Arcing detection method and related device

Abstract

The invention provides an arc discharge detection method and a related device. The method comprises the following steps: performing polling calculation on state information of at least two arcing detection points according to a preset sequence, and acquiring a sampling signal corresponding to the arcing detection point in real time in a state information calculation process of each arcing detection point; based on the frequency spectrum of the sampling signal corresponding to the arc discharge detection point, state information of the arc discharge detection point is determined, and the state information comprises an arc discharge undetermined state and a normal undetermined state; if it is detected that the first cumulative number reaches the first preset number when the polling number is not larger than the preset polling number, it is judged that the arc discharge fault happens to the arc discharge detection point. According to the invention, a polling calculation mode is adopted, so that the sampling signal can be detected for a long time to prevent external sudden interference from influencing the accuracy of a detection result, and the calculation amount of arc discharge detection can be reduced, thereby improving the efficiency of arc discharge detection.

Description

Technical Field

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

[0002] With the development and wide application of photovoltaic power generation technology, the technical requirements for the power generation power of photovoltaic systems are also getting higher and higher. A photovoltaic system is composed of photovoltaic panels, photovoltaic DC cables, inverters and other structures. It uses solar photovoltaic panels exposed outdoors to collect solar energy and perform photoelectric conversion to achieve photovoltaic power generation.

[0003] The arc output of the photovoltaic panel means that in a photovoltaic power generation system, due to reasons such as voltage fluctuations, an arc discharge phenomenon occurs between photovoltaic panels, which is likely to damage circuit components and cause system failures. Therefore, it is necessary to detect arc faults in a photovoltaic power generation system.

[0004] With the continuous expansion of the scale of photovoltaic power generation systems, the number of photovoltaic panels is increasing day by day. In existing arc detection schemes, it is usually judged whether an arc fault occurs by sampling signals within a short period. However, when sudden interference occurs in the photovoltaic panel, it will lead to misjudgment of arc detection. Summary of the Invention

[0005] Embodiments of the present invention provide an arc detection method and related device to solve the problem of low accuracy of the arc detection method.

[0006] In a first aspect, embodiments of the present invention provide an arc detection method, including:

[0007] Polling and calculating the status information of at least two arc detection points in a preset order, and in the process of calculating the status information of each arc detection point, obtaining the sampling signal corresponding to the arc detection point in real time; determining the status information of the arc detection point based on the spectrum of the sampling signal corresponding to the arc detection point, where the status information includes an arc pending state and a normal pending state; the sampling signal includes N continuous sampling signal segments; and N≥1;

[0008] If it is detected that the first cumulative number reaches a first preset number when the polling number is not greater than a preset polling number, it is determined that an arc fault occurs at the arc detection point; the first cumulative number is the cumulative number of times that the status information of the arc detection point is in the arc pending state.

[0009] In a second aspect, embodiments of the present invention provide an arc detection device, including:

[0010] A status information determination module, configured to poll and calculate the status information of at least two arc striking detection points in a preset order, and during the calculation process of the status information of each arc striking detection point, obtain the sampling signal corresponding to the arc striking detection point in real time; determine the status information of the arc striking detection point based on the spectrum of the sampling signal corresponding to the arc striking detection point, where the status information includes an arc striking pending status and a normal pending status; the sampling signal includes N consecutive sampling signal segments; and N≥1;

[0011] An arc striking fault detection module, configured to determine that an arc striking fault occurs at the arc striking detection point if it is detected that a first cumulative number reaches a first preset number when the polling number is not greater than a preset polling number; the first cumulative number is the cumulative number of times that the status information of the arc striking detection point is in the arc striking pending status.

[0012] In a third aspect, an embodiment of the present invention provides a terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the arc striking detection method in any possible implementation manner of the first aspect above are implemented.

[0013] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps of the arc striking detection method in the first aspect or any possible implementation manner of the first aspect above are implemented.

[0014] In a fifth aspect, an embodiment of the present invention provides a photovoltaic system, including: a plurality of photovoltaic modules and the terminal described in the third aspect above.

