Photovoltaic module testing method and device

Abstract

The present application relates to a photovoltaic module testing method and device. The method includes electrically connecting the positive electrode of a measuring power supply to the positive electrode of a photovoltaic module, and electrically connecting the negative electrode of the measuring power supply to the negative electrode of the photovoltaic module; applying a preset current through the measuring power supply and measuring a first voltage value of the photovoltaic module; applying a preset breakdown voltage through the measuring power supply for a first preset duration, and then applying a preset current through the measuring power supply and measuring a second voltage value of the photovoltaic module; if the first and second voltage values ​​are within a first preset voltage range, determining that the bypass diodes in the photovoltaic module are operating normally; if the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, determining that a broken-down bypass diode exists in the photovoltaic module, and the corresponding bypass diode is completely broken down by the preset breakdown voltage. This avoids the problem of missed detection due to a relatively mild breakdown of the bypass diode, improves test accuracy, and thereby improves the reliability of the photovoltaic module.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic module testing method and device. Background Art

[0002] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electricity. Because they are environmentally friendly and do not cause environmental pollution, and because solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.

[0003] In a photovoltaic module, a battery string is formed by multiple solar cells connected in series. In order to overcome the hot spot effect of the photovoltaic module and ensure the power generation efficiency and safety of the photovoltaic module, a bypass diode is usually installed in the photovoltaic module. The bypass diode is connected in reverse parallel with the battery string.

[0004] In related technologies, after the lamination or framing process, photovoltaic modules must undergo power testing and electroluminescence testing to detect defects. However, during this testing process, problems such as missed detection often occur. For example, a bypass diode with a relatively minor breakdown in a photovoltaic module may not be detected, resulting in reduced reliability of the photovoltaic module. Summary of the Invention

[0005] Based on this, the present application provides a photovoltaic module testing method and device to improve the accuracy of photovoltaic module testing and improve the reliability of photovoltaic modules.

[0006] An embodiment of a first aspect of the present application provides a photovoltaic module testing method for testing a photovoltaic module, wherein the photovoltaic module includes a plurality of battery strings and a plurality of bypass diodes, each of the battery strings is connected in reverse parallel to a bypass diode, and the plurality of bypass diodes are connected in series. The method includes:

[0007] The positive electrode of the measuring power supply is electrically connected to the positive electrode of the photovoltaic module, and the negative electrode of the measuring power supply is electrically connected to the negative electrode of the photovoltaic module;

[0008] Loading a preset current through the measuring power supply and measuring a first voltage value across the photovoltaic component;

[0009] Applying a preset breakdown voltage through the measurement power supply for a first preset time period, then applying a preset current through the measurement power supply to measure a second voltage value across the photovoltaic module;

[0010] If the first voltage value and the second voltage value are both within the first preset voltage range, it is determined that all the bypass diodes in the photovoltaic assembly are operating normally;

[0011] If the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, it is determined that a broken-down bypass diode exists in the photovoltaic assembly and the corresponding bypass diode is completely broken down by the preset breakdown voltage.

[0012] In one embodiment, the method further comprises:

[0013] loading the preset current through the measurement power supply to acquire a first image of the photovoltaic assembly, and measuring a third voltage value across the photovoltaic assembly;

[0014] Applying the preset breakdown voltage through the measurement power supply for the first preset time duration, then applying the preset current through the measurement power supply to measure a fourth voltage value across the photovoltaic module;

[0015] If the third voltage value and the fourth voltage value are both equal to the second voltage value, it is determined based on the first image that a broken-down bypass diode exists in the photovoltaic assembly.

[0016] In one embodiment, the preset breakdown voltage is (32V-36V)×the number of the bypass diodes.

[0017] In one embodiment, the first preset voltage range is (resistance value of the photovoltaic module×the preset current×3 / 4) to (resistance value of the photovoltaic module×the preset current).

[0018] In one embodiment, the second preset voltage range is 0 to (resistance value of the photovoltaic module×the preset current×3 / 4).

[0019] In one embodiment, the first preset duration is 14ms to 18ms.

