Junction box, photovoltaic module and photovoltaic power generation system

Abstract

The utility model provides a junction box, which is applied to a photovoltaic module and comprises a box body. And the bypass diode is arranged in the box body. The first conductive band is connected with the positive electrode of the bypass diode, the first conductive band is further used for being connected with a positive electrode lead of a power generation layer of the photovoltaic module and the positive electrode end of a connecting line, and the positive electrode end of the connecting line is used for being electrically connected with a positive direct current bus. And the second conductive band is connected with the cathode of the bypass diode and is also used for connecting a cathode lead of the power generation layer of the photovoltaic module and the cathode end of the connecting line, and the cathode end of the connecting line is used for being electrically connected with the negative direct current bus. The utility model also provides a photovoltaic module and a photovoltaic power generation system. By arranging the first conductive band and the second conductive band, the design of electric connection between the bypass diode and the positive electrode and the negative electrode of the photovoltaic module and between the bypass diode and a connecting line connected with other photovoltaic modules or a direct current bus can be simplified.

Description

Technical Field

[0001] The present application relates to the field of new energy, and in particular to a junction box, a photovoltaic module and a photovoltaic power generation system. Background Art

[0002] With the development of new energy generation technology, bypass diodes are usually installed in the junction box of photovoltaic curved tiles to prevent hot spot effects on the cells. However, the bypass diodes are usually cylindrical and high, which makes the junction box high, so that the photovoltaic curved tiles may not match the shape of the photovoltaic curved tiles for installation, and the electrical connection design between the bypass diodes and the positive and negative electrodes of the photovoltaic modules and the connecting wires used to connect to other photovoltaic modules or DC busbars is relatively cumbersome. Utility Model Content

[0003] In view of the above problems, the present application provides a junction box, a photovoltaic module and a photovoltaic power generation system.

[0004] In a first aspect, the present application provides a junction box for use in a photovoltaic module, the junction box comprising: a box body. A bypass diode disposed in the box body. A first conductive strip, the first conductive strip connected to the positive electrode of the bypass diode, the first conductive strip is also used to connect the positive lead of the power generation layer of the photovoltaic module and the positive end of the connecting wire, the positive end of the connecting wire is used to electrically connect to the positive DC bus. A second conductive strip, the second conductive strip connected to the negative electrode of the bypass diode, the second conductive strip is also used to connect the negative lead of the power generation layer of the photovoltaic module and the negative end of the connecting wire, the negative end of the connecting wire is used to electrically connect to the negative DC bus. By providing the first conductive strip and the second conductive strip, the electrical connection design between the bypass diode and the positive and negative electrodes of the photovoltaic module and the connecting wires used to connect to other photovoltaic modules or the DC bus can be simplified.

[0005] In some possible implementations, the first conductive tape and the second conductive tape each include a first connection point and a second connection point. The first connection point of the first conductive tape is connected to the positive electrode of the bypass diode, and the second connection point of the first conductive tape is connected to the positive electrode lead of the power generation layer and the positive end of the connecting line. The first connection point of the second conductive tape is connected to the negative electrode of the bypass diode, and the second connection point of the second conductive tape is connected to the negative electrode lead of the power generation layer and the negative end of the connecting line.

[0006] In some possible implementations, the first conductive tape and / or the second conductive tape is a tinned copper tape or a conductive adhesive.

[0007] In some possible implementations, the bypass diode is a Schottky diode, and the thickness of the Schottky diode is no greater than 2 mm.

[0008] In a second aspect, the present application provides a photovoltaic assembly, including a photovoltaic curved tile and a junction box provided in any possible implementation of the first aspect, the photovoltaic curved tile including at least one curved surface, and the junction box is disposed in a cavity formed by the curved surface.

[0009] In some possible implementations, the height of the junction box is no higher than half the height of the photovoltaic curved tile.