[0015] An embodiment of the present invention provides an arc striking detection method and related devices. In view of the characteristic that after an arc striking fault occurs, it is usually not a short-term sudden occurrence but lasts for a period of time, this method polls and calculates the status information of at least two arc striking detection points in a preset order. This polling calculation method can, on the one hand, ensure long-term monitoring of the sampling signal, effectively avoid the adverse impact of short-term spectrum uplift caused by external sudden interference on the accuracy of the detection result; on the other hand, it can reduce the calculation amount of arc striking detection, thereby improving the efficiency of arc striking detection. In addition, during the calculation process of the status information of each arc striking detection point, using the spectrum information of the sampling signal to determine the status information of the arc striking detection point helps to amplify the degree of change of the signal characteristics, thereby enhancing the accuracy of arc striking detection. Description of the Drawings

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

[0017] Figure 1 It is an application scenario diagram of the arc drawing detection method provided by an embodiment of the present invention;

[0018] Figure 2 It is a flowchart of the implementation of the arc drawing detection method provided by an embodiment of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the arc drawing detection device provided by an embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the terminal provided by an embodiment of the present invention. Detailed implementation manners

[0021] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0022] In the description of the specification and the appended claims of the present application, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present application specification, referring to "one embodiment" or "some embodiments" etc. means that a specific feature, structure, or characteristic described in combination with this embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "include", "comprise", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0024] In addition, the "multiple" mentioned in the embodiments of the present application should be interpreted as two or more.

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will be described through specific embodiments with reference to the accompanying drawings.

[0026] Figure 1 FIG. is an application scenario diagram of the arc striking detection method provided by an embodiment of the present invention. As Figure 1 shown, the arc striking detection method can be applied to a photovoltaic system. The photovoltaic system includes multiple photovoltaic panels (PV1, PV2 to PVn), corresponding photovoltaic inverters for each photovoltaic panel, signal sampling modules (C1, C2 to Cn), and a processor. The output terminals of each photovoltaic panel are connected to the DC terminals of the photovoltaic inverters, and the AC terminals of the photovoltaic inverters are used to connect to the AC bus of the photovoltaic system. The sampling terminals of each signal sampling module (C1, C2 to Cn) are connected to the output terminals of the corresponding photovoltaic panels (PV1, PV2 to PVn) for collecting the output signals of the photovoltaic panels (PV1, PV2 to PVn) and sending the output signals of each photovoltaic panel (PV1, PV2 to PVn) to the processor. The processor performs arc striking detection on the photovoltaic panels based on the output signals of each photovoltaic panel (PV1, PV2 to PVn), that is, the arc striking detection points in the photovoltaic system are the output terminals of each photovoltaic panel.

[0027] It can be understood that the arc striking detection method provided in this embodiment can also be applied to other electrical devices. The multiple arc striking detection points collected by the processor can be located in the same electrical device or in different electrical devices, which is not limited herein.

[0028] Refer to Figure 2 , which shows the implementation flowchart of the arc striking detection method provided by an embodiment of the present invention, and is described in detail as follows:

[0029] S101: Poll and calculate the status information of at least two arc striking detection points in a preset order, and during the calculation process of the status information of each arc striking detection point, obtain the sampling signal corresponding to this arc striking detection point in real time; determine the status information of this arc striking detection point based on the spectrum of the sampling signal corresponding to this arc striking detection point. The status information includes an arc striking pending state and a normal pending state; the sampling signal includes N consecutive sampling signal segments; and N≥1.

[0030] The execution subject of this embodiment can be the above-mentioned processor or other terminals. Hereinafter, taking the terminal as an example, the arc striking detection method provided in this embodiment will be explained.

[0031] Specifically, there are multiple arc striking detection points, and the terminal polls and calculates the status information of all arc striking detection points in a preset order. The preset order can be the label order of each arc striking detection point or the order arranged according to the importance of each arc striking detection point.

[0032] In the process of calculating the status information for each arcing detection point, when polling the first arcing detection point, the sampling signal corresponding to the first arcing detection point is obtained in real time. This sampling signal can be the sampling signal for at least one current sampling period. The sampling signal for one sampling period includes, but is not limited to, 1024 sampling points or 512 sampling points. The sampling signal can include a current sampling signal or a voltage sampling signal. Among them, the first arcing detection point is any arcing detection point.

