CN111726079A - Active photovoltaic string arc fault detection method and system - Google Patents

Abstract

The invention provides an active photovoltaic string arc fault detection method and system, which comprises the following steps: active signal injection: actively generating a high-frequency signal, and actively outputting the high-frequency signal at the string side of the photovoltaic group; current signal acquisition: measuring and recording current signals on the direct current bus at the string side of the photovoltaic group to obtain current signal information on the direct current bus at the string side of the photovoltaic group; an arc fault judgment step: according to current signal information on a direct current bus at the string side of the photovoltaic group, wavelet transformation processing is carried out, signal characteristics after wavelet transformation processing are analyzed, the signal characteristics after wavelet transformation processing are compared with input high-frequency signals, whether an arc fault occurs in the photovoltaic group string or not is judged, and active photovoltaic group string arc fault detection result information is obtained. The invention carries out detection on the serial side of the photovoltaic group, thereby fundamentally solving the influence of noise and different operation working conditions of the inverter on the detection.

Description

Active photovoltaic string arc fault detection method and system

technical field

The invention relates to the technical field of arc fault detection, in particular to an active photovoltaic string arc fault detection method and system.

Background technique

In recent years, with the improvement of my country's environmental protection requirements and the advancement of renewable energy power generation technology, the scale of clean energy utilization has been enlarged and developed rapidly. For example, as of 2019, the cumulative installed capacity of photovoltaic power generation in my country has reached 204GW, ranking first in the world. However, due to the arc fault of photovoltaic strings, the frequent occurrence of fire accidents in photovoltaic power plants, resulting in huge economic losses and serious personal safety hazards, has attracted the attention of the industry. At present, there are two main types of arc fault detection technologies for photovoltaic strings: one is a detection method based on the changes in physical properties such as sound, light, and heat during the arc development process; the other is a time-frequency detection method based on arc electric signals.

However, there are still many problems with these technologies. The former method, that is, the detection method based on changes in physical properties such as sound, light, and heat, has the disadvantage that the sensors used are generally expensive, and at the same time, they are easily affected by factors such as sound, light, and heat in the environment, and are not easy to use. Distinguish whether it is caused by the arc fault of the PV string, causing misjudgment. The latter method is based on detecting the time-frequency signal of the arc electric signal. This method is stable and can directly determine whether the arc occurs from the electric signal. However, relying on a single time domain or frequency domain criterion, the detection rate is low and the misjudgment rate is high. , while the mixed time-frequency criterion is not yet mature. At the same time, the arc signal characteristics will inevitably be affected by external conditions, such as inverter noise, different operating conditions, etc., resulting in misjudgment.

Patent document CN107181460A discloses a 4-layer transformation algorithm using db6 wavelet to reduce the interference of inverter switching frequency, thereby reducing the misjudgment rate; patent document CN104601105A discloses a photovoltaic system fault arc detection under abnormal lighting conditions Methods; "Research on Characteristics and Detection Methods of DC Arc Faults in Photovoltaic Systems" (Mu Longhua, Wang Yijian, Jiang Wei, et al., Chinese Journal of Electrical Engineering, 2016, 36(19): 5236-5244) discloses a method combining three effective methods. A hybrid judgment method based on the advantages of time-frequency domain criteria, considering the influence of different voltages, powers and load currents on detection; in the article "Research on the Characteristics and Identification Technology of DC Series Fault Arcs in Photovoltaic Systems" (Ji Shujie, Liaoning University of Engineering and Technology, 2017 ) Combining time domain and frequency domain analysis to study the problem of series arc fault of photovoltaic system, based on the characteristic difference of current peak-to-peak value and current average value during normal operation of photovoltaic system and occurrence of series fault arc, analyze the current time domain characteristics in series arc fault arc The feasibility of identification, the conclusion is that the standard deviation of the low-frequency coefficient and the standard deviation of the high-frequency coefficient of the current three-layer wavelet decomposition are higher than the normal state when the series arc fault occurs in the photovoltaic system. These inventions all focus on how to enhance the adaptability to certain external conditions, such as overcoming the influence of inverter noise on the detection results. However, it cannot adapt to the situation where multiple environmental factors work together, and cannot guarantee high reliability when multiple influencing factors are involved.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide an active photovoltaic string arc fault detection method and system.