[0020] The embodiment of the second aspect of the present application provides a photovoltaic module testing device for testing photovoltaic modules, wherein the photovoltaic module includes a plurality of battery strings and a plurality of bypass diodes, each of the battery strings is connected in reverse parallel with a bypass diode, and the plurality of bypass diodes are connected in series with each other; the device includes a power connection module, a measurement module and a processor; the power connection module is used to electrically connect the positive electrode of the measurement power supply to the positive electrode of the photovoltaic module, and the negative electrode of the measurement power supply to the negative electrode of the photovoltaic module; the measurement module is used to measure a first voltage value at both ends of the photovoltaic module when the measurement power supply is loaded with a preset current; the measurement module is also used to measure a first voltage value at both ends of the photovoltaic module when the measurement power supply is loaded with a preset current; the measurement module is also used to measure a first voltage value at both ends of the photovoltaic module when the measurement power supply is loaded with a preset current The source loads a preset breakdown voltage for a first preset time period, and when the measuring power source loads a preset current, measures a second voltage value at both ends of the photovoltaic component; the processor is electrically connected to the power connection module and the measurement module; the processor is used to determine that all the bypass diodes in the photovoltaic component are working normally when the first voltage value and the second voltage value are both within a first preset voltage range; the processor is also used to determine that there is a broken-down bypass diode in the photovoltaic component when the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, and the corresponding bypass diode is completely broken down by the preset breakdown voltage.

[0021] In one embodiment, it further includes an image acquisition mechanism, which is electrically connected to the processor; the measurement module is also used to measure the third voltage value across the photovoltaic component when the measurement power supply is loaded with the preset current; the measurement module is also used to load the measurement power supply with a preset breakdown voltage for a first preset time period, and measure the fourth voltage value across the photovoltaic component when the measurement power supply is loaded with the preset current; the image acquisition mechanism is used to capture a first image of the photovoltaic component; the processor is also used to determine, based on the first image, that there is a breakdown bypass diode in the photovoltaic component when the third voltage value and the fourth voltage value are both equal to the second voltage value.

[0022] In one embodiment, the power connection module includes a switch, and the switch is used to be arranged between the positive electrode of the measurement power supply and the positive electrode of the photovoltaic component.

[0023] In one embodiment, the switch comprises a contactor switch.

[0024] In one embodiment, the measurement module includes a voltage monitoring unit, and the voltage monitoring unit is used to connect with the photovoltaic component to monitor the voltage of the photovoltaic component.

[0025] In one embodiment, the voltage monitoring unit includes a voltmeter.

[0026] In one embodiment, a conductive component is further included, wherein the conductive component includes a conductive member and a driving member; the conductive member is electrically connected to the measurement power supply; and the driving member is used to drive the conductive member to contact or move away from the photovoltaic component.

[0027] In one embodiment, a timing module is further included, which is electrically connected to the processor and the driving component, and is used to time the contact time between the conductive component and the photovoltaic component and the time when the power connection module is in the second action; the processor is used to control the power connection module to switch between the first action and the second action according to the information of the timing module.

[0028] In one embodiment, an alarm module is further included, and the alarm module is electrically connected to the processor.

[0029] In one embodiment, the alarm module includes an alarm.

[0030] In one embodiment, the measuring power supply includes a power supply having a constant current mode and a constant voltage mode, and the measuring power supply is electrically connected to the processor; when the measuring power supply is in the constant current mode, the measuring power supply outputs the preset current; when the measuring power supply is in the constant voltage mode, the measuring power supply outputs the preset breakdown voltage.

[0031] The above-mentioned photovoltaic module testing method is to load a preset current by measuring the power supply and measure a first voltage value at both ends of the photovoltaic module; load a preset breakdown voltage by measuring the power supply and continue for a first preset time, and then measure a second voltage value at both ends of the photovoltaic module by measuring the power supply loading a preset current; if all bypass diodes in the photovoltaic module are working normally, the preset breakdown voltage will not affect all bypass diodes, and the second voltage value and the first voltage value are both within the first preset pressure range; if there is a bypass diode with a lighter breakdown degree in the photovoltaic module, under the action of the preset breakdown voltage, the bypass diode with a lighter breakdown degree will be completely broken down, so that the battery string connected in parallel with the completely broken-down bypass diode will be short-circuited, the resistance of the photovoltaic module will be reduced, and the corresponding measured second voltage value will be lower than the first voltage value, that is, the first voltage value is within the first preset voltage range, and the second voltage value is within the second preset voltage range. In this way, by comparing the first voltage value and the second voltage value after loading the preset breakdown voltage, it can be determined whether there is a broken-down bypass diode in the photovoltaic module according to the preset voltage range within which the first voltage value and the second voltage value fall, thereby avoiding the problem of missed detection due to the relatively light breakdown of the bypass diode, improving the accuracy of photovoltaic module testing, and further improving the reliability of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1This is a flow chart of a photovoltaic module testing method in some embodiments of the present application.

[0033] Figure 2 This is a schematic structural diagram of a photovoltaic module in some embodiments of the present application.

[0034] Figure 3 This is another flow chart of a photovoltaic module testing method in some embodiments of the present application.

[0035] Figure 4 Schematic diagram of the structure of a photovoltaic module testing device in some embodiments of the present application.

