Power attenuation calculation method of photovoltaic system

Abstract

The invention discloses a power attenuation calculation method of a photovoltaic system, and relates to the technical field of photovoltaic power generation. The photovoltaic system comprises a plurality of photovoltaic modules and a plurality of photovoltaic connectors, the photovoltaic connectors are used for being connected with the photovoltaic modules, and the power attenuation calculation method of the photovoltaic system comprises the steps that the swing times of the photovoltaic connectors in each quality guarantee year in the using process and the rated power of the photovoltaic modules are obtained; when the photovoltaic system reaches a quality guarantee year, carrying out a swing test on at least one photovoltaic connector in the photovoltaic system according to preset test parameters, and obtaining a test resistance value and a test current value of the photovoltaic connector corresponding to the number of swing times in each quality guarantee year; and calculating the power attenuation proportion of the photovoltaic module according to the test resistance value and the test current value of the photovoltaic connector corresponding to the swing times in each warranty year and the rated power of the photovoltaic module. According to the invention, the accuracy of power attenuation evaluation is improved.

Description

A method for calculating the power attenuation of a photovoltaic system Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a method for calculating the power attenuation of a photovoltaic system. Background Technology

[0002] With the continuous development of solar energy utilization technology, photovoltaic modules are being used more and more widely in various photovoltaic power station systems, especially in outdoor application scenarios such as large-scale ground power stations, distributed residential and commercial rooftops. Photovoltaic modules are exposed to the natural environment for a long time, and various stress factors such as wind, rain, and alternating hot and cold temperatures can affect the overall power generation efficiency and operational stability of the photovoltaic system.

[0003] In existing technologies, the reliability of photovoltaic (PV) modules is typically assessed through environmental tests, such as temperature and humidity cycling, salt spray testing, and high and low temperature aging. However, these tests pay less attention to PV connectors in PV systems. As key components for electrical interconnection between PV modules, PV connectors often experience slight oscillations due to wind-induced vibrations or structural loosening during long-term use, leading to increased contact resistance and power loss in the PV system. Current environmental testing methods lack consistency with the actual operating scenarios of PV modules, making it impossible to systematically evaluate and quantify the power degradation of PV modules caused by PV connectors under outdoor micro-oscillation conditions. Summary of the Invention

[0004] This invention provides a method for calculating the power degradation of a photovoltaic system. By accurately calculating the power degradation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, the accuracy of power degradation assessment is improved.

[0005] The first aspect of this invention provides a method for calculating the power attenuation of a photovoltaic system. The photovoltaic system includes multiple photovoltaic modules and multiple photovoltaic connectors. The photovoltaic connectors are used to connect the photovoltaic modules. The method for calculating the power attenuation of the photovoltaic system includes: obtaining the number of swings of the photovoltaic connectors during each warranty year and the rated power of the photovoltaic modules; when the photovoltaic system reaches its warranty period, performing a swing test on at least one photovoltaic connector in the photovoltaic system using preset test parameters, and obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year; and calculating the power attenuation ratio of the photovoltaic modules based on the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year and the rated power of the photovoltaic modules.

[0006] Optionally, obtaining the number of swings of the photovoltaic connector within each warranty year during use includes: obtaining wind speed information and swing wind speed threshold of the environment where the photovoltaic connector is located within each warranty year; and determining the number of swings of the photovoltaic connector within the warranty year based on the wind speed information and swing wind speed threshold of the photovoltaic connector within the warranty year.

[0007] Optionally, determining the number of swings of the photovoltaic connector within the warranty period based on the wind speed information and the swing wind speed threshold within the warranty period includes: determining the annual swing duration of the photovoltaic connector within the warranty period based on the wind speed information and the swing wind speed threshold within the warranty period; obtaining the actual swing speed of the photovoltaic connector during use; and determining the number of swings of the photovoltaic connector within the warranty period based on the annual swing duration and the actual swing speed.

[0008] Optionally, during the swing test of the photovoltaic connector, the first end of the photovoltaic connector is connected to the first end of the first test lead, the second end of the photovoltaic connector is connected to the first end of the second test lead, the photovoltaic connector is fixed on the test bracket, the second ends of the first test lead and the second ends of the second test lead are both connected to the resistance detection device, and a preset weight is suspended on the first test lead and / or the second test lead; the swing test is performed on at least one photovoltaic connector in the photovoltaic system with preset test parameters, including: controlling the test bracket to swing at a preset swing angle and a preset swing speed at a preset test temperature; wherein, the preset swing angle and the preset swing speed are determined according to the actual swing angle and actual swing speed of the photovoltaic connector during use; during the swing of the photovoltaic connector, the number of swings of the photovoltaic connector is acquired in real time, and the swing test ends when the number of swings reaches a preset number.

[0009] Optionally, before acquiring the number of swings of the photovoltaic connector in real time, the method further includes: acquiring the current swing angle and current swing speed of the test bracket, and the current resistance value detected by the resistance detection device; determining whether the current swing angle, the current swing speed, and the current resistance value meet preset conditions; if so, then executing the step of acquiring the number of swings of the photovoltaic connector in real time; wherein, the preset conditions include the difference between the current swing angle and the preset swing angle being within a preset range, the difference between the current swing speed and the preset swing speed being within a preset range, and the current resistance value fluctuating within a preset fluctuation range.

[0010] Optionally, obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings within each warranty year includes: when the current number of swings of the photovoltaic connector is the number of swings within the warranty year, obtaining the test resistance value and test current value of the photovoltaic connector at the current number of swings as the test resistance value and test current value corresponding to the number of swings within the warranty year.

[0011] Optionally, the power degradation ratio of the photovoltaic module is calculated based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module. This includes: after controlling the test bracket to start swinging, obtaining the resistance value detected by the resistance detection device within a preset time period; when the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches a preset fluctuation range, determining the current resistance value detected by the resistance detection device as the initial resistance value of the photovoltaic connector; determining the resistance difference value corresponding to each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year; determining the annual degradation ratio of the photovoltaic module corresponding to each warranty year based on the resistance difference value corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module; and calculating the power degradation ratio of the photovoltaic module based on the annual degradation ratio of the photovoltaic module corresponding to each warranty year.

[0012] Optionally, determining the resistance difference value corresponding to each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year includes: when determining the resistance difference value corresponding to the first year of the warranty years, determining the resistance difference value corresponding to the first year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within the first year; when determining the resistance difference value corresponding to each year of the warranty years other than the first year, sequentially determining each warranty year as a test warranty year, and determining the resistance difference value corresponding to the test warranty year based on the test resistance value of the photovoltaic connector corresponding to the number of swings within the previous year of the test warranty year and the test resistance value of the photovoltaic connector corresponding to the number of swings within the test warranty year.