According to an active photovoltaic string arc fault detection method provided by the present invention, the method includes: the step of actively injecting a signal: actively generating a high-frequency signal, and actively outputting the high-frequency signal on the photovoltaic string side by means of coil coupling; the current signal collecting step : Measure and record the current signal on the DC bus on the PV string side, and obtain the current signal information on the DC bus on the PV string side; the arc fault judgment steps: According to the current signal information on the DC bus on the PV string side, perform wavelet transform processing, Analyze the signal characteristics after wavelet transform processing, compare the signal characteristics after wavelet transform processing with the input high-frequency signal, judge whether an arc fault occurs in the photovoltaic string, and obtain the information of the arc fault detection result of the active photovoltaic string.

Preferably, the step of actively injecting signals: the first frequency band setting step: generating a high-frequency signal by a signal generator, setting the frequency band of the signal to be 10kHz-100kHz, and the amplitude to be 0-10V; the signal generator generates a high-frequency signal Use a sine wave.

Preferably, the step of actively injecting signals: the second frequency band setting step: coupling the coil to the high-frequency signal on the side of the photovoltaic string, so that the frequency band of the high-frequency signal coupled by the coil to the side of the photovoltaic string is 10 kHz to 100 kHz, and the amplitude It is 0-2V; the high-frequency signal coupled by the coil to the photovoltaic string side adopts a sine wave.

Preferably, the current signal acquisition step: the current signal measurement step: measure the current signal on the DC bus of the photovoltaic string side, and record the sampling frequency used, the current signal is processed by the current signal amplifying unit and the A/D conversion unit and then recorded and stored ; wherein, the sampling frequency is greater than or equal to 200kHz.

Preferably, the arc fault judging step includes: judging whether an arc fault has occurred in the photovoltaic string; if so, acquiring information on the occurrence of an arc fault; if not, acquiring information on the absence of an arc fault; information to obtain the information on the detection result of the arc fault of the active PV string.

An active photovoltaic string arc fault detection system provided according to the present invention includes: an active injection signal module: actively generating a high-frequency signal, and actively outputting the high-frequency signal on the photovoltaic string side by means of coil coupling; a current signal acquisition module : Measure and record the current signal on the DC bus on the PV string side to obtain the current signal information on the DC bus on the PV string side; Arc fault judgment module: According to the current signal information on the DC bus on the PV string side, perform wavelet transform processing, Analyze the signal characteristics after wavelet transform processing, compare the signal characteristics after wavelet transform processing with the input high-frequency signal, judge whether an arc fault occurs in the photovoltaic string, and obtain the information of the arc fault detection result of the active photovoltaic string.

Preferably, the active injection signal module: a first frequency band setting module: a high frequency signal is generated by a signal generator, the frequency band of the set signal is 10kHz-100kHz, and the amplitude is 0-10V; the signal generator generates a high-frequency signal Use a sine wave.

Preferably, the active signal injection module: a second frequency band setting module: couples the coil to the high-frequency signal on the side of the photovoltaic string, so that the frequency band of the high-frequency signal coupled to the side of the photovoltaic string is 10 kHz to 100 kHz, and the amplitude It is 0-2V; the high-frequency signal coupled by the coil to the photovoltaic string side adopts a sine wave.

Preferably, the current signal acquisition module: the current signal measurement module: measures the current signal on the DC bus of the photovoltaic string side, and records the sampling frequency used, and the current signal is processed by the current signal amplifying unit and the A/D conversion unit and then recorded and stored ; wherein, the sampling frequency is greater than or equal to 200kHz.