[0010] In some possible implementations, the photovoltaic module further includes a power generation layer and a current transmission layer. The power generation layer is disposed between the photovoltaic curved tile and the current transmission layer. The power generation layer is used to generate power generation current after photoelectric conversion, and the current transmission layer is used to lead the power generation current to the positive lead and the negative lead of the power generation layer. The materials of the power generation layer and the current transmission layer are flexible silicon-based, and the current transmission layer supports the power generation layer to bend with the photovoltaic curved tile.

[0011] In some possible implementations, the power generation layer includes at least one solar cell, and the solar cell is a BC crystalline silicon photovoltaic solar cell with full back electrode contact.

[0012] In a third aspect, the present application provides a photovoltaic power generation system, which includes a conversion circuit and a photovoltaic component provided by any possible implementation method of the second aspect, the photovoltaic component is used to output voltage to a positive DC bus and a negative DC bus, the conversion circuit is connected to the positive DC bus and the negative DC bus, and the conversion circuit is used to convert the bus voltage between the positive DC bus and the negative DC bus.

[0013] In some possible implementations, the photovoltaic power generation system further includes an energy storage device, which is electrically connected to the conversion circuit and is used to store the electric energy output by the conversion circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the photovoltaic power generation system provided for this application.

[0015] Figure 2 Structural diagram of the curved photovoltaic tile provided for this application.

[0016] Figure 3 Schematic diagram of the junction box provided for this application.

[0017] Figure 4 Schematic diagram of a Schottky diode provided for this application.

[0018] Figure 5 Another structural diagram of the curved photovoltaic tile provided for this application. DETAILED DESCRIPTION

[0019] In the description of this application, the connection relationship refers to direct or indirect connection. For example, A and B are connected, which can be either A and B directly connected, or A and B are indirectly connected mechanically, electrically, etc. through one or more objects. For example, A and C can be directly connected, and C and B can be directly connected, so that A and B are connected through C. It is also understandable that the "A connected to B" described in this application can be A and B directly connected, or A and B can be indirectly connected through one or more other electrical components.

[0020] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0021] In the description of this application, words such as "first" and "second" are only used to distinguish different objects, and do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0022] The technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application.

[0023] With the development of new energy power generation technology, bypass diodes are usually installed in the junction boxes of photovoltaic curved tiles to prevent hot spot effects on cells. Specifically, when a cell is shaded and cannot generate electricity, it will be equivalent to a load, and the current generated by other cells will flow through the bypass diodes connected in parallel with the shaded cells, and will not flow through the shaded cells, thereby avoiding hot spots on the shaded cells. However, the bypass diode is usually cylindrical and has a large volume, and the electrical connection design between the bypass diode and the positive and negative electrodes of the photovoltaic module and the connecting wires used to connect to other photovoltaic modules or the DC bus is relatively cumbersome.

[0024] In view of this, the present application provides a junction box, a photovoltaic module and a photovoltaic power generation system to reduce the volume of the bypass diode, while simplifying the electrical connection design between the bypass diode and the positive and negative electrodes of the photovoltaic module and the connecting wires used to connect to other photovoltaic modules or a DC bus.

[0025] Specifically, see Figure 1 , Figure 1 Schematic diagram of a photovoltaic power generation system 100 provided in the present application. The photovoltaic power generation system 100 includes a power generation source 101 and a conversion circuit 102 .

[0026] The power source 101 is electrically connected to the conversion circuit 102. The power source 101 is used to output a voltage, which is converted by the conversion circuit 102 and then output to an external device.

[0027] Among them, the power generation source 101 may include multiple photovoltaic modules, and the multiple photovoltaic modules are connected in series and / or in parallel to form multiple photovoltaic subsystems. The multiple photovoltaic subsystems are connected in series and / or in parallel and then connected to a DC bus to provide a DC bus voltage as an input voltage of the conversion circuit 102.

