Photovoltaic module

Abstract

The utility model discloses a photovoltaic assembly. The photovoltaic assembly comprises a first battery unit and a second battery unit. The first battery unit comprises a plurality of first battery strings, the plurality of first battery strings are connected in parallel, and each first battery string comprises a plurality of first welding strips; the second battery units and the first battery units are connected in series, the second battery units are arranged on one side of the first battery units in the first direction, the second battery units are connected in parallel, each second battery string comprises a plurality of second welding strips, and the cross sectional areas of the first welding strips and the second welding strips are different. According to the photovoltaic module provided by the utility model, the battery pieces with different specifications are used for the battery strings in the same photovoltaic module, so that the cross sectional areas of the welding strips for connecting the corresponding battery pieces are different, and the parameters of the first welding strip and the second welding strip are reasonably set, so that the differentiated design of a plurality of welding strips in the same photovoltaic module is realized; therefore, the photovoltaic module can ensure the output power, the material consumption of the solder strip is reduced, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic module technical field especially is related to a photovoltaic module. BACKGROUND

[0002] Prior art, for photovoltaic module including different specifications cell piece formed battery string uses equal specifications solder strip, but due to the different power consumption of the battery string formed by different cell pieces, the resistance of part of the battery string is wasted, and the cost is high. SUMMARY

[0003] The utility model discloses at least one of the technical problems in the prior art. To this end, one purpose of the utility model is to provide a photovoltaic module, which optimizes the structure of the photovoltaic module and reduces the cost.

[0004] According to the photovoltaic module of the utility model embodiment, the first cell unit includes a plurality of first battery strings, and the plurality of first battery strings are connected in parallel. The first battery string includes a plurality of first solder strips. The second cell unit and the first cell unit are connected in series. The second cell unit includes a plurality of second battery strings, and the plurality of second battery strings are connected in parallel. The cross-sectional area of the first solder strip is different from that of the second solder strip.

[0005] According to the photovoltaic module of the utility model, different specifications of cell pieces are used for the battery strings in the same photovoltaic module, so that the cross-sectional area of the solder strip connected to the corresponding cell piece is different. The parameters of the first solder strip and the second solder strip are reasonably set, the differential design of a plurality of solder strips in the same photovoltaic module is realized, so that the photovoltaic module can ensure the output power while reducing the use of solder strip material and reducing the cost.

[0006] In some embodiments, the cross-sectional area of the first solder strip is S11, and the cross-sectional area of the second solder strip is S21, wherein the S11, S21 satisfy: 0.45≤S11 / S21≤0.75.

[0007] According to the photovoltaic module of the utility model, by limiting the cross-sectional area ratio of the first solder strip and the second solder strip, the parameters of the first solder strip and the second solder strip are reasonably set, or the cross-sectional area of the first solder strip is determined according to the cross-sectional area of the second solder strip with larger power consumption, so that the resistance of the first solder strip is increased and the cross-sectional area of the first solder strip is reduced under the condition that the total resistance of the first battery string and the second battery string is the same, the structure of the photovoltaic module is optimized, and the cost is effectively reduced.

[0008] In some embodiments, the S11, S21 further satisfy: 0.45≤S11 / S21≤0.51.

[0009] The photovoltaic module according to this utility model can effectively avoid the waste of resistance and achieve the best cost control effect while ensuring that the first and second solder strips used in the photovoltaic module meet the output power requirements.

[0010] In some embodiments, the first battery string includes a plurality of first battery cells, wherein the first battery cell is a quarter battery cell cut from a complete battery cell, and the second battery string includes a plurality of second battery cells, wherein the second battery cells are half battery cells cut from a complete battery cell;

[0011] The area of ​​the second battery cell is larger than that of the first battery cell, and the cross-sectional area of ​​the second solder strip is larger than that of the first solder strip.

[0012] The photovoltaic module of this utility model reduces the cross-sectional area of ​​the first solder strip, which helps to reduce the use of the first solder strip material. Therefore, the technical solution of this application can effectively reduce the production cost of the photovoltaic module.

[0013] In some embodiments, the first solar cell includes n main bus lines, the sum of the cross-sectional areas of the plurality of first solder strips corresponding to the first solar cell is S1, and the cross-sectional area of ​​each first solder strip is S11, wherein S11, S1, and n satisfy: 0.85S1 / n≤S11≤1.15S1 / n; and / or, the second solar cell includes n main bus lines, the sum of the cross-sectional areas of the plurality of second solder strips corresponding to the second solar cell is S2, and the cross-sectional area of ​​each second solder strip is S21, wherein S21, S2, and n satisfy: 0.85S2 / n≤S12≤1.15S2 / n.

