Photovoltaic junction box device

Abstract

This application relates to a photovoltaic junction box device, comprising: a positive junction box, including a first end for connecting a positive cable and an opposite second end; a first electrical conduction module electrically connected to a photovoltaic cell is included between the first and second ends; an electroluminescence (EL) test connector is disposed at the second end, the EL test connector being electrically connected to the first electrical conduction module for electrical connection to the photovoltaic cell via the first electrical conduction module; and a negative junction box, including a third end for connecting a negative cable and an opposite fourth end; a second electrical conduction module electrically connected to the photovoltaic cell is included between the third and fourth ends; during the EL test, the third end is electrically connected to the EL test connector via the photovoltaic cell. The technical solution of this application can improve the quality of photovoltaic modules.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic junction box device. Background Technology

[0002] Photovoltaic power generation technology converts solar radiation into electrical energy through the photovoltaic effect, making it a green and clean energy source. Promoting photovoltaic power generation technology helps reduce carbon emissions and improve the ecological environment. The core structure of photovoltaic power generation is the photovoltaic cell, also known as a photovoltaic module.

[0003] As the core electrical connection device of photovoltaic modules, the photovoltaic junction box plays a dual role in current conduction and system protection: on the one hand, it efficiently discharges the electrical energy generated by the photovoltaic modules, requiring the resistance of conductive materials and contact resistance to be minimized; on the other hand, it prevents local high temperature damage to the photovoltaic modules by short-circuiting faulty cells through bypass diodes.

[0004] However, existing photovoltaic modules still suffer from performance instability and require various tests. Utility Model Content

[0005] In view of this, this application provides a photovoltaic junction box device to solve at least one problem existing in the prior art.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0007] This application provides a photovoltaic junction box device, including:

[0008] A positive terminal junction box includes a first end for connecting a positive terminal cable and an opposite second end; a first electrical conduction module for electrically connecting a photovoltaic cell is included between the first end and the second end; an electroluminescence (EL) test connector is provided at the second end, the EL test connector being electrically connected to the first electrical conduction module to be electrically connected to the photovoltaic cell via the first electrical conduction module;

[0009] The negative terminal box includes a third end for connecting the negative terminal cable and an opposite fourth end; a second electrical conduction module electrically connected to the photovoltaic cell is included between the third end and the fourth end; during the EL test, the third end is electrically connected to the EL test connector via the photovoltaic cell.

[0010] In one optional embodiment, the photovoltaic junction box device further includes an intermediate junction box located between the positive terminal junction box and the negative terminal junction box; the intermediate junction box includes a third electrical conduction module electrically connected to the photovoltaic cell; during the EL test, the third electrical conduction module is electrically connected to the EL test connector via the photovoltaic cell.

[0011] In one optional embodiment, the EL test connector is a negative connector.

[0012] In one optional embodiment, the first electrical conduction module is provided with a bypass protection device; the bypass protection device is a unidirectional electronic device, and its two ends are respectively electrically connected to the two ends of the photovoltaic cell to form a parallel electrical connection with the photovoltaic cell.

[0013] In one optional embodiment, the first electrical conduction module is further provided with an anti-reverse current conduction device; the anti-reverse current conduction device is a unidirectional electronic device; the anti-reverse current conduction device and the bypass protector are connected in series.

[0014] In one optional embodiment, both the bypass protection device and the anti-reverse current conduction device are diodes.

[0015] In one optional embodiment, the first electrical conduction module includes a first lead frame, a second lead frame, and a third lead frame, with the bypass protection device electrically connected between the second lead frame and the third lead frame; and the anti-reverse current conduction device electrically connected between the first lead frame and the second lead frame.

[0016] In one optional embodiment, the first electrical conduction module further includes a first jumper device and a second jumper device; the first jumper device is used to electrically connect the bypass protection device to one of the second lead frame and the third lead frame; the second jumper device is used to electrically connect the anti-reverse current conduction device to one of the first lead frame and the second lead frame.

[0017] In one optional embodiment, the first electrical conduction module further includes a first potting compound, which is used to encapsulate and solidify the second lead frame and the third lead frame with the bypass protection device as a whole, and also to encapsulate and solidify the first lead frame and the second lead frame with the anti-reverse current conduction device as a whole.

[0018] In one alternative embodiment, the EL test connector includes a connector and a port plug, the port plug being configured to block the connector to prevent moisture from entering the EL test connector.

