voltage stabilizing unit is connected between the band-pass filtering unit and the current acquisition module; The clamping unit is connected between the band-pass filtering unit and the buffer unit, and / or the clamping unit is connected between the buffer unit and the parameter adjustment unit.

[0011] In one embodiment, the filtering parameter includes a center frequency and a quality factor Q. The bandwidth BW of the programmable filtering module is obtained by the following formula: ; where the adjustable range of the quality factor Q is from 0.5 to 64.

[0012] In one embodiment, it further includes a power supply module, an interface module, and a communication module; the control module includes a storage unit; The power supply module is connected to the control module for accessing the power supply of the photovoltaic panel; The interface module includes an external interface unit and a communication interface unit, and the communication module includes a first communication unit and a second communication unit; The storage unit is connected to the inverter through the first communication unit and the communication interface module. The first communication unit is used to realize the communication connection between the control module and the inverter; The second communication unit is used to implement a wireless communication connection between the control module and the host computer.

[0013] A second aspect of the embodiments of the present application provides a DC arc detection method, which is applied to the above DC arc detection device, and includes the steps of: Collect the current signal on the branch between the output side of the photovoltaic panel and the input side of the inverter; Perform filtering processing on the current signal based on the filtering parameters; Analyze the current signal after filtering processing to determine whether there is a DC arc fault; When it is determined that there is a DC arc fault, control the inverter to disconnect the connection with the photovoltaic panel.

[0014] A third aspect of the embodiments of the present application provides a photovoltaic system, which includes a photovoltaic panel and an inverter, and further includes the DC arc detection device provided in the first aspect of the embodiments of the present application.

[0015] The beneficial effects of the embodiments of the present application are as follows: The current acquisition module collects the current signal on the branch between the output side of the photovoltaic panel and the input side of the inverter. The program-controlled filtering module performs filtering processing on the current signal based on the filtering parameters. The control module adjusts the filtering parameters, and analyzes the current signal after filtering processing to determine whether there is a DC arc fault. When it is determined that there is a DC arc fault, control the inverter to disconnect the connection with the photovoltaic panel. The control module can dynamically adjust the filtering parameters according to actual needs to achieve adaptation to different inverter models, improve the sensitivity and accuracy of DC arc detection, and the device has a simple structure and low cost. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic diagram of the principle of the DC arc detection device provided in an embodiment of the present application; Figure 2 It is a schematic diagram of the principle of the DC arc detection device provided in another embodiment of the present application; Figure 3 It is a partial circuit principle schematic diagram of the program-controlled filtering module provided in an embodiment of the present application; Figure 4 It is a circuit principle schematic diagram of the parameter adjustment unit provided in an embodiment of the present application; Figure 5 The circuit principle of the voltage follower provided by an embodiment of the present application; Figure 6 The schematic diagram of the principle of the DC arc detection device provided by another embodiment of the present application; Figure 7 The schematic flow chart of the DC arc detection method provided by an embodiment of the present application; Figure 8 The working flow schematic diagram of the DC detection device provided by an embodiment of the present application; Figure 9 The schematic diagram of the principle of the photovoltaic system provided by an embodiment of the present application. Specific embodiments

[0018] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0020] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0021] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0022] Such as Figure 1As shown in the figure, in the first aspect of the embodiment of the present application, a DC arc detection device 10 is provided, which includes a current acquisition module 100, a programmable filter module 200, and a control module 300. The current acquisition module 100 is used to acquire the current signal on the branch between the output side of the photovoltaic panel 20 and the input side of the inverter 30. The programmable filter module 200 is used to filter the current signal based on the filter parameters. The control module 300 is used to adjust the filter parameters and analyze the filtered current signal to determine whether there is a DC arc fault. The control module 300 is further used to control the inverter 30 to disconnect the connection with the photovoltaic panel 20 when it is determined that there is a DC arc fault.

[0023] In one embodiment, the current acquisition module 100 includes a current transformer. The current transformer is connected to the branch between the photovoltaic panel 20 and the inverter 30 and is used to acquire the current signal on the corresponding branch and determine whether there is a DC arc on the output side of the photovoltaic panel 20 by analyzing the current signal. When the control module 300 determines that there is an arc fault on the DC side, the inverter 30 disconnects the circuit connection between it and the photovoltaic panel 20 to protect the safety of the inverter 30.