[0013] Optionally, the annual degradation ratio of the photovoltaic module corresponding to each warranty year is determined based on the resistance difference corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module. This includes: determining the power degradation value of the photovoltaic module corresponding to each warranty year based on the resistance difference corresponding to each warranty year and the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year; and determining the annual degradation ratio of the photovoltaic module corresponding to each warranty year based on the rated power of the photovoltaic module and the power degradation value of the photovoltaic module corresponding to each warranty year.

[0014] Optionally, calculating the power degradation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module, further includes: when performing swing tests on multiple photovoltaic connectors in the photovoltaic system with preset test parameters, calculating the average test resistance corresponding to the number of swings within the warranty year based on the test resistance values ​​of each photovoltaic connector corresponding to the number of swings within the same warranty year, and calculating the average test current corresponding to the number of swings within the warranty year based on the test current values ​​corresponding to the number of swings within the same warranty year; and calculating the power degradation ratio of the photovoltaic module based on the average test resistance and the average test current corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module.

[0015] The technical solution of this invention provides a data foundation for simulating the swing conditions of photovoltaic connectors in actual outdoor environments and accurately calculating the power degradation ratio of photovoltaic modules by obtaining the number of swings of the photovoltaic connector within each warranty year during use and the rated power of the photovoltaic module. By performing a swing test on at least one photovoltaic connector in the photovoltaic system with preset test parameters when the photovoltaic system reaches its warranty period, the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year can be obtained. This overcomes the problem of lack of environmental condition matching in traditional laboratory accelerated aging tests, significantly improving the accuracy and reliability of photovoltaic module power degradation assessment. By calculating the actual power loss caused by increased connector contact resistance in each warranty year based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, and by combining this with the rated power of the photovoltaic module, the power degradation ratio of the photovoltaic module is calculated year by year. This improves the accuracy, systematicness, and repeatability of power degradation assessment, while also enhancing the efficiency and reliability of photovoltaic module power degradation calculation. It avoids operational errors or subjective biases that may exist in manual calculation, providing an accurate data basis for the performance degradation assessment of photovoltaic systems, and further improving the operational reliability and service life of photovoltaic systems.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a flowchart illustrating a method for calculating the power attenuation of a photovoltaic system according to Embodiment 1 of the present invention; Figure 2 is a flowchart illustrating a method for calculating the power attenuation of a photovoltaic system according to Embodiment 2 of the present invention; Figure 3 is a structural schematic diagram of a swing test device according to Embodiment 3 of the present invention; Figure 4 is a flowchart illustrating a method for calculating the power attenuation of a photovoltaic system according to Embodiment 3 of the present invention; Figure 5 is a flowchart illustrating a method for calculating the power attenuation of a photovoltaic system according to Embodiment 4 of the present invention; Figure 6 is a structural schematic diagram of a power attenuation curve of a photovoltaic module according to Embodiment 4 of the present invention; Figure 7 is a structural schematic diagram of a power attenuation calculation device for a photovoltaic system according to Embodiment 5 of the present invention; Figure 8 is a structural schematic diagram of a controller for a photovoltaic system according to Embodiment 6 of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Figure 1 is a flowchart illustrating a power attenuation calculation method for a photovoltaic system according to Embodiment 1 of the present invention. This embodiment can be used to calculate the power attenuation ratio of photovoltaic modules in a photovoltaic system. This method can be executed by a power attenuation calculation device for the photovoltaic system. This device can be implemented by software and / or hardware and is generally integrated into the controller of the photovoltaic system. Accordingly, as shown in Figure 1, the power attenuation calculation method for the photovoltaic system may include: S101, obtaining the number of swings of the photovoltaic connector during each warranty year and the rated power of the photovoltaic module.

[0022] A photovoltaic (PV) system comprises multiple PV modules and multiple PV connectors. PV connectors can connect between PV modules or to the output terminals of PV modules, enabling electrical connections between PV modules or between PV modules and combiner devices. Under long-term outdoor operation, wind disturbances can cause periodic, slight oscillations in the PV connectors, leading to increased contact resistance and a gradual decrease in the output power of the PV modules. Therefore, to simulate the oscillation conditions of PV connectors in a real outdoor environment and accurately calculate the power degradation ratio of the PV modules, the number of oscillations of the PV connector within each warranty year (e.g., 25 years) can be obtained. For example, based on historical wind speed information and a preset oscillation wind speed threshold, the number of hours with wind speeds exceeding the threshold in each warranty year can be calculated. This, combined with the actual oscillation speed of the PV connector, can then be used to estimate the number of oscillations in each warranty year. Furthermore, the rated power of the PV modules (i.e., the maximum output power they can deliver under standard testing conditions) can be obtained from their factory-set parameters. By obtaining the number of swings of the photovoltaic connector during each warranty year and the rated power of the photovoltaic module, a data foundation is provided for the subsequent accurate calculation of the power degradation ratio of the photovoltaic module.

[0023] S102. When the photovoltaic system reaches the warranty period, perform a swing test on at least one photovoltaic connector in the photovoltaic system using preset test parameters, and obtain the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year.

[0024] Specifically, when a photovoltaic (PV) system reaches its warranty period, one or more PV connectors in the system can be subjected to oscillation tests using preset test parameters. This means that either any representative PV connector in the system can be tested with preset parameters, or multiple PV connectors in the system can be tested in parallel with preset parameters, thereby enhancing the coverage and accuracy of the oscillation test results. It is understood that by constructing a controllable oscillation test platform, it is possible to simulate the oscillation conditions of the PV connectors to match actual outdoor usage scenarios. For example, based on the ambient temperature, actual oscillation angle, and oscillation speed of the PV modules during use, the PV connectors can be subjected to oscillation loading under laboratory conditions. Simultaneously, during the oscillation test of the PV connectors, the test resistance and test current values ​​of the PV connectors can be obtained in real time through a resistance detection device. This allows for the acquisition of the test resistance and test current values ​​of the PV connectors corresponding to the number of oscillations within each warranty year. By obtaining the test resistance and test current values ​​of the PV connectors corresponding to the number of oscillations within each warranty year, a precise data foundation is provided for subsequently calculating the power loss value and overall power attenuation ratio caused by the increase in PV connector contact resistance within each warranty year.

[0025] By conducting oscillation tests on photovoltaic connectors, the lack of environmental condition matching in traditional laboratory accelerated aging tests is overcome, significantly improving the accuracy and reliability of photovoltaic module power degradation assessment. By comprehensively considering typical outdoor environmental factors such as wind speed and temperature, and by setting parameters such as oscillation angle and speed, the oscillation loading process of the photovoltaic connector can be precisely controlled. This allows for a more comprehensive assessment of the impact of photovoltaic connector mechanical fatigue on photovoltaic module performance, effectively compensating for the technical shortcomings of existing testing methods that struggle to comprehensively consider the interaction of multiple environmental factors.

[0026] S103. Calculate the power attenuation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, as well as the rated power of the photovoltaic module.