[0036] Figure 5 Schematic diagram of the structure of photovoltaic module testing devices in other embodiments of the present application.

[0037] Description of reference numerals:

[0038] 10. Photovoltaic module testing device; 110. Measurement power supply; 120. Power connection module; 130. Measurement module; 140. Processor; 150. Image acquisition mechanism; 160. Timing module; 170. Alarm module;

[0039] 20. Photovoltaic module; 210. Battery string; 220. Bypass diode. DETAILED DESCRIPTION

[0040] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0041] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0042] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0043] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0044] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0045] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0046] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electricity. Because they are environmentally friendly and do not cause environmental pollution, and because solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.

[0047] Solar energy utilization relies on photovoltaic modules to absorb solar energy. These modules are typically installed in arrays outdoors or on buildings to form a photovoltaic system. A photovoltaic module consists of multiple solar cells connected in series to form a string. To overcome the hot spot effect and ensure the module's power generation efficiency and safety, a bypass diode is typically installed in the module, connected in anti-parallel with the string.

[0048] In related technologies, after the lamination or framing process, photovoltaic modules must undergo power testing and electroluminescence testing to detect defects. However, the inventors have discovered that even photovoltaic modules that pass power and electroluminescence testing can still experience problems during outdoor use. For example, the junction box within the photovoltaic module may burn out, affecting the normal use of the photovoltaic module.

[0049] After research, the inventors found that the cause of the above-mentioned problem is that: after power testing and electroluminescence testing, the test results of photovoltaic modules with bypass diodes with a relatively light breakdown degree and photovoltaic modules with all bypass diodes working normally are basically the same. This makes it impossible to detect the bypass diodes with a relatively light breakdown degree in the photovoltaic modules, resulting in missed detection problems; when the photovoltaic modules with bypass diodes with breakdown are used outdoors, due to the breakdown of the bypass diodes, the bypass diodes and their corresponding battery strings form a reverse loop. Under the action of reverse resistance and current, the diodes heat up abnormally, causing the junction box to burn, affecting the normal use of the photovoltaic modules and reducing the reliability of the photovoltaic modules.

[0050] Based on the above technical problems, the present application provides a photovoltaic module testing method and device to improve the accuracy of photovoltaic module testing and improve the reliability of photovoltaic modules.

[0051] Figure 1 A flow chart showing a photovoltaic module testing method in some embodiments of the present application is shown; Figure 2 A schematic structural diagram of a photovoltaic module in some embodiments of the present application is shown.

[0052] First, see Figure 1 and Figure 2 As shown, an embodiment of the first aspect of the present application provides a photovoltaic module testing method for testing a photovoltaic module 20, wherein the photovoltaic module 20 includes a plurality of battery strings 210 and a plurality of bypass diodes 220, each battery string 210 is connected in reverse parallel with a bypass diode 220, and the plurality of bypass diodes 220 are connected in series. The method includes:

[0053] S10, electrically connecting the positive electrode of the measuring power supply 110 to the positive electrode of the photovoltaic assembly 20, and electrically connecting the negative electrode of the measuring power supply 110 to the negative electrode of the photovoltaic assembly 20;

[0054] S20, loading a preset current through the measuring power supply 110, and measuring a first voltage value across the photovoltaic assembly 20;

[0055] S30, applying a preset breakdown voltage through the measuring power supply 110 for a first preset duration, then applying a preset current through the measuring power supply 110 to measure a second voltage value across the photovoltaic module 20;

[0056] S40: If the first voltage value and the second voltage value are both within the first preset voltage range, it is determined that all bypass diodes 220 in the photovoltaic assembly 20 are operating normally.

[0057] S50: If the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, it is determined that a broken-down bypass diode 220 exists in the photovoltaic assembly 20 and the corresponding bypass diode 220 is completely broken down by the preset breakdown voltage.

[0058] The photovoltaic module testing method provided in the embodiment of the present application loads a preset current through the measuring power supply 110 and measures a first voltage value across the photovoltaic module 20; loads a preset breakdown voltage through the measuring power supply 110 and continues for a first preset time, then loads a preset current through the measuring power supply 110 and measures a second voltage value across the photovoltaic module 20; if all bypass diodes 220 in the photovoltaic module 20 are operating normally, the preset breakdown voltage will not affect all bypass diodes 220, and the second voltage value and the first voltage value are both within a first preset pressure range; if there is a bypass diode 220 with a relatively light breakdown degree in the photovoltaic module 20, under the action of the preset breakdown voltage, the bypass diode 220 with a relatively light breakdown degree will be completely broken down, so that the battery string 210 connected in parallel with the completely broken-down bypass diode 220 will be short-circuited, the resistance of the photovoltaic module 20 will be reduced, and the corresponding measured second voltage value will be lower than the first voltage value, that is, the first voltage value is within the first preset voltage range, and the second voltage value is within the second preset voltage range. In this way, by comparing the first voltage value and the second voltage value after loading the preset breakdown voltage, it can be determined whether there is a broken-down bypass diode 220 in the photovoltaic component 20 according to the preset voltage range within which the first voltage value and the second voltage value fall, thereby avoiding the occurrence of missed detection due to the relatively light breakdown degree of the bypass diode 220, improving the accuracy of the photovoltaic component 20 test, and further improving the reliability of the photovoltaic component 20.