[0014] In some embodiments, a portion of the plurality of first battery strings is arranged along a first direction, another portion of the plurality of first battery strings is arranged along a first direction, and the portion of the plurality of first battery strings and the other portion of the plurality of first battery strings are arranged symmetrically along a second direction; the plurality of second battery strings are arranged symmetrically along the second direction, and the first direction and the second direction are perpendicular.

[0015] In some embodiments, the plurality of first battery strings include: a plurality of first sub-strings and a plurality of second sub-strings, wherein the plurality of first sub-strings are spaced apart along a first direction and the plurality of first sub-strings are connected in parallel; the plurality of second sub-strings are spaced apart along the first direction and the plurality of second sub-strings are connected in parallel, and the plurality of first sub-strings and the plurality of second sub-strings are respectively arranged opposite to each other along the second direction.

[0016] In some embodiments, the second battery string comprises at least a plurality of battery columns, the plurality of battery columns are arranged along a first direction, and the plurality of battery columns are connected in series; a plurality of the second battery strings correspond to a plurality of the battery columns arranged oppositely along the second direction, respectively.

[0017] According to the photovoltaic module, two battery columns are connected in series to form a second battery string, and two second battery strings are connected in parallel and connected in series with the first battery string.

[0018] In some embodiments, the photovoltaic module further comprises a first bus bar arranged at a middle region of the first battery unit and the second battery unit along a second direction, the first battery unit and the second battery unit are symmetrically arranged about the first bus bar, and the first battery string and the second battery string are connected to the first bus bar, respectively.

[0019] According to the photovoltaic module, one end of the first battery string included in the first battery unit adjacent to a middle region of the photovoltaic module is connected to the first bus bar, and one end of the second battery string included in the second battery unit adjacent to the middle region of the photovoltaic module is connected to the first bus bar. The two ends of the first bus bar along the first direction are formed into a positive electrode end and a negative electrode end, respectively, and the current flows out from the positive electrode end after being collected from the negative electrode end through the first bus bar, the second battery unit, and the second battery unit, respectively.

[0020] In some embodiments, the photovoltaic module further comprises a first diode arranged on the first bus bar and connected in anti-parallel between two second battery strings arranged oppositely along the second direction.

[0021] According to the photovoltaic module, the protection of the second battery unit is realized.

[0022] In some embodiments, the photovoltaic module further comprises a plurality of second bus bars arranged at two ends of the first battery unit along the second direction, and the second bus bars are connected to a plurality of the first battery strings at the two ends of the first battery unit, respectively.

[0023] According to the photovoltaic module, the second bus bar is arranged to facilitate the connection between the adjacent two first battery strings, so as to form a current path in the first battery unit.

[0024] In some embodiments, the first battery unit is a plurality of first battery units arranged along a first direction, and the photovoltaic module further comprises a third bus bar arranged between adjacent two first battery units, and two ends of the third bus bar are connected to a plurality of the second bus bars and the first bus bar, respectively.

[0025] The photovoltaic module according to the utility model, the second bus bar is convenient for connecting two first battery units at the end in the second direction.

[0026] In some embodiments, further comprising: a second diode and a third diode, the second diode is arranged on the first bus bar, and the second diode is reversely connected in parallel with one of the first battery units; the third diode is arranged on the first bus bar, and the third diode is reversely connected in parallel with another of the first battery units; the second diode and the third diode are arranged on both sides of the third bus bar along the first direction.

[0027] The photovoltaic module according to the utility model, the third bus bar and the arrangement of the second diode and the third diode can increase the protection of the photovoltaic module.

[0028] Additional aspects and advantages of the utility model will be partially given in the following description, some will become obvious from the following description, or be understood by the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0029] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:

[0030] Figure 1 is the arrangement schematic view of the first battery unit and the second battery unit according to the utility model embodiment;

[0031] Figure 2 is the schematic view about the first battery unit according to the utility model embodiment;

[0032] Figure 3 is the schematic view about the second battery unit according to the utility model embodiment;

[0033] Figure 4 is the distribution schematic view about the bus bar and the diode according to the utility model embodiment;

[0034] Figure 5 is the arrangement schematic view of the first battery piece and the second battery piece according to the utility model embodiment.