[0019] The photovoltaic junction box device provided in this application includes: a positive junction box, comprising a first end connected to a positive cable and an opposite second end; a first electrical conduction module electrically connected to a photovoltaic cell is included between the first and second ends; an electroluminescence (EL) test connector is provided at the second end, the EL test connector being electrically connected to the first electrical conduction module to be electrically connected to the photovoltaic cell via the first electrical conduction module; and a negative junction box, comprising a third end connected to a negative cable and an opposite fourth end; a second electrical conduction module electrically connected to the photovoltaic cell is included between the third and fourth ends; during the EL test, the third end is electrically connected to the EL test connector via the photovoltaic cell. It can be seen that the photovoltaic junction box device of this application, by providing an EL test connector at one end of the positive junction box, can conveniently and quickly test the EL performance of photovoltaic modules, improving the quality of photovoltaic modules. Therefore, the photovoltaic junction box device of this application can improve the testing efficiency of EL testing, thereby improving the quality of photovoltaic modules.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of a photovoltaic junction box device provided in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the input and output of the photovoltaic junction box device provided in the embodiments of this application during EL testing;

[0024] Figure 3 A schematic diagram of the circuit principle of the photovoltaic junction box device provided in the embodiments of this application;

[0025] Figure 4 A schematic diagram of the circuit principle of the photovoltaic junction box device provided in the embodiments of this application during EL testing;

[0026] Figure 5 This is a schematic diagram of the positive terminal box in the photovoltaic junction box device provided in the embodiments of this application;

[0027] Figure 6 This is an exploded view (exploded view) of the positive terminal box in the photovoltaic junction box device provided in the embodiments of this application.

[0028] Explanation of reference numerals in the attached figures:

[0029] 10. Positive terminal junction box; 11. Positive cable; 12. First electrical conduction module; 121. First lead frame; 122. Second lead frame; 123. Third lead frame; 124. First jumper device; 125. Second jumper device; 126. First potting compound; 13. Box body; 14. Pin; 20. EL test connector; 21. Wiring port; 22. Port plug; 23. Sealing ring; 30. Negative terminal junction box; 31. Negative cable; 32. Second electrical conduction module; 40. Intermediate junction box; 41. Third electrical conduction module; 50. Photovoltaic cell; 51. First branch; 52. Second branch; 53. Third branch; 60. Bypass protection device; 70. Anti-reverse current conduction device. Detailed Implementation

[0030] To make the technical solution and beneficial effects of this application more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0031] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0032] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" may explicitly include at least one of those features. In the description of this application, "multiple" means at least two, such as two, three, etc.; "several" means at least one, such as one, two, three, etc., unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In this application, unless otherwise expressly defined, the terms "above," "on top of," "over," "above," "below," "below," "below," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "over," and "below" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0035] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solution of this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0036] The applicant of this application discovered during the research and development that existing photovoltaic junction boxes require additional connection of test connectors or other accessories to perform electroluminescence (EL) testing, resulting in low EL testing efficiency and high cost.

[0037] Therefore, based on further research and development by the applicant, the following technical solution was proposed.

[0038] This application provides a photovoltaic junction box device. (See reference...) Figure 1 and Figure 2 The photovoltaic junction box device includes:

[0039] The positive terminal junction box 10 includes a first end for connecting the positive terminal cable 11 and a second end opposite to it; between the first end and the second end is a first electrical conduction module 12 for electrically connecting the photovoltaic cell 50; the second end is provided with an electroluminescence (EL) test connector 20, which is electrically connected to the first electrical conduction module 12 to be electrically connected to the photovoltaic cell 50 via the first electrical conduction module 12.

[0040] The negative terminal box 30 includes a third end for connecting the negative terminal cable 31 and a fourth end opposite to it; between the third end and the fourth end is a second electrical conduction module 32 that is electrically connected to the photovoltaic cell 50; during the EL test, the third end is electrically connected to the EL test connector 20 via the photovoltaic cell 50.

[0041] That is, when the EL test is performed, the electrical energy loaded for the EL test is input from the third terminal, output from the EL test connector 20 via the photovoltaic cell 50.