[0059] like Figure 3 As shown, in one embodiment, the method further includes:

[0060] S60, loading a preset current through the measurement power supply 110 to obtain a first image of the photovoltaic assembly 20, and measuring a third voltage value across the photovoltaic assembly 20;

[0061] Specifically, an image acquisition mechanism 150 (such as a camera) may be used to acquire the first image of the photovoltaic assembly 20 .

[0062] S70 , applying a preset breakdown voltage through the measuring power supply 110 for a first preset time period, then applying a preset current through the measuring power supply 110 to measure a fourth voltage value across the photovoltaic assembly 20 .

[0063] S80 : If the third voltage value and the fourth voltage value are both equal to the second voltage value, determine that a broken-down bypass diode 220 exists in the photovoltaic assembly 20 according to the first image.

[0064] During the electroluminescence test, the bypass diode 220 in the photovoltaic module 20 may also break down. To eliminate this situation, in this embodiment, the photovoltaic module 20 is subjected to an electroluminescence test by loading a preset current through the measuring power supply 110 to obtain a first image of the photovoltaic module 20 and measure a third voltage value across the photovoltaic module 20; a preset breakdown voltage is loaded through the measuring power supply 110 for a first preset time period, and then a preset current is loaded through the measuring power supply 110 to measure a fourth voltage value across the photovoltaic module 20; the third and fourth voltage values ​​are compared with the second voltage value. If the third and fourth voltage values ​​are both equal to the second voltage value, it indicates that the normally operating bypass diode 220 of the photovoltaic module 20 is still in a normal working state during the electroluminescence test, thereby avoiding the situation where the bypass diode 220 of the photovoltaic module 20 breaks down during the electroluminescence test without being detected. In addition, after excluding the situation where the bypass diode 220 of the photovoltaic component 20 breaks down during the electroluminescence test, the presence of the broken-down bypass diode 220 in the photovoltaic component 20 can be accurately determined based on the first image, so that the photovoltaic component 20 can be returned for repair, thereby improving the reliability of the photovoltaic component 20.

[0065] In one embodiment, the predetermined breakdown voltage is (32V-36V)×the number of the bypass diodes 220 .

[0066] In this way, it can be ensured that the bypass diodes 220 with a lighter breakdown degree in the photovoltaic module 20 are completely broken down, so that the bypass diodes 220 with a lighter breakdown degree in the photovoltaic module 20 can be detected, reducing the probability of missed detection, improving the accuracy of the photovoltaic module 20 test, and thus improving the reliability of the photovoltaic module 20.

[0067] In one embodiment, the first preset voltage range is (resistance of the photovoltaic component 20×preset current×3 / 4) to (resistance of the photovoltaic component 20×preset current).

[0068] The first preset voltage range can be used to conveniently determine the working status of all bypass diodes 220 in the photovoltaic module 20. If the measured voltage value across the photovoltaic module 20 is within the first preset voltage range, it is determined that all bypass diodes 220 in the photovoltaic module 20 are in normal operation. If the measured voltage value across the photovoltaic module 20 is lower than the lower end value of the first preset voltage range (that is, the resistance value of the photovoltaic module 20 × the preset current × 3 / 4), it is determined that there is a broken-down bypass diode 220 in the photovoltaic module 20, and that the bypass diode 220 is completely broken down under the action of the preset breakdown voltage, which is beneficial to the testing of the photovoltaic module 20, can improve the accuracy of the testing of the photovoltaic module 20, and further improve the reliability of the photovoltaic module 20.

[0069] In one embodiment, the second preset voltage range is 0 to (resistance of the photovoltaic component 20 × preset current × 3 / 4).

[0070] Through the second preset voltage range, it is convenient to determine whether there is a bypass diode 220 that has broken down in the photovoltaic component 20, and whether the corresponding bypass diode 220 is completely broken down by the preset breakdown voltage, which is beneficial to the testing of the photovoltaic component 20, can improve the accuracy of the testing of the photovoltaic component 20, and further improve the reliability of the photovoltaic component 20.

[0071] In one embodiment, the first preset duration is 14ms to 18ms.