[0033] Specifically, when arcing occurs, the current and voltage will change and fluctuate rapidly, thereby generating electromagnetic signals with specific frequencies. These signals will show corresponding amplitude changes in the frequency spectrum, and their spectral amplitudes will be significantly different from the normal state at certain specific frequencies or frequency bands. By detecting and analyzing the changes in these specific spectral amplitudes, it is possible to determine whether an arcing fault has occurred, and there is a certain correlation between the severity of the arcing fault and the magnitude of the spectral amplitude. The more severe the arcing, the stronger the electromagnetic interference generated, and the larger the corresponding spectral amplitude.

[0034] Based on the above principle, in this embodiment, after obtaining the sampling signal of the first arcing detection point, the sampling signal is converted from the time domain to the frequency domain, and then the status information of the first arcing detection point is determined according to the magnitude of the spectral amplitude of the sampling signal, that is, it is determined whether an arcing fault has occurred at the first arcing detection point.

[0035] S102: If it is detected that the first cumulative number reaches the first preset number when the polling number is not greater than the preset polling number, it is determined that an arcing fault has occurred at this arcing detection point; the first cumulative number is the cumulative number of times that the status information of this arcing detection point is in the arcing pending state.

[0036] In this embodiment, first, the current round and the cumulative numbers of each arcing detection point are initialized to 0, and the arcing detection points are polled and calculated in sequence according to the preset order. Specifically, the status information of the current arcing detection point is calculated according to the method of S101. If its status information is in the arcing pending state, the cumulative number of times that the status information of the current arcing detection point is in the arcing pending state is increased by a unit value, and then the next arcing detection point in the order is used as the current arcing detection point, and the process returns to calculate the status information of the current arcing detection point according to the method of S101 and continues to execute until the calculation of all arcing detection points in the current round is completed, and the current round is added to the unit value; the process returns to poll and calculate each arcing detection point in sequence according to the preset order and continues to execute. When it is detected that the cumulative number of times that the status information of the first arcing detection point is in the arcing pending state reaches the first preset number when the polling number is not greater than the preset polling number, it is determined that an arcing fault has occurred at the first arcing detection point, otherwise it is determined that no fault has occurred at the first arcing detection point. Among them, the unit value can be 1.

[0037] Exemplarily, the preset polling count is M. When the polling count corresponding to the first arcing detection point is not greater than M, if it is detected that the first cumulative count corresponding to the first arcing detection point reaches the first preset count Q, it is determined that an arcing fault occurs at the first arcing detection point. If the number of times the first arcing detection point is polled reaches the preset polling count, or it is detected that an arcing fault occurs at the first arcing detection point, then both the polling count and the first cumulative count of the first arcing detection point are cleared to zero.

[0038] Specifically, the first preset count Q is less than the preset polling count M.

[0039] As can be seen from the above embodiments, the embodiments of the present invention provide an arcing detection method and related device. In view of the characteristic that after an arcing fault occurs, it is usually not a short-term sudden occurrence but lasts for a period of time, this method polls and calculates the status information of at least two arcing detection points in a preset order. This polling calculation method can, on the one hand, ensure long-term monitoring of the sampling signal, effectively avoiding the adverse impact of short-term spectrum uplift caused by external sudden interference on the accuracy of the detection result; on the other hand, it can reduce the calculation amount of arcing detection, thereby improving the efficiency of arcing detection. In addition, during the calculation process of the status information of each arcing detection point, using the spectrum information of the sampling signal to determine the status information of the arcing detection point helps to amplify the degree of change in the signal characteristics, thereby enhancing the accuracy of arcing detection.

[0040] In a possible implementation manner, the specific implementation process of determining the status information of the arcing detection point based on the spectrum of the sampling signal corresponding to the arcing detection point in S101 includes:

[0041] S201: Perform FFT (Fast Fourier Transform) processing on each sampling signal segment corresponding to the first arcing detection point to obtain the spectrum corresponding to each sampling signal segment of the first arcing detection point; the first arcing detection point is any arcing detection point.

[0042] S202: Determine the status information of the arcing detection point based on the amplitude of the spectrum corresponding to each sampling signal segment of the first arcing detection point and the arcing detection threshold.

[0043] In this embodiment, the arcing detection threshold includes a first arcing detection threshold, the sampling signal includes multiple sampling signal segments, each sampling signal segment includes the sampling signal of one sampling period, and when the first arcing detection point is polled each time, at most N consecutive sampling signal segments are collected for the first arcing detection point.

