Method and system for detecting performance degradation degree of photovoltaic panel

Abstract

The invention discloses a method for detecting the performance degradation degree of a photovoltaic panel, and the method comprises the steps: carrying out the testing of the open-circuit voltage and short-circuit current of the photovoltaic panel under a standard testing condition, obtaining the values of the open-circuit voltage and short-circuit current of the photovoltaic panel, carrying out the feature zooming, and obtaining the mapping values of the open-circuit voltage and short-circuit current; performing a color change test on the surface material of the photovoltaic panel to obtain a color change quantitative value of the surface material of the photovoltaic panel, and performing feature scaling to obtain a color change quantitative mapping value; performing electroluminescent imaging detection to obtain the ratio of the normal luminous area of the surface of the photovoltaic panel to the surface area of the photovoltaic panel, and performing feature scaling to obtain an electroluminescent imaging mapping value; and finally, calculating the performance degradation degree of the photovoltaic panel through each mapping value. According to the method, the performance degradation degree of the photovoltaic panel is visually represented in a numerical form, the detection result is accurate, the detection process does not depend on a complex algorithm, huge calculation process and calculation amount do not exist, and implementation and landing are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic panel status detection, and in particular to a method and system for detecting the degree of performance attenuation of a photovoltaic panel. Background Art

[0002] Photovoltaic panels, as one of the core components of solar photovoltaic systems, are also called solar panels. They are usually composed of many solar cells. These cells use the photoelectric effect to convert sunlight directly into electrical energy, thereby generating electric current and realizing a clean energy supply method.

[0003] Detection of the degree of performance degradation of photovoltaic panels is crucial to ensuring the safety and reliability of solar photovoltaic systems. Photovoltaic panels with a large degree of performance degradation will greatly reduce the photoelectric conversion efficiency of the solar photovoltaic system and even affect the safety of the entire photovoltaic power generation system. Through this test, we can understand the degree of performance degradation of photovoltaic panels and the health of the main structure of photovoltaic panels, thereby improving the staff's overall understanding of the solar photovoltaic system.

[0004] However, the existing photovoltaic panel performance degradation detection method cannot numerically represent the degree of photovoltaic panel performance degradation, and the detection elements are not comprehensive enough, resulting in a lack of accuracy and guidance in the detection results. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a method and system for detecting the degree of performance degradation of photovoltaic panels, aiming to solve the problem that the current method for detecting the degree of performance degradation of photovoltaic panels cannot numerically represent the degree of performance degradation of photovoltaic panels, and the detection elements are not comprehensive enough, resulting in the problem that the detection results lack accuracy and guidance.

[0006] In view of the above problems, the present application provides a method and system for detecting the degree of performance degradation of a photovoltaic panel.

[0007] In a first aspect disclosed in the present application, a method for detecting the degree of performance degradation of a photovoltaic panel is provided, comprising the following steps: Step 1: Under standard test conditions, perform an open circuit voltage test on the photovoltaic panel to obtain the open circuit voltage value of the photovoltaic panel, perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, where the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; Step 2: Under standard test conditions, perform a photovoltaic panel short-circuit current test to obtain the short-circuit current value of the photovoltaic panel, perform feature scaling on the short-circuit current value, and obtain a short-circuit current mapping value x2, where the short-circuit current is the output current when the photovoltaic panel load resistance is zero; Step 3: Perform a test on the color change of the surface material of the photovoltaic panel to obtain a quantitative value of the color change of the surface material of the photovoltaic panel, perform feature scaling on the color change quantitative value, and obtain a color change quantitative mapping value x3; Step 4: Perform electroluminescence imaging detection to obtain the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, and obtain the electroluminescence imaging mapping value x4; Step 5: Perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4, and calculate the photovoltaic panel performance attenuation degree h using formula (1), where α, β, γ and ξ represent the weighted coefficients corresponding to each mapping value: h=1-(αx1+βx2+γx3+ξx4)×100% formula (1).