[0028] In some embodiments, the conversion circuit 102 may be a DC-DC conversion circuit, a DC-AC conversion circuit, etc. For example, when the conversion circuit 102 is a DC-DC conversion circuit, a DC voltage conversion may be performed to step up or step down the DC voltage output by the power generation source 101 and then supply DC power to an external device. Here, the external device may be a device that receives DC power, such as a DC load, an energy storage device, or a battery, for example, an energy storage device 100a. For another example, when the conversion circuit 102 is a DC-AC conversion circuit, an inversion conversion may be performed to convert the DC power of the power generation source 101 into AC power and then supply AC power to an external device. Here, the external device may be a device or structure that receives AC power, such as an AC load or a power grid.

[0029] In some embodiments, the conversion circuit 102 includes both a DC-DC conversion circuit and a DC-AC conversion circuit.

[0030] In some embodiments, the power generation source 101 can be electrically connected to the conversion circuit 102 through a switch circuit. The switch circuit is used to at least partially conduct or disconnect the electrical connection between the multiple photovoltaic components in the power generation source 101 and the conversion circuit 102, so as to enhance the working stability of the photovoltaic power generation system 100. For example, the switch circuit can at least partially disconnect the electrical connection between the multiple photovoltaic components and the conversion circuit 102 when the grid voltage is abnormal, thereby reducing the output voltage of the photovoltaic power generation system 100 to the grid, or stop the photovoltaic power generation system 100 from outputting electric energy to the grid, so as to suppress the influence of the abnormal grid voltage. For another example, the switch circuit can at least partially disconnect the electrical connection between the multiple photovoltaic components and the conversion circuit 102 when the DC bus voltage is abnormal, so as to adjust the DC bus voltage according to the situation, so that the DC bus voltage tends to normal as soon as possible. For another example, the switch circuit can disconnect the electrical connection between the failed photovoltaic component and the conversion circuit 102 when some or all of the photovoltaic components fail, so as to prevent the failed photovoltaic component from affecting the DC bus voltage or other photovoltaic components that have not failed, and facilitate timely maintenance of the failed photovoltaic component.

[0031] In this application, the photovoltaic module is a curved photovoltaic tile. Figure 2, Figure 2 The structure diagram of the curved photovoltaic tile 103 provided in the present application. The curved photovoltaic tile 103 includes a photovoltaic curved tile 1031, a connection layer 1032, a power generation layer 1033, a current transmission layer 1036, a back plate 1034 and a junction box 1035. The photovoltaic curved tile 1031, the connection layer 1032, the power generation layer 1033, the connection layer 1032, the back plate 1034 and the junction box 1035 are stacked in sequence to form the curved photovoltaic tile 103.

[0032] The photovoltaic curved tile 1031 is a panel with a curved surface shape. The curved surface shape can be a single crest arc-shaped curved surface or multiple crest arc-shaped curved surfaces. For example, the photovoltaic curved tile 1031 includes a first crest surface 1031a, a first trough surface 1031b, and a second crest surface 1031c connected in sequence to form a curved surface shape. In this way, the shape of the curved photovoltaic tile 103 fits the shape of the building, is beautiful in appearance, and can maximize the energy utilization rate of light energy.

[0033] In some embodiments, the material of the photovoltaic curved tile 1031 may include hard polymer materials, rigid glass, etc., which have the characteristics of transparency and high hardness, and have the advantages of both aesthetics and ensuring structural strength.

[0034] In some embodiments, the radius of curvature of the first wave crest surface 1031a, the first wave valley surface 1031b, and the second wave crest surface 1031c is 25 mm-200 mm.

[0035] The power generation layer 1033 is disposed close to the back plate 1034 . The power generation layer 1033 includes a plurality of battery cells, and the battery cells are used to convert light energy into electrical energy.

[0036] The current transport layer 1036 is provided with conductive wires in the shape of strips or sheets, and the current transport layer 1036 is connected to the power generation layer 1033 by welding, conductive adhesive bonding or direct physical connection, so as to lead the current generated by the battery cell from the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033 through leads.

