Photovoltaic junction box and photovoltaic battery assembly

Abstract

The utility model provides a photovoltaic junction box and a photovoltaic cell assembly, relates to the field of photovoltaic technology, and aims to solve the technical problem that the photovoltaic cell assembly is easy to crack during lamination due to the structure of the photovoltaic junction box. The photovoltaic junction box comprises a box body and two conductive parts which are arranged in the box body and are electrically connected with each other, wherein each conductive part is provided with a connecting part; the connecting part is provided with a first section and a second section which are far away from the conductive part, the first section and the second section are arranged at an included angle, the first section extends to the outer side of the bottom wall of the box body along the direction far away from the conductive part, and the surface of the second section far away from the bottom wall of the box body is used for fitting a bus bar of the photovoltaic cell module. By using the photovoltaic junction box of the utility model, the bus bar of the photovoltaic cell assembly does not need to be erected or folded, and the quality problem caused by subfissure of the cell can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a photovoltaic junction box and a photovoltaic cell assembly. Background Art

[0002] The statements in this section merely provide background technology related to the present invention and do not necessarily constitute prior art.

[0003] In the field of photovoltaic cell technology, the pursuit of lower production costs and higher photoelectric conversion efficiency is the core goal of the photovoltaic cell industry. High-density packaging of photovoltaic cell modules can reduce the gap between cells / strings to increase the proportion of cell area in photovoltaic cell modules. For example, the busbar is stacked on the cell through an insulating layer.

[0004] In related technologies, such as Figure 1-Figure 3 As shown, due to the structure of the photovoltaic junction box itself, the two busbars arranged at intervals and electrically connected through the photovoltaic junction box need to be bent at the ends and then erected so as to be inserted into the photovoltaic junction box for welding. However, during the lamination process of the photovoltaic cell assembly, the ends of the erected busbars will be folded on the surface of the photovoltaic cell assembly, resulting in a large thickness at the folded part, and the problem of hidden cracks or even fragments of the cell sheets may occur at this position during the lamination process. Utility Model Content

[0005] The utility model aims to provide a photovoltaic junction box and a photovoltaic cell assembly to solve the technical problem that the photovoltaic cell assembly is prone to hidden cracks during lamination due to the structure of the photovoltaic junction box.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] In a first aspect, the utility model provides a photovoltaic junction box, comprising a box body and two conductive parts electrically connected to each other located in the box body, each of the conductive parts being provided with a connecting part;

[0008] The connecting portion comprises a first section and a second section which are distributed away from the conductive portion, the first section and the second section are arranged at an angle, the first section extends to the outside of the bottom wall of the box body in a direction away from the conductive portion, and the surface of the second section which is away from the bottom wall of the box body is used to fit the bus bar of the photovoltaic cell assembly.

[0009] According to at least one embodiment of the present invention, the second section of each connecting portion extends in a direction close to another connecting portion; or,

[0010] The second section of each connecting portion extends in a direction away from the other connecting portion.

[0011] According to at least one embodiment of the present invention, the second section has a welding opening, and the welding opening is a through hole penetrating the second section.

[0012] According to at least one embodiment of the present utility model, the conductive portion has an avoidance opening, and the orthographic projection of each of the welding openings on the surface of the conductive portion falls within the range of the corresponding avoidance opening.

[0013] According to at least one embodiment of the present invention, the shape of the welding port includes one of a circle, an ellipse, a triangle or a regular polygon.

[0014] According to at least one embodiment of the present utility model, each of the conductive parts and the corresponding connecting part are an integral structure.

[0015] In a second aspect, the utility model provides a photovoltaic cell assembly, comprising at least two bus bars arranged at intervals, each of the bus bars being stacked on a cell sheet of the photovoltaic cell assembly, and a surface of each bus bar facing away from the cell sheet being a flat surface;

[0016] The two bus bars arranged at intervals are electrically connected through the photovoltaic junction box, and the photovoltaic junction box is the photovoltaic junction box described in the first aspect.