[0035] REFERENCE NUMERALS:

[0036] 1, photovoltaic module;

[0037] 10, first battery unit;11, first battery string;111, first battery piece;112, first solder strip;14, first sub-string;15, second sub-string;

[0038] 20. Second battery cell; 21. Second battery string; 211. Second battery cell; 212. Second solder strip; 22. Battery array;

[0039] 31. First busbar; 32. Second busbar; 33. Third busbar;

[0040] 41. First diode; 42. Second diode; 43. Third diode. Detailed Implementation

[0041] The embodiments of this utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Figures 1-5 A photovoltaic module 1 according to an embodiment of the present utility model is described. The photovoltaic module 1 includes: a first battery unit 10 and a second battery unit 20.

[0042] Specifically, such as Figures 1-3 As shown, the first battery unit 10 includes multiple first battery strings 11 connected in parallel, and each first battery string 11 includes multiple first solder strips 112; the second battery unit 20 is connected in series with the first battery unit 10, and the second battery unit 20 is located on one side of the first battery unit 10 in a first direction, and multiple second battery strings 21 are connected in parallel, each second battery string 21 including multiple second solder strips 212, and the cross-sectional areas of the first solder strips 112 and the second solder strips 212 are different.

[0043] Optionally, the first battery string 11 includes a plurality of first battery cells 111 and a plurality of first solder strips 112. The plurality of first battery cells 111 are arranged along a second direction and are electrically connected by the plurality of first solder strips 112. The second battery unit 20 includes a plurality of second battery strings 21. The second battery strings 21 include a plurality of second battery cells 211 and a plurality of second solder strips 212. The plurality of second battery cells 211 are arranged along a second direction and are electrically connected by the plurality of second solder strips 212. The area of ​​the second battery cells 211 is different from the area of ​​the first battery cells 111.

[0044] Optionally, the first battery string 11 includes first battery pieces 111 which are quarter of the whole battery piece, and the second battery string 21 includes second battery pieces 211 which are half of the whole battery piece. The first battery piece 111 and the second battery piece 211 form different projected areas along the thickness direction of the photovoltaic module 1, and in this application, the projected area of the second battery piece 211 is greater than that of the first battery piece 111. Under this premise, it has been verified that when the cross-sectional areas of the first solder strip 112 and the second solder strip 212 are the same, the power loss of the first battery string 11 is less than that of the second battery string 21. The cross-sectional areas of the first solder strip 112 connecting a plurality of first battery pieces 111 and the second solder strip 212 connecting a plurality of second battery pieces 211 are different. It can be understood that for the photovoltaic module 1, the output unit is power, the first solder strip 112 and the second solder strip 212 are conductive materials themselves, but the solder strip itself has resistance which will lose the transmitted power. The first solder strip 112 and the second solder strip 212 with different cross-sectional areas have different power losses in the transmission process, which affects the overall output power of the photovoltaic module 1.

[0045] According to the relationship between the power loss and the resistance Ploss=I2R, the power loss of the corresponding solder strip can be increased by increasing the resistance of the solder strip. Therefore, in the case of keeping the power losses of the first battery string 11 and the second battery string 21 the same, the resistance of the first battery string 11 and the resistance of the second battery string 21 are controlled to be the same, and the resistance R=pl / s of the solder strip is combined, wherein p is the resistivity of the solder strip, l is the length of the solder strip corresponding to a single battery piece, and s is the cross-sectional area of the solder strip. It can be known that increasing the resistance of the solder strip reduces the cross-sectional area of the corresponding solder strip, so the cross-sectional area of the solder strip corresponding to the battery string with smaller actual power loss is changed, and the cost is reduced. This application takes into account the solder strip cost and the output power of the photovoltaic module 1, and differentiates the design of the solder strip used by different battery units, that is, the cross-sectional areas of the first solder strip 112 and the second solder strip 212 are different, so as to realize the reduction of the solder strip specification, control the cost of the solder strip, and ensure the power of the photovoltaic module 1.

[0046] According to the photovoltaic module 1 of the utility model, different specifications of battery pieces are used in the same photovoltaic module 1, so that the cross-sectional areas of the solder strips connecting the corresponding battery pieces are different, the parameters of the first solder strip 112 and the second solder strip 212 are reasonably set, the differential design of a plurality of solder strips in the same photovoltaic module 1 is realized, so that the photovoltaic module 1 can ensure the output power while reducing the use of solder strip material and reducing the cost.