[0027] Specifically, after obtaining the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, the power degradation ratio of the photovoltaic module can be calculated year by year based on these values ​​and in conjunction with the rated power of the photovoltaic module. For example, the actual power loss caused by increased connector contact resistance within each warranty year can be calculated first, based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year. After obtaining the actual power loss caused by increased connector contact resistance within each warranty year, the degradation ratio of the photovoltaic module corresponding to each warranty year can be calculated year by year in conjunction with the rated power of the photovoltaic module. This allows for the plotting of a long-term power degradation curve for the photovoltaic module, providing an accurate data basis for assessing the performance degradation of the photovoltaic system and further improving the operational reliability and lifespan of the photovoltaic system.

[0028] Understandably, by conducting oscillation tests on photovoltaic (PV) connectors and using the test resistance and current values ​​obtained from these tests to accurately calculate the power degradation ratio of PV modules, the accuracy, systematicity, and repeatability of power degradation assessment are improved. This method of calculating the power degradation ratio of PV modules by combining test resistance, test current, and the rated power of the PV modules is applicable to various application scenarios where PV modules are in different environments. It also improves the efficiency and reliability of PV module power degradation calculation, avoiding operational errors or subjective biases that may exist in manual calculations. Therefore, it provides strong technical support for subsequent structural optimization, quality control, and operation and maintenance strategy formulation for PV systems.

[0029] Optionally, the calculation of the power degradation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connectors corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module, further includes: when performing swing tests on multiple photovoltaic connectors in the photovoltaic system with preset test parameters, calculating the average test resistance corresponding to the number of swings within the warranty year based on the test resistance values ​​of each photovoltaic connector corresponding to the number of swings within the same warranty year, and calculating the average test current corresponding to the number of swings within the warranty year based on the test current values ​​corresponding to the number of swings within the same warranty year; and calculating the power degradation ratio of the photovoltaic module based on the average test resistance and average test current corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module.

[0030] Specifically, when multiple photovoltaic connectors in a photovoltaic system are simultaneously subjected to swing tests using preset test parameters, the test resistance and test current values ​​of each photovoltaic connector corresponding to the number of swings within the same warranty year can be obtained. Based on the test results of multiple photovoltaic connectors, the average test resistance and average test current corresponding to the number of swings within the warranty year can be calculated. For example, in the swing test, six photovoltaic connectors in the photovoltaic system can be selected simultaneously as test samples and tested synchronously under the same test temperature, swing angle, and swing speed conditions. This allows the calculation of the power degradation ratio of the photovoltaic module based on the average test resistance and average test current of the six photovoltaic connectors corresponding to the number of swings within each warranty year, as well as the rated power of the photovoltaic module. By introducing multiple sets of photovoltaic connectors for synchronous swing tests under the same test conditions and averaging the test data, the impact of individual photovoltaic connector test errors, occasional outliers, and minor structural differences is effectively reduced, enhancing the stability and robustness of the swing test data, thereby improving the accuracy and reliability of photovoltaic module power degradation assessment.

[0031] This embodiment provides a data foundation for simulating the oscillation conditions of photovoltaic connectors in actual outdoor environments and accurately calculating the power degradation ratio of photovoltaic modules by acquiring the number of oscillations of the photovoltaic connector during each warranty year and the rated power of the photovoltaic module. By performing an oscillation test on at least one photovoltaic connector in the photovoltaic system with preset test parameters when the photovoltaic system reaches its warranty period, the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of oscillations in each warranty year can be obtained. This overcomes the problem of lack of environmental condition matching in traditional laboratory accelerated aging tests, significantly improving the accuracy and reliability of photovoltaic module power degradation assessment. By calculating the actual power loss caused by increased connector contact resistance in each warranty year based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, and by combining this with the rated power of the photovoltaic module, the power degradation ratio of the photovoltaic module is calculated year by year. This improves the accuracy, systematicness, and repeatability of power degradation assessment, while also enhancing the efficiency and reliability of photovoltaic module power degradation calculation. It avoids operational errors or subjective biases that may exist in manual calculation, providing an accurate data basis for the performance degradation assessment of photovoltaic systems, and further improving the operational reliability and service life of photovoltaic systems.

[0032] Figure 2 is a flowchart illustrating a method for calculating the power attenuation of a photovoltaic system according to Embodiment 2 of the present invention. Based on the above embodiments, this embodiment provides a detailed description of the method for obtaining the number of swings of the photovoltaic connector in each warranty year during use. Accordingly, as shown in Figure 2, the method for calculating the power attenuation of the photovoltaic system in this embodiment may include: S201, obtaining the wind speed information of the environment where the photovoltaic connector is located and the swing wind speed threshold in each warranty year.

[0033] Specifically, to accurately calculate the number of oscillations of the photovoltaic (PV) connector within each warranty year, the wind speed information and oscillation wind speed threshold of the environment where the PV module is located can be obtained for each warranty year. Wind speed information can be obtained through meteorological monitoring stations, third-party meteorological data platforms, or locally installed wind speed sensors. The wind speed information can cover hourly wind speed records for the PV connector throughout each warranty year, allowing for a detailed hourly assessment of the wind impact on the PV connector's environment. The oscillation wind speed threshold can be understood as a pre-set wind speed critical value used to determine whether the PV connector is in a state where oscillation is possible. When the wind speed value for a certain hour within the warranty year is greater than or equal to the oscillation wind speed threshold, it can be determined that the PV connector is in a oscillation state during that hour, which may affect the electrical performance of the PV module. For example, the oscillation wind speed threshold can be 8 m / s.

[0034] S202. Based on the wind speed information and oscillation wind speed threshold of the photovoltaic connector within the warranty period, determine the number of oscillations of the photovoltaic connector within the warranty period.

[0035] Specifically, after obtaining the wind speed information and oscillation wind speed threshold of the environment where the photovoltaic connector is located in each warranty year, the number of oscillations of the photovoltaic connector in that warranty year can be determined based on the wind speed information and oscillation wind speed threshold of the photovoltaic connector in that warranty year. This provides a data basis for obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of oscillations in each warranty year through the subsequent oscillation test of the photovoltaic connector.

[0036] Optionally, based on the wind speed information and oscillation wind speed threshold of the photovoltaic connector within the warranty period, the number of oscillations of the photovoltaic connector within the warranty period is determined, including: determining the annual oscillation duration of the photovoltaic connector within the warranty period based on the wind speed information and oscillation wind speed threshold of the warranty period; obtaining the actual oscillation speed of the photovoltaic connector during use; and determining the number of oscillations of the photovoltaic connector within the warranty period based on the annual oscillation duration and actual oscillation speed of the photovoltaic connector within the warranty period.

[0037] Specifically, to accurately calculate the number of oscillations of the photovoltaic (PV) connector within each warranty year, the system first identifies all hours in the warranty year where the wind speed exceeds the oscillation wind speed threshold, based on wind speed information and oscillation wind speed thresholds. This allows determination of the annual oscillation duration of the PV connector within that warranty year. Next, the actual oscillation speed of the PV connector during use can be obtained, such as the average number of oscillations of the PV module per unit time. Combining the annual oscillation duration and actual oscillation speed within the warranty year, the total number of oscillations of the PV connector within that warranty year can be determined. The number of oscillations of the PV connector within each warranty year serves as the basis for subsequent PV connector oscillation testing and power degradation calculations. This helps accurately simulate the stress and wear conditions of the PV connector within each warranty year, improving the accuracy of power degradation assessment.