[0024] The DC arc detection device 10 provided by the embodiment of the present application acquires the current signal on the branch between the output side of the photovoltaic panel 20 and the input side of the inverter 30 through the current acquisition module 100, filters the current signal based on the filter parameters through the programmable filter module 200, adjusts the filter parameters through the control module 300, and analyzes the filtered current signal to determine whether there is a DC arc fault. When it is determined that there is a DC arc fault, the control module 300 controls the inverter 30 to disconnect the connection with the photovoltaic panel 20. The DC arc detection device 10 provided by the present application can dynamically adjust the filter parameters according to actual needs, achieve adaptation to different types of inverters 30, improve the sensitivity and accuracy of DC arc detection, and has a simple device structure and low cost.

[0025] In one embodiment, please refer to Figure 2, the programmable filter module 200 includes a band-pass filter unit 210, a buffer unit 220, and a parameter adjustment unit 230 that are connected in sequence. The band-pass filter unit 210 is used to limit the frequency of the input current signal. The buffer unit 220 is used to maintain the integrity of the current signal. The parameter adjustment unit 230 is used to filter the current signal according to the filtering parameters generated by the control module 300. The current acquisition module 100, that is, the current transformer, filters out the DC component of the current that is irrelevant to the DC arc detection. The acquired current signal enters the band-pass filter unit 210 for primary band-pass filtering to limit the frequency of the input signal. Subsequently, the current signal enters the buffer unit 220. The buffer unit 220 has the characteristics of low input impedance and high output impedance, enhancing the current driving ability, making the current signal more stable. Finally, the current signal is input to the parameter adjustment unit 230 for further filtering processing.

[0026] In the embodiment of the present application, the programmable filter module 200 limits the frequency range of the input current signal by setting the band-pass filter unit 210, effectively filters out high-frequency noise and low-frequency interference (such as power frequency interference) that are irrelevant to the DC arc, focuses on the target frequency band signal, and significantly improves the signal-to-noise ratio. By setting the buffer unit 220, the load effect on the previous-stage circuit, that is, the band-pass filter unit 210, is reduced, signal attenuation is avoided, the influence of the subsequent-stage parameter adjustment unit 230 on the previous stage is isolated, signal reflection or distortion is prevented, and the integrity of the signal during long-distance transmission is ensured. By the control module 300, the filtering parameters of the parameter adjustment unit 230 are further adjusted in real time to adapt to different working conditions (such as load changes, environmental noise fluctuations), improving the flexibility of the system.

[0027] Further, please combine Figure 2 refer to Figure 3 and Figure 4 , Figure 3 and Figure 4 as shown in the power supply schematic diagram of the programmable filter module 200.

[0028] In one embodiment, the parameter adjustment unit 230 includes a filter chip U1. The filter chip U1 and the band-pass filter unit 210 cooperate to form a second-order band-pass filter. In the embodiment of the present application, the filter chip U1 and the band-pass filter unit 210 jointly constitute a second-order band-pass filter. Compared with a first-order filter, the second-order structure has a steeper roll-off slope at the passband edge, can extract the current signal (DC arc characteristic frequency) of the target frequency band more accurately, while suppressing out-of-band noise, and the filter chip U1 integrates amplification, filtering, and adjustment functions, reducing the number of peripheral components, improving the reliability of the circuit, and reducing the hardware cost.

[0029] In one embodiment, the filter chip U1 itself can form a second-order band-pass filter. The output pin (BPA) of the band-pass filter in one channel of the filter chip U1 is shorted to the input pin (INB) of another band-pass filter channel to form a second-order band-pass filter circuit.

[0030] In one embodiment, the filter chip U1 is configured to change the center frequency of the second-order band-pass filter based on the first control signal and the clock signal of the control module 300 , and adjust the quality factor Q of the second-order band-pass filter based on the second control signal of the control module 300.

[0031] Specifically, in one embodiment, please refer to Figure 4 , the filter chip U1 includes a signal input pin INA, a signal output pin BPB, several control signal pins, and a clock pin.