[0017] According to at least one embodiment of the present utility model, the ends of the two busbars disposed at intervals and close to each other are both provided with positioning holes, and each positioning hole is opposite to the corresponding welding opening of the second section.

[0018] According to at least one embodiment of the present invention, each positioning hole has the same shape as the corresponding welding opening of the second section; and / or,

[0019] The orthographic projection of each positioning hole on the surface of the second section facing away from the bottom wall of the box body falls within the range of the corresponding welding port.

[0020] According to at least one embodiment of the present utility model, the photovoltaic cell assembly further includes a welding structure, at least a portion of the welding structure is located in the welding port, and at least another portion of the welding structure is located in the corresponding positioning hole.

[0021] One or more technical solutions provided in the exemplary embodiments of the present utility model can achieve at least one of the following beneficial effects.

[0022] The photovoltaic junction box of the exemplary embodiment of the utility model includes a box body and two conductive parts that are electrically connected to each other and are located in the box body. The connecting part has a connecting part extending to the outside of the box body, and the part exposed to the outside of the box body through the connecting part is fitted with the busbar of the photovoltaic cell assembly, so that the busbars arranged at intervals form an electrical connection. Specifically, the connecting part has a first section extending from the conductive part to the outside of the box body, and the connecting part is bent outside the box body to form a second section. Since the second section is arranged at an angle with the first section, the surface of the second section facing away from the bottom wall of the box body has a sufficient area, and can be fitted on the corresponding busbar of the photovoltaic cell assembly to form a reliable electrical connection. Therefore, compared with the prior art, when using this photovoltaic junction box, the busbar of the photovoltaic cell assembly does not need to be erected or folded, so as to avoid thickening, thereby avoiding the problem of hidden cracks in the battery cell due to thickening at the bend of the busbar during the lamination process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings illustrate exemplary embodiments of the present invention and are used to explain the principles of the present invention together with the description thereof, wherein these drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification;

[0024] Figure 1 It is a schematic diagram of the structure of a photovoltaic cell string array in the prior art;

[0025] Figure 2 It is a schematic diagram of the structure of the busbar before lamination of the photovoltaic cell assembly in the prior art;

[0026] Figure 3 It is a schematic diagram of the structure of the busbar after lamination of photovoltaic cell components in the prior art;

[0027] Figure 4 It is a schematic diagram of the top view structure of a photovoltaic junction box according to an embodiment of the utility model;

[0028] Figure 5 is a schematic structural diagram of a conductive module according to an embodiment of the utility model;

[0029] Figure 6 It is a schematic diagram of a longitudinal sectional isometric structure of a photovoltaic junction box according to an embodiment of the utility model;

[0030] Figure 7 It is a schematic diagram of a longitudinal cross-sectional structure of a photovoltaic junction box according to an embodiment of the utility model;

[0031] Figure 8 It is a schematic diagram of the structure of a photovoltaic cell assembly according to an embodiment of the utility model;

[0032] Fig. 9 yes Figure 8 A partial enlarged view of the middle part;

[0033] Fig.10 It is a schematic diagram of the busbar structure of a photovoltaic cell assembly according to an embodiment of the utility model.

[0034] Figure numerals: 11, conductive part; 111, avoidance opening; 12, connecting part; 121, first section; 122, second section; 123, welding port; 20, box body; 30, diode module; 40, cable line; 50, bus bar; 51, positioning hole; 60, insulating strip; 70, welding structure. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] In order to reduce the cost of photovoltaic power generation, the most direct way is to increase the power generation per unit area of ​​photovoltaic cell modules. For example, high-density packaging. The main purpose of high-density packaging is to reduce the gap between solar cells / strings. Since the busbar is generally a tinned copper flat strip with a large cross-sectional area, the cross-sectional area is generally more than 1mm 2 The thickness is generally greater than 0.3mm and the width is greater than 4mm. The busbars are generally located at both ends of the battery string. In order to reduce the ineffective area occupied by the busbars and improve the efficiency of the photovoltaic cell assembly, the busbars are directly stacked on the battery cells, and an insulating strip is provided between the busbars and the battery cells for isolation, so as to reduce the gap between the battery strings.