[0044] Specifically, for each sampled signal segment collected at the first arcing detection point, the number of sampled segments is increased by a unit value, and then the FFT processing is performed on this sampled signal segment to obtain its corresponding frequency spectrum. After obtaining the frequency spectrum, calculate the average value of the modulus of the amplitude of each frequency point in the frequency spectrum corresponding to this sampled signal segment to obtain the frequency spectrum amplitude corresponding to this sampled signal segment. When the frequency spectrum amplitude corresponding to this sampled signal segment is greater than the first arcing detection threshold, the second cumulative count is increased by a unit value, and then the above operations are continued for the next sampled signal segment corresponding to the first arcing detection point.

[0045] Among them, the unit value can be 1.

[0046] In a possible implementation manner, the specific implementation process of S202 includes:

[0047] S301: For each sampled signal segment in turn, calculate the modulus of the amplitude of each frequency component in the frequency spectrum corresponding to this sampled signal segment, and sum the modulus of the amplitude of each frequency component in the frequency spectrum corresponding to this sampled signal segment to obtain the total frequency spectrum amplitude corresponding to this sampled signal segment; determine whether the total frequency spectrum amplitude of this sampled signal segment is greater than the arcing detection threshold. If the total frequency spectrum amplitude of this sampled signal segment is greater than the arcing detection threshold, the second cumulative count is increased by a unit value;

[0048] S302: If the number of sampled signal segments obtained at the first arcing detection point in the current round is not greater than N and the corresponding second cumulative count is greater than the preset quantity threshold, it is determined that the status information of the first arcing detection point in the current round is the arcing pending state, otherwise it is determined that the status information of the first arcing detection point in the current round is the normal pending state.

[0049] In this embodiment, the arcing detection threshold includes the second arcing detection threshold. The frequency spectrum amplitude of the sampled signal segment can also be the sum of the moduli of the amplitudes corresponding to all frequency points in this sampled signal segment. S302 calculates the total frequency spectrum amplitude of each sampled signal segment in turn. For the currently calculated sampled signal segment, calculate whether the total frequency spectrum amplitude corresponding to the current sampled signal segment is greater than the second arcing detection threshold. If the total frequency spectrum amplitude corresponding to the current sampled signal segment is greater than the second arcing detection threshold, it is determined that the frequency spectrum amplitude of this sampled signal segment is too high and an arcing fault may occur. Therefore, the second cumulative count is increased by a unit value to obtain the updated second cumulative count.

[0050] If the number of sampled segments corresponding to the first arcing detection point is not greater than N, and the corresponding second cumulative count is greater than the preset quantity threshold, it is determined that the status information of the first arcing detection point in the current round is the arcing pending state, otherwise it is determined that the status information of the first arcing detection point in the current round is the normal pending state.

[0051] In this embodiment, when the terminal detects that the number of sampling segments corresponding to the first arcing detection point is equal to N but the corresponding second cumulative count is not greater than the preset quantity threshold, or the status information is in the arcing pending state, it clears the number of sampling segments and the second cumulative count, and proceeds to the next arcing detection point for status information calculation.

[0052] In a possible implementation manner, before S302, the method provided in this embodiment further includes:

[0053] Determine the preset quantity threshold according to the formula M = ceil(N×k); where M represents the preset quantity threshold, N represents the number of sampling signal segments, ceil() represents the ceiling function, and k represents a preset coefficient, and 0 < k < 1.

[0054] In this embodiment, the number of sampling signal segments can be 1 or multiple. When the number of sampling signal segments is 1, the preset quantity threshold is 1. When the number of sampling signal segments is multiple, the preset quantity threshold is less than the value of the sampling signal segments. Exemplarily, k = 2 / 3.

[0055] In a possible implementation manner, after obtaining the sampling signal corresponding to the arcing detection point in real time, it is necessary to perform filtering processing on the sampling signal. The average value of the sampling signal can be taken for filtering processing on the sampling signal. The specific implementation process includes:

[0056] Calculate the average value of the values of each sampling point in the first sampling signal segment to obtain the current signal segment average value corresponding to the first sampling signal segment; the first sampling signal segment is any sampling signal segment corresponding to the first arcing detection point, and the first arcing detection point is any arcing detection point;

[0057] Subtract the value of each sampling point in the first sampling signal segment from the corresponding current signal segment average value to obtain the processed first sampling signal segment;

[0058] Correspondingly, the specific implementation process of determining the status information of the arcing detection point based on the spectrum of the sampling signal corresponding to the arcing detection point includes:

[0059] Determine the status information of the arcing detection point based on the spectrum of the processed sampling signal of the arcing detection point.