[0037] In some embodiments, the cell may be a full back contact (BC) crystalline silicon photovoltaic cell. Thus, the current transmission layer 1036 is disposed on the side of the cell away from the photovoltaic curved tile 1031 , and the wires may be hidden under the cell, thereby improving the aesthetics of the curved photovoltaic tile 103 .

[0038] In addition, the materials of the current transfer layer 1036 and the power generation layer 1033 can be flexible planar silicon-based materials, so that the power generation layer 1033 can bend along the bending direction of the photovoltaic curved tile 1031. Since the current transfer layer 1036 is arranged on the side of the battery cell away from the photovoltaic curved tile 1031, the current transfer layer 1036 can support the power generation layer to bend along the bending direction of the photovoltaic curved tile 1031, so that the power generation layer 1033 can be used in curved photovoltaic tiles 103 with a larger curvature, that is, a larger degree of curvature, thereby reducing the possibility of the power generation layer breaking and improving the working stability and structural strength of the power generation layer 1033.

[0039] The back plate 1034 is a flexible panel. Through holes 1034a and 1034b are provided on the back plate 1034. Leads for extracting current connected to the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033 pass through the through holes 1034a and 1034b, respectively.

[0040] The connecting layer 1032 is disposed between the photovoltaic curved tile 1031 and the power generation layer 1033 , and between the power generation layer 1033 and the back plate 1034 , and is used to bond the photovoltaic curved tile 1031 and the power generation layer 1033 , and between the power generation layer 1033 and the back plate 1034 .

[0041] In some embodiments, the connection layer 1032 may be a photovoltaic adhesive film.

[0042] The junction box 1035 is used to connect the leads passing through the through holes 1034a and 1034b, so that the electric energy generated by the curved photovoltaic tiles 103 can be exported to other curved photovoltaic tiles 103, DC bus, inverter and other external devices or components.

[0043] Specifically, see Figure 3 , Figure 3 FIG. 1 is a schematic diagram of a junction box 1035 provided in the present application. The junction box 1035 includes a housing 10351 , in which a Schottky diode 1035a and two conductive strips 1035b are disposed.

[0044] The Schottky diode 1035a is flat and is a bypass diode. Two pins of the Schottky diode 1035a are respectively connected to the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033, and are used to bypass the curved photovoltaic tile 103 when the curved photovoltaic tile 103 is blocked, cracked or otherwise fails, thereby preventing the curved photovoltaic tile 103 from being burned due to the hot spot effect.

[0045] Two conductive strips 1035b are respectively arranged at two pins of the Schottky diode 1035a, and the conductive strips 1035b are used to electrically connect the Schottky diode 1035a, the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033, and the external device. Among them, the two pins of the Schottky diode 1035a are the positive electrode and the negative electrode of the Schottky diode 1035a, respectively, the conductive strip 1035b arranged at the positive electrode pin of the Schottky diode 1035a is the first conductive strip, and the conductive strip 1035b arranged at the negative electrode pin of the Schottky diode 1035a is the second conductive strip. The external device can be other curved photovoltaic tiles 103, other photovoltaic modules, DC bus, conversion circuit 12, etc.

[0046] Specifically, each conductive strip 1035b is provided with a connection point 1035b_1 and a connection point 1035b_2, the positive electrode 1033a lead 1035e of the power generation layer 1033 and the positive end of the connection line 1035c connected to the external device are welded or bonded together to the connection point 1035b_1 of the first conductive strip, and the negative electrode 1033b lead 1035f of the power generation layer 1033 and the negative end of the connection line 1035c connected to the external device are welded or bonded together to the connection point 1035b_1 of the second conductive strip, thereby realizing the electrical connection between the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033 and the external device.

