Method, System, Device and Medium for Determining the Principal Component of the Photovoltaic String IV Curve Fault

Abstract

The present invention belongs to the technical field of solar power generation, and discloses a method, system, device and medium for determining the main component of the IV curve fault of a photovoltaic string, including obtaining the IV curves of each photovoltaic string, obtaining the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and obtaining the abnormal results of each photovoltaic string according to a preset parameter abnormality judgment method; according to the abnormal results of each photovoltaic string and the deviation degree of each characteristic parameter of the photovoltaic string, the main component of the IV curve fault of the photovoltaic string is obtained. The method for determining the main component of the IV curve fault of the photovoltaic string in the present invention can accurately determine the main component of the IV curve fault of the photovoltaic string, effectively overcomes the defects of the existing photovoltaic string-level fault diagnosis, realizes the accurate determination of the main component of the fault by analyzing which characteristic parameter in the IV curve of the photovoltaic string has the highest degree of abnormality, and further improves the diagnostic accuracy of the photovoltaic string fault diagnosis by analyzing the main component of the fault.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar power generation, and relates to a method, system, device and medium for determining the main components of photovoltaic string IV curve faults. Background Art

[0002] In recent years, with the booming development of the photovoltaic industry, it is an irresistible trend to comprehensively improve the intelligent level of photovoltaic power stations. Based on digital information technology, the solution of matching string inverters with the IV curve diagnosis system of station-side photovoltaic strings can realize the rapid I-V scanning and fault diagnosis of photovoltaic strings, greatly reducing the operation and maintenance labor costs and being favored by the market.

[0003] For the diagnosis of photovoltaic string IV curves, faults are mainly classified according to the abnormal changes of IV curve characteristic values. If only one fault characteristic value changes abnormally, the corresponding fault can be accurately diagnosed. However, affected by the on-site environment, measurement accuracy and calculation accuracy, multiple characteristic values of a fault IV curve will change abnormally, affecting the results of fault diagnosis and classification. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a method, system, device and medium for determining the main components of photovoltaic string IV curve faults.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect of the present invention, a method for determining the main components of photovoltaic string IV curve faults includes the following steps:

[0007] Obtain the IV curves of each photovoltaic string;

[0008] According to the IV curves of each photovoltaic string, obtain the characteristic parameters of each photovoltaic string, and according to the preset parameter abnormal change judgment method, obtain the abnormal change results of each photovoltaic string; the characteristic parameters include short-circuit current, open-circuit voltage, fill factor, horizontal pillar slope, vertical pillar slope and curve part slope;

[0009] When the abnormal change result of the current photovoltaic string is that one characteristic parameter changes abnormally: take this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string;

[0010] When the abnormal result of the current photovoltaic string is that at least two characteristic parameters are abnormal: When all the abnormal characteristic parameters are the first group of characteristic parameters or the second group of characteristic parameters, obtain the deviation degrees of the characteristic parameters within the first group of characteristic parameters or the second group of characteristic parameters, and use the characteristic parameter with the largest deviation degree within the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; When there are abnormal characteristic parameters in both the first group of characteristic parameters and the second group of characteristic parameters, obtain the deviation degree of the fill factor and the deviation degrees of the characteristic parameters within the first group of characteristic parameters; When the deviation degree of the fill factor is the largest, obtain the deviation degrees of the characteristic parameters within the second group of characteristic parameters, and use the characteristic parameter with the largest deviation degree within the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; Otherwise, use the characteristic parameter with the largest deviation degree within the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; Among them, the short-circuit current and the open-circuit voltage are the first group of characteristic parameters; The horizontal strut slope, the vertical strut slope, and the curve part slope are the second group of characteristic parameters.

[0011] A further improvement of the method for determining the main component of the IV curve fault of the photovoltaic string in the present invention lies in:

[0012] The specific method for obtaining the IV curve of each photovoltaic string is:

[0013] Scan each photovoltaic string through a string inverter to obtain the IV curve of each photovoltaic string.

[0014] When obtaining the deviation degrees of the characteristic parameters within the first group of characteristic parameters, the deviation degree ΔIsc of the short-circuit current is obtained through the following formula:

[0015]

[0016] Among them, Isc is the short-circuit current of the current photovoltaic string, is the average value of the short-circuit currents of all photovoltaic strings.