[0037] In the related art, the busbars on the cells of the photovoltaic cell assembly need to be led out from the cells in order to be electrically connected to the photovoltaic junction box. Due to the structure of the existing photovoltaic junction box, the part of the busbar to be connected needs to be bent and erected, and then electrically connected to the conductive part in the conductive module inside the photovoltaic junction box. The bent and erected part of the busbar is folded on the surface of the photovoltaic cell assembly during the lamination process, causing the thickness at that position to increase. In this process, it is possible to cause hidden cracks or even breakage of the cell at that location. In other processing methods, since the conductive part in the conductive module of the photovoltaic junction box does not extend outside the box body, the part of the busbar to be connected needs to be provided with a protrusion in order to form an electrical connection with the photovoltaic junction box. Such a protrusion may also cause hidden cracks in the cell at that location.

[0038] In view of the above problems, the conductive part of the photovoltaic junction box provided by the exemplary embodiment of the utility model is provided with a connecting part that can extend out of the bottom of the box body, wherein the connecting part is bent to form a surface that fits with the bus bar, so that the bus bar can be flatly attached to the photovoltaic cell assembly to achieve electrical connection with the photovoltaic junction box, and the reliability is high. Based on this, since there is no additional thickening, the photovoltaic cell assembly with the bus bar is not prone to hidden cracks or fragments during the lamination process.

[0039] Figure 4 It is a schematic diagram of the top view structure of a photovoltaic junction box according to an embodiment of the utility model; Figure 5 Schematic diagram of the structure of the conductive module according to the embodiment of the present utility model. Figure 4 and Figure 5 As shown, the photovoltaic junction box provided by the exemplary embodiment of the utility model includes a box body 20 and two conductive parts 11 electrically connected to each other located in the box body 20, each conductive part 11 is provided with a connecting part 12; the connecting part 12 has a first section 121 and a second section 122 distributed away from the conductive part 11, the first section 121 and the second section 122 are arranged at an angle, the first section 121 extends to the outer side of the bottom wall of the box body 20 along the direction away from the conductive part 11, and the surface of the second section 122 facing away from the bottom wall of the box body 20 is used to fit the bus bar 50 of the photovoltaic cell assembly.

[0040] For practical applications, please refer to Figure 6 As shown, Figure 6 It is a schematic diagram of the longitudinal section axonometric structure of the photovoltaic junction box according to the embodiment of the utility model. The second section 122 of the two connecting parts 12 has a fitting surface, which is respectively fitted with the ends of the two bus bars 50 arranged at intervals and close to each other to form an electrical connection. The current of the battery assembly is connected to the photovoltaic junction box via the second section 122, the first section 121 and the corresponding conductive part 11, that is, the two bus bars 50 arranged at intervals form an electrical connection through the photovoltaic junction box. Based on this, since the second section 122 is located outside the box body 20 and has a fitting surface, it can form a reliable electrical connection with the bus bar 50, and the bus bar 50 can be flat on the surface of the photovoltaic cell assembly, and the end to be connected does not need to be erected and folded or set with a protrusion, so that there is no additional thickening at this position, and then the photovoltaic cell assembly can try to avoid the occurrence of hidden cracks or even fragments of the battery cells at this position during the lamination process, thereby ensuring the quality stability of the photovoltaic cell assembly.

[0041] For example, Figure 5 As shown, the two conductive parts 11 located in the box body 20 are electrically connected to each other through the diode module 30. The diode module 30 can be a bypass diode, which can ensure that the current flows only in a predetermined direction, prevent backflow, prevent overvoltage and dissipate heat, thereby ensuring the stable operation and safety performance of the photovoltaic system.