[0038] S203. Obtain the rated power of the photovoltaic module.

[0039] S204. When the photovoltaic system reaches the warranty period, perform a swing test on at least one photovoltaic connector in the photovoltaic system using preset test parameters, and obtain the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year.

[0040] S205. Calculate the power attenuation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, as well as the rated power of the photovoltaic module.

[0041] In this embodiment, by acquiring the wind speed information and oscillation wind speed threshold of the environment where the photovoltaic connector is located within each warranty year, the annual oscillation duration of the photovoltaic connector within that warranty year can be determined based on the wind speed information and oscillation wind speed threshold. By acquiring the actual oscillation speed of the photovoltaic connector during use, the number of oscillations of the photovoltaic connector within that warranty year can be determined based on the annual oscillation duration and actual oscillation speed. The number of oscillations of the photovoltaic connector within each warranty year during use can serve as the basis for subsequent photovoltaic connector oscillation testing and power attenuation calculation, helping to accurately simulate the stress and wear conditions of the photovoltaic connector within each warranty year and improving the accuracy of power attenuation assessment.

[0042] Figure 3 is a schematic diagram of the swing test device provided in Embodiment 3 of the present invention. As shown in Figure 3, when the photovoltaic connector 1 is subjected to a swing test, the first end of the photovoltaic connector 1 is connected to the first end of the first test lead 01, the second end of the photovoltaic connector 1 is connected to the first end of the second test lead 02, the photovoltaic connector 1 is fixed on the test bracket 2, the second end of the first test lead 01 and the second end of the second test lead 02 are both connected to the resistance detection device 3, and a weight 4 of a preset weight is suspended on the first test lead 01 and / or the second test lead 02.

[0043] Specifically, during the swing test of photovoltaic connector 1, the first end of photovoltaic connector 1 is connected to the first end of the first test lead 01, and the second end of photovoltaic connector 1 is connected to the first end of the second test lead 02. Photovoltaic connector 1 is fixedly mounted on test bracket 2, allowing the test bracket 2 to swing during the swing test, thus simulating the swing conditions of photovoltaic connector 1 in a real outdoor environment. Before starting the swing test, the length of the test lead can be checked to ensure it meets the standard length requirements. If not, it should be adjusted. The test lead length can be 60 cm to ensure it matches the actual component lead length. The test lead can also be visually inspected for breaks or aging; if any are found, it should be replaced. Furthermore, the test lead can be cleaned to remove surface dust or foreign matter.

[0044] The second ends of the first test lead 01 and the second test lead 02 are respectively connected to the resistance detection device 3, enabling real-time monitoring of the resistance change of the photovoltaic connector 1 during the swing test. For example, the resistance detection device 3 can apply a test voltage to the second ends of the first test lead 01 and the second test lead 02 to monitor the test resistance and test current values ​​of the photovoltaic connector 1 in real-time during the swing test. Furthermore, to further simulate the mechanical stress of the photovoltaic connector due to gravity in outdoor use scenarios, a preset weight, such as a 5N weight 4, can be suspended on the first test lead 01 and / or the second test lead 02 below the photovoltaic connector 1 to apply a longitudinal load to the photovoltaic connector 1, further enhancing the realism of the swing test experiment.

[0045] Figure 4 is a schematic flowchart of a power attenuation calculation method for a photovoltaic system provided in Embodiment 3 of the present invention. Based on the above embodiments, this embodiment provides a detailed description of a method for performing a swing test on at least one photovoltaic connector in the photovoltaic system with preset test parameters when the photovoltaic system reaches the warranty period, and obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year. Accordingly, as shown in Figure 4, the power attenuation calculation method for the photovoltaic system in this embodiment may include: S301, obtaining the number of swings of the photovoltaic connector in each warranty year during use and the rated power of the photovoltaic module.

[0046] S302. When the photovoltaic system reaches its warranty period, at a preset test temperature, control the test bracket to swing at a preset swing angle and preset swing speed.

[0047] The preset swing angle and preset swing speed are determined based on the actual swing angle and actual swing speed of the photovoltaic connector during use.

[0048] Specifically, when the photovoltaic system reaches its warranty period, a swing test can be initiated on the photovoltaic connector. During the swing test, the test bracket can be controlled to swing at a preset angle and speed under a preset test temperature to simulate the swing conditions of the photovoltaic connector in a real outdoor environment. The preset swing angle and speed are determined based on the actual swing angle and speed of the photovoltaic connector during use. For example, the preset test temperature can be 25°C, the preset swing angle can be ±10°, and the preset swing speed can be 7 swings per minute. Each complete swing can be understood as the photovoltaic connector swinging from a -10° position to a 10° position, thus more realistically simulating the mechanical stress and electrical contact aging process experienced by the photovoltaic connector in actual application.

[0049] S303. During the swinging process of the photovoltaic connector, the number of swings of the photovoltaic connector is acquired in real time, and the swing test ends when the number of swings reaches the preset number.

[0050] Specifically, to obtain the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, the number of swings of the photovoltaic connector can be acquired in real time during the swinging process. The swing test ends when the acquired number of swings reaches a preset number. This preset number covers the total number of swings that the photovoltaic module may experience throughout the entire warranty year; for example, the preset number could be 1.2 million swings. This ensures the authenticity and accuracy of the swing test results and lays the foundation for subsequently obtaining the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year.

[0051] Optionally, before acquiring the number of swings of the photovoltaic connector in real time, the method further includes: acquiring the current swing angle and current swing speed of the test bracket, and the current resistance value detected by the resistance detection device; determining whether the current swing angle, current swing speed, and current resistance value meet preset conditions; if so, then executing the step of acquiring the number of swings of the photovoltaic connector in real time; wherein, the preset conditions include the difference between the current swing angle and the preset swing angle being within a preset range, the difference between the current swing speed and the preset swing speed being within a preset range, and the current resistance value fluctuating within a preset fluctuation range.

[0052] Specifically, before acquiring the real-time swing count of the photovoltaic connector, the current swing angle and speed of the test bracket, as well as the current resistance value detected by the resistance detection device, can be acquired first. The resistance value detected by the resistance detection device can be acquired every 5 seconds. Then, it can be determined whether the difference between the current swing angle and the preset swing angle is within the preset angle tolerance range, whether the difference between the current swing speed and the preset swing speed is within the preset speed tolerance range, and whether the current resistance value is within the preset resistance fluctuation range. Only when all three conditions are met will the step of acquiring the real-time swing count of the photovoltaic connector continue. This ensures that the photovoltaic connector is in a stable swing state and the resistance measurement data of the resistance detection device fluctuates stably before recording the valid swing count. This avoids test errors caused by swing disturbances or poor contact at the start of the swing test device, which can lead to abnormal test resistance, further improving the accuracy and reliability of the photovoltaic module power degradation assessment process.