[0047] Optionally, the first solder ribbon 112 corresponding to the first battery string 11 has a cross-sectional area S11, and the second solder ribbon 212 corresponding to the second battery string 21 has a cross-sectional area S21, wherein S11, S21 satisfy: 0.45≤S11 / S21≤0.75. For example, the ratio of S11, S21 is 0.48, 0.5, 0.6 or 0.7. The photovoltaic module 1 includes at least two first battery strings 11 and one second battery string 21 in the first direction, the two first battery strings 11 are connected in parallel, and the adjacent first battery string 11 and the second battery string 21 are connected in series. Thus, by limiting the cross-sectional area ratio of the first solder ribbon 112 and the second solder ribbon 212, the parameters of the first solder ribbon 112 and the second solder ribbon 212 are reasonably set, or the cross-sectional area of the first solder ribbon 112 is determined according to the second solder ribbon 212 with larger power loss, so as to increase the resistance of the first solder ribbon 112, reduce the cross-sectional area of the first solder ribbon 112, optimize the structure of the photovoltaic module 1, and effectively reduce the cost under the condition that the total resistance of the first battery string 11 and the second battery string 21 is the same.

[0048] In some embodiments, the total resistance of the first battery string 11 is R1, and the total resistance of the second battery string 21 is R2, R1, R2 satisfy: R1=R2. That is, compared with using different specifications of battery pieces to form the first battery string 11 and the second battery string 21, and using the same specification of solder ribbon for the first battery string 11 and the second battery string 21, the power loss of the first battery string 11 and the second battery string 21 is different, wherein the power loss of the first battery string 11 is lower, causing waste of resistance on the first battery string 11. In the present application, the total resistance of the first battery string 11 and the total resistance of the second battery string 21 are the same, the resistance of the first battery string 11 is increased to make the resistance of the first battery string 11 and the second battery string 21 the same, the cross-sectional area of the first solder ribbon 112 corresponding to the first battery string 11 is reduced, the use of materials for forming the first solder ribbon 112 is reduced, and the cost is reduced.

[0049] Optionally, S11, S21 further satisfy: 0.45≤S11 / S21≤0.51. For example, the ratio of S11, S21 is 0.45 or 0.48. Thus, the first solder ribbon 112 and the second solder ribbon 212 used by the photovoltaic module 1 can be guaranteed to satisfy the output power, effectively avoid the waste of resistance, and have the best effect of controlling the cost.

[0050] Specifically, as Figure 5As shown, the area of the second cell piece 211 is greater than the area of the first cell piece 111, and the cross-sectional area of the second solder strip 212 is greater than the cross-sectional area of the first solder strip 112. Alternatively, in the present application, the plurality of cell strings includes the first cell piece 111 and the second cell piece 211 with different areas, the first solder strip 112 connects a plurality of first cell pieces 111 to form a first cell string 11, and the second solder strip 212 connects a plurality of second cell pieces 211 to form a second cell string 21. Wherein, the cross-sectional area of the first solder strip 112 is smaller than the cross-sectional area of the second solder strip 212, the resistance of the first solder strip 112 is greater than the resistance of the second solder strip 212, and the resistance of the first cell string 11 and the resistance of the second cell string 12 are the same.

[0051] Alternatively, in combination with Figure 5 Since the first cell piece 111 is a quarter piece and the second cell piece 211 is a half piece, in the second direction, the length of the first solder strip 112 corresponding to the first cell piece 111 is smaller than the length of the second solder strip 212 corresponding to the second cell piece 211. According to the formula of the resistance of the solder strip R = p l / s, where p is the resistivity of the solder strip, l is the length of the solder strip corresponding to a single cell piece, and s is the cross-sectional area of the solder strip. Analysis shows that the length of the second solder strip 212 is greater than the length of the first solder strip 112. Under the premise of ensuring that the resistance of the first cell piece 111 and the second cell piece 211 is the same and the number of solder strips corresponding to the first cell piece 111 and the second cell piece 211 is the same, the cross-sectional area of the first solder strip 112 is smaller than the cross-sectional area of the second solder strip 212.

[0052] Therefore, in the present application, by designing the cell string formed by different sizes of cell pieces, by ensuring the power of the different specifications of the cell string formed, when the string resistance of the first cell string 11 and the second cell string 12 is the same, in order to facilitate the string resistance of the first cell string 11 to be equal to the string resistance of the second cell string 12, the string resistance of the first cell string 11 needs to be increased. According to the formula of the resistance and the cross-sectional area of the solder strip, it can be known that it can be realized by reducing the cross-sectional area of the first solder strip 112, which is beneficial to reduce the use of the material of the first solder strip 112, thereby the technical solution of the present application can effectively reduce the production cost of the photovoltaic module 1.

[0053] In some embodiments, the first solder strip 112 extends out of the first cell piece 111 by a length L1 in the second direction, and the second solder strip 212 extends out of the second cell piece 211 by a length L2 in the second direction, wherein L1 and L2 satisfy: 3mm≤L1≤6mm, 3mm≤L2≤6mm. Alternatively, L1 is 3mm, 4mm, 4.5mm, 5mm or 6mm, and L2 is 3mm, 4mm, 4.5mm, 5mm or 6mm.