[0017] The deviation degree ΔVoc of the open-circuit voltage is obtained through the following formula:

[0018]

[0019] Among them, Voc is the open-circuit voltage of the current photovoltaic string, is the average value of the open-circuit voltages of all photovoltaic strings.

[0020] When obtaining the deviation degrees of the characteristic parameters within the second group of characteristic parameters, the deviation degree ΔKt of the horizontal strut slope is obtained through the following formula:

[0021]

[0022] Among them, Kt is the slope of the horizontal strut of the current photovoltaic string, which is the average value of the slopes of the horizontal struts of each photovoltaic string.

[0023] When obtaining the deviation degrees of the characteristic parameters in the second set of characteristic parameters, the deviation degree ΔKl of the longitudinal strut slope is obtained through the following formula:

[0024]

[0025] Among them, Kl is the slope of the longitudinal strut of the current photovoltaic string, which is the average value of the slopes of the longitudinal struts of all photovoltaic strings.

[0026] When obtaining the deviation degrees of the characteristic parameters in the second set of characteristic parameters, the deviation degree ΔKc of the slope of the curve part is obtained through the following formula:

[0027]

[0028] Among them, Kc is the slope of the curve part of the current photovoltaic string, which is the average value of the slopes of the curve parts of all photovoltaic strings.

[0029] The specific method for obtaining the deviation degree of the fill factor is:

[0030] The deviation degree ΔFF of the fill factor is obtained through the following formula:

[0031]

[0032] Among them, FF is the fill factor of the current photovoltaic string, which is the average value of the fill factors of all photovoltaic strings.

[0033] In the second aspect of the present invention, a system for determining the principal components of the IV curve failure of a photovoltaic string includes:

[0034] An acquisition module, configured to acquire the IV curves of each photovoltaic string;

[0035] An abnormal movement determination module, configured to obtain the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and obtain the abnormal movement results of each photovoltaic string according to a preset parameter abnormal movement judgment method; the characteristic parameters include short-circuit current, open-circuit voltage, fill factor, slope of the horizontal strut, slope of the longitudinal strut, and slope of the curve part;

[0036] An analysis module, when the abnormal movement result of the current photovoltaic string is that one characteristic parameter has an abnormal movement: takes this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string; when the abnormal movement result of the current photovoltaic string is that at least two characteristic parameters have an abnormal movement: when the characteristic parameters with abnormal movement are all in the first group of characteristic parameters or the second group of characteristic parameters, obtains the deviation degrees of each characteristic parameter within the first group of characteristic parameters or the second group of characteristic parameters, and takes the characteristic parameter with the largest deviation degree within the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; when there are characteristic parameters with abnormal movement in both the first group of characteristic parameters and the second group of characteristic parameters, obtains the deviation degree of the fill factor and the deviation degrees of each characteristic parameter within the first group of characteristic parameters; when the deviation degree of the fill factor is the largest, obtains the deviation degrees of each characteristic parameter within the second group of characteristic parameters, and takes the characteristic parameter with the largest deviation degree within the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; otherwise, takes the characteristic parameter with the largest deviation degree within the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; where the short-circuit current and the open-circuit voltage are the first group of characteristic parameters; the lateral strut slope, the longitudinal strut slope, and the curve part slope are the second group of characteristic parameters.

[0037] In the third aspect of the present invention, a computer device includes 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 above method for determining the main component of the IV curve fault of the photovoltaic string are implemented.

[0038] In the fourth aspect of the present invention, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method for determining the main component of the IV curve fault of the photovoltaic string are implemented.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The method for determining the main components of the IV curve fault of a photovoltaic string in the present invention determines the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and then obtains the abnormal results of each photovoltaic string according to a preset parameter abnormal judgment method. On the basis of the abnormal results of each photovoltaic string, the characteristic parameters of the photovoltaic string are analyzed in groups. The short-circuit current and open-circuit voltage are divided into the first group of characteristic parameters; the horizontal pillar slope, vertical pillar slope, and curve part slope are divided into the second group of characteristic parameters. Then, by combining the deviation degrees of each characteristic parameter, the main components of the IV curve fault of the photovoltaic string are obtained. It can accurately determine the main components of the IV curve fault of the photovoltaic string, effectively overcome the defects of the existing photovoltaic string-level fault diagnosis, and accurately determine the main components of the fault by analyzing which characteristic parameter in the IV curve of the photovoltaic string has the highest degree of abnormality. Furthermore, the main components of the fault are analyzed to improve the diagnostic accuracy of the photovoltaic string fault diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flowchart of the method for determining the main components of the IV curve fault of the photovoltaic string in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0044] The present invention will be further described in detail below in conjunction with the accompanying drawings:

[0045] In an embodiment of the present invention, a method for determining the main components of the IV curve fault of a photovoltaic string is provided, which specifically includes the following steps.