[0042] Understandably, in a photovoltaic power generation system, the photovoltaic junction box is configured to output the electrical energy generated by the photovoltaic cell 50 to the outside. Therefore, both the positive junction box 10 and the negative junction box 30 are connected to cables, namely the positive cable 11 and the negative cable 31. Understandably, the positive cable 11 is electrically connected to the photovoltaic cell 50 through the first electrical conduction module 12. The negative cable 31 is electrically connected to the photovoltaic cell 50 through the second electrical conduction module 32.

[0043] Understandably, EL testing requires an electrical connection to the photovoltaic cell 50, which also needs to be done via the first electrical conduction module 12. Therefore, the EL test connector 20 is electrically connected to the first electrical conduction module 12.

[0044] The photovoltaic junction box device of this application embodiment, by setting an EL test connector 20 at one end of the positive terminal junction box 10, can conveniently and quickly test the EL performance of the photovoltaic module and improve the quality of the photovoltaic module.

[0045] In some embodiments of this application, the photovoltaic junction box device further includes an intermediate junction box 40, which is located between the positive junction box 10 and the negative junction box 30; the intermediate junction box 40 includes a third electrical conduction module 41 electrically connected to the photovoltaic cell 50; during the EL test, the third electrical conduction module 41 is electrically connected to the EL test connector 20 via the photovoltaic cell 50.

[0046] That is, when the EL test is performed, the electrical energy loaded by the EL test flows into the corresponding photovoltaic cell 50 via the third electrical conduction module 41.

[0047] Accordingly, the photovoltaic cell 50 can be a branch of the photovoltaic cell 50 between the positive terminal junction box 10 and the negative terminal junction box 30. This branch can be a portion of the cells in the entire battery module corresponding to the photovoltaic junction box device.

[0048] In some embodiments of this application, the EL test connector 20 is a negative connector.

[0049] Understandably, the negative connector can be an existing connector from the photovoltaic junction box prior to the improvements in this application, requiring no additional design and thus reducing costs. Understandably, there are various types of negative connectors, and the negative connector structure used in the EL test connector 20 may not be the same as the negative connector of the negative junction box.

[0050] In some embodiments of this application, reference is made to Figures 3-5 The first electrical conduction module 12 is provided with a bypass protection device 60; the bypass protection device 60 is a unidirectional electronic device; the two ends of the bypass protection device 60 are respectively electrically connected to the two ends of the photovoltaic cell 50 to form a parallel electrical connection with the photovoltaic cell.

[0051] Understandably, a unidirectional electronic device can have both forward and reverse directions; it conducts in the forward direction and is cut off in the reverse direction. Although a unidirectional electronic device can conduct in the forward direction, its forward resistance is still greater than that of a typical unloaded circuit, such as a regular wire or photovoltaic cell 50. Therefore, when photovoltaic cell 50 is operating normally, its resistance is less than that of the bypass protection device 60. The bypass protection device 60 is short-circuited by photovoltaic cell 50, and its forward direction is not conducting. That is, the unidirectional electronic device is connected in reverse parallel across photovoltaic cell 50. When photovoltaic cell 50 is operating normally, the circuit between the unidirectional electronic device and photovoltaic cell 50 is in a reverse cut-off state. This circuit is open, with virtually no current, and the current generated by photovoltaic cell 50 flows out normally. When photovoltaic cell 50 malfunctions, such as due to a hot spot effect, its resistance increases. Current can then flow through the relatively low-resistance bypass protection device 60, causing a drop in current to the malfunctioning cell. This results in other cells consuming energy on the malfunctioning cell, leading to localized overheating. At this point, the reverse-parallel unidirectional electronic device provides another circuit to discharge the energy from the malfunctioning cell, effectively short-circuiting it through the bypass protection device 60. This prevents the faulty cell from being damaged by overheating. Furthermore, due to the reverse-blocking characteristic of the unidirectional electronic device, the reverse resistance is close to infinite, maintaining a cut-off state regardless of whether the photovoltaic cell is operating normally or experiencing an overload, thus preventing reverse current flow.

[0052] Specifically, each junction box is equipped with a bypass protection device 60, for example, both the positive junction box 10 and the negative junction box 30 are equipped with one. This reduces the damage to each branch of the photovoltaic cell 50 caused by the light spot effect, thereby controlling the degree of damage.

[0053] In some embodiments of this application, reference is made to Figure 3The first electrical conduction module 12 is also provided with an anti-reverse current conduction device 70; the anti-reverse current conduction device 70 is a unidirectional electronic device; the anti-reverse current conduction device and the bypass protector are connected in series.