[0008] Preferably, the step 1 specifically includes: Step 1.1: Under standard test conditions, connect the positive and negative poles of the photovoltaic panel to a digital voltmeter to ensure that the photovoltaic panel is in an open circuit state, and obtain the open circuit voltage value of the photovoltaic panel; Step 1.2: pre-acquire a first threshold and a second threshold of an open circuit voltage value, wherein the first threshold is the open circuit voltage value of a photovoltaic panel with completely degraded performance under standard test conditions, and the second threshold is the open circuit voltage value of a new and flawless photovoltaic panel under standard test conditions; Step 1.3: Use formula (2) to perform feature scaling on the open circuit voltage value to obtain the open circuit voltage mapping value x1: .

[0009] Preferably, the step 2 specifically includes: Step 2.1: Under standard test conditions, short-circuit the positive and negative poles of the photovoltaic panel, use a digital ammeter to measure the current reading, and obtain the short-circuit current value of the photovoltaic panel; Step 2.2: pre-acquire a third threshold and a fourth threshold of the short-circuit current value, wherein the third threshold is the short-circuit current value of a photovoltaic panel with completely degraded performance under standard test conditions, and the fourth threshold is the short-circuit current value of a new and flawless photovoltaic panel under standard test conditions; Step 2.3: Use formula (3) to perform feature scaling on the short-circuit current value to obtain the short-circuit current mapping value x2: .

[0010] Preferably, the step 3 specifically includes: Step 3.1: Use the camera device to obtain the surface image of the photovoltaic panel, randomly sample n pixels in the image, and obtain the R, G, and B values ​​of these n pixels in the RGB color space, which are recorded as n three-dimensional vectors c i =[R i ,G i ,B i ], where i=1,2, ... ,n, represents the i-th pixel, R i , G i , B i They correspond to the R, G, and B values ​​of the i-th pixel in the RGB color space, and the average value avg of the n three-dimensional vectors is obtained using formula (4): ; Step 3.2: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of a brand new and flawless photovoltaic panel surface image, and then use the same method as step 3.1 to obtain the average value avg' of the three-dimensional vector composed of all pixels in the RGB color space; Step 3.3: Use Manhattan distance to calculate the quantitative value D of the color change of the surface material of the photovoltaic panel, where Represent the three components of avg respectively, and Represent the three components of avg' respectively. The Manhattan distance is the sum of the absolute wheelbases of avg and avg' in the three-dimensional coordinate system: ; Step 3.4: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of the photovoltaic panel surface image with completely attenuated performance, use the same method as step 3.1 to obtain the average value of the three-dimensional vector composed of the RGB color space of all pixels, and then use the same method as step 3.3 to obtain the quantitative value D' of the color change of the photovoltaic panel surface material with completely attenuated performance; Step 3.5: Use formula (6) to perform feature scaling on the quantized value of the color change of the photovoltaic panel to obtain the color change quantized mapping value x3: .

[0011] Preferably, the step 4 specifically includes: Step 4.1: Using the electroluminescence principle of the photovoltaic panel, apply a forward bias current to the photovoltaic panel in a dark box, and use an infrared camera to obtain a near-infrared image of the photovoltaic panel at this time; Step 4.2: Grayscale the near-infrared image to generate a grayscale image, count the number of pixels with a brightness level greater than 127 in the grayscale image, and calculate the ratio r of the number of pixels with a brightness level greater than 127 in the grayscale image to the number of pixels in the grayscale image, as the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel; Step 4.3: Obtain in advance the ratio of the normal luminous area of ​​the photovoltaic panel surface that can be completely attenuated to the surface area of ​​the photovoltaic panel , the ratio of the normal luminous area of ​​a new and flawless photovoltaic panel to the surface area of ​​the photovoltaic panel ; Step 4.4: Use formula (7) to perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel to obtain the electroluminescent imaging mapping value x4: .

[0012] Preferably, the weighting coefficients corresponding to the respective mapping values ​​are: α=β=γ= =0.25.