Preferably, the arc fault judging module includes: judging whether an arc fault occurs in the photovoltaic string; if so, acquiring information on the occurrence of an arc fault; if not, acquiring information on the absence of an arc fault; information to obtain the information on the detection result of the arc fault of the active PV string.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention adopts an active detection method, which is more sensitive to the change of the characteristics of the circuit loop. Compared with the passive method, its anti-interference is stronger and more accurate;

2. The present invention adopts a comparative judgment method when judging faults, which can effectively reduce the misjudgment rate of the detection device;

3. The present invention performs detection on the photovoltaic string side, which fundamentally solves the influence of inverter noise and different operating conditions on detection.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic diagram of an arc fault detection process of an active photovoltaic string according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of an active photovoltaic string arc fault detection system in an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

As shown in Figure 1-2, an active photovoltaic string arc fault detection method provided by the present invention includes: the step of actively injecting a signal: actively generating a high-frequency signal, and actively outputting it on the photovoltaic string side by means of coil coupling High-frequency signal; current signal collection steps: measure and record the current signal on the DC bus on the PV string side to obtain current signal information on the PV string side DC bus; arc fault judgment steps: according to the current on the PV string side DC bus Signal information, perform wavelet transform processing, analyze the signal characteristics after wavelet transform processing, compare the signal characteristics after wavelet transform processing with the input high-frequency signal, determine whether an arc fault occurs in the photovoltaic string, and obtain the information on the detection result of the active photovoltaic string arc fault. .

The present invention adopts an active detection method, which is more sensitive to the change of circuit loop characteristics. Compared with passive methods, its anti-interference and environmental adaptability are stronger.

The present invention injects a high-frequency signal with certain characteristics, and the high-frequency signal coupled to the photovoltaic string side is a sine wave with a frequency range of 10kHz to 100kHz and an amplitude of 0 to 2V, which is suitable for arc detection; The method of discrimination, that is, comparing the characteristic difference between the input signal and the output signal, instead of a fixed threshold, effectively reduces the false positive rate of the detection device; the detection method on the PV string side effectively suppresses the influence of inverter noise .

Preferably, the step of actively injecting signals: the first frequency band setting step: generating a high-frequency signal by a signal generator, setting the frequency band of the signal to be 10kHz-100kHz, and the amplitude to be 0-10V; the signal generator generates a high-frequency signal Use a sine wave.

Preferably, the step of actively injecting signals: the second frequency band setting step: coupling the coil to the high-frequency signal on the side of the photovoltaic string, so that the frequency band of the high-frequency signal coupled by the coil to the side of the photovoltaic string is 10 kHz to 100 kHz, and the amplitude It is 0-2V; the high-frequency signal coupled by the coil to the photovoltaic string side adopts a sine wave.

Preferably, the current signal acquisition step: the current signal measurement step: measure the current signal on the DC bus of the photovoltaic string side, and record the sampling frequency used, the current signal is processed by the current signal amplifying unit and the A/D conversion unit and then recorded and stored ; wherein, the sampling frequency is greater than or equal to 200kHz.

Preferably, the arc fault judging step includes: judging whether an arc fault has occurred in the photovoltaic string; if so, acquiring information on the occurrence of an arc fault; if not, acquiring information on the absence of an arc fault; information to obtain the information on the detection result of the arc fault of the active PV string.

An active photovoltaic string arc fault detection system provided according to the present invention includes: an active injection signal module: actively generating a high-frequency signal, and actively outputting the high-frequency signal on the photovoltaic string side by means of coil coupling; a current signal acquisition module : Measure and record the current signal on the DC bus on the PV string side to obtain the current signal information on the DC bus on the PV string side; Arc fault judgment module: According to the current signal information on the DC bus on the PV string side, perform wavelet transform processing, Analyze the signal characteristics after wavelet transform processing, compare the signal characteristics after wavelet transform processing with the input high-frequency signal, judge whether an arc fault occurs in the photovoltaic string, and obtain the information of the arc fault detection result of the active photovoltaic string.

Preferably, the active injection signal module: a first frequency band setting module: a high frequency signal is generated by a signal generator, the frequency band of the set signal is 10kHz-100kHz, and the amplitude is 0-10V; the signal generator generates a high-frequency signal Use a sine wave.