[0046] S1: Obtain the IV curves of each photovoltaic string.

[0047] Specifically, in this embodiment, the string inverter scans each photovoltaic string to obtain the IV curves of each photovoltaic string.

[0048] S2: Obtain the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and obtain the abnormal result of each photovoltaic string according to the preset parameter abnormality judgment method; the characteristic parameters include short - circuit current, open - circuit voltage, fill factor, horizontal pillar slope, vertical pillar slope, and curve part slope.

[0049] Among them, the preset parameter abnormality judgment method can adopt existing common judgment methods. For example, using the Pauta criterion, the characteristic value limit = average value ± 3 * standard deviation. Then, according to the characteristics of the characteristic value, determine whether to select the upper limit value or the lower limit value as the abnormal discrimination limit value of the characteristic value. The parameter exceeding the abnormal discrimination limit value is an abnormal parameter. Among them, when the judgment is made through the preset parameter abnormality judgment method, when only one characteristic parameter has an abnormality, the abnormal result of the current photovoltaic string is that one characteristic parameter has an abnormality. When two or more characteristic parameters have an abnormality, the abnormal result of the current photovoltaic string is that at least two characteristic parameters have an abnormality. When no characteristic parameter has an abnormality, the abnormal result of the current photovoltaic string is that the IV curve is normal.

[0050] S3: When the abnormal result of the current photovoltaic string is that one characteristic parameter has an abnormality: Take this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string; when the abnormal result of the current photovoltaic string is that at least two characteristic parameters have an abnormality: When the abnormal characteristic parameters are all in the first group of characteristic parameters or the second group of characteristic parameters, obtain the deviation degree of each characteristic parameter in the first group of characteristic parameters or the second group of characteristic parameters, and take the characteristic parameter with the largest deviation degree in the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; when there are abnormal characteristic parameters in both the first group of characteristic parameters and the second group of characteristic parameters, obtain the deviation degree of the fill factor and the deviation degree of each characteristic parameter in the first group of characteristic parameters; when the deviation degree of the fill factor is the largest, obtain the deviation degree of each characteristic parameter in the second group of characteristic parameters, and take the characteristic parameter with the largest deviation degree in the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; otherwise, take the characteristic parameter with the largest deviation degree in the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; among them, the short - circuit current and the open - circuit voltage are the first group of characteristic parameters; the horizontal pillar slope, the vertical pillar slope, and the curve part slope are the second group of characteristic parameters.

[0051] Specifically, in this embodiment, when obtaining the deviation degree of each characteristic parameter in the first group of characteristic parameters, the deviation degree ΔIsc of the short - circuit current is obtained through the following formula:

[0052]

[0053] Among them, Isc is the short - circuit current of the current photovoltaic string, which is the average value of the short - circuit currents of each photovoltaic string.

[0054] Specifically, in this embodiment, when obtaining the deviation degrees of the characteristic parameters in the first group of characteristic parameters, the deviation degree ΔVoc of the open - circuit voltage is obtained by the following formula:

[0055]

[0056] Among them, Voc is the open - circuit voltage of the current photovoltaic string, which is the average value of the open - circuit voltages of each photovoltaic string.

[0057] Specifically, in this embodiment, when obtaining the deviation degrees of the characteristic parameters in the second group of characteristic parameters, the deviation degree ΔKt of the transverse strut slope is obtained by the following formula:

[0058]

[0059] Among them, Kt is the transverse strut slope of the current photovoltaic string, which is the average value of the transverse strut slopes of each photovoltaic string.

[0060] Specifically, in this embodiment, when obtaining the deviation degrees of the characteristic parameters in the second group of characteristic parameters, the deviation degree ΔKl of the longitudinal strut slope is obtained by the following formula:

[0061]

[0062] Among them, Kl is the longitudinal strut slope of the current photovoltaic string, which is the average value of the longitudinal strut slopes of each photovoltaic string.