[0013] The second aspect disclosed in the present application provides a photovoltaic panel performance degradation degree detection system, the system is used for the above-mentioned photovoltaic panel performance degradation degree detection method, the system comprises: An open circuit voltage module, which is used to perform an open circuit voltage test of a photovoltaic panel under standard test conditions to obtain an open circuit voltage value of the photovoltaic panel, and to perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, wherein the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; A short-circuit current module, which is used to perform a photovoltaic panel short-circuit current test under standard test conditions to obtain a short-circuit current value of the photovoltaic panel, and to perform feature scaling on the short-circuit current value to obtain a short-circuit current mapping value x2, wherein the short-circuit current is the output current when the load resistance of the photovoltaic panel is zero; A color change quantification module, which is used to perform a color change test on the surface material of the photovoltaic panel, obtain a color change quantification value of the surface material of the photovoltaic panel, perform feature scaling on the color change quantification value, and obtain a color change quantification mapping value x3; An electroluminescent module, wherein the electroluminescent module is used to perform electroluminescent imaging detection, obtain a ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, and obtain an electroluminescent imaging mapping value x4; A weighted summation module is used to perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4 to calculate the photovoltaic panel performance attenuation degree h.

[0014] The beneficial effects of the present invention are: (1) The performance degradation of photovoltaic panels is expressed in numerical form, which is more intuitive and convenient for staff to understand the health of photovoltaic panels and the overall performance of solar photovoltaic systems; (2) The performance degradation of photovoltaic panels is tested from multiple dimensions. The test elements are comprehensive, the test results are accurate and instructive; (3) The detection process does not rely on complex algorithms, does not involve huge calculation processes and amounts of computation, and is therefore easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 The figure is an overall flow chart of a method for detecting the degree of performance degradation of a photovoltaic panel.

[0017] Figure 2 A near-infrared image of a photovoltaic panel.

[0018] Figure 3 The figure is an overall structural diagram of a photovoltaic panel performance degradation detection system. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the embodiment of the present application provides a method for detecting the degree of performance degradation of a photovoltaic panel, comprising the following steps: Step 1: Under standard test conditions, perform an open circuit voltage test on the photovoltaic panel to obtain the open circuit voltage value of the photovoltaic panel, perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, where the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; Step 2: Under standard test conditions, perform a photovoltaic panel short-circuit current test to obtain the short-circuit current value of the photovoltaic panel, perform feature scaling on the short-circuit current value, and obtain a short-circuit current mapping value x2, where the short-circuit current is the output current when the photovoltaic panel load resistance is zero; Step 3: Perform a test on the color change of the surface material of the photovoltaic panel to obtain a quantitative value of the color change of the surface material of the photovoltaic panel, perform feature scaling on the color change quantitative value, and obtain a color change quantitative mapping value x3; Step 4: Perform electroluminescence imaging detection to obtain the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, and obtain the electroluminescence imaging mapping value x4; Step 5: Perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4, and calculate the photovoltaic panel performance attenuation degree h using formula (1), where α, β, γ and ξ represent the weighted coefficients corresponding to each mapping value: h=1-(αx1+βx2+γx3+ξx4)×100% formula (1).

[0021] Furthermore, the step 1 specifically includes: Step 1.1: Under standard test conditions, connect the positive and negative poles of the photovoltaic panel to a digital voltmeter to ensure that the photovoltaic panel is in an open circuit state, and obtain the open circuit voltage value of the photovoltaic panel; Step 1.2: pre-acquire a first threshold and a second threshold of an open circuit voltage value, wherein the first threshold is the open circuit voltage value of a photovoltaic panel with completely degraded performance under standard test conditions, and the second threshold is the open circuit voltage value of a new and flawless photovoltaic panel under standard test conditions; Step 1.3: Use formula (2) to perform feature scaling on the open circuit voltage value to obtain the open circuit voltage mapping value x1: .

[0022] Furthermore, the step 2 specifically includes: Step 2.1: Under standard test conditions, short-circuit the positive and negative poles of the photovoltaic panel, use a digital ammeter to measure the current reading, and obtain the short-circuit current value of the photovoltaic panel; Step 2.2: pre-acquire a third threshold and a fourth threshold of the short-circuit current value, wherein the third threshold is the short-circuit current value of a photovoltaic panel with completely degraded performance under standard test conditions, and the fourth threshold is the short-circuit current value of a new and flawless photovoltaic panel under standard test conditions; Step 2.3: Use formula (3) to perform feature scaling on the short-circuit current value to obtain the short-circuit current mapping value x2: .