[0054] Specifically, each photovoltaic junction box device is equipped with an anti-reverse current conduction device 70. Here, the photovoltaic junction box refers to a module, including a positive terminal junction box 10 and a negative terminal junction box 30; some also include an intermediate junction box 40. That is, when two or more branches are grouped together, the anti-reverse current conduction device 70 is installed between the groups.

[0055] Understandably, when the photovoltaic cell 50 is operating normally, the anti-reverse current conduction device 70 is forward-biased. This reduces the reverse current flow, i.e., circulating current, that would occur due to voltage differences between the branches of the photovoltaic cell 50.

[0056] Specifically, refer to Figure 5 In this embodiment, the anti-backflow conducting device 70 can be encapsulated within the positive terminal junction box. This achieves an integrated structure of the anti-backflow conducting device 70 and the junction box body, simplifying the overall structure, reducing the number of components, and decreasing the product's size. Furthermore, it improves the waterproof and dustproof performance of the entire junction box, for example, meeting IP68 waterproof and dustproof requirements.

[0057] In some embodiments of this application, both the bypass protection device 60 and the anti-reverse current conduction device 70 are diodes.

[0058] Understandably, diodes have the characteristics of forward conduction and reverse cutoff, and are low in cost. Specifically, the forward conduction voltage of a diode is between 0.2V and 0.7V, making it suitable for use in photovoltaic cells.

[0059] Specifically, see Figure 2 and Figure 3 The photovoltaic junction box assembly includes a positive terminal junction box 10, an intermediate terminal junction box 40, and a negative terminal junction box 30. Therefore, the corresponding photovoltaic cell 50 includes three branches, each branch connected in parallel with a bypass protection device 60. A reverse current protection device 70 is connected in series between two adjacent photovoltaic junction box assemblies. Specifically, the three branches can be referred to as the first branch 51, the second branch 52, and the third branch 53, respectively.

[0060] In some embodiments of this application, the first electrical conduction module 12 includes a first lead frame 121, a second lead frame 122, and a third lead frame 123, with the bypass protection device 60 electrically connected between the second lead frame 122 and the third lead frame 123; and the anti-reverse current conduction device 70 electrically connected between the first lead frame 121 and the second lead frame 122.

[0061] Specifically, the lead frame may be made of conductive metal or partially of conductive metal, and is used to connect the busbar to the photovoltaic cell 50.

[0062] Specifically, two parallel branches are provided between the second lead frame 122 and the third lead frame 123. One branch flows through the photovoltaic cell 50, and the other branch flows through the bypass protection device 60.

[0063] Specifically, there is only one branch between the first lead frame 121 and the second lead frame 122, namely the anti-reverse current conduction device 70, which is connected in series with the bypass protection device 60, or connected in series with the photovoltaic cell 50.

[0064] In some embodiments of this application, the first electrical conduction module 12 further includes a first jumper device 124 and a second jumper device 125; the first jumper device 124 is used to electrically connect the bypass protection device 60 to one of the second lead frame 122 and the third lead frame 123; the second jumper device 125 is used to electrically connect the anti-reverse current conduction device 70 to one of the first lead frame 121 and the second lead frame 122.

[0065] Specifically, the bypass protection device 60 is fixed in one of the lead frames, for example, fixed on the third lead frame 123, that is, the bypass protection device 60 is electrically connected to the third lead frame 123. Then, the bypass protection device 60 is electrically connected to the second lead frame 122 through a jumper device. The jumper device is a collective term for the first jumper device 124 and the second jumper device 125, and the lead frame is a collective term for the first lead frame 121, the second lead frame 122, and the third lead frame 123.

[0066] Similarly, the anti-backflow conduction device 70 is also fixed to one of the lead frames and then electrically connected to the other lead frame through a jumper device.

[0067] In some embodiments of this application, reference is made to Figure 1 The first electrical conduction module 12 further includes a first potting compound 126, which is used to encapsulate and solidify the second lead frame 122 and the third lead frame 123 with the bypass protection device 60 into one unit, and is also used to encapsulate and solidify the first lead frame 121 and the second lead frame 122 with the anti-backflow conduction device 70 into one unit.