[0032] The signal input pin INA is used to access the current signal, the signal output pin BPB is used to output the current signal, some control signal pins are used to access the first control signal, and some control signal pins are used to access the second control signal. Among them, the five pins F0, F1, F2, F3, and F4 of the filter chip U1 are used as control signal pins to access the first control signal. The first control signal adopts a selectable five-bit binary signal and is used to set the N value, and the range of the N value is 0-31.

[0033] The seven pins Q0, Q1, Q2, Q3, Q4, Q5, Q6, and Q7 of the filter chip U1 are used as control signal pins to access the second control signal. Among them, the pins Q0, Q1, and Q2 are shorted and connected to the -5V voltage source, the pins Q5 and Q6 are shorted and connected to the +5V voltage source, and the pins Q3 and Q4 are used to access the level signal provided by the control module 300 to adjust the quality factor Q of the filter circuit. In one embodiment, the adjustable range of the quality factor Q is 0.5 to 64.

[0034] The clock signal pins include a first clock signal pin CLKA and a second clock signal pin CLKB. The first clock signal pin CLKA and the second clock signal pin CLKB are shorted and connected to the control module 300 for accessing the clock signal of the control module 300.

[0035] In one embodiment, the filter parameters include the center frequency and the quality factor Q. The bandwidth BW of the programmable filter module 200 is obtained through the following formula: ; Based on the foregoing, it can be understood that the programmable filter module 200 provided by the embodiments of the present application realizes the center frequency of the filter parameters through the clock signal provided by the control module 300 and the N value set by the first control signal Adjustment.

[0036] When the N value is set to 31, according to the required center frequency it is possible to calculate the lower limit value, and the calculation process is as follows: ; When the N value is set to 0, according to the required center frequency it is possible to calculate the upper limit value, and the calculation process is as follows: ; The calculated frequency range is from 2 MHz to 10 MHz. Therefore, a clock frequency of 10 MHz is selected. The cut-off frequency of 10 kHz to 100 kHz is achieved by changing the N value, and the quality factor Q of the filter circuit is set by the Q value setting bit, and the filter bandwidth BW is calculated. Through the above method in the embodiment of the present application, dynamic adjustment of filter parameters is achieved, high-precision filtering, dynamic parameter adaptation and system-level optimization are realized, which is particularly suitable for the DC arc detection scenario with complex noise environment and variable signal characteristics, and comprehensively improves performance, flexibility and reliability.

[0037] In one embodiment, please refer to Figure 3 , the programmable filter module 200 further includes a voltage stabilizing unit 240 and a clamping unit 250. The voltage stabilizing unit 240 is connected between the band-pass filtering unit 210 and the current acquisition module 100. The voltage stabilizing unit 240 includes a bidirectional voltage stabilizing diode R1. The bidirectional voltage stabilizing diode R1 is connected to the output end of the current transformer CT. One end of the bidirectional voltage stabilizing diode R1 is grounded through a capacitor C1. The bidirectional voltage stabilizing diode R1 is used to limit the amplitude of the current signal output by the current acquisition module 100 within a safe range to prevent the input stage of the operational amplifier in the band-pass filtering unit 210 from being broken down or distorted due to overvoltage.

[0038] The clamping unit 250 is connected between the band-pass filtering unit 210 and the buffer unit 220, and / or the clamping unit 250 is connected between the buffer unit 220 and the parameter adjustment unit 230. In one embodiment, the clamping unit 251 is connected between the band-pass filtering unit 210 and the buffer unit 220. The clamping unit 251 includes a resistor R4 and a clamping diode D2. One end of the resistor R4 is connected to the output end of the band-pass filtering unit 210, and the other end of the resistor R4 is connected to one end of the clamping diode D2. The other end of the clamping diode D2 is connected to the ground through a diode D1. The clamping unit 252 is connected between the buffer unit 220 and the parameter adjustment unit 230. The clamping unit 252 includes a double series diode D4. By setting the clamping unit 250 in the embodiment of the present application, the circuit is protected from damage caused by electrostatic discharge, overvoltage or transient interference, and the stability of the circuit is improved.

[0039] In one embodiment, refer to Figure 3 , the band-pass filtering unit 210 includes an RC low-pass filter and an RC high-pass filter connected in series in sequence. The RC low-pass filter is composed of a filtering resistor R2 and a filtering capacitor C2, and the RC high-pass filter is composed of a filtering resistor R3 and a filtering capacitor C3.