[0023] Furthermore, the step 3 specifically includes: Step 3.1: Use the camera device to obtain the surface image of the photovoltaic panel, randomly sample n pixels in the image, and obtain the R, G, and B values ​​of these n pixels in the RGB color space, which are recorded as n three-dimensional vectors c i =[R i ,G i ,B i ], where i=1,2, ... ,n, represents the i-th pixel, R i , G i , B i They correspond to the R, G, and B values ​​of the i-th pixel in the RGB color space, and the average value avg of the n three-dimensional vectors is obtained using formula (4): ; Step 3.2: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of a brand new and flawless photovoltaic panel surface image, and then use the same method as step 3.1 to obtain the average value avg' of the three-dimensional vector composed of all pixels in the RGB color space; Step 3.3: Use Manhattan distance to calculate the quantitative value D of the color change of the surface material of the photovoltaic panel, where Represent the three components of avg respectively, and Represent the three components of avg' respectively. The Manhattan distance is the sum of the absolute wheelbases of avg and avg' in the three-dimensional coordinate system: ; Step 3.4: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of the photovoltaic panel surface image with completely attenuated performance, use the same method as step 3.1 to obtain the average value of the three-dimensional vector composed of the RGB color space of all pixels, and then use the same method as step 3.3 to obtain the quantitative value D' of the color change of the photovoltaic panel surface material with completely attenuated performance; Step 3.5: Use formula (6) to perform feature scaling on the quantized value of the color change of the photovoltaic panel to obtain the color change quantized mapping value x3: .

[0024] Furthermore, the step 4 specifically includes: Step 4.1: Using the electroluminescence principle of photovoltaic panels, apply a forward bias current to the photovoltaic panels in a dark box, and use an infrared camera to obtain a near-infrared image of the photovoltaic panels at this time, such as Figure 2 As shown; Step 4.2: Grayscale the near-infrared image to generate a grayscale image, count the number of pixels with a brightness level greater than 127 in the grayscale image, and calculate the ratio r of the number of pixels with a brightness level greater than 127 in the grayscale image to the number of pixels in the grayscale image, as the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel; Step 4.3: Obtain in advance the ratio of the normal luminous area of ​​the photovoltaic panel surface that can be completely attenuated to the surface area of ​​the photovoltaic panel , the ratio of the normal luminous area of ​​a new and flawless photovoltaic panel to the surface area of ​​the photovoltaic panel ; Step 4.4: Use formula (7) to perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel to obtain the electroluminescent imaging mapping value x4: .

[0025] Furthermore, the weighting coefficients corresponding to the mapping values ​​are α=β=γ= =0.25.

[0026] In summary, the method for detecting the degree of performance degradation of a photovoltaic panel provided in the embodiment of the present application has the following technical effects: (1) The performance degradation of photovoltaic panels is expressed in numerical form, which is more intuitive and convenient for staff to understand the health of photovoltaic panels and the overall performance of solar photovoltaic systems; (2) The performance degradation of photovoltaic panels is tested from multiple dimensions. The test elements are comprehensive, the test results are accurate and instructive; (3) The detection process does not rely on complex algorithms, does not involve huge calculation processes and amounts of computation, and is therefore easy to implement.

[0027] Based on the same inventive concept as the method for detecting the degree of degradation of photovoltaic panel performance in the aforementioned embodiment, Figure 3 As shown, the present application provides a photovoltaic panel performance degradation degree detection system, the system comprising: An open circuit voltage module, which is used to perform an open circuit voltage test of a photovoltaic panel under standard test conditions to obtain an open circuit voltage value of the photovoltaic panel, and to perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, wherein the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; A short-circuit current module, which is used to perform a photovoltaic panel short-circuit current test under standard test conditions to obtain a short-circuit current value of the photovoltaic panel, and to perform feature scaling on the short-circuit current value to obtain a short-circuit current mapping value x2, wherein the short-circuit current is the output current when the load resistance of the photovoltaic panel is zero; A color change quantification module, which is used to perform a color change test on the surface material of the photovoltaic panel, obtain a color change quantification value of the surface material of the photovoltaic panel, perform feature scaling on the color change quantification value, and obtain a color change quantification mapping value x3; An electroluminescent module, wherein the electroluminescent module is used to perform electroluminescent imaging detection, obtain a ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, and obtain an electroluminescent imaging mapping value x4; A weighted summation module is used to perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4 to calculate the photovoltaic panel performance attenuation degree h.