Preferably, the active signal injection module: a second frequency band setting module: couples the coil to the high-frequency signal on the side of the photovoltaic string, so that the frequency band of the high-frequency signal coupled to the side of the photovoltaic string is 10 kHz to 100 kHz, and the amplitude It is 0-2V; the high-frequency signal coupled by the coil to the photovoltaic string side adopts a sine wave.

Preferably, the current signal acquisition module: the current signal measurement module: measures the current signal on the DC bus of the photovoltaic string side, and records the sampling frequency used, and the current signal is processed by the current signal amplifying unit and the A/D conversion unit and then recorded and stored ; wherein, the sampling frequency is greater than or equal to 200kHz.

Preferably, the arc fault judging module includes: judging whether an arc fault occurs in the photovoltaic string; if so, acquiring information on the occurrence of an arc fault; if not, acquiring information on the absence of an arc fault; information to obtain the information on the detection result of the arc fault of the active PV string.

Specifically, in one embodiment, an active photovoltaic string arc fault detection method includes the following steps: actively injecting a signal step: generating a high-frequency signal, and actively outputting the high-frequency signal on the photovoltaic string side by means of coil coupling ;

Current signal acquisition steps: sample and measure the current signal on the DC bus on the PV string side and record it;

Arc fault judgment step: perform wavelet transformation according to the recorded current signal on the DC bus on the side of the photovoltaic string, analyze and process its characteristics, and compare with the input high-frequency signal to determine whether an arc fault occurs in the photovoltaic string;

The arc fault judging steps include:

The arc fault judgment steps are detailed as follows:

Step S1, system initialization;

Step S2, intercepting the original current data into a current signal of 4096 data lengths;

In step S3, wavelet transform is performed on the intercepted original data, and the energy e _i of each frequency band is analyzed and calculated. A normalization process is performed, that is, E _i =e _i /Σe _i .

Step S4, the energy distribution of each frequency band is stable when there is no arc fault. Calculate the energy distribution range of each frequency band: Calculate the energy distribution range of each frequency band when there is no arc fault according to the preset values K _min and K _max . The preset value K _min gives the lower bound and K _max gives the upper bound.

Step S5, comparing with the input high frequency signal, if the energy of the selected characteristic frequency band deviates from the preset value, it is determined that an arc fault occurs, and the process goes to step S6, and the preset value is determined according to the input high frequency signal. If the energy distribution of the selected characteristic frequency band deviates from the stable value of the previous time period, it is determined that an arc fault has occurred, and the process proceeds to step S6.

Step S6, sending a fault signal.

Preferably, the high frequency signal is a sine wave with a frequency range of 10kHz to 100kHz and an amplitude of 0 to 10V; the high frequency signal coupled to the photovoltaic string side is a sine wave with a frequency range of 10kHz to 100kHz and an amplitude of 0 to 2V Wave.

Preferably, the current signal acquisition step includes current signal measurement, current signal amplification, A/D conversion and record storage. Its sampling frequency is at least 200kHz.

An active photovoltaic string arc fault detection system provided according to the present invention includes: an active injection signal unit, a current signal acquisition unit and an arc fault judgment unit, wherein:

The active injection signal unit is used for actively outputting high-frequency signals to the photovoltaic strings;

The current signal acquisition unit is used to measure and record the current signal on the DC bus on the photovoltaic string side;

The arc fault judging unit performs wavelet transformation according to the recorded current signal, and compares it with the input high-frequency signal to judge whether a photovoltaic arc fault occurs, and if so, sends a fault signal.

Preferably, the active signal injection unit includes a signal generator, a coupling coil and a single-chip microcomputer. The single-chip microcomputer controls the signal generator to actively output and record high-frequency signals on the photovoltaic string side by means of coil coupling.

Preferably, the frequency band of the high-frequency signal generated by the signal generator is a sine wave with an amplitude of 0 to 10V; ~2V sine wave.

Preferably, the arc fault detection unit includes a Rogowski coil, a current signal amplification module, an A/D conversion module and a storage module.

Preferably, the arc fault judging unit includes a processor. The processor processes the collected current signals to determine whether an arc fault occurs in the photovoltaic string, and if so, sends a fault signal.