[0060] Specifically, when the sampling signal includes multiple sampling signal segments, for each sampling signal segment, calculate the average value of the values of each sampling point in the sampling signal segment corresponding to the first arcing detection point to obtain the current signal segment average value;

[0061] Subtract the value of each sampling point in the sampling signal segment corresponding to the first arcing detection point from the current signal segment average value to obtain the processed sampling signal segment corresponding to the first arcing detection point.

[0062] In this embodiment, after obtaining the sampling signal, the terminal can also take the median value of the sampling signal to perform filtering processing on the sampling signal. The specific implementation process includes:

[0063] Select the median value of the sampling points in the first sampling signal segment as the current signal segment median value corresponding to the first sampling signal segment; the first sampling signal segment is any sampling signal segment corresponding to the first arcing detection point, and the first arcing detection point is any arcing detection point;

[0064] Subtract the value of each sampling point in the first sampling signal segment from the corresponding current signal segment median value to obtain the processed first sampling signal segment.

[0065] In a possible implementation manner, after subtracting the value of each sampling point in the sampling signal corresponding to the first arcing detection point from the current signal average value to obtain the processed sampling signal corresponding to the first arcing detection point, the method provided in this embodiment further includes:

[0066] Perform Hanning window processing on the processed first sampling signal segment.

[0067] In this embodiment, each processed sampling signal segment corresponding to the first arcing detection point is all processed by the formula [Y] Hanning = [Y]·Q 15 to perform Hanning window processing to obtain the processed sampling signal. Among them, [Y] Hanning represents the matrix corresponding to the sampling signal segment after Hanning window processing, and the elements in this matrix are the values of the sampling points in the sampling signal segment after Hanning window processing. [Y] represents the matrix corresponding to the sampling signal segment without Hanning window processing, and the elements in this matrix are the values of the sampling points in the sampling signal segment without Hanning window processing. Q 15 represents a preset coefficient.

[0068] The sampling signal provided in this embodiment can be more easily detected by the terminal after Hanning window processing, improving the accuracy of arcing detection.

[0069] As a specific embodiment, a specific implementation process of the arcing detection point provided in this embodiment includes:

[0070] Step 1: Initialize the current polling count to zero; initialize the first cumulative count of each arcing detection point to zero;

[0071] Step 2: Poll and calculate the status information of at least two arcing detection points in a preset order;

[0072] Step 3: Initialize the second cumulative count and the current sampling signal segment count of the current arcing detection point to zero;

[0073] Step 4: Obtain the current sampling signal segment corresponding to the current arcing detection point in real time; calculate the average value of the values of each sampling point in the current sampling signal segment to obtain the current signal segment average value corresponding to the current sampling signal segment;

[0074] Step 5: Subtract the value of each sampling point in the current sampling signal segment from the corresponding current signal segment average value to obtain the processed current sampling signal segment;

[0075] Step 6: Perform Hanning window processing on the processed current sampling signal segment;

[0076] Step 7: Perform FFT processing on the current sampling signal segment after Hanning window processing to obtain the spectrum corresponding to the current sampling signal segment, calculate the modulus value of the amplitude of each frequency component in the spectrum corresponding to the current sampling signal segment, and sum the modulus values of the amplitude of each frequency component in the spectrum corresponding to the current sampling signal segment to obtain the total amplitude of the spectrum corresponding to the current sampling signal segment;

[0077] Step 8: Determine whether the total amplitude of the spectrum of the current sampling signal segment is greater than the arcing detection threshold. If the total amplitude of the spectrum of the current sampling signal segment is greater than the arcing detection threshold, increment the second cumulative count by 1; otherwise, keep the current second cumulative count unchanged;