[0054] Optionally, the length of the projection of the first solder strip 112 on the first battery piece 111 along the second direction is L3, the length of the projection of the second solder strip 212 on the second battery piece 211 along the second direction is L4, the resistivity of the first solder strip 112 is p1 and the resistivity of the second solder strip 212 is p2, the resistance of the plurality of first solder strips 112 on the first battery piece 111 is R1, the resistance of the plurality of second solder strips 212 on the second battery piece 211 is R2, the sum of the cross-sectional areas of the plurality of first solder strips 112 on the first battery piece 111 is S1, and the sum of the cross-sectional areas of the plurality of second solder strips 212 on the second battery piece 211 is S2, according to R = p1 / s, when the resistance of the first battery piece 111 and the resistance of the second battery piece 211 are the same, S1 / S2 satisfies: S1 / S2 = p1(L3-L1) / p2(L4-L2).

[0055] Specifically, for the first battery piece 111 formed by cutting four and the second battery piece 211 formed by cutting two, at least one side of the first battery piece 111 is provided with a plurality of first solder strips 112, and at least one side of the second battery piece 211 is provided with a plurality of second solder strips 212. Since the first battery piece 111 and the second battery piece 211 are both formed by cutting a complete battery piece of the same specification by different cutting processes, when the first solder strip 112 and the second solder strip 212 are arranged, the length of the solder strip along the string extending direction is greater than the length of the battery piece along the second direction, that is, the length of the solder strip along the string extending direction is greater than the length of the battery piece along the second direction. For ease of calculation, L1 can be 4.5 mm and L2 can be 5 mm. Taking the specification of the complete battery piece as 210 mm x 210 mm as an example, S1 / S2 = p1(L3-L1) / p2(L4-L2) = (210 / 4-4.5) / (210 / 2-5) = 0.48.

[0056] In some embodiments, the first battery piece 111 includes n main grid lines, the sum of the cross-sectional areas of the plurality of first solder strips 112 corresponding to the first battery piece 111 is S1, and the cross-sectional area of each first solder strip 112 is S11, S11, S1, and n satisfy: 0.85S1 / n≤S11≤1.15S1 / n.

[0057] In some embodiments, the second battery piece 211 includes n main grid lines, the sum of the cross-sectional areas of the plurality of second solder strips 212 corresponding to the second battery piece 211 is S2, and the cross-sectional area of each second solder strip 212 is S21, S21, S2, and n satisfy: 0.85S2 / n≤S12≤1.15S2 / n.

[0058] Optionally, in this application, the number of main grid lines arranged along the first direction on the first battery cell 111 and the second battery cell 211 is n, that is, the number of first solder ribbons 112 and the number of second solder ribbons 212 arranged opposite to the main grid lines are n respectively. Based on the distance between the first solder ribbons 112 arranged on the first battery cell 111, the cross-sectional area of ​​a single first solder ribbon 112 is S11 = S1 / n. When the number of main grid lines increases, the cross-sectional area of ​​the first solder ribbon 112 decreases, the transmission distance on the sub-grid lines decreases, the current increases, and the power loss increases while the resistance remains constant. If the number of main grid lines decreases, the cross-sectional area of ​​the first solder ribbon 112 increases, the current transmission distance on the sub-grid lines increases, the current decreases, and the power loss decreases while the resistance remains constant. That is, while maintaining the same resistance between the first battery cell 111 and the second battery cell 211, the cross-sectional area of ​​the solder ribbons can be adjusted according to the number of first solder ribbons 112 on the first battery cell 111 and the number of second solder ribbons 212 on the second battery cell 211, ensuring output power while effectively controlling costs.

[0059] Optionally, under the premise that the resistance of the first battery cell 111 and the second battery cell 211 are the same, and the number of the first solder strips 112 of the first battery cell 111 and the number of the second solder strips 212 of the second battery cell 211 are the same, the cost can be reduced by decreasing the cross-sectional area of ​​the first solder strip 112 and reducing the amount of material used in the first solder strip 112.

[0060] In some embodiments, the cross-sectional shape of the first solder strip 112 is circular or polygonal; or, the cross-sectional shape of the second solder strip 212 is circular or polygonal. Optionally, the first solder strip 112 and the second solder strip 212 have the same shape, which is circular or polygonal, and one of the first solder strip 112 and the second solder strip 212 has a circular cross-sectional shape, while the other has a polygonal cross-sectional shape. The shapes of the first solder strip 112 and the second solder strip 212 are not specifically limited.