[0047] At the same time, the two pins of the Schottky diode 1035a are also welded or bonded to the two conductive strips 1035b. Specifically, the positive electrode of the Schottky diode 1035a is welded or bonded to the connection point 1035b_2 of the first conductive strip, and the negative electrode of the Schottky diode 1035a is welded or bonded to the connection point 1035b_2 of the second conductive strip. In this way, the conductive strip 1035b can electrically connect the Schottky diode 1035a, the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033, and the external device to each other, which can simplify the wiring design in the junction box 1035, and ensure that the connecting wire 1035c, the positive and negative electrodes of the curved photovoltaic tile 103, and the Schottky diode 1035a can quickly and conveniently complete the electrical connection.

[0048] In addition, each curved photovoltaic tile 103 is provided with a corresponding Schottky diode 1035a, which can save costs and reduce installation difficulty compared to providing a corresponding Schottky diode 1035a for a single solar cell.

[0049] In some embodiments, the material of the conductive tape 1035b can be tin-plated copper tape, so that the Schottky diode 1035a, the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033, and the external device are electrically connected to each other through welding, or the material of the conductive tape 1035b can be conductive glue, so that the Schottky diode 1035a, the positive electrode 1033a and the negative electrode 1033b of the power generation layer 1033, and the external device are electrically connected to each other through bonding.

[0050] See also Figure 4 , Figure 4 The schematic diagram of the Schottky diode 1035a provided by the present application is shown. Compared with the cylindrical diode, the Schottky diode 1035a has a lower thickness and a smaller volume, so the height of the junction box 1035 accommodating the Schottky diode 1035a can be reduced, so that the junction box 1035 is more compatible with the shape of the photovoltaic curved tile 1031, and can be adapted to the photovoltaic curved tile 1031 with different curvatures, thereby reducing the occupied area of ​​the curved photovoltaic tile 103.

[0051] In addition, the Schottky diode 1035a has a low voltage drop and a high switching speed, so that the curved photovoltaic tile 103 can quickly bypass the corresponding curved photovoltaic tile 103 when a hot spot effect occurs. It also has a small voltage drop and has little impact on the system voltage of the photovoltaic power generation system 100, thereby reducing the power generation efficiency loss of the photovoltaic power generation system 100.

[0052] See also Figure 5 , Figure 5 Another structural diagram of the curved photovoltaic tile 103 provided by the present application is shown. The box body of the junction box 1035 is roughly flat and rectangular, and the long side of the junction box 1035 is parallel to the short side direction of the curved photovoltaic tile 103, and the short side direction is also the Y direction in the figure. The junction box 1035 is arranged in the convex cavity formed by the first wave crest surface 1031a. In this way, the installation space of the junction box 1035 can be saved, the occupied volume of the curved photovoltaic tile 103 can be reduced, and at the same time, the photovoltaic subsystem formed by multiple curved photovoltaic tiles 103 connected in series and / or in parallel can be installed on the photovoltaic bracket, and the cable layout of multiple curved photovoltaic tiles 103 connected in series and / or in parallel can be facilitated.

[0053] In some embodiments, the junction box 1035 can be fixedly connected to the photovoltaic curved surface tile 1031 at the center of the first wave crest surface 1031a, and the height of the junction box 1035 is not higher than the distance from the center line of the photovoltaic curved surface tile 1031 to the first wave crest surface 1031a or the first wave valley surface 1031b. The center line of the photovoltaic curved surface tile 1031 is a horizontal line at the half of the vertical distance between the top of the first wave crest surface 1031a and the bottom of the first wave valley surface 1031b, as shown by the dotted line in the figure. In this way, the junction box 1035 can be completely accommodated in the convex cavity formed by the first wave crest surface 1031a, and will not cause the photovoltaic curved tile 1031 to bulge, nor will it interfere with the fixation of the edge of the curved photovoltaic tile 103 and the mounting parts. At the same time, the junction box 1035 is also hidden behind the back plate 1034, and will not block the photovoltaic curved tile 1031 from receiving light energy and affect the normal operation of the curved photovoltaic tile 103, and can improve the overall aesthetics of the curved photovoltaic tile 103.