[0078] Step 9: Increment the current sampling signal segment of the current detection point by 1, and return to Step 4 to repeat the execution until it is detected that the second cumulative count is greater than the preset count threshold when the sampling signal segment count at the current arcing detection point is not greater than N. Then, determine that the status information of the current arcing detection point in the current round is the arcing pending state, and increment the first cumulative count by 1; otherwise, determine that the status information of the current arcing detection point in the current round is the normal pending state;

[0079] Step 10: Take the next arcing detection point as the current arcing detection point, and return to Step 3 to continue the execution. Repeat the above Steps 1 to 10 until the calculations for all arcing detection points in the current round are completed. Increment the current polling count by 1, and return to Step 2 to repeat the execution until it is detected that the first cumulative count reaches the first preset count when the polling count at the current arcing detection point is not greater than the preset polling count. Then, determine that an arcing fault has occurred at the current arcing detection point; otherwise, return to Step 1 to repeat the execution.

[0080] When performing arc-drawing detection in each round, the above method calculates the state information of the arc-drawing detection points multiple times, thereby improving the accuracy of arc-drawing detection. At the same time, polling calculations are performed on all arc-drawing detection points in multiple rounds, which can ensure long-term monitoring of the sampling signal, effectively avoiding the adverse impact of short-term spectrum uplift caused by external sudden interference on the accuracy of the detection result, and further improving the accuracy of arc-drawing detection; on the other hand, through the method of polling calculation, only a small number of arc-drawing detections are performed in a relatively long period of time, and it is possible to accurately determine whether arc-drawing detection occurs, thereby reducing the calculation amount of arc-drawing detection and improving the efficiency of arc-drawing detection.

[0081] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0082] The following is an embodiment of the device of the present invention. For the details not described in detail, reference can be made to the corresponding method embodiment above.

[0083] Figure 3 The structural schematic diagram of the arc-drawing detection device provided by the embodiment of the present invention is shown. For the sake of convenience of description, only the parts related to the embodiment of the present invention are shown, and are described in detail as follows:

[0084] As Figure 3 shown, the arc-drawing detection device 100 includes:

[0085] A state information determination module 110, configured to perform polling calculations on the state information of at least two arc-drawing detection points in a preset order, and in the process of calculating the state information of each arc-drawing detection point, obtain the sampling signal corresponding to the arc-drawing detection point in real time; based on the spectrum of the sampling signal corresponding to the arc-drawing detection point, determine the state information of the arc-drawing detection point, where the state information includes an arc-drawing pending state and a normal pending state; the sampling signal includes N consecutive sampling signal segments; and N≥1;

[0086] An arc-drawing fault detection module 120, configured to determine that an arc-drawing fault occurs at the arc-drawing detection point if it is detected that the first cumulative number reaches a first preset number when the polling number is not greater than a preset polling number; the first cumulative number is the cumulative number of times that the state information of the arc-drawing detection point is in the arc-drawing pending state.

[0087] In a possible implementation manner, the state information determination module 110 includes:

[0088] A spectrum acquisition unit, configured to perform FFT processing on each sampling signal segment corresponding to the first arc-drawing detection point to obtain the spectrum corresponding to each sampling signal segment of the first arc-drawing detection point; the first arc-drawing detection point is any arc-drawing detection point;

[0089] A status information determination unit, configured to determine the status information of the arc strike detection point based on the amplitude of the spectrum corresponding to each sampling signal segment of the first arc strike detection point and the arc strike detection threshold.

[0090] In a possible implementation manner, the status information determination unit includes:

[0091] An accumulated threshold statistics subunit, configured to sequentially calculate, for each sampling signal segment, the modulus of the amplitude of each frequency component in the spectrum corresponding to the sampling signal segment, and sum the moduli of the amplitudes of each frequency component in the spectrum corresponding to the sampling signal segment to obtain the total amplitude of the spectrum corresponding to the sampling signal segment; determine whether the total amplitude of the spectrum of the sampling signal segment is greater than the arc strike detection threshold, and if the total amplitude of the spectrum of the sampling signal segment is greater than the arc strike detection threshold, increase the second accumulated count by a unit value.

[0092] A status information determination subunit, configured to determine that the status information of the first arc strike detection point in the current round is in an arc strike pending state if the number of sampling signal segments obtained by the first arc strike detection point in the current round is not greater than N and the corresponding second accumulated count is greater than a preset number threshold, otherwise determine that the status information of the first arc strike detection point in the current round is in a normal pending state.