[0061] In some embodiments, such as Figure 2 and Figure 3 As shown, a portion of the plurality of first battery strings 11 is arranged along a first direction, another portion of the plurality of first battery strings 11 is arranged along a first direction, and the portion of the plurality of first battery strings 11 and the other portion of the plurality of first battery strings 11 are arranged symmetrically along a second direction; a plurality of second battery strings 21 are arranged symmetrically along a second direction, and the first direction and the second direction are perpendicular.

[0062] Optionally, the first battery unit 10 includes four first battery strings 11 connected in parallel, with each pair of the four first battery strings 11 connected in parallel and arranged opposite each other along a second direction. The second battery unit 20 includes two second battery strings 21 connected in parallel, with the two second battery strings 21 arranged opposite each other along a second direction.

[0063] Further, in combination Figure 2 The first battery string 11 includes a plurality of first sub-strings 14 and a plurality of second sub-strings 15. The plurality of first sub-strings 14 are arranged in parallel and are spaced apart along a first direction. The plurality of second sub-strings 15 are arranged in parallel and are spaced apart along the first direction. The plurality of first sub-strings 14 and the plurality of second sub-strings 15 are arranged opposite to each other along a second direction.

[0064] Optionally, the first battery unit 10 includes a plurality of first sub-strings 14 and a plurality of second sub-strings 15 arranged along a first direction. The plurality of first sub-strings 14 and the plurality of second sub-strings 15 are arranged opposite to each other along a second direction. That is, the plurality of first sub-strings 14 are arranged at one end along the second direction, and the plurality of second sub-strings 15 are arranged at the other end along the second direction.

[0065] In some embodiments, as shown in Figure 3 The second battery string 21 includes a plurality of battery columns 22 arranged in series along a first direction. The plurality of battery columns 22 of the second battery string 21 are arranged opposite to each other along a second direction.

[0066] Optionally, the second battery unit 20 includes two second battery strings 21 arranged opposite to each other along a second direction. Each of the second battery strings 21 includes two battery columns 22 arranged in series. The two battery columns 22 are arranged at one end along the second direction. The two battery columns 22 are arranged along a first direction. The two battery columns 22 of each of the second battery strings 21 are arranged opposite to each other along the second direction.

[0067] The number of the battery pieces of the first battery string 11 is the same as the number of the battery pieces of the second battery string 21. The string resistance of the first battery string 11 is the same as the string resistance of the second battery string 21. Since the first battery piece 111 is a cut-four battery piece and the second battery piece 211 is a cut-two battery piece, the length of the first solder strip 112 is smaller than the length of the second solder strip 212. In the case of the same reserved length, the ratio of the cross-sectional area of the first solder strip 112 to the cross-sectional area of the second solder strip 212 is 1 / 2.

[0068] Optionally, according to the parameters of actual experiments, the cross-sectional area of the first solder strip 112 is 48% of the cross-sectional area of the second solder strip 212. Taking a 20BB BC battery as an example, that is, taking a back contact battery with 20 main grid lines on each photovoltaic module 1 as an example, if the specification of the second solder strip 212 arranged on the second battery piece 211 is 0.6mm×0.25mm, the specification of the first solder strip 112 arranged on the first battery piece 111 can be selected as 0.4mm×0.18mm.

[0069] Optionally, the first solder strip 112 and the second solder strip 212 are taken as an example of flat solder strip, i.e. solder strip with polygonal cross-sectional shape, the specification of the second solder strip 212 arranged on the second battery piece 211 is 0.6mm x 0.15mm~0.6mm x 0.25mm, and the specification of the first solder strip 112 arranged on the first battery piece 111 can be optionally 0.4mm x 0.11mm~0.4mm x 0.18mm.

[0070] Optionally, the first solder strip 112 and the second solder strip 212 are taken as an example of round wire solder strip, i.e. solder strip with circular cross-sectional shape, the specification of the second solder strip 212 arranged on the second battery piece 211 is φ0.25mm~φ0.35mm, and the specification of the first solder strip 112 arranged on the first battery piece 111 can be optionally φ0.2mm~φ0.26mm.