[0042] like Figure 4 As shown, one of the two conductive parts 11 is also connected to a cable 40 through a riveted part, so that the current of the photovoltaic cell assembly is electrically connected to other devices of the photovoltaic system through the photovoltaic junction box and the cable 40. For example, three photovoltaic junction boxes are arranged between two battery strings of a photovoltaic cell assembly, such as Fig.10 As shown, a photovoltaic junction box is arranged at the position where the busbars 50 are arranged every two intervals. Fig.10 It is a schematic diagram of the busbar structure of the photovoltaic cell assembly according to the embodiment of the utility model. Among them, the photovoltaic junction box located in the middle does not need to lead out the cable 40, which is used to connect the two busbars 50 set at intervals at this position, and the photovoltaic junction boxes located on both sides need the cable 40 to be led out as the positive and negative poles respectively, that is, the lead-out directions of the cable 40 of the photovoltaic junction boxes on both sides are respectively the outside of the photovoltaic cell assembly, and the photovoltaic junction boxes on both sides are connected to the cable 40 on the conductive parts 11 far away from each other, and accordingly, the opening positions of the box bodies 20 of the photovoltaic junction boxes on both sides for the cable 40 are also different.

[0043] For example, Figure 5 As shown, the two conductive parts 11 and the corresponding connecting part 12 are both plate-shaped structures. One end of the first section 121 of the connecting part 12 is connected to the conductive part 11, and the other end is connected to the second section 122. The first section 121 and the second section 122 are arranged at an angle, that is, the connecting part 12 is roughly L-shaped. The first section 121 can be arranged vertically, and the angle between the first section 121 and the second section 122 is 90°. The first section 121 can also be arranged at an angle, for example, along the direction away from the conductive part 11, the angle is inclined toward or away from the other conductive part 11. Therefore, the angle between the first section 121 and the second section 122 can be an obtuse angle or an acute angle, so that the second section 122 is parallel to the surface of the busbar 50 to be connected.

[0044] In some embodiments, Figure 6 As shown, since the busbar 50 is a tinned copper flat strip and the second section 122 is a plate-like structure with a fitting surface, the contact area between the two is large. Therefore, the busbar 50 and the second section 122 can be welded to each other through the solder on the busbar 50 to form a stable and reliable electrical connection.

[0045] Taking into account the size and structural layout of the photovoltaic junction box, in the photovoltaic junction box provided by the exemplary embodiment of the present utility model, the extension directions of the second sections 122 of the two connecting parts 12 can be the same or different.

[0046] For example, when the second segments 122 of the two connecting parts 12 extend in different directions, the second segment 122 of each connecting part 12 extends in a direction close to the other connecting part 12. With the position between the two connecting parts 12 as the inner side, the second segments 122 of the two connecting parts 12 extend inwardly, that is, the two second segments 122 extend in a direction close to each other. This structure can make the structure of the photovoltaic junction box more compact, which is conducive to the electrical connection of the busbars 50 with smaller intervals.

[0047] In another optional embodiment, when the second segments 122 of the two connecting portions 12 extend in different directions, the second segment 122 of each connecting portion 12 extends in a direction away from the other connecting portion 12. The second segments 122 of the two connecting portions 12 both extend outward, that is, the two second segments 122 extend away from each other, so as to form an electrical connection between two busbars 50 with a large interval.

[0048] It should be noted that the first section 121 of the connecting portion 12 may be located on the conductive portion 11 close to the diode module 30 , or at a position spaced a certain distance from the diode module 30 , which is selected according to actual needs.

[0049] In order to further enhance the reliability of the electrical connection between the photovoltaic junction box and the corresponding bus bar 50. In the photovoltaic junction box provided by the exemplary embodiment of the utility model, the second section 122 of the connecting portion 12 has a welding opening 123, and the welding opening 123 is a through hole that penetrates the second section 122. Exemplarily, the axial direction of the welding opening 123 is the distribution direction from the box body 20 to the bus bar 50.

[0050] Figure 7 Schematic diagram of the longitudinal cross-sectional structure of a photovoltaic junction box according to an embodiment of the present utility model. Figure 7 As shown, by providing a through welding port 123 in the second section 122, a solder such as solder can be used in the welding port 123 to form a welding connection in the welding port 123 and at a position of the bus bar 50 opposite to the welding port 123, thereby enhancing the stability and reliability of the electrical connection between the second section 122 and the bus bar 50.