[0093] In a possible implementation manner, the status information determination unit further includes:

[0094] A preset number threshold determination subunit, configured to determine the preset number threshold according to the formula M = ceil(N×k); where M represents the preset number threshold, N represents the number of sampling signal segments, ceil() represents the ceiling function, k represents a preset coefficient, and 0 < k < 1.

[0095] In a possible implementation manner, the status information determination module 110 further includes a signal preprocessing unit, configured to:

[0096] Calculate the average value of the values of each sampling point in the first sampling signal segment to obtain the current signal segment average value corresponding to the first sampling signal segment; the first sampling signal segment is any sampling signal segment corresponding to the first arc strike detection point, and the first arc strike detection point is any arc strike detection point.

[0097] Subtract the value of each sampling point in the first sampling signal segment from the corresponding current signal segment average value to obtain the processed first sampling signal segment.

[0098] Correspondingly, the spectrum acquisition unit is configured to:

[0099] Determine the status information of the arc strike detection point based on the spectrum of the processed sampling signal of the arc strike detection point.

[0100] In a possible implementation, the signal preprocessing unit is further configured to:

[0101] Perform Hanning window processing on the processed first sampled signal segment.

[0102] As can be seen from the above embodiments, the arcing detection device provided in this embodiment is based on the characteristic that an arcing fault usually continues without human intervention after it occurs, and polls and calculates the status information of at least two arcing detection points in a preset order. This polling calculation method can not only ensure long-term detection of the sampled signal to avoid the influence of external sudden interference on the accuracy of the detection result, but also reduce the calculation amount of arcing detection, thereby improving the efficiency of arcing detection. In addition, during the calculation of the status information of each arcing detection point, determining the status information of the arcing detection point through the spectrum information of the sampled signal can amplify the change amplitude of the signal characteristics, thereby improving the accuracy of arcing detection.

[0103] Figure 4 is a schematic diagram of a terminal provided by an embodiment of the present invention. As Figure 4 shown, the terminal 4 of this embodiment includes: a processor 40 and a memory 41. The memory 41 is used to store a computer program 42, and the processor 40 is used to call and run the computer program 42 stored in the memory 41, and execute the steps in the above-mentioned various embodiments of the arcing detection method, such as Figure 2 the steps S101 to S102 shown. Alternatively, the processor 40 is used to call and run the computer program 42 stored in the memory 41 to implement the functions of each module / unit in the above-mentioned device embodiments, such as Figure 3 the functions of the modules 110 to 130 shown.

[0104] Exemplarily, the computer program 42 can be divided into one or more modules / units. The one or more modules / units are stored in the memory 41 and executed by the processor 40 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the computer program 42 in the terminal 4.

[0105] The terminal 4 can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art can understand that Figure 4 this is only an example of the terminal 4 and does not constitute a limitation on the terminal 4. It may include more or fewer components than shown in the figure, or combine some components, or different components. For example, the terminal may further include input / output devices, network access devices, a bus, etc.

[0106] The so-called processor 40 may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0107] The memory 41 may be an internal storage unit of the terminal 4, such as the hard disk or memory of the terminal 4. The memory 41 may also be an external storage device of the terminal 4, such as a plug-in hard disk equipped on the terminal 4, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Further, the memory 41 may also include both the internal storage unit of the terminal 4 and the external storage device. The memory 41 is used to store the computer program and other programs and data required by the terminal. The memory 41 may also be used to temporarily store data that has been output or is to be output.

[0108] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiments can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0109] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0110] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0111] In the embodiments provided by the present invention, it should be understood that the disclosed device / terminal and method can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0112] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0113] In addition, the functional units in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0114] When the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described arc detection method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0115] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention 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 various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. An arc striking detection method, characterized in that, Including: Poll and calculate the status information of at least two arc strike detection points in a preset order, and in the process of calculating the status information of each arc strike detection point, obtain the sampling signal corresponding to this arc strike detection point in real time; Based on the spectrum of the sampling signal corresponding to this arc strike detection point, determine the status information of this arc strike detection point, where the status information includes an arc strike pending state and a normal pending state; the sampling signal includes N consecutive sampling signal segments; and N≥1; If it is detected that the first cumulative number reaches the first preset number when the number of polling times does not exceed the preset polling number, it is determined that an arc strike fault occurs at this arc strike detection point; the first cumulative number is the cumulative number of times that the status information of this arc strike detection point is in the arc strike pending state.