[0072] In this way, the preset breakdown voltage can act on the bypass diode 220 for a sufficient period of time to ensure that the bypass diode 220 with a lighter breakdown degree is completely broken down by the preset breakdown voltage, so that the bypass diode 220 with a lighter breakdown degree in the photovoltaic module 20 can be detected, reducing the probability of missed detection, improving the accuracy of the photovoltaic module 20 test, and thereby improving the reliability of the photovoltaic module 20.

[0073] Figure 2 A schematic structural diagram of a photovoltaic assembly 20 in some embodiments of the present application is shown; Figure 4 Schematic diagram of the structure of a photovoltaic module testing device 10 in some embodiments of the present application is shown; Figure 5 Schematic diagrams of the structures of photovoltaic module testing devices 10 in other embodiments of the present application are shown.

[0074] Second, see Figure 2 、 Figure 4 and Figure 5As shown, an embodiment of the present application provides a photovoltaic module testing device 10 for testing a photovoltaic module 20. The photovoltaic module 20 includes a plurality of battery strings 210 and a plurality of bypass diodes 220. Each battery string 210 is connected in reverse parallel with a bypass diode 220, and the plurality of bypass diodes 220 are connected in series. The device includes a power connection module 120, a measurement module 130, and a processor 140. The power connection module 120 is used to electrically connect the positive electrode of the measurement power supply 110 to the positive electrode of the photovoltaic module 20, and the negative electrode of the measurement power supply 110 to the negative electrode of the photovoltaic module 20; the measurement module 130 is used to measure the first voltage value across the photovoltaic module 20 when the measurement power supply 110 is loaded with a preset current; the measurement module 130 is also used to load a preset breakdown voltage on the measurement power supply 110 for a first preset time period, and to measure the photovoltaic voltage when the measurement power supply 110 is loaded with a preset current. The second voltage value at both ends of the component 20; the processor 140 is electrically connected to the power connection module 120 and the measurement module 130, and the processor 140 is used to determine that all bypass diodes 220 in the photovoltaic component 20 are working normally when the first voltage value and the second voltage value are both within the first preset voltage range; the processor 140 is also used to determine that there is a broken-down bypass diode 220 in the photovoltaic component 20 when the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, and the corresponding bypass diode 220 is completely broken down by the preset breakdown voltage.

[0075] The photovoltaic module testing device 10 provided in the embodiment of the present application electrically connects the positive electrode of the measuring power supply 110 to the positive electrode of the photovoltaic module 20, and electrically connects the negative electrode of the measuring power supply 110 to the negative electrode of the photovoltaic module 20 through the power connection module 120; measures the first voltage value at both ends of the photovoltaic module 20 when the measuring power supply 110 is loaded with a preset current through the measuring module 130; loads a preset breakdown voltage on the measuring power supply 110 through the measuring module 130 for a first preset time period, and measures the second voltage value at both ends of the photovoltaic module 20 when the measuring power supply 110 is loaded with a preset current; if all the bypass diodes 220 in the photovoltaic module 20 are working normally, the preset breakdown voltage will not affect all the bypass diodes 220, and the second voltage value and the first voltage value are both within the first preset pressure range; if there is a bypass diode 220 with a lighter breakdown degree in the photovoltaic module 20, under the action of the preset breakdown voltage, the bypass diode with a lighter breakdown degree 220 will be completely broken down, so that the battery string 210 connected in parallel with the completely broken down bypass diode 220 will be short-circuited, the resistance of the photovoltaic component 20 will be reduced, and the corresponding measured second voltage value is lower than the first voltage value, the first voltage value is within the first preset voltage range, and the second voltage value is within the second preset voltage range; that is, when the first voltage value and the second voltage value are both within the first preset voltage range, the processor 140 determines that all bypass diodes 220 in the photovoltaic component 20 are working normally; when the first voltage value is within the first preset voltage range and the second voltage value is within the second preset voltage range, it is determined that there is a broken-down bypass diode 220 in the photovoltaic component 20, and the corresponding bypass diode 220 is completely broken down by the preset breakdown voltage, thereby avoiding the problem of missed detection due to the relatively light breakdown degree of the bypass diode 220, improving the accuracy of the photovoltaic component 20 test, and thereby improving the reliability of the photovoltaic component 20.

[0076] like Figure 4 As shown, in one embodiment, it also includes an image acquisition mechanism 150, which is electrically connected to the processor 140; the measuring module 130 is also used to measure the third voltage value across the photovoltaic component 20 when the measuring power supply 110 is loaded with a preset current; the measuring module 130 is also used to load a preset breakdown voltage on the measuring power supply 110 for a first preset time period, and measure the fourth voltage value across the photovoltaic component 20 when the measuring power supply 110 is loaded with a preset current; the image acquisition mechanism 150 is used to capture a first image of the photovoltaic component 20; the processor 140 is also used to determine, based on the first image, that a broken-down bypass diode 220 exists in the photovoltaic component 20 when the third voltage value and the fourth voltage value are both equal to the second voltage value.