[0054] Therefore, the junction box 1035 provided by the present application is small in size and low in height, and is suitable for the curved photovoltaic tile 103 with a curved surface shape, and can be completely accommodated in the accommodation space formed by the crest surface of the curved photovoltaic tile 103, without occupying additional space. In addition, the junction box 1035 provided by the present application can also realize the connection line 1035c connected to the external device, the positive and negative electrodes of the curved photovoltaic tile 103, and the Schottky diode 1035a to quickly and conveniently complete the electrical connection, simplifying the wiring design of the junction box 1035.

[0055] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A junction box, applied to a photovoltaic module, characterized in that: The junction box comprises: Box body; A bypass diode disposed in the box body; A first conductive tape, the first conductive tape is connected to the positive electrode of the bypass diode, and the first conductive tape is also used to connect the positive lead of the power generation layer of the photovoltaic module and the positive end of the connecting wire, and the positive end of the connecting wire is used to electrically connect to the positive DC bus; A second conductive tape, the second conductive tape is connected to the negative electrode of the bypass diode, and the second conductive tape is also used to connect the negative lead of the power generation layer of the photovoltaic module and the negative end of the connecting wire, and the negative end of the connecting wire is used to electrically connect to the negative DC bus.

2. The junction box according to claim 1, characterized in that: The first conductive strip and the second conductive strip each include a first connection point and a second connection point; The first connection point of the first conductive strip is connected to the positive electrode of the bypass diode, and the second connection point of the first conductive strip is connected to the positive electrode lead of the power generation layer and the positive end of the connection line; The first connection point of the second conductive tape is connected to the cathode of the bypass diode, and the second connection point of the second conductive tape is connected to the cathode lead of the power generation layer and the cathode end of the connection line.

3. The junction box according to claim 1, characterized in that: The first conductive tape and / or the second conductive tape is / are tinned copper tape or conductive adhesive.

4. The junction box according to any one of claims 1 to 3, characterized in that: The bypass diode is a Schottky diode, and the thickness of the Schottky diode is not greater than 2 mm.

5. A photovoltaic module, characterized in that: It comprises a photovoltaic curved tile and a junction box as claimed in any one of claims 1 to 4, wherein the photovoltaic curved tile comprises at least one arc-shaped surface, and the junction box is arranged in a cavity formed by the arc-shaped surface.

6. The photovoltaic module according to claim 5, characterized in that: The height of the junction box is not higher than half the height of the photovoltaic curved tile.

7. The photovoltaic module according to claim 5, characterized in that: The photovoltaic module also includes a power generation layer and a current transmission layer, wherein the power generation layer is arranged between the photovoltaic curved tile and the current transmission layer, the power generation layer is used to generate power generation current after photoelectric conversion, and the current transmission layer is used to lead the power generation current to the positive lead and the negative lead of the power generation layer; The materials of the power generation layer and the current transmission layer are flexible silicon-based, and the current transmission layer supports the power generation layer to bend along with the photovoltaic curved tile.

8. The photovoltaic module according to claim 5, characterized in that: The power generation layer includes at least one cell, and the cell is a BC crystalline silicon photovoltaic cell with full back electrode contact.

9. A photovoltaic power generation system, characterized in that: The photovoltaic power generation system includes a conversion circuit and a photovoltaic component as described in any one of claims 6 to 8, wherein the photovoltaic component is used to output voltage to a positive DC bus and a negative DC bus, the conversion circuit is connected to the positive DC bus and the negative DC bus, and the conversion circuit is used to convert the bus voltage between the positive DC bus and the negative DC bus.

10. The photovoltaic power generation system according to claim 9, characterized in that: The photovoltaic power generation system further includes an energy storage device, which is electrically connected to the conversion circuit and is used to store the electric energy output by the conversion circuit.

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