2. The arc striking detection method according to claim 1, wherein The determining the status information of this arc strike detection point based on the spectrum of the sampling signal corresponding to this arc strike detection point includes: Perform FFT processing on each sampling signal segment corresponding to the first arc strike detection point to obtain the spectrum corresponding to each sampling signal segment of the first arc strike detection point; the first arc strike detection point is any arc strike detection point; Based on the amplitude of the spectrum corresponding to each sampling signal segment of the first arc strike detection point and the arc strike detection threshold, determine the status information of this arc strike detection point.

3. The arc starting detection method according to claim 2, wherein The determining the status information of this arc strike detection point based on the amplitude of the spectrum corresponding to each sampling signal segment of the first arc strike detection point and the arc strike detection threshold includes: For each sampling signal segment in turn, calculate the modulus of the amplitude of each frequency component in the spectrum corresponding to this sampling signal segment, and sum the modulus of the amplitude of each frequency component in the spectrum corresponding to this sampling signal segment to obtain the total amplitude of the spectrum corresponding to this sampling signal segment; determine whether the total amplitude of the spectrum of this sampling signal segment is greater than the arc strike detection threshold, if the total amplitude of the spectrum of this sampling signal segment is greater than the arc strike detection threshold, increase the second cumulative number by a unit value; If the number of sampling signal segments obtained by the first arc strike detection point in the current round is not greater than N and the corresponding second cumulative number is greater than the preset number threshold, it is determined that the status information of the first arc strike detection point in the current round is in the arc strike pending state, otherwise it is determined that the status information of the first arc strike detection point in the current round is in the normal pending state.

4. The arc striking detection method according to claim 3, wherein Before the second cumulative number corresponding to the first arc strike detection point is greater than the preset number threshold under the preset condition, the method further includes: Determine the preset number threshold according to the formula M = ceil(N×k); where M represents the preset number threshold, N represents the number of sampling signal segments, ceil() represents the ceiling function, k represents the preset coefficient, and 0 < k < 1.

5. The arc striking detection method according to any one of claims 1 to 4, characterized in that, After the sampling signal corresponding to this arc strike detection point is obtained in real time, the method further includes: Average the values of each sampling point in the first sampling signal segment to obtain the current signal segment average value corresponding to the first sampling signal segment; the first sampling signal segment is any sampling signal segment corresponding to the first arc strike detection point, and the first arc strike detection point is any arc strike detection point; Subtract the value of each sampling point in the first sampling signal segment from the corresponding current signal segment average value to obtain a processed first sampling signal segment; Correspondingly, determining the status information of the arcing detection point based on the spectrum of the sampling signal corresponding to the arcing detection point includes: Determining the status information of the arcing detection point based on the spectrum of the processed sampling signal of the arcing detection point.

6. The arc striking detection method according to claim 5, characterized in that After subtracting the value of each sampling point in the first sampling signal segment from the corresponding current signal segment average value to obtain a processed first sampling signal segment, the method further includes: Performing Hanning window processing on the processed first sampling signal segment.

7. An arc striking detection device, characterized in that, Including: A status information determination module, configured to perform polling calculations on the status information of at least two arcing detection points in a preset order, and in the process of calculating the status information of each arcing detection point, obtain the sampling signal corresponding to the arcing detection point in real time; Determining the status information of the arcing detection point based on the spectrum of the sampling signal corresponding to the arcing detection point, where the status information includes an arcing pending status and a normal pending status; the sampling signal includes N consecutive sampling signal segments; and N≥1; An arcing fault detection module, configured to determine that an arcing fault occurs at the arcing detection point if it is detected that the first cumulative number reaches a first preset number when the polling number is not greater than a preset polling number; the first cumulative number is the cumulative number of times that the status information of the arcing detection point is in the arcing pending status.

8. A terminal, characterized in that, Including a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the arcing detection method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the arcing detection method according to any one of claims 1 to 6 above.

10. A photovoltaic system, characterized in that, Including: A plurality of photovoltaic modules and a terminal according to claim 8; and arcing detection points are provided at the output ends of each photovoltaic module.

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