Specifically, in one embodiment, as shown in FIG. 1 , an active photovoltaic string arc fault detection method provided according to the present invention includes:

Steps of active signal injection: The active signal injection module actively outputs high-frequency signals on the photovoltaic string side by means of coil coupling, and records the information of the injected high-frequency signals. The high-frequency signal generated by the signal module is a sine wave with a frequency of 10kHz to 100kHz and an amplitude of 0 to 10V. The high-frequency signal injected into the PV string side is a sine wave with a frequency of 10kHz to 100kHz and an amplitude of 0 to 2V.

Current signal acquisition steps: The current signal acquisition module collects the current signal on the photovoltaic DC bus, first measures the current, then amplifies it through the current signal amplification module, converts it by the A/D conversion module, and records and stores it.

The arc fault judgment step: the arc fault judgment module processes the data recorded by the current signal acquisition module, compares it with the characteristics of the injected high frequency signal, and judges whether an arc fault occurs in the photovoltaic string, and if so, sends a fault signal.

If there is no arc fault in the PV string, the high-frequency signal in the measured output current signal will be stable and its characteristics will be stable. Therefore, no arc fault is that the output signal shows that the difference between the output signal and the input high frequency signal is stable and unchanged, and the second is that its own characteristics remain stable.

The arc fault judgment steps are detailed as follows:

Step S1, system initialization;

Step S2, intercepting the original current data into a current signal of 4096 data lengths;

In step S3, wavelet transform is performed on the intercepted original data, and the energy e _i of each frequency band is analyzed and calculated. A normalization process is performed, that is, E _i =e _i /Σe _i .

Step S4, the energy distribution of each frequency band is stable when there is no arc fault. Calculate the energy distribution range of each frequency band: Calculate the energy distribution range of each frequency band when there is no arc fault according to the preset values K _min and K _max . The preset value K _min gives the lower bound and K _max gives the upper bound.

Step S5, comparing with the input high frequency signal, if the energy of the selected characteristic frequency band deviates from the preset value, it is determined that an arc fault occurs, and the process goes to step S6, and the preset value is determined according to the input high frequency signal. If the energy distribution of the selected characteristic frequency band deviates from the stable value of the previous time period, it is determined that an arc fault has occurred, and the process proceeds to step S6.

Step S6, sending a fault signal.

As shown in Figure 2, the active photovoltaic string arc fault detection system provided according to the present invention includes:

Active injection signal unit, current signal acquisition unit and arc fault judgment unit. The active injection signal unit is controlled by a single-chip microcomputer, and the high-frequency signal generated by the signal generator is a sine wave with a frequency of 10kHz to 100kHz and an amplitude of 0 to 10V. The high-frequency signal injected into the PV string side by means of coil coupling is a sine wave with a frequency of 10kHz to 100kHz and an amplitude of 0 to 2V. The single-chip computer records the information of the high-frequency signal generated by the signal generator.

The current signal acquisition unit includes a Rogowski coil, a current signal amplification module, an A/D conversion module and a storage module. The Rogowski coil measures the current signal on the DC bus on the PV string side, and is amplified by the current signal amplifying module to the input requirements of the A/D conversion module, and is recorded and stored after being processed by the A/D conversion module.

The arc fault judging unit includes a processor, and the processor performs wavelet transform processing on the measured current signal according to the active photovoltaic string arc fault detection method provided by the present invention, analyzes its characteristics, and compares with the characteristics of the input signal to determine whether an arc occurs. Fault, if so, send fault signal.

The present invention adopts the method of active detection, which is more sensitive to the change of the characteristics of the circuit loop. Compared with the passive method, its anti-interference is stronger and more accurate; The false positive rate of the detection device; the present invention performs detection on the photovoltaic string side, and fundamentally solves the influence of inverter noise and different operating conditions on detection.

In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", The orientation or positional relationship indicated by "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essential content of the present invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily, provided that there is no conflict.