[0053] S304. When the current number of swings of the photovoltaic connector is the number of swings within the warranty period, obtain the test resistance value and test current value of the photovoltaic connector at the current number of swings as the test resistance value and test current value corresponding to the number of swings within the warranty period.

[0054] Specifically, during the oscillation test of the photovoltaic connector, when the current oscillation count of the photovoltaic connector reaches the oscillation count within a certain warranty year, the test resistance value and test current value of the photovoltaic connector at the current oscillation count are obtained. These test resistance and test current values ​​are then used as the test resistance and test current values ​​corresponding to the oscillation count within that warranty year. It can be understood that the oscillation count within the warranty year is an accumulated value, meaning that starting from the first year of the warranty year, the newly added oscillation count within the current warranty year is added year by year. For example, if the oscillation count in the first year of the warranty year is 40,000 times, and the oscillation count in the second year is 40,100 times, then the cumulative oscillation count corresponding to the second year is 80,100 times. During the oscillation test, when the current oscillation count of the photovoltaic connector reaches 80,100 times, the test resistance value and test current value of the photovoltaic connector at that moment are obtained, and these are used as the test resistance and test current values ​​corresponding to the oscillation count in the second year. Subsequent years follow the same pattern, with cumulative judgment and data collection performed sequentially.

[0055] By obtaining the test resistance and test current values ​​corresponding to the number of swings within each warranty year, it is possible to accurately obtain the electrical performance status of the photovoltaic connector after simulating the usage load corresponding to that warranty year. This provides a data basis for the subsequent accurate assessment of the power degradation ratio of photovoltaic modules, improves the accuracy and scientific nature of power degradation assessment, and provides strong data support for the design optimization, life prediction and warranty strategy formulation of photovoltaic modules.

[0056] S305. Calculate the power attenuation ratio of the photovoltaic module based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, as well as the rated power of the photovoltaic module.

[0057] In this embodiment, when the photovoltaic system reaches its warranty period, the test bracket is controlled to swing at a preset angle and speed under a preset test temperature. This allows for real-time acquisition of the number of swings of the photovoltaic connector during the swing process. The swing test ends when the preset number of swings is reached. This enables the acquisition of the test resistance and test current values ​​of the photovoltaic connector at the current number of swings within the warranty year, serving as the test resistance and test current values ​​corresponding to the number of swings within that warranty year. By acquiring the test resistance and test current values ​​corresponding to the number of swings within each warranty year, the electrical performance state of the photovoltaic connector can be accurately obtained after simulating the usage load corresponding to that warranty year. This provides a data foundation for subsequent accurate assessment of the power degradation ratio of the photovoltaic module, improving the accuracy and scientific rigor of power degradation assessment. Ultimately, this provides strong data support for photovoltaic module design optimization, lifespan prediction, and warranty strategy formulation.

[0058] Figure 5 of Embodiment 4 is a schematic flowchart of a photovoltaic system power attenuation calculation method provided in Embodiment 4 of the present invention. Based on the above embodiments, this embodiment provides a detailed description of the method for calculating the power attenuation ratio of a photovoltaic module based on the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year, as well as the rated power of the photovoltaic module. Accordingly, as shown in Figure 5, the photovoltaic system power attenuation calculation method of this embodiment may include: S401, obtaining the number of swings of the photovoltaic connector in each warranty year during use and the rated power of the photovoltaic module.

[0059] S402. When the photovoltaic system reaches the warranty period, perform a swing test on at least one photovoltaic connector in the photovoltaic system using preset test parameters, and obtain the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year.

[0060] S403. After the control test bracket starts swinging, obtain the resistance value detected by the resistance detection device within a preset time period.

[0061] Specifically, in order to determine the resistance difference for each warranty year and the annual degradation ratio of the photovoltaic module for each warranty year, the resistance values ​​detected by the resistance detection device within a preset time period can be obtained to determine the initial resistance change state of the photovoltaic connector after it starts to swing.

[0062] S404. When the fluctuation of the resistance value detected by the resistance detection device reaches the preset fluctuation range within a preset time period, the current resistance value detected by the resistance detection device is determined as the initial resistance value of the photovoltaic connector.

[0063] Specifically, after obtaining the resistance value detected by the resistance detection device within a preset time period, it can be further determined whether the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches a preset fluctuation range, such as ±0.1mΩ. If the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches the preset fluctuation range, it is determined that the electrical connection state of the photovoltaic connector has entered a stable state, and the current resistance value detected by the resistance detection device can be determined as the initial resistance value of the photovoltaic connector. The initial resistance value is used as a benchmark reference value for calculating the resistance difference in the subsequent power attenuation assessment process. By determining the initial resistance value when the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches the preset fluctuation range, the initial test error caused by factors such as the unstable contact state of the photovoltaic connector and the resistance detection device still being in a dynamic fluctuation stage when the swing test is first started can be effectively avoided, thus improving the accuracy and stability of the swing test and power attenuation assessment.

[0064] S405. Determine the resistance difference for each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year.

[0065] Specifically, after obtaining the test resistance value and initial resistance value of the photovoltaic connector corresponding to the number of swings in each warranty year, the resistance difference corresponding to each warranty year can be determined based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings in each warranty year. This provides a data basis for calculating the annual degradation ratio of the photovoltaic module corresponding to each warranty year based on the resistance difference corresponding to each warranty year.

[0066] Optionally, the resistance difference for each warranty year is determined based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year. This includes: when determining the resistance difference for the first year within the warranty period, the resistance difference for the first year is determined based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within the first year; when determining the resistance difference for each year other than the first year within the warranty period, each warranty year is sequentially designated as a test warranty year, and the resistance difference for that test warranty year is determined based on the test resistance value of the photovoltaic connector corresponding to the number of swings in the previous year of the test warranty year and the test resistance value of the photovoltaic connector corresponding to the number of swings within the test warranty year.

[0067] Specifically, when determining the resistance difference for the first year within the warranty period, the difference can be calculated by taking the initial resistance value and the difference between the test resistance value of the photovoltaic connector corresponding to the number of swings within the first year and the initial resistance value. When determining the resistance difference for each year within the warranty period other than the first year, each warranty year can be sequentially set as a test year. The resistance difference for that test year can then be determined by calculating the difference between the test resistance value of the photovoltaic connector corresponding to the number of swings within that test warranty year and the test resistance value of the photovoltaic connector corresponding to the number of swings in the previous year. For example, the resistance difference for the second year within the warranty period is the test resistance value of the photovoltaic connector corresponding to the number of swings in the second year and the test resistance value of the photovoltaic connector corresponding to the number of swings in the first year; similarly, the resistance difference for the third year within the warranty period is the test resistance value of the photovoltaic connector corresponding to the number of swings in the third year and the test resistance value of the photovoltaic connector corresponding to the number of swings in the second year. By calculating the resistance difference for each warranty year, the amount of resistance change of the photovoltaic connector caused by fretting wear or contact degradation due to wind-induced swaying can be accurately reflected in each warranty year. This helps to assess power degradation based on the annual resistance difference trend.