[0068] The potting compound can mechanically fix the relative position of the bypass protection device 60 and the lead frame, and also isolate it from various external corrosion sources. This makes the bypass protection device 60, which is used outdoors for extended periods, more stable and reliable in its operation.

[0069] In some embodiments of this application, reference is made to Figure 6 The EL test connector 20 includes a connection port 21 and a port plug 22, the port plug 22 being configured to block the connection port 21 to prevent moisture from entering the EL test connector 20.

[0070] Understandably, during testing, the test leads can be electrically connected to the EL test connector 20 through the connector 21. During normal operation, the port plug 22 blocks the connector 21, preventing moisture from entering the EL test connector 20 and reducing the risk of corrosion.

[0071] In some embodiments of this application, the EL test connector 20 further includes a sealing ring 23 located between the port plug 22 and the wiring port 21.

[0072] The sealing performance of the port plug 22 is increased by the sealing ring 23, further reducing the risk of corrosion of the EL test connector 20.

[0073] Specifically, the positive terminal box 10 further includes a housing 13 and conductive pins 14. The housing 13 is configured to house the first electrical conduction module 12, and the conductive pins 14 are configured to be electrically connected to the relevant connector for EL testing.

[0074] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the technical solutions contained in this application. Various modifications and changes can be made to the above embodiments without departing from the scope of this application. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this application that may not be explicitly described. Therefore, the above embodiments merely illustrate several implementations of this application and do not limit the scope of protection of this patent application.

Claims

1. A photovoltaic junction box device, characterized in that, include: A positive terminal junction box includes a first end for connecting a positive terminal cable and an opposite second end; a first electrical conduction module for electrically connecting a photovoltaic cell is included between the first end and the second end; an electroluminescence (EL) test connector is provided at the second end, the EL test connector being electrically connected to the first electrical conduction module to be electrically connected to the photovoltaic cell via the first electrical conduction module; The negative terminal box includes a third end for connecting the negative terminal cable and an opposite fourth end; a second electrical conduction module electrically connected to the photovoltaic cell is included between the third end and the fourth end; during the EL test, the third end is electrically connected to the EL test connector via the photovoltaic cell.

2. The photovoltaic junction box device according to claim 1, characterized in that, The photovoltaic junction box device further includes an intermediate junction box located between the positive terminal junction box and the negative terminal junction box; the intermediate junction box includes a third electrical conduction module electrically connected to the photovoltaic cell; during the EL test, the third electrical conduction module is electrically connected to the EL test connector via the photovoltaic cell.

3. The photovoltaic junction box device according to claim 1, characterized in that, The EL test connector is a negative electrode connector.

4. The photovoltaic junction box device according to claim 1, characterized in that, The first electrical conduction module is equipped with a bypass protection device; the bypass protection device is a unidirectional electronic device, and its two ends are respectively electrically connected to the two ends of the photovoltaic cell to form a parallel electrical connection with the photovoltaic cell.

5. The photovoltaic junction box device according to claim 4, characterized in that, The first electrical conduction module is also provided with a reverse current protection device; the reverse current protection device is a unidirectional electronic device; the reverse current protection device and the bypass protector are connected in series.

6. The photovoltaic junction box device according to claim 5, characterized in that, Both the bypass protection device and the anti-reverse current conduction device are diodes.

7. The photovoltaic junction box device according to claim 5, characterized in that, The first electrical conduction module includes a first lead frame, a second lead frame, and a third lead frame. The bypass protection device is electrically connected between the second lead frame and the third lead frame. The anti-reverse current conduction device is electrically connected between the first lead frame and the second lead frame.

8. The photovoltaic junction box device according to claim 7, characterized in that, The first electrical conduction module further includes a first jumper device and a second jumper device; the first jumper device is used to electrically connect the bypass protection device to one of the second lead frame and the third lead frame; the second jumper device is used to electrically connect the anti-reverse current conduction device to one of the first lead frame and the second lead frame.

9. The photovoltaic junction box device according to claim 7, characterized in that, The first electrical conduction module further includes a first potting compound, which is used to encapsulate and solidify the second lead frame and the third lead frame with the bypass protection device into one unit, and also to encapsulate and solidify the first lead frame and the second lead frame with the anti-reverse current conduction device into one unit.

10. The photovoltaic junction box device according to claim 1, characterized in that, The EL test connector includes a connector and a port plug, the port plug being configured to block the connector to prevent moisture from entering the EL test connector.

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