[0063] Specifically, in this embodiment, when obtaining the deviation degrees of the characteristic parameters in the second group of characteristic parameters, the deviation degree ΔKc of the curve - part slope is obtained by the following formula:

[0064]

[0065] Among them, Kc is the curve - part slope of the current photovoltaic string, which is the average value of the curve - part slopes of each photovoltaic string.

[0066] Specifically, in this embodiment, the specific method for obtaining the deviation degree of the fill factor is: the deviation degree ΔFF of the fill factor is obtained by the following formula:

[0067]

[0068] Among them, FF is the fill factor of the current PV string, and is the average value of the fill factors of each PV string.

[0069] See Figure 1 , which shows the detailed process of the method for determining the main components of the PV string IV curve fault of the present invention.

[0070] Step 1: Use a string inverter to perform IV curve scanning on each PV string connected to the string.

[0071] Step 2: Calculate the short-circuit current Isc, open-circuit voltage Voc, fill factor FF, horizontal pillar slope Kt, vertical pillar slope Kl, and curve part slope Kc of each PV string.

[0072] Step 3: Calculate the average value of the short-circuit currents of all PV strings scanned this time the average value of the open-circuit voltages the average value of the fill factors the average value of the horizontal pillar slopes the average value of the vertical pillar slopes and the average value of the curve part slopes

[0073] Step 4: Judge the abnormal conditions of the short-circuit current Isc, open-circuit voltage Voc, horizontal pillar slope Kt, vertical pillar slope Kl, and curve part slope Kc of each PV string. If there is no abnormal movement of the characteristic parameters, the IV curve is normal. If there is an abnormal movement of one characteristic parameter, then this characteristic parameter is the main component of the fault. If there are abnormal movements of two characteristic parameters, then perform the following steps.

[0074] Step 5: Take the short-circuit current Isc and open-circuit voltage Voc of this PV string as group 1, and the horizontal pillar slope Kt, vertical pillar slope Kl, and curve part slope Kc as group 2, and judge which group of characteristic parameters has an abnormal movement.

[0075] Step 6: If only the short-circuit current Isc and open-circuit voltage Voc in group 1 of this PV string have abnormal movements, the main component judgment method:

[0076] ① Calculate the deviation degree of the short-circuit current Isc of this PV string:

[0077] ② Calculate the deviation degree of the open-circuit voltage Voc of this PV string:

[0078] Compare Δisc and ΔVoc, among which, the one with the largest value is the characteristic parameter of the main component of the fault.

[0079] Step 7, if only the lateral strut slope Kt, longitudinal strut slope Kl, and curve part slope Kc of Group 2 of the photovoltaic string change abnormally, the principal component judgment method is as follows:

[0080] ① Calculate the deviation degree of Kt of this string:

[0081] ① Calculate the deviation degree of Kl of this string:

[0082] ① Calculate the deviation degree of Kc of this string:

[0083] Compare ΔKt, ΔKl, and ΔKc. Among them, the one with the largest value is the characteristic parameter of the fault principal component.

[0084] Step 8, if the two out-of-limit characteristic values of the photovoltaic string belong to different groups respectively, then according to the method in Step 6, calculate Δisc and ΔVoc, and then according to Calculate the deviation degree of the fill factor, and judge which of the values of ΔIsc, Δvoc, and ΔFF is the largest. If ΔI or ΔV is the largest, then end the discrimination process, and this characteristic parameter is the fault principal component. If the value of ΔFF is the largest, then according to Step 7, calculate ΔKt, ΔKl, and ΔKc. Among them, the one with the largest value is the characteristic parameter of the fault principal component.

[0085] The method for determining the fault principal component of the IV curve of the photovoltaic string in the present invention determines the characteristic parameters of each photovoltaic string according to the IV curve of each photovoltaic string, and then obtains the abnormal results of each photovoltaic string according to the preset parameter abnormal judgment method. On the basis of the abnormal results of each photovoltaic string, the characteristic parameters of the photovoltaic string are analyzed by group. The short-circuit current and open-circuit voltage are divided into the first group of characteristic parameters; the lateral strut slope, longitudinal strut slope, and curve part slope are divided into the second group of characteristic parameters. Then, by combining the deviation degrees of each characteristic parameter, the fault principal component of the IV curve of the photovoltaic string is obtained. It can accurately determine the fault principal component of the IV curve of the photovoltaic string, effectively overcome the defects of the existing photovoltaic string-level fault diagnosis, and realize the accurate determination of the fault principal component by analyzing which characteristic parameter in the IV curve of the photovoltaic string has the highest degree of abnormality. Furthermore, analyze the fault principal component to improve the diagnostic accuracy of the photovoltaic string fault diagnosis.