[0051] Since soldering is performed in the welding port 123 , manual labor or a welding robot arm is required to reach the position. The conductive part 11 located above the second section 122 will block the welding components, so an avoidance opening 111 needs to be opened at the corresponding position of the conductive part 11 .

[0052] In some embodiments, Figure 5As shown, each conductive part 11 has an avoidance opening 111, and the orthographic projection of each welding opening 123 on the surface of the conductive part 11 falls within the range of the corresponding avoidance opening 111. That is, the size of the avoidance opening 111 is greater than or equal to the size of the welding opening 123, so as to facilitate the welding component to penetrate into the position of the welding opening 123 for welding.

[0053] Exemplarily, the shape of the welding opening 123 includes one of a circle, an ellipse, a triangle or a regular polygon.

[0054] In some embodiments, Figure 5 As shown, each conductive part 11 and the corresponding connecting part 12 are an integral structure. The conductive part 11 and the connecting part 12 are seamlessly connected together to form a whole. This design can ensure that there is a good electrical connection and physical connection between the conductive part 11 and the connecting part 12, thereby improving the reliability and stability of the photovoltaic system. The integrated structure can also simplify the manufacturing process and the installation process, reduce the connection points between the various components, and improve the manufacturing efficiency. That is, the material of the connecting part 12 and the material of the conductive part 11 are both conductive materials, such as copper.

[0055] An exemplary embodiment of the utility model also provides a photovoltaic cell assembly, comprising at least two bus bars 50 arranged at intervals, each bus bar 50 being stacked on a cell sheet of the photovoltaic cell assembly, and a surface of each bus bar 50 facing away from the cell sheet being a flat surface; the two bus bars 50 arranged at intervals are connected by a photovoltaic junction box, and the photovoltaic junction box is a photovoltaic junction box of any of the above-mentioned embodiments.

[0056] Figure 8 It is a schematic diagram of the structure of a photovoltaic cell assembly according to an embodiment of the utility model; Fig. 9 yes Figure 8 A partial enlarged view of the middle part; Fig.10 Schematic diagram of the busbar structure of a photovoltaic cell assembly according to an embodiment of the present utility model. Figure 8-Figure 10As shown, the busbar 50 of the exemplary embodiment of the utility model is stacked on the cell sheet of the photovoltaic cell assembly. Specifically, the lower part of the busbar 50 is insulated from the cell sheet of the photovoltaic cell assembly by an insulating strip 60, so as to reduce the gap between the two cell strings. The busbar 50 does not need to be bent, erected, etc., nor does it need to set a protrusion on the position to be connected of the busbar 50. It only needs to be flat on the cell sheet, that is, the surface of the busbar 50 away from the cell sheet of the photovoltaic cell assembly is a flat surface, which can form a stable electrical connection with the fitting surface of the second section 122 of the photovoltaic junction box. Based on this, through the structural design of the photovoltaic junction box, the bending and vertical processing process of the busbar 50 can be reduced, the difficulty of manufacturing the photovoltaic cell assembly is reduced, and it is easier to mass-produce. At the same time, since the flat busbar 50 does not increase the thickness, the risk of hidden cracks or fragmentation of the photovoltaic cell assembly at this position during the lamination process is reduced.

[0057] In some embodiments, Fig. 9 As shown, two busbars 50 disposed at intervals are each provided with positioning holes 51 at their ends close to each other, and each positioning hole 51 is opposite to the welding opening 123 of the corresponding second section 122 .

[0058] When the two second sections 122 in the photovoltaic junction box are respectively connected to the ends of the two spaced-apart busbars 50 close to each other, the placement position of the photovoltaic junction box can be more accurate through the relative positions of the welding opening 123 and the corresponding positioning hole 51. On the other hand, the positioning hole 51 set at the end of the busbar 50 to be connected can cooperate with the welding opening 123, and at least part of the welding structure 70 is located in the welding opening 123, and at least another part is located in the corresponding positioning hole 51. That is, the solder is filled into the positioning hole 51 and the welding opening 123, as shown in FIG. Figure 7 As shown, the second segment 122 and the bus bar have a more stable welding connection and reliable electrical connectivity.