[0040] In one embodiment, the cut-off frequency range of the band-pass filtering unit 210 is between 10KHz and 270KHz, and its calculation formula is as follows: ; ; In one embodiment, refer to Figure 4 and Figure 5 , between the output end of the parameter adjustment unit 230 of the programmable filtering module 200 and the control module 300, a voltage follower is further connected. Figure 5 The circuit schematic diagram of the voltage follower is shown as follows. Before the control module 300 samples the current signal, by setting the voltage follower, signal attenuation is prevented to ensure the complete transmission of the weak current signal (such as the DC arc characteristic) after filtering. When the control module 300 performs ADC sampling on the current signal, signal transmission loss is reduced.

[0041] In one embodiment, refer to Figure 5 , the DC arc detection device 10 further includes a power supply module 400, an interface module 500, and a communication module 600, and the control module 300 includes a storage unit 310.

[0042] The control module 300 includes a main control unit 320 and a storage unit 310. The main control unit 320 is connected to the programmable filtering module 200 and is used to sample the current signal and analyze and process the current signal to determine whether there is a DC arc fault. The storage unit 310 is Flash. Flash is used to store arc data, which can be erased and written by area, automatically upload the original waveform data and filtering parameters to the energy management platform, can realize online diagnosis of the power station, timely analyze the misjudged data and supply it for model training such as AI, and then store the updated data.

[0043] The power supply module 400 is connected to the control module 300 and is used to access the power supply of the photovoltaic panel 20, so as to realize the self-power supply of the photovoltaic panel 20 to the DC arc detection device 10 of the embodiment of the present application, and there is no need to additionally set up an independent power supply module.

[0044] The interface module 500 includes an external interface unit (not shown in the figure) and a communication interface unit (not shown in the figure). The communication module 600 includes a first communication unit 610 and a second communication unit 620. The storage unit 310 is connected to the inverter 30 through the first communication unit 610 and the interface module 500. The first communication unit 610 is used to realize the communication connection between the control module 300 and the inverter 30. Specifically, the first communication unit 610 is an RS485 communication circuit, and the first communication unit 610 is used to realize the communication between the control module 300 and the inverter 30. When the control module 300 determines that there is a DC arc fault, an instruction is sent to the inverter 30 through the first communication unit 610 to control the relay of the inverter 30 to achieve a quick disconnection. When no arc data is detected, the system enters the low-power mode to save energy.

[0045] The second communication unit 620 is a WIFI communication module, which is used to realize the wireless communication connection between the control module 300 and the upper computer. When performing firmware upgrade, for example, when updating the firmware of the control module 300, the external upper computer can download the firmware or arc model data to be upgraded to the control module 300 through the WIFI communication module, so as to realize the remote debugging and upgrade of the DC arc detection device 10.

[0046] Please refer to Figure 7 , the second aspect of the embodiment of the present application provides a DC arc detection method, which is applied to the DC arc detection device 10 provided in the first aspect of the embodiment of the present application. The DC arc detection method includes the following steps: S100. Collect the current signal on the branch between the output side of the photovoltaic panel and the input side of the inverter.

[0047] S200. Filter the current signal based on the filtering parameters.

[0048] S300. Analyze the filtered current signal to determine whether there is a DC arc fault.

[0049] S400. When it is determined that there is a DC arc fault, control the inverter to disconnect the connection with the photovoltaic panel.

[0050] Further, in order to better illustrate the working principle of the DC arc detection device 10 provided in the embodiment of the present application, please refer to Figure 8 , Figure 8 The working flow chart of the DC arc detection device 10 in the embodiment of the present application is shown. The specific steps will not be elaborated here.

[0051] The DC arc detection device 10 provided by the embodiment of the present application collects the current signal on the branch between the output side of the photovoltaic panel and the input side of the inverter through the current acquisition module 100, filters the current signal based on the filtering parameters through the programmable filtering module 200, adjusts the filtering parameters through the control module 300, and analyzes the current signal after filtering to determine whether there is a DC arc fault. When it is determined that there is a DC arc fault, the inverter is controlled to disconnect the connection with the photovoltaic panel. The DC arc detection device 10 provided by the present application can dynamically adjust the filtering parameters according to actual needs, achieve adaptation to different inverter models, improve the sensitivity and accuracy of DC arc detection, and has a simple device structure and low cost.