[0071] In some embodiments, as shown in FIG. 1, the photovoltaic module 1 further comprises a first busbar 31 arranged in the middle region of the first battery unit 10 and the second battery unit 20 along a second direction, the first battery unit 10 and the second battery unit 20 are symmetrically arranged about the first busbar 31, and the first battery string 11 and the second battery string 21 are respectively connected to the first busbar 31. Figure 4

[0072] Optionally, the first battery unit 10 and the second battery unit 20 are symmetrically arranged about the first busbar 31, and the two parts of the first battery unit 10 and the second battery unit 20 about the first busbar 31 are connected in parallel. The first battery string 11 included in the first battery unit 10 is connected to the first busbar 31 at one end adjacent to the middle region of the photovoltaic module 1, and the second battery string 21 included in the second battery unit 20 is connected to the first busbar 31 at one end adjacent to the middle region of the photovoltaic module 1. The two ends of the first busbar 31 along the first direction are respectively formed as a positive electrode end and a negative electrode end, and the current flows out from the positive electrode end after being collected from the negative electrode end through the first busbar 31, the second battery unit 20 and the second battery unit 20.

[0073] Optionally, as shown in FIG. 1, the photovoltaic module 1 further comprises a first diode 41 arranged on the first busbar 31, and the first diode 41 is connected in anti-parallel between two second battery strings arranged oppositely along the second direction. Figure 4

[0074] In some embodiments, as shown in FIG. 1, the photovoltaic module 1 further comprises a first busbar 31 arranged in the middle region of the first battery unit 10 and the second battery unit 20 along a second direction, the first battery unit 10 and the second battery unit 20 are symmetrically arranged about the first busbar 31, and the first battery string 11 and the second battery string 21 are respectively connected to the first busbar 31. Figure 4 ​​As shown, the photovoltaic module 1 further comprises a plurality of second bus bars 32, the second bus bars 32 are respectively arranged at two ends of the first battery unit 10 along a second direction, and the second bus bars 32 are respectively connected to the plurality of first battery strings 11 at the two ends of the first battery unit 10.

[0075] Optionally, since the first battery unit 10 comprises a plurality of first battery strings 11, part of the first battery strings 11 are arranged along the first direction, and part of the first battery strings 11 are oppositely arranged along the second direction. In the present application, the first battery strings 11 are four, two of which are arranged along the first direction, and the other two are symmetrically arranged with respect to the first bus bar 31 and the two. Thus, the arrangement of the second bus bar 32 facilitates the connection between the adjacent two first battery strings 11, so as to form a current path in the first battery unit 10.

[0076] In some embodiments, in combination Figure 4 , the first battery unit 10 is a plurality, and the plurality of first battery units 10 are arranged along the first direction. The photovoltaic module 1 further comprises a third bus bar 33, the third bus bar 33 is arranged between adjacent two first battery units 10, and the two first battery units 10 are symmetrically arranged with respect to the third bus bar 33. The two ends of the third bus bar 33 are respectively connected to the plurality of second bus bars 32 and the intermediate first bus bar 31 along the second direction. The end of the second bus bar 32 in the second direction is connected to the two first battery units 10.

[0077] Optionally, as Figure 4 shown, the photovoltaic module 1 further comprises a second diode 42 and a third diode 43. The second diode 42 is arranged on the first bus bar 31, and the second diode 42 is connected in anti-parallel with one of the plurality of first battery units 10. The third diode 43 is arranged on the first bus bar 31, and the third diode 43 is connected in anti-parallel with another of the plurality of first battery units 10. The second diode 42 and the third diode 43 are arranged on both sides of the third bus bar 33 along the first direction.

[0078] Optionally, the currents of the first battery strings 11 arranged on both sides of the third bus bar 33 along the first direction are opposite along the second direction. When the first battery string 11 located on the side of the third bus bar 33 away from the second bus bar 32 is short-circuited, the current collected by the photovoltaic module 1 flows through the second battery string 21 and the first battery string 11 adjacent to the second battery string 21 on the side of the third bus bar 33 away from the second battery string 21, and then flows out through the third bus bar 33 and the two second diodes away from the first diode 41. Thus, the arrangement of the third bus bar 33 and the second diode 42 and the third diode 43 can increase the protection of the photovoltaic module 1.

[0079] Optionally, the battery piece of 210 mm x 210 mm is selected in the design, and the back contact battery with 20 main grid lines is taken as an example. The parameters of the second welding strip 212 used for the second battery string 21 are 0.6 mm x 0.2 mm, the number of each battery column 22 is 11 pieces, and the current is 14 A. The sum of the cross-sectional areas of the plurality of second welding strips 212 of the second battery string 21 is S2 = 0.6 x 0.2 x 10 = 1.2 mm2, the resistance of the second welding strip 212 is R2 = 1.7 x 10 -8 × 100 mm / 1.2 mm2= 1.42 mΩ, the string resistance of the second battery string 21 is R3 = 1.42 mΩ x 11 x 2 = 31.24 mΩ, and the power loss caused by the second welding strip 212 corresponding to the second battery string 21 is P1 = I2R3 = 14 x 14 x 0.03124 = 6.12 W.