[0068] S406. Based on the resistance difference corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings in each warranty year, and the rated power of the photovoltaic module, determine the annual degradation ratio of the photovoltaic module corresponding to each warranty year.

[0069] Specifically, after obtaining the resistance difference value corresponding to each warranty year, the annual degradation ratio of the photovoltaic module corresponding to each warranty year can be determined based on the resistance difference value corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings in each warranty year, and the rated power of the photovoltaic module. This allows for the quantification of the impact of the contact performance degradation of the photovoltaic connector caused by long-term swing stress on the output power of the photovoltaic module, providing a data basis for subsequent calculation of the power degradation ratio of the photovoltaic module.

[0070] Optionally, the annual degradation ratio of the photovoltaic module for each warranty year is determined based on the resistance difference corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module. This includes: determining the power degradation value of the photovoltaic module for each warranty year based on the resistance difference corresponding to each warranty year and the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year; and determining the annual degradation ratio of the photovoltaic module for each warranty year based on the rated power of the photovoltaic module and the power degradation value of the photovoltaic module for each warranty year.

[0071] Specifically, to determine the annual degradation rate of the photovoltaic (PV) module for each warranty year, the power degradation value of the PV module for each warranty year can first be determined based on the resistance difference for that warranty year and the test current value of the PV connector corresponding to the number of oscillations within that warranty year. For example, for a given warranty year, the corresponding power degradation value is the product of the resistance difference for that warranty year and the square of the test current value of the PV connector for that year. After calculating the power degradation value of the PV module for each warranty year, the annual degradation rate of the PV module for each warranty year can be further determined based on the rated power of the PV module and the power degradation value for each warranty year. For example, the annual degradation rate of the PV module for each warranty year can be the ratio between the power degradation value of the PV module for each warranty year and the rated power of the PV module, thereby quantifying the year-to-year impact of the deterioration of the PV connector's contact performance on the output power of the PV module in real-world outdoor applications. By using the power degradation value of photovoltaic modules corresponding to each warranty year, the annual degradation ratio of photovoltaic modules corresponding to each warranty year can be assessed and compared, thereby improving the accuracy, systematicness and repeatability of power degradation assessment.

[0072] S407. Calculate the power degradation ratio of the photovoltaic module based on the annual degradation ratio of the photovoltaic module for each warranty year.

[0073] Specifically, after determining the annual degradation rate of the photovoltaic (PV) modules for each warranty year, these rates can be summed to calculate the power degradation rate over the entire warranty period. Calculating the annual degradation rate for each warranty year allows for the plotting of a long-term power degradation curve for the PV modules. Combined with the calculated power degradation rate, this provides a clear and systematic quantification of the cumulative power loss caused by contact degradation due to connector oscillation within the warranty period. This provides an accurate data foundation for assessing the performance degradation of the PV system, further improving its operational reliability and lifespan.

[0074] In this embodiment, after the test bracket starts swinging, the resistance value detected by the resistance detection device within a preset time period is obtained. When the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches a preset fluctuation range, the current resistance value detected by the resistance detection device is determined as the initial resistance value of the photovoltaic connector. This allows for the determination of the resistance difference for each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year. By using the resistance difference for each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module, the annual degradation ratio of the photovoltaic module for each warranty year is determined. This facilitates the plotting of the long-term power degradation curve of the photovoltaic module and the calculation of the power degradation ratio of the photovoltaic module based on the annual degradation ratio for each warranty year. This provides a direct and systematic quantification of the cumulative power loss caused by contact degradation due to photovoltaic connector swinging within the warranty period, offering an accurate data basis for assessing the performance degradation of the photovoltaic system and further improving the operational reliability and service life of the photovoltaic system.

[0075] The following will further describe specific embodiments of the power attenuation calculation method applicable to the photovoltaic system described above.

[0076] In one feasible embodiment, statistical analysis was performed on the wind speed information of the environment where the photovoltaic module is located. Based on meteorological data, it is known that the average number of hours with an annual wind speed of 8 m / s or higher in this region is 103 hours. Furthermore, considering the actual operating state of the photovoltaic connector, it is assumed that its oscillation frequency under continuous wind speed is 6.7 times / minute, meaning approximately 402 oscillations per hour. Based on this, it is estimated that under typical outdoor operating conditions in the test area, the photovoltaic connector will experience approximately 41,406 oscillations per year. Based on this, and combining the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of oscillations obtained from the oscillation test within each warranty year, as well as the rated power of the photovoltaic module, the power degradation of the module caused by the oscillation of the photovoltaic connector is calculated to be approximately 0.04% per year. Figure 6 is a structural schematic diagram of the power degradation curve of a photovoltaic module provided in Embodiment 4 of the present invention. As shown in Figure 6, after the entire warranty period of the photovoltaic module, i.e., 25 years, the cumulative power degradation caused by the photovoltaic connector does not exceed 1%, verifying the practicality and accuracy of the power degradation assessment method provided in this embodiment in long-term reliability prediction.

[0077] Figure 7 is a schematic diagram of a power attenuation calculation device for a photovoltaic system provided in Embodiment 5 of the present invention. This device can implement the power attenuation calculation method for a photovoltaic system provided in this embodiment of the invention. The device can be implemented by software and / or hardware and is generally integrated into the controller of the photovoltaic system. As shown in Figure 7, the device includes: a parameter acquisition module 501, a photovoltaic connector test parameter acquisition module 502, and a power attenuation calculation module 503. The specific structure of the device is as follows: The parameter acquisition module 501 is used to acquire the number of swings of the photovoltaic connector in each warranty year during use and the rated power of the photovoltaic module.

[0078] The photovoltaic connector test parameter acquisition module 502 is used to perform a swing test on at least one photovoltaic connector in the photovoltaic system with preset test parameters when the photovoltaic system reaches the warranty period, and to acquire the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year.

[0079] The power attenuation calculation module 503 is used to calculate the power attenuation ratio of the photovoltaic module based on the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year, as well as the rated power of the photovoltaic module.

[0080] In an optional embodiment of the present invention, the parameter acquisition module 501 may also be used to: acquire wind speed information and swing wind speed threshold of the environment in which the photovoltaic connector is located within each warranty year; and determine the number of swings of the photovoltaic connector within the warranty year based on the wind speed information and swing wind speed threshold of the photovoltaic connector within the warranty year.

[0081] In an optional embodiment of the present invention, the parameter acquisition module 501 may also be used to: determine the annual swing duration of the photovoltaic connector within the warranty period based on the wind speed information and swing wind speed threshold within the warranty period; acquire the actual swing speed of the photovoltaic connector during use; and determine the number of swings of the photovoltaic connector within the warranty period based on the annual swing duration and actual swing speed of the photovoltaic connector within the warranty period.