[0077] During the electroluminescence test, the bypass diode 220 in the photovoltaic module 20 may also break down. To eliminate this situation, in this embodiment, the measuring module 130 measures a third voltage value across the photovoltaic module 20 when the measuring power supply 110 is loaded with a preset current. The measuring module 130 loads a preset breakdown voltage on the measuring power supply 110 for a first preset time period, and measures a fourth voltage value across the photovoltaic module 20 when the measuring power supply 110 is loaded with a preset current. The image acquisition mechanism 150 captures a first image of the photovoltaic module 20. The processor 140 compares the third and fourth voltage values ​​with the second voltage value. If the third and fourth voltage values ​​are both equal to the second voltage value, it indicates that the normally operating bypass diode 220 of the photovoltaic module 20 is still in a normal working state during the electroluminescence test, thereby avoiding the situation where the bypass diode 220 of the photovoltaic module 20 breaks down during the electroluminescence test without being detected. In addition, after excluding the situation where the bypass diode 220 of the photovoltaic component 20 breaks down during the electroluminescence test, the processor 140 can accurately determine the presence of a broken-down bypass diode 220 in the photovoltaic component 20 based on the first image, thereby facilitating the return of the photovoltaic component 20 for repair, thereby improving the reliability of the photovoltaic component 20.

[0078] like Figure 5 As shown, in one embodiment, the power connection module 120 includes a switch, and the switch is used to be arranged between the positive pole of the measurement power source 110 and the positive pole of the photovoltaic assembly 20.

[0079] Through multiple experiments and studies, the inventors found that when the switch is set between the negative pole of the measuring power supply 110 and the negative pole of the photovoltaic module 20, abnormal pulse voltage is likely to appear in the test circuit of the photovoltaic module testing device 10, and there is a risk of the pulse voltage breaking down the bypass diode 220. For this reason, in this embodiment, by setting the switch between the positive pole of the measuring power supply 110 and the positive pole of the photovoltaic module 20, abnormal pulse voltage can be effectively avoided during the test process, the probability of damage to the photovoltaic module 20 during the test process can be reduced, and the safety and reliability of the photovoltaic module testing device 10 can be improved.

[0080] In one embodiment, the switch includes a contactor switch, which can meet the requirement of frequent shutoff of the test circuit during the test process, thereby improving the reliability of the photovoltaic module testing device 10.

[0081] In one embodiment, the measurement module 130 includes a voltage monitoring unit, which is configured to be connected to the photovoltaic assembly 20 to monitor the voltage of the photovoltaic assembly 20 .

[0082] In one embodiment, the voltage monitoring unit includes a voltmeter, which can be connected to the photovoltaic module 20 to measure the voltage of the photovoltaic module 20 . The voltmeter is low in cost, thereby reducing the cost of the photovoltaic module testing device 10 .

[0083] In one embodiment, a conductive component (not shown) is further included, which includes a conductive member and a driving member; the conductive member is electrically connected to the measurement power supply 110; the driving member can be electrically connected to the processor 140, and the driving member is used to drive the conductive member to contact or move away from the photovoltaic component 20.

[0084] When conducting a test, the conductive member can be driven by the driving member to contact the photovoltaic component 20, and then the switch can be closed to connect the measuring power supply 110 to the photovoltaic component 20 for power supply; when the test is completed, the switch can be opened first, and then the conductive member can be driven by the driving member to move away from the photovoltaic component 20, so that the measuring power supply 110 is disconnected from the photovoltaic component 20 and the power is cut off. In this way, the conductive member and the photovoltaic component 20 can be effectively avoided from being in contact with and separated from each other with electricity, thereby effectively reducing the probability of damage to the photovoltaic component 20 during the test, effectively improving the safety and reliability of the photovoltaic component testing device 10, and thus helping to improve the accuracy of the test of the photovoltaic component 20 and improve the reliability of the photovoltaic component 20.

[0085] In some embodiments, the conductive member includes a mounting portion (not shown) and at least one conductive portion (not shown). The mounting portion is electrically connected to the measurement power supply 110, the conductive portion is disposed on the mounting portion, and a driving member is connected to the mounting portion. The driving member is configured to drive the mounting portion toward or away from the photovoltaic assembly 20, thereby driving the conductive portion to contact or move away from the photovoltaic assembly 20. The driving member may be a telescopic mechanism, such as a cylinder, and the conductive portion may be configured in a needle shape to facilitate contact between the conductive portion and the photovoltaic assembly 20.