[0052] Please refer to Figure 9 , the embodiment of the present application also provides a photovoltaic system, including a photovoltaic panel 20 and an inverter 30, and further including the DC arc detection device 10 provided by the first aspect of the embodiment of the present application.

[0053] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the DC arc detection method provided by the second aspect of the embodiment of the present application.

[0054] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0055] The memory may include non-permanent memory in the computer-readable medium, forms such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory. The memory is an example of a computer-readable medium.

[0056] Computer-readable media include both permanent and non-permanent, removable and non-removable storage media. The storage media can implement information storage by any method or technology, and the information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PCM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), ROM, digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, computer-readable media do not include transitory computer-readable media such as modulated data signals and carrier waves.

[0057] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A DC arc detection device, characterized in that: include: A current acquisition module is used to collect current signals on the branch between the output side of the photovoltaic panel and the input side of the inverter; A program-controlled filtering module, used for filtering the current signal based on filtering parameters; The control module is used to adjust the filtering parameters and analyze the current signal after filtering to determine whether a DC arc fault exists. The control module is also used to control the inverter to disconnect from the photovoltaic panel when it is determined that a DC arc fault exists.

2. The DC arc detection device according to claim 1, characterized in that: The program-controlled filtering module comprises a band-pass filtering unit, a buffer unit and a parameter adjustment unit connected in sequence; The bandpass filter unit is used to limit the frequency of the input current signal; the buffer unit is used to maintain the integrity of the current signal; and the parameter adjustment unit is used to filter the current signal according to the filter parameters generated by the control module.

3. The DC arc detection device according to claim 2, characterized in that: The parameter adjustment unit includes a filter chip, and the filter chip cooperates with the bandpass filter unit to form a second-order bandpass filter.

4. The DC arc detection device according to claim 3, characterized in that: The filter chip is configured to change the center frequency of the second-order bandpass filter based on the first control signal and the clock signal of the control module, and to adjust the quality factor of the second-order bandpass filter based on the second control signal of the control module.

5. The DC arc detection device according to claim 4, characterized in that: The filter chip includes a signal input pin, a signal output pin, a plurality of control signal pins and a clock pin; The signal input pin is used to receive the current signal, and the signal output pin is used to output the current signal; Some of the control signal pins are used to access the first control signal, and some of the control signal pins are used to access the second control signal; The clock signal pin includes a first clock signal pin and a second clock signal pin. The first clock signal pin and the second clock signal pin are short-circuited and connected to the control module for receiving the clock signal.

6. The DC arc detection device according to claim 2, characterized in that: The program-controlled filter module also includes a voltage stabilizing unit and a clamping unit; The voltage stabilizing unit is connected between the bandpass filtering unit and the current acquisition module; The clamping unit is connected between the bandpass filtering unit and the buffering unit, and / or the clamping unit is connected between the buffering unit and the parameter adjusting unit.

7. The DC arc detection device according to claim 1, characterized in that: The filtering parameters include the center frequency And the quality factor Q, the bandwidth BW of the programmable filter module is obtained by the following formula: ; Wherein, the adjustable range of the quality factor Q is 0.5 to 64.

8. The DC arc detection device according to claim 1, characterized in that: It also includes a power module, an interface module and a communication module; the control module includes a storage unit; The power supply module is connected to the control module and is used to access the power supply of the photovoltaic panel; The interface module includes an external interface unit and a communication interface unit, and the communication module includes a first communication unit and a second communication unit; The storage unit is connected to the inverter through the first communication unit and the communication interface module, and the first communication unit is used to realize the communication connection between the control module and the inverter; The second communication unit is used to realize wireless communication connection between the control module and the host computer.

9. A DC arc detection method, applied to the DC arc detection device according to any one of claims 1 to 8, characterized in that: Includes steps: Collecting the current signal on the branch between the output side of the photovoltaic panel and the input side of the inverter; Performing filtering processing on the current signal based on a filtering parameter; Analyzing the filtered current signal to determine whether there is a DC arc fault; When it is determined that a DC arc fault exists, the inverter is controlled to disconnect from the photovoltaic panel.

10. A photovoltaic system, comprising a photovoltaic panel and an inverter, characterized in that: It also includes a DC arc detection device as described in any one of claims 1 to 8.

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