Claims (10)

1. an active photovoltaic string arc fault detection method, is characterized in that, comprises: Steps of actively injecting signals: actively generating high-frequency signals, and actively outputting high-frequency signals on the PV string side; Current signal acquisition steps: measure and record the current signal on the DC bus on the PV string side to obtain the current signal information on the DC bus on the PV string side; Arc fault judgment steps: According to the current signal information on the DC bus on the PV string side, perform wavelet transform processing, analyze the signal characteristics after wavelet transform processing, and compare the signal characteristics after wavelet transform processing with the input high-frequency signal to determine whether the PV string has occurred. Arc fault, obtain the information on the detection result of the active photovoltaic string arc fault. 2. The method for detecting an arc fault of an active photovoltaic string according to claim 1, wherein the step of actively injecting a signal: The first frequency band setting step: a high frequency signal is generated by the signal generator, and the frequency band of the signal is set to 10kHz~100kHz and the amplitude is 0~10V; The signal generator generates a high frequency signal using a sine wave. 3. The method for detecting an arc fault of an active photovoltaic string according to claim 1, wherein the step of actively injecting a signal: The second frequency band setting step: couple the coil to the high-frequency signal on the PV string side, so that the frequency band of the coil coupled to the high-frequency signal on the PV string side is 10kHz~100kHz, and the amplitude is 0~2V; The high-frequency signal coupled to the side of the photovoltaic string by the coil adopts a sine wave. 4. The active photovoltaic string arc fault detection method according to claim 1, wherein the current signal collection step: Current signal measurement steps: measure the current signal on the DC bus on the PV string side, and record the sampling frequency used. The current signal is recorded and stored after being processed by the current signal amplifying unit and the A/D conversion unit; Wherein, the sampling frequency is greater than or equal to 200kHz. 5. The method for detecting an arc fault of an active photovoltaic string according to claim 1, wherein the arc fault judging step comprises: Determine whether an arc fault occurs in the PV string; If so, obtain information about the occurrence of arc fault; If not, obtain the information that the arc fault has not occurred; According to the arc fault occurrence information and the arc fault non-occurrence information, obtain the arc fault detection result information of the active photovoltaic string. 6. An active photovoltaic string arc fault detection system, characterized in that it comprises: Active injection signal module: Actively generate high-frequency signals, and actively output high-frequency signals on the PV string side; Current signal acquisition module: measure and record the current signal on the DC bus on the PV string side, and obtain the current signal information on the DC bus on the PV string side; Arc fault judgment module: According to the current signal information on the DC bus on the PV string side, perform wavelet transform processing, analyze the signal characteristics after wavelet transform processing, and compare the signal characteristics after wavelet transform processing with the input high-frequency signal to determine whether the PV string occurs. Arc fault, obtain the information on the detection result of the active photovoltaic string arc fault. 7. The active photovoltaic string arc fault detection method according to claim 6, wherein the active injection signal module: The first frequency band setting module: the high frequency signal is generated by the signal generator, and the frequency band of the set signal is 10kHz~100kHz and the amplitude is 0~10V; The signal generator generates a high frequency signal using a sine wave. 8 . The active photovoltaic string arc fault detection system according to claim 6 , wherein the active injection signal module: Second frequency band setting module: couple the coil to the high-frequency signal on the PV string side, so that the frequency band of the high-frequency signal coupled to the PV string side is 10kHz~100kHz, and the amplitude is 0~2V; The high-frequency signal coupled to the side of the photovoltaic string by the coil adopts a sine wave. 9. The active photovoltaic string arc fault detection system according to claim 6, wherein the current signal acquisition module: Current signal measurement module: measure the current signal on the DC bus of the PV string side, and record the sampling frequency used. The current signal is recorded and stored after being processed by the current signal amplification unit and the A/D conversion unit; Wherein, the sampling frequency is greater than or equal to 200kHz. 10. The active photovoltaic string arc fault detection system according to claim 6, wherein the arc fault judgment module comprises: Determine whether an arc fault occurs in the PV string; If so, obtain information about the occurrence of arc fault; If not, obtain the information that the arc fault has not occurred; According to the arc fault occurrence information and the arc fault non-occurrence information, obtain the arc fault detection result information of the active photovoltaic string.

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