[0086] like Figure 4 As shown, in one embodiment, a timing module 160 is further included. The timing module 160 is electrically connected to the processor 140 and the driving component. The timing module 160 is used to time the contact time between the conductive component and the photovoltaic component 20 and the time when the power connection module 120 is in the second action; the processor 140 is used to control the power connection module 120 to switch between the first action and the second action according to the information of the timing module 160.

[0087] During the test, the driving member drives the conductive member to contact the photovoltaic assembly 20, and the timing module 160 begins to measure the contact time between the conductive member and the photovoltaic assembly 20. When the contact time between the conductive member and the photovoltaic assembly 20 reaches a second preset time, the processor 140 controls the power connection module 120 to be in the first action (i.e., the switch is closed), so that the measurement power supply 110 is connected to the photovoltaic assembly 20 for power supply. When the test is completed, the processor 140 controls the power connection module 120 to switch to the second action (i.e., the switch is open), and the timing module 160 begins to measure the time that the power connection module 120 is in the second action (i.e., the switch is open). When the time that the power connection module 120 is in the second action (i.e., the switch is open) reaches a third preset time, the processor 140 controls the driving member to operate, and the driving member drives the conductive member away from the photovoltaic assembly 20, so that the measurement power supply 110 is disconnected from the photovoltaic assembly 20, thereby disconnecting the power supply. In this way, the photovoltaic assembly testing device 10 can be automatically controlled, thereby improving the safety and reliability of the photovoltaic assembly testing device 10.

[0088] In some embodiments, the second preset time length may be 0.1 to 2 seconds, and the third preset time length may be 0.1 to 2 seconds.

[0089] like Figure 4 and Figure 5 As shown, in one embodiment, an alarm module 170 is further included and electrically connected to the processor 140. If the voltage value across the photovoltaic module 20 measured by the measurement module 130 is within a second preset voltage range, the processor 140 controls the alarm module 170 to promptly issue an alarm. This more intuitively notifies the operator of a defect in the photovoltaic module 20, reduces the probability of missed detection, and improves the efficiency of photovoltaic module 20 testing.

[0090] In one embodiment, the alarm module 170 includes an alarm. The alarm is widely available and has low cost, which can reduce the cost of the photovoltaic module testing device 10 .

[0091] In one embodiment, the measuring power supply 110 includes a power supply having a constant current mode and a constant voltage mode, and the measuring power supply 110 is electrically connected to the processor 140; when the measuring power supply 110 is in the constant current mode, the measuring power supply 110 outputs a preset current; when the measuring power supply 110 is in the constant voltage mode, the measuring power supply 110 outputs a preset breakdown voltage.

[0092] Therefore, by switching the measuring power supply 110 between the constant current mode and the constant voltage mode, the measuring power supply 110 can output a preset current or a preset breakdown voltage, thereby improving the working efficiency of the photovoltaic module testing device 10 and improving the testing efficiency of the photovoltaic module 20.

[0093] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0094] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A photovoltaic module testing method for testing a photovoltaic module, wherein the photovoltaic module comprises a plurality of battery strings and a plurality of bypass diodes, wherein each battery string is connected in reverse parallel to a bypass diode, and the plurality of bypass diodes are connected in series; characterized in that: The method comprises: The positive electrode of the measuring power supply is electrically connected to the positive electrode of the photovoltaic module, and the negative electrode of the measuring power supply is electrically connected to the negative electrode of the photovoltaic module; Loading a preset current through the measuring power supply and measuring a first voltage value across the photovoltaic component; A preset breakdown voltage is applied through the measurement power supply for a first preset time period, so that the bypass diode that is experiencing breakdown is completely broken down under the action of the preset breakdown voltage, and then a preset current is applied through the measurement power supply to measure a second voltage value across the photovoltaic module; If the first voltage value and the second voltage value are both within the first preset voltage range, it is determined that all the bypass diodes in the photovoltaic assembly are operating normally; If the second voltage value is lower than the first voltage value, the first voltage value is within the first preset voltage range, and the second voltage value is within the second preset voltage range, it is determined that a broken-down bypass diode exists in the photovoltaic component, and the corresponding bypass diode is completely broken down by the preset breakdown voltage.

2. The photovoltaic module testing method according to claim 1, characterized in that: The method further comprises: Loading the preset current through the measurement power supply to obtain a first image of the photovoltaic component; and measuring a third voltage value across the photovoltaic component; Applying the preset breakdown voltage through the measurement power supply for the first preset time duration, then applying the preset current through the measurement power supply to measure a fourth voltage value across the photovoltaic module; If the third voltage value and the fourth voltage value are both equal to the second voltage value, it is determined based on the first image that a broken-down bypass diode exists in the photovoltaic assembly.