[0028] Through the above-mentioned detailed description of a method for detecting the degree of performance degradation of a photovoltaic panel, those skilled in the art can clearly know a system for detecting the degree of performance degradation of a photovoltaic panel in this embodiment. Since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0029] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0030] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting the degree of performance attenuation of a photovoltaic panel, characterized in that: The following steps are involved: Step 1: Under standard test conditions, perform an open circuit voltage test on the photovoltaic panel to obtain the open circuit voltage value of the photovoltaic panel, perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, where the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; Step 2: Under standard test conditions, perform a photovoltaic panel short-circuit current test to obtain the short-circuit current value of the photovoltaic panel, perform feature scaling on the short-circuit current value, and obtain a short-circuit current mapping value x2, where the short-circuit current is the output current when the photovoltaic panel load resistance is zero; Step 3: Perform a test on the color change of the surface material of the photovoltaic panel to obtain a quantitative value of the color change of the surface material of the photovoltaic panel, perform feature scaling on the color change quantitative value, and obtain a color change quantitative mapping value x3; Step 4: Perform electroluminescence imaging detection to obtain the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel, and obtain the electroluminescence imaging mapping value x4; Step 5: Perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4, and calculate the photovoltaic panel performance attenuation degree h using formula (1), where α, β, γ and ξ represent the weighted coefficients corresponding to each mapping value: h=1-(αx1+βx2+γx3+ξx4)×100% formula (1).