[0082] In an optional embodiment of the present invention, the photovoltaic connector test parameter acquisition module 502 can also be used to: perform a swing test on at least one photovoltaic connector in the photovoltaic system with preset test parameters, including: controlling the test bracket to swing at a preset swing angle and a preset swing speed at a preset test temperature; wherein the preset swing angle and preset swing speed are determined according to the actual swing angle and actual swing speed of the photovoltaic connector during use; during the swing of the photovoltaic connector, the number of swings of the photovoltaic connector is acquired in real time, and the swing test ends when the number of swings reaches a preset number.

[0083] In an optional embodiment of the present invention, the photovoltaic connector test parameter acquisition module 502 may also be used to: acquire the current swing angle and current swing speed of the test bracket, and the current resistance value detected by the resistance detection device, before acquiring the number of swings of the photovoltaic connector in real time; determine whether the current swing angle, current swing speed, and current resistance value meet preset conditions; if so, execute the step of acquiring the number of swings of the photovoltaic connector in real time; wherein, the preset conditions include the difference between the current swing angle and the preset swing angle being within a preset range, the difference between the current swing speed and the preset swing speed being within a preset range, and the current resistance value fluctuating within a preset fluctuation range.

[0084] In an optional embodiment of the present invention, the photovoltaic connector test parameter acquisition module 502 may also be used to: when the current number of swings of the photovoltaic connector is the number of swings within the warranty year, acquire the test resistance value and test current value of the photovoltaic connector at the current number of swings as the test resistance value and test current value corresponding to the number of swings within the warranty year.

[0085] In an optional embodiment of the present invention, the power attenuation calculation module 503 may further be used to: after the control test bracket starts swinging, obtain the resistance value detected by the resistance detection device within a preset time period; when the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches a preset fluctuation range, determine the current resistance value detected by the resistance detection device as the initial resistance value of the photovoltaic connector; determine the resistance difference value corresponding to each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings in each warranty year; determine the annual attenuation ratio of the photovoltaic module corresponding to each warranty year based on the resistance difference value corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings in each warranty year, and the rated power of the photovoltaic module; and calculate the power attenuation ratio of the photovoltaic module based on the annual attenuation ratio of the photovoltaic module corresponding to each warranty year.

[0086] In an optional embodiment of the present invention, the power attenuation calculation module 503 may also be used to: when determining the resistance difference value corresponding to the first year in the warranty period, determine the resistance difference value corresponding to the first year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings in the first year; when determining the resistance difference value corresponding to each year other than the first year in the warranty period, sequentially determine each warranty year as the test warranty year, and determine the resistance difference value corresponding to the test warranty year based on the test resistance value of the photovoltaic connector corresponding to the number of swings in the previous year of the test warranty year and the test resistance value of the photovoltaic connector corresponding to the number of swings in the test warranty year.

[0087] In an optional embodiment of the present invention, the power attenuation calculation module 503 may also be used to: determine the power attenuation value of the photovoltaic module corresponding to each warranty year based on the resistance difference corresponding to each warranty year and the test current value of the photovoltaic connector corresponding to the number of swings in each warranty year; and determine the annual attenuation ratio of the photovoltaic module corresponding to each warranty year based on the rated power of the photovoltaic module and the power attenuation value of the photovoltaic module corresponding to each warranty year.

[0088] In an optional embodiment of the present invention, the power attenuation calculation module 503 may also be used to: when performing a swing test on multiple photovoltaic connectors in a photovoltaic system with preset test parameters, calculate the average test resistance corresponding to the number of swings within the warranty year based on the test resistance value of each photovoltaic connector corresponding to the number of swings within the same warranty year, and calculate the average test current corresponding to the number of swings within the warranty year based on the test current value corresponding to the number of swings within the same warranty year; and calculate the power attenuation ratio of the photovoltaic module based on the average test resistance and average test current corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module.

[0089] The power attenuation calculation device for the photovoltaic system described above can execute the power attenuation calculation method for the photovoltaic system provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method. Technical details not described in detail in this embodiment can be found in the power attenuation calculation method for the photovoltaic system provided in any embodiment of the present invention.

[0090] Since the photovoltaic system power attenuation calculation device described above is capable of executing the photovoltaic system power attenuation calculation method in the embodiments of the present invention, those skilled in the art can understand the specific implementation and various variations of the photovoltaic system power attenuation calculation device in this embodiment based on the photovoltaic system power attenuation calculation method described in the embodiments of the present invention. Therefore, how the photovoltaic system power attenuation calculation device implements the photovoltaic system power attenuation calculation method in the embodiments of the present invention will not be described in detail here. Any device used by those skilled in the art to implement the photovoltaic system power attenuation calculation method in the embodiments of the present invention falls within the scope of protection of this application.

[0091] Figure 8 of Embodiment Six illustrates a schematic diagram of the controller of a photovoltaic system that can be used to implement the power attenuation calculation method for a photovoltaic system according to embodiments of the present invention. The controller can take various forms to suit the internal environment and requirements of the photovoltaic system, such as microcontroller units, field-programmable gate arrays, application-specific integrated circuits (ASICs), embedded image processing units, and real-time control modules. These devices are specifically designed to calculate the power attenuation ratio of the photovoltaic modules based on the test resistance and test current values ​​of the photovoltaic connectors corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic modules. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0092] As shown in Figure 8, the controller 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the controller 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0093] Multiple components in the controller 10 are connected to the I / O interface 15, including: an input unit 16, such as parameter setting buttons, a graphical user interface, etc.; an output unit 17, such as a visual display screen, a running status indicator, etc.; a storage unit 18, such as embedded flash memory, SD card memory, etc.; and a communication unit 19, such as a remote data transmission module, a local area network communication module, etc. The communication unit 19 allows the controller 10 to exchange information / data with other photovoltaic system-related equipment through, for example, industrial automation control networks and / or ground data acquisition systems.

[0094] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the power attenuation calculation method for a photovoltaic system.

[0095] In some embodiments, the power attenuation calculation method for a photovoltaic system can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as a storage unit. In some embodiments, part or all of the computer program can be loaded into and / or installed onto the photovoltaic system of the above embodiments via ROM and / or a communication unit. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the power attenuation calculation method for the photovoltaic system described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to execute the power attenuation calculation method for the photovoltaic system by any other suitable means (e.g., by means of firmware).

[0096] Optionally, a method for calculating the power degradation of a photovoltaic system may include: obtaining the number of swings of the photovoltaic connector during each warranty year and the rated power of the photovoltaic module; when the photovoltaic system reaches the warranty period, performing a swing test on at least one photovoltaic connector in the photovoltaic system using preset test parameters, and obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year; and calculating the power degradation ratio of the photovoltaic module based on the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year and the rated power of the photovoltaic module.