3. The photovoltaic module testing method according to claim 1, characterized in that: The preset breakdown voltage is (32V to 36V)×the number of the bypass diodes.

4. The photovoltaic module testing method according to claim 1, characterized in that: The first preset voltage range is (resistance value of the photovoltaic module×the preset current×3 / 4) to (resistance value of the photovoltaic module×the preset current).

5. The photovoltaic module testing method according to claim 1, characterized in that: The second preset voltage range is 0 to (resistance value of the photovoltaic module×the preset current×3 / 4).

6. The photovoltaic module testing method according to claim 1, characterized in that: The first preset time length is 14ms to 18ms.

7. A photovoltaic module testing device for testing a photovoltaic module, wherein the photovoltaic module comprises a plurality of battery strings and a plurality of bypass diodes, each battery string being connected in reverse parallel to a bypass diode, and the plurality of bypass diodes being connected in series; characterized in that: The device comprises: A power connection module is used to electrically connect the positive electrode of the measuring power supply to the positive electrode of the photovoltaic module, and the negative electrode of the measuring power supply to the negative electrode of the photovoltaic module; a measuring module, the measuring module being configured to measure a first voltage value across the photovoltaic assembly when a preset current is applied to the measuring power supply; the measuring module being further configured to apply a preset breakdown voltage to the measuring power supply for a first preset duration, so that the bypass diode that is experiencing breakdown is completely broken down under the action of the preset breakdown voltage, and to measure a second voltage value across the photovoltaic assembly when the preset current is applied to the measuring power supply; A processor is electrically connected to the power connection module and the measurement module, and the processor is used to determine that all the bypass diodes in the photovoltaic module are operating normally when the first voltage value and the second voltage value are both within a first preset voltage range; the processor is also used to determine that there is a broken-down bypass diode in the photovoltaic module when the second voltage value is lower than the first voltage value, the first voltage value is within the first preset voltage range, and the second voltage value is within the second preset voltage range, and the corresponding bypass diode is completely broken down by the preset breakdown voltage.

8. The photovoltaic module testing device according to claim 7, characterized in that: It also includes an image acquisition mechanism, wherein the image acquisition mechanism is electrically connected to the processor; The measuring module is further configured to measure a third voltage value across the photovoltaic assembly when a preset current is applied to the measuring power supply; the measuring module is further configured to apply a preset breakdown voltage to the measuring power supply for a first preset time period, and to measure a fourth voltage value across the photovoltaic assembly when a preset current is applied to the measuring power supply; The image acquisition mechanism is used to acquire a first image of the photovoltaic assembly; The processor is further configured to determine, based on the first image, that a broken-down bypass diode exists in the photovoltaic assembly when both the third voltage value and the fourth voltage value are equal to the second voltage value.

9. The photovoltaic module testing device according to claim 7, characterized in that: The power connection module includes a switch, and the switch is used to be arranged between the positive electrode of the measurement power supply and the positive electrode of the photovoltaic component.

10. The photovoltaic module testing device according to claim 9, characterized in that: The switch comprises a contactor switch.

11. The photovoltaic module testing device according to claim 7, characterized in that: The measurement module includes a voltage monitoring unit, and the voltage monitoring unit is used to be connected to the photovoltaic assembly to monitor the voltage of the photovoltaic assembly.

12. The photovoltaic module testing device according to claim 11, characterized in that: The voltage monitoring unit includes a voltmeter.

13. The photovoltaic module testing device according to claim 7, characterized in that: It also includes a conductive component, which includes a conductive member and a driving member; the conductive member is electrically connected to the measurement power supply; and the driving member is used to drive the conductive member to contact or move away from the photovoltaic component.

14. The photovoltaic module testing device according to claim 13, characterized in that: It also includes a timing module, which is electrically connected to the processor and the driving component. The timing module is used to time the contact time between the conductive component and the photovoltaic component and the time when the power connection module is in the second action; the processor is used to control the power connection module to switch between the first action and the second action according to the information of the timing module.

15. The photovoltaic module testing device according to claim 7, characterized in that: It also includes an alarm module, which is electrically connected to the processor.

16. The photovoltaic module testing device according to claim 15, characterized in that: The alarm module includes an alarm.

17. The photovoltaic module testing device according to claim 7, characterized in that: The measuring power supply includes a power supply having a constant current mode and a constant voltage mode, and the measuring power supply is electrically connected to the processor; when the measuring power supply is in the constant current mode, the measuring power supply outputs the preset current; when the measuring power supply is in the constant voltage mode, the measuring power supply outputs the preset breakdown voltage.

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