[0059] In some embodiments, each positioning hole 51 is consistent in shape with the corresponding welding opening 123 of the second section 122. That is, each positioning hole 51 can also be one of a circle, an ellipse, a triangle or a regular polygon. The positioning hole 51 is consistent in shape with the corresponding welding opening 123, so that the positioning of the two is more accurate.

[0060] For example, the orthographic projection of each positioning hole 51 on the surface of the bottom wall of the second section 122 away from the box body 20 falls within the range of the corresponding welding port 123. That is, the size of the welding port 123 is equal to or greater than the size of the positioning hole 51. For example, the shape of the welding port 123 and the shape of the positioning hole 51 are both circular, and the radius of the welding port 123 is greater than the radius of the positioning hole 51. When performing preliminary positioning, the radius of the welding port 123 is larger, which is conducive to observing the position of the positioning hole 51. When performing precise positioning, when the centers of the two circles coincide, it can be determined that the two have formed a positioning, and then they can be fixed by welding to form an effective electrical connection. Based on this, the installation position of the photovoltaic junction box of the photovoltaic cell assembly of the exemplary embodiment of the utility model is accurate, which reduces the difficulty of installing the photovoltaic junction box.

[0061] It should be noted that the photovoltaic cell assembly of the exemplary embodiment of the utility model, in addition to the photovoltaic cell string and busbars formed by the cell sheets, also includes a packaging film located on both sides of the photovoltaic cell string, as well as a front glass and a back panel. Therefore, holes are opened at corresponding positions on the back panel to expose the ends of the two busbars 50 to be electrically connected to the photovoltaic junction box.

[0062] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A photovoltaic junction box, characterized in that: It comprises a box body and two conductive parts which are located in the box body and are electrically connected to each other, and each of the conductive parts is provided with a connecting part; The connecting portion comprises a first section and a second section which are distributed away from the conductive portion, the first section and the second section are arranged at an angle, the first section extends to the outside of the bottom wall of the box body in a direction away from the conductive portion, and the surface of the second section which is away from the bottom wall of the box body is used to fit the bus bar of the photovoltaic cell assembly.

2. The photovoltaic junction box according to claim 1, characterized in that: The second section of each connecting portion extends in a direction close to another connecting portion; or, The second section of each connecting portion extends in a direction away from the other connecting portion.

3. The photovoltaic junction box according to claim 1, characterized in that: The second section has a welding opening, and the welding opening is a through hole penetrating the second section.

4. The photovoltaic junction box according to claim 3, characterized in that: The conductive portion has an avoidance opening, and the orthographic projection of each welding opening on the surface of the conductive portion falls within the range of the corresponding avoidance opening.

5. The photovoltaic junction box according to claim 3, characterized in that: The shape of the welding port includes one of a circle, an ellipse, a triangle or a regular polygon.

6. The photovoltaic junction box according to any one of claims 1 to 5, characterized in that: Each of the conductive parts and the corresponding connecting part are an integral structure.

7. A photovoltaic cell assembly, characterized in that: At least two bus bars are arranged at intervals, each of the bus bars is stacked on the cell sheet of the photovoltaic cell assembly, and the surface of each bus bar facing away from the cell sheet is a flat surface; The two bus bars arranged at intervals are electrically connected through the photovoltaic junction box, and the photovoltaic junction box is the photovoltaic junction box according to any one of claims 1-6.

8. The photovoltaic cell assembly according to claim 7, characterized in that: The two busbars disposed at intervals and close to each other are both provided with positioning holes at their ends, and each positioning hole is opposite to the corresponding welding opening of the second section.

9. The photovoltaic cell assembly according to claim 8, characterized in that: Each of the positioning holes has the same shape as the corresponding welding opening of the second section; and / or, The orthographic projection of each positioning hole on the surface of the second section facing away from the bottom wall of the box body falls within the range of the corresponding welding port.

10. The photovoltaic cell assembly according to claim 8, characterized in that: The photovoltaic cell assembly further comprises a welding structure, at least a portion of which is located in the welding opening, and at least another portion of which is located in the corresponding positioning hole.

Images