[0086] The following is the device embodiment of the present invention, which can be used to execute the method embodiment of the present invention. For the details not disclosed in the device embodiment, please refer to the method embodiment of the present invention.

[0087] In another embodiment of the present invention, a system for determining the main components of a photovoltaic string IV curve fault is provided, which can be used to implement the method for determining the main components of a photovoltaic string IV curve fault described above. Specifically, the system for determining the main components of a photovoltaic string IV curve fault includes an acquisition module, a deviation determination module, and an analysis module.

[0088] Among them, the acquisition module is used to acquire the IV curves of each photovoltaic string; the deviation determination module is used to obtain the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and obtain the deviation results of each photovoltaic string according to a preset parameter deviation judgment method; the characteristic parameters include short-circuit current, open-circuit voltage, fill factor, horizontal pillar slope, vertical pillar slope, and curve part slope; the analysis module is used when the deviation result of the current photovoltaic string is that one characteristic parameter has a deviation: taking this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string; when the deviation result of the current photovoltaic string is that at least two characteristic parameters have a deviation: when the characteristic parameters with deviations are all the first group of characteristic parameters or the second group of characteristic parameters, obtaining the deviation degrees of the characteristic parameters within the first group of characteristic parameters or the second group of characteristic parameters, and taking the characteristic parameter with the largest deviation degree within the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; when there are characteristic parameters with deviations in both the first group of characteristic parameters and the second group of characteristic parameters, obtaining the deviation degree of the fill factor and the deviation degrees of the characteristic parameters within the first group of characteristic parameters; when the deviation degree of the fill factor is the largest, obtaining the deviation degrees of the characteristic parameters within the second group of characteristic parameters, and taking the characteristic parameter with the largest deviation degree within the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; otherwise, taking the characteristic parameter with the largest deviation degree within the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; where the short-circuit current and the open-circuit voltage are the first group of characteristic parameters; the horizontal pillar slope, the vertical pillar slope, and the curve part slope are the second group of characteristic parameters.

[0089] In another embodiment of the present invention, a computer device is provided. The computer device includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor 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. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function. The processor described in the embodiment of the present invention can be used for the operation of the method for determining the main components of the PV string IV curve fault.

[0090] In another embodiment of the present invention, a storage medium is also provided, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in the computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. And, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the method for determining the main components of the PV string IV curve fault in the above embodiment.

[0091] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0092] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0093] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A method for determining the main components of photovoltaic string IV curve faults, characterized in that, It includes the following steps: Obtain the IV curves of each photovoltaic string; Based on the IV curves of each photovoltaic string, obtain the characteristic parameters of each photovoltaic string, and according to the preset parameter anomaly judgment method, obtain the anomaly results of each photovoltaic string; the characteristic parameters include short-circuit current, open-circuit voltage, fill factor, horizontal strut slope, vertical strut slope, and curve part slope; When the anomaly result of the current photovoltaic string is that one characteristic parameter has an anomaly: Take this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string; When the anomaly result of the current photovoltaic string is that at least two characteristic parameters have an anomaly: When the characteristic parameters with anomalies are all the first group of characteristic parameters or the second group of characteristic parameters, obtain the deviation degrees of the characteristic parameters within the first group of characteristic parameters or the second group of characteristic parameters, and take the characteristic parameter with the largest deviation degree within the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; when there are characteristic parameters with anomalies in both the first group of characteristic parameters and the second group of characteristic parameters, obtain the deviation degree of the fill factor and the deviation degrees of the characteristic parameters within the first group of characteristic parameters; when the deviation degree of the fill factor is the largest, obtain the deviation degrees of the characteristic parameters within the second group of characteristic parameters, and take the characteristic parameter with the largest deviation degree within the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; otherwise, take the characteristic parameter with the largest deviation degree within the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; where, the short-circuit current and the open-circuit voltage are the first group of characteristic parameters; the horizontal strut slope, the vertical strut slope, and the curve part slope are the second group of characteristic parameters; Wherein, the deviation degree is the ratio of the absolute value of the difference between the characteristic parameter and the average value of the characteristic parameter to the average value of the characteristic parameter.

2. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, The specific method for obtaining the IV curves of each photovoltaic string is: Scan each photovoltaic string through a string inverter to obtain the IV curves of each photovoltaic string.

3. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, When obtaining the deviation degrees of the characteristic parameters within the first group of characteristic parameters, the deviation degree ΔIsc of the short-circuit current is obtained through the following formula: where Isc is the short-circuit current of the current PV string, and is the average value of the short-circuit currents of all PV strings; The deviation degree ΔVoc of the open-circuit voltage is obtained through the following formula: Among them, Voc is the open-circuit voltage of the current PV string, which is the average value of the open-circuit voltages of all PV strings.

4. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, When obtaining the deviation degrees of the characteristic parameters within the second group of characteristic parameters, the deviation degree ΔKt of the horizontal strut slope is obtained through the following formula: where Kt is the slope of the horizontal strut of the current PV string, and is the average value of the slopes of the horizontal struts of each PV string.

5. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, When obtaining the deviation degrees of the characteristic parameters within the second group of characteristic parameters, the deviation degree ΔKl of the vertical strut slope is obtained through the following formula: where Kl is the longitudinal strut slope of the current PV string, and is the average value of the longitudinal strut slopes of all PV strings.

6. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, When obtaining the deviation degrees of the characteristic parameters within the second group of characteristic parameters, the deviation degree ΔKc of the curve part slope is obtained through the following formula: Among them, Kc is the slope of the curve part of the current PV string, the average value of the slopes of the curve parts of all PV strings.

7. The method for determining the main components of photovoltaic string IV curve faults according to claim 1, characterized in that, The specific method for obtaining the deviation degree of the fill factor is: The deviation degree ΔFF of the fill factor is obtained through the following formula: Among them, FF is the fill factor of the current PV string, and is the average value of the fill factors of all PV strings.

8. A system for determining the main components of photovoltaic string IV curve faults, characterized in that, It includes: An acquisition module for obtaining the IV curves of each photovoltaic string; An anomaly determination module for obtaining the characteristic parameters of each photovoltaic string according to the IV curves of each photovoltaic string, and obtaining the anomaly results of each photovoltaic string according to the preset parameter anomaly judgment method; the characteristic parameters include short-circuit current, open-circuit voltage, fill factor, horizontal strut slope, vertical strut slope, and curve part slope; An analysis module, when the abnormal result of the current photovoltaic string is that one characteristic parameter has an abnormality: uses this characteristic parameter as the main component of the IV curve fault of the current photovoltaic string; when the abnormal result of the current photovoltaic string is that at least two characteristic parameters have an abnormality: when all the abnormal characteristic parameters are the first group of characteristic parameters or the second group of characteristic parameters, obtains the deviation degrees of each characteristic parameter within the first group of characteristic parameters or the second group of characteristic parameters, and uses the characteristic parameter with the largest deviation degree within the first group of characteristic parameters or the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; when there are abnormal characteristic parameters in both the first group of characteristic parameters and the second group of characteristic parameters, obtains the deviation degree of the fill factor and the deviation degrees of each characteristic parameter within the first group of characteristic parameters; when the deviation degree of the fill factor is the largest, obtains the deviation degrees of each characteristic parameter within the second group of characteristic parameters, and uses the characteristic parameter with the largest deviation degree within the second group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; otherwise, uses the characteristic parameter with the largest deviation degree within the first group of characteristic parameters as the main component of the IV curve fault of the current photovoltaic string; wherein, the short-circuit current and the open-circuit voltage are the first group of characteristic parameters; the horizontal strut slope, the vertical strut slope, and the curve part slope are the second group of characteristic parameters; Wherein, the deviation degree is the ratio of the absolute value of the difference between the characteristic parameter and the average value of the characteristic parameter to the average value of the characteristic parameter.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for determining the main component of the IV curve fault of the photovoltaic string according to any one of claims 1 to 7.

10. 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 method for determining the main component of the IV curve fault of the photovoltaic string according to any one of claims 1 to 7.

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