2. A method for detecting the degree of performance attenuation of a photovoltaic panel as claimed in claim 1, characterized in that: The step 1 specifically includes: Step 1.1: Under standard test conditions, connect the positive and negative poles of the photovoltaic panel to a digital voltmeter to ensure that the photovoltaic panel is in an open circuit state, and obtain the open circuit voltage value of the photovoltaic panel; Step 1.2: pre-acquire a first threshold and a second threshold of an open circuit voltage value, wherein the first threshold is the open circuit voltage value of a photovoltaic panel with completely degraded performance under standard test conditions, and the second threshold is the open circuit voltage value of a new and flawless photovoltaic panel under standard test conditions; Step 1.3: Use formula (2) to perform feature scaling on the open circuit voltage value to obtain the open circuit voltage mapping value x1: 。 3. A method for detecting the degree of performance attenuation of a photovoltaic panel as claimed in claim 1, characterized in that: The step 2 specifically includes: Step 2.1: Under standard test conditions, short-circuit the positive and negative poles of the photovoltaic panel, use a digital ammeter to measure the current reading, and obtain the short-circuit current value of the photovoltaic panel; Step 2.2: pre-acquire a third threshold and a fourth threshold of the short-circuit current value, wherein the third threshold is the short-circuit current value of a photovoltaic panel with completely degraded performance under standard test conditions, and the fourth threshold is the short-circuit current value of a new and flawless photovoltaic panel under standard test conditions; Step 2.3: Use formula (3) to perform feature scaling on the short-circuit current value to obtain the short-circuit current mapping value x2: 。 4. A method for detecting the degree of performance attenuation of a photovoltaic panel as claimed in claim 1, characterized in that: The step 3 specifically includes: Step 3.1: Use the camera device to obtain the surface image of the photovoltaic panel, randomly sample n pixels in the image, and obtain the R, G, and B values ​​of these n pixels in the RGB color space, which are recorded as n three-dimensional vectors c i =[R i ,G i ,B i ], where i=1,2, ... ,n, represents the i-th pixel, R i , G i , B i They correspond to the R, G, and B values ​​of the i-th pixel in the RGB color space, and the average value avg of the n three-dimensional vectors is obtained using formula (4): ； Step 3.2: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of a brand new and flawless photovoltaic panel surface image, and then use the same method as step 3.1 to obtain the average value avg' of the three-dimensional vector composed of all pixels in the RGB color space; Step 3.3: Use Manhattan distance to calculate the quantitative value D of the color change of the surface material of the photovoltaic panel, where Represent the three components of avg respectively, and Represent the three components of avg' respectively. The Manhattan distance is the sum of the absolute wheelbases of avg and avg' in the three-dimensional coordinate system: ； Step 3.4: Pre-acquire the R, G, and B values ​​of all pixels in the RGB color space of the photovoltaic panel surface image with completely attenuated performance, use the same method as step 3.1 to obtain the average value of the three-dimensional vector composed of the RGB color space of all pixels, and then use the same method as step 3.3 to obtain the quantitative value D' of the color change of the photovoltaic panel surface material with completely attenuated performance; Step 3.5: Use formula (6) to perform feature scaling on the quantized value of the color change of the photovoltaic panel to obtain the color change quantized mapping value x3: 。 5. A method for detecting the degree of performance attenuation of a photovoltaic panel as claimed in claim 1, characterized in that: The step 4 specifically includes: Step 4.1: Using the electroluminescence principle of the photovoltaic panel, apply a forward bias current to the photovoltaic panel in a dark box, and use an infrared camera to obtain a near-infrared image of the photovoltaic panel at this time; Step 4.2: Grayscale the near-infrared image to generate a grayscale image, count the number of pixels with a brightness level greater than 127 in the grayscale image, and calculate the ratio r of the number of pixels with a brightness level greater than 127 in the grayscale image to the number of pixels in the grayscale image, as the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel; Step 4.3: Obtain in advance the ratio of the normal luminous area of ​​the photovoltaic panel surface that can be completely attenuated to the surface area of ​​the photovoltaic panel , the ratio of the normal luminous area of ​​a new and flawless photovoltaic panel to the surface area of ​​the photovoltaic panel ; Step 4.4: Use formula (7) to perform feature scaling on the ratio of the normal luminous area of ​​the photovoltaic panel surface to the surface area of ​​the photovoltaic panel to obtain the electroluminescent imaging mapping value x4: 。 6. A method for detecting the degree of performance attenuation of a photovoltaic panel as claimed in claim 1, characterized in that: The weighting coefficients corresponding to the mapping values ​​are α=β=γ= =0.

25.

7. A photovoltaic panel performance attenuation degree detection system, characterized in that: include: An open circuit voltage module, which is used to perform an open circuit voltage test of a photovoltaic panel under standard test conditions to obtain an open circuit voltage value of the photovoltaic panel, and to perform feature scaling on the open circuit voltage value to obtain an open circuit voltage mapping value x1, wherein the open circuit voltage is the output voltage of the photovoltaic panel when there is no load; A short-circuit current module, which is used to perform a photovoltaic panel short-circuit current test under standard test conditions to obtain a short-circuit current value of the photovoltaic panel, and to perform feature scaling on the short-circuit current value to obtain a short-circuit current mapping value x2, wherein the short-circuit current is the output current when the load resistance of the photovoltaic panel is zero; A color change quantification module, which is used to perform a color change test on the surface material of the photovoltaic panel, obtain a color change quantification value of the surface material of the photovoltaic panel, perform feature scaling on the color change quantification value, and obtain a color change quantification mapping value x3; An electroluminescent module, wherein the electroluminescent module is used to perform electroluminescent imaging detection, obtain a ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, perform feature scaling on the ratio of a normal luminescent area on the surface of the photovoltaic panel to a surface area of ​​the photovoltaic panel, and obtain an electroluminescent imaging mapping value x4; A weighted summation module is used to perform weighted summation on the open circuit voltage mapping value x1, the short circuit current mapping value x2, the color change quantization mapping value x3 and the electroluminescence imaging mapping value x4 to calculate the photovoltaic panel performance attenuation degree h.

Images