[0097] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0098] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0099] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0100] To provide user interaction, the systems and techniques described herein can be implemented on a controller having: a display device for displaying information to the user (e.g., an image display screen for presenting wind speed distribution information, oscillation count, test resistance value, test current value, and power attenuation curve); and a keyboard and pointing device (e.g., a button or touchscreen adjustment interface) through which the user can provide input to the controller. Other types of devices can also be used to provide user interaction; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0101] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0102] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0103] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0104] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for calculating the power attenuation of a photovoltaic system, characterized in that, The photovoltaic system includes multiple photovoltaic modules and multiple photovoltaic connectors. The photovoltaic connectors are used to connect the photovoltaic modules. The power degradation calculation method of the photovoltaic system includes: obtaining the number of swings of the photovoltaic connectors in each warranty year during use and the rated power of the photovoltaic modules; when the photovoltaic system reaches the warranty period, performing a swing test on at least one photovoltaic connector in the photovoltaic system with preset test parameters, and obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year; and calculating the power degradation ratio of the photovoltaic modules based on the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings in each warranty year and the rated power of the photovoltaic modules.

2. The method for calculating power attenuation of a photovoltaic system according to claim 1, characterized in that, Obtaining the number of swings of the photovoltaic connector within each warranty year during its use includes: obtaining wind speed information and swing wind speed threshold of the environment where the photovoltaic connector is located within each warranty year; and determining the number of swings of the photovoltaic connector within the warranty year based on the wind speed information and swing wind speed threshold of the photovoltaic connector within the warranty year.

3. The method for calculating power attenuation of a photovoltaic system according to claim 2, characterized in that, Determining the number of swings of the photovoltaic connector within the warranty period based on the wind speed information and the swing wind speed threshold within the warranty period includes: determining the annual swing duration of the photovoltaic connector within the warranty period based on the wind speed information and the swing wind speed threshold within the warranty period; obtaining the actual swing speed of the photovoltaic connector during use; and determining the number of swings of the photovoltaic connector within the warranty period based on the annual swing duration and the actual swing speed.

4. The method for calculating power attenuation of a photovoltaic system according to claim 1, characterized in that, When the photovoltaic connector is subjected to a swing test, the first end of the photovoltaic connector is connected to the first end of the first test lead, the second end of the photovoltaic connector is connected to the first end of the second test lead, the photovoltaic connector is fixed on the test bracket, the second end of the first test lead and the second end of the second test lead are both connected to the resistance detection device, and a preset weight is suspended on the first test lead and / or the second test lead. A swing test is performed on at least one photovoltaic connector in the photovoltaic system using preset test parameters, including: controlling the test bracket to swing at a preset swing angle and a preset swing speed at a preset test temperature; wherein the preset swing angle and the preset swing speed are determined based on the actual swing angle and actual swing speed of the photovoltaic connector during use; during the swing of the photovoltaic connector, the number of swings of the photovoltaic connector is acquired in real time, and the swing test ends when the number of swings reaches a preset number.

5. The method for calculating power attenuation of a photovoltaic system according to claim 4, characterized in that, Before acquiring the number of swings of the photovoltaic connector in real time, the method further includes: acquiring the current swing angle and current swing speed of the test bracket, and the current resistance value detected by the resistance detection device; determining whether the current swing angle, the current swing speed, and the current resistance value meet preset conditions; if so, then executing the step of acquiring the number of swings of the photovoltaic connector in real time; wherein, the preset conditions include the difference between the current swing angle and the preset swing angle being within a preset range, the difference between the current swing speed and the preset swing speed being within a preset range, and the current resistance value fluctuating within a preset fluctuation range.

6. The method for calculating power attenuation of a photovoltaic system according to claim 4, characterized in that, Obtaining the test resistance value and test current value of the photovoltaic connector corresponding to the number of swings within each warranty year includes: when the current number of swings of the photovoltaic connector is the number of swings within the warranty year, obtaining the test resistance value and test current value of the photovoltaic connector at the current number of swings as the test resistance value and test current value corresponding to the number of swings within the warranty year.

7. The method for calculating power attenuation of a photovoltaic system according to claim 4, characterized in that, The power degradation ratio of the photovoltaic module is calculated based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module. This includes: after controlling the test bracket to start swinging, obtaining the resistance value detected by the resistance detection device within a preset time period; when the fluctuation of the resistance value detected by the resistance detection device within the preset time period reaches a preset fluctuation range, determining the current resistance value detected by the resistance detection device as the initial resistance value of the photovoltaic connector; determining the resistance difference value corresponding to each warranty year based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year; determining the annual degradation ratio of the photovoltaic module corresponding to each warranty year based on the resistance difference value corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module; and calculating the power degradation ratio of the photovoltaic module based on the annual degradation ratio of the photovoltaic module corresponding to each warranty year.

8. The method for calculating power attenuation of a photovoltaic system according to claim 7, characterized in that, The resistance difference value corresponding to each warranty year is determined based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within each warranty year. This includes: when determining the resistance difference value corresponding to the first year of the warranty years, the resistance difference value corresponding to the first year is determined based on the initial resistance value and the test resistance value of the photovoltaic connector corresponding to the number of swings within the first year; when determining the resistance difference value corresponding to each year of the warranty years other than the first year, each warranty year is sequentially determined as a test warranty year, and the resistance difference value corresponding to the test warranty year is determined based on the test resistance value of the photovoltaic connector corresponding to the number of swings in the previous year of the test warranty year and the test resistance value of the photovoltaic connector corresponding to the number of swings within the test warranty year.

9. The method for calculating the power attenuation of a photovoltaic system according to claim 7, characterized in that, Based on the resistance difference corresponding to each warranty year, the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year, and the rated power of the photovoltaic module, the annual degradation ratio of the photovoltaic module corresponding to each warranty year is determined, including: determining the power degradation value of the photovoltaic module corresponding to each warranty year based on the resistance difference corresponding to each warranty year and the test current value of the photovoltaic connector corresponding to the number of swings within each warranty year; and determining the annual degradation ratio of the photovoltaic module corresponding to each warranty year based on the rated power of the photovoltaic module and the power degradation value of the photovoltaic module corresponding to each warranty year.

10. The method for calculating power attenuation of a photovoltaic system according to claim 1, characterized in that, The calculation of the power degradation ratio of the photovoltaic module, based on the test resistance and test current values ​​of the photovoltaic connector corresponding to the number of swings within each warranty year and the rated power of the photovoltaic module, further includes: when performing swing tests on multiple photovoltaic connectors in the photovoltaic system with preset test parameters, calculating the average test resistance corresponding to the number of swings within the warranty year based on the test resistance values ​​of each photovoltaic connector corresponding to the number of swings within the same warranty year, and calculating the average test current corresponding to the number of swings within the warranty year based on the test current values ​​corresponding to the number of swings within the same warranty year; and calculating the power degradation ratio of the photovoltaic module based on the average test resistance and the average test current corresponding to the number of swings within each warranty year and the rated power of the photovoltaic module.

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