[0080] Optionally, the battery piece of 210 mm x 210 mm is selected in the design, and the back contact battery with 20 main grid lines is taken as an example. The parameters of the second welding strip 212 used for the second battery string 21 are 0.6 mm x 0.2 mm, the number of each battery column 22 is 11 pieces, and the current is 14 A. The sum of the cross-sectional areas of the plurality of second welding strips 212 of the second battery string 21 is S2 = 0.6 x 0.2 x 10 = 1.2 mm2, the resistance of the second welding strip 212 is R2 = 1.7 x 10 -8 × 48 mm / 1.2 mm2= 0.68 mΩ, the string resistance of the second battery string 21 is R3 = 1.42 mΩ x 11 x 2 = 31.24 mΩ, and the power loss caused by the second welding strip 212 corresponding to the second battery string 21 is P1 = I2R3 = 14 x 14 x 0.03124 = 6.12 W.

[0081] Optionally, in combination with the power loss of the first welding strip 112 and the second welding strip 212, when the first welding strip 112 and the second welding strip 212 included in the first battery string 11 and the second battery string 21 are of the same specification, the resistance loss of the first welding strip 112 is lower, and the power loss is lower, that is, for the first battery string 11, the specification of the first welding strip 112 used is not reasonable, which is not conducive to the cost design of the photovoltaic module 1.

[0082] Optionally, when the power loss of the first welding strip 112 corresponding to the first battery string 11 and the power loss of the second welding strip 212 corresponding to the second battery string 21 are the same, which is 6 W, the string resistance of the first battery string 11 and the string resistance of the second battery string 21 are the same, which is 31.2 mΩ. At this time, the resistance R6 of the first battery piece 111 is 31.2 / 22 = 1.42 Ω, and the sum of the cross-sectional areas of the plurality of first welding strips 112 corresponding to the first battery piece 111 is Stotal = 1.7 x 10 -8X48 ÷ 1.42 = 0.576 mm2, so the cross-sectional area of the first solder strip 112 is 0.0576 mm2, which is significantly reduced compared to 0.12 mm2, effectively reducing the specification used by the first solder strip 112 and effectively reducing costs.

[0083] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0084] In the description of the present application, "first feature" and "second feature" can include one or more features. In the description of the present application, "multiple" means two or more. In the description of the present application, "above" or "below" the first feature of the second feature can include direct contact between the first and second features, or can include indirect contact between the first and second features through another feature therebetween. In the description of the present application, "above", "above" and "above" of the first feature of the second feature include the first feature directly above and obliquely above the second feature, or only indicate that the first feature is higher than the second feature in horizontal height.

[0085] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example.

[0086] Although embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized in that, include: A first battery cell, the first battery cell comprising a plurality of first battery strings connected in parallel, the plurality of first battery strings comprising a plurality of first solder strips; The second battery cell is connected in series with the first battery cell. The second battery cell includes multiple second battery strings connected in parallel. The second battery strings include multiple second solder strips. The cross-sectional areas of the first solder strip and the second solder strip are different.

2. The photovoltaic module according to claim 1, characterized in that, The cross-sectional area of ​​the first solder strip is S11, and the cross-sectional area of ​​the second solder strip is S21, wherein S11 and S21 satisfy: 0.45≤S11 / S21≤0.

75.

3. The photovoltaic module according to claim 2, characterized in that, S11 and S21 further satisfy: 0.45≤S11 / S21≤0.

51.

4. The photovoltaic module according to claim 1, characterized in that, The first battery string includes multiple first battery cells, each of which is a quarter-cell battery cell cut from a complete battery cell; the second battery string includes multiple second battery cells, each of which is a half-cell battery cell cut from a complete battery cell. The area of ​​the second battery cell is larger than that of the first battery cell, and the cross-sectional area of ​​the second solder strip is larger than that of the first solder strip.

5. The photovoltaic module according to claim 4, characterized in that, The first solar cell includes n main bus lines. The sum of the cross-sectional areas of the multiple first solder strips corresponding to the first solar cell is S1, and the cross-sectional area of ​​each first solder strip is S11. S11, S1, and n satisfy: 0.85S1 / n ≤ S11 ≤ 1.15S1 / n; and / or, The second battery cell includes n main grid lines. The sum of the cross-sectional areas of the multiple second solder strips corresponding to the second battery cell is S2, and the cross-sectional area of ​​each second solder strip is S21. S21, S2, and n satisfy: 0.85S2 / n≤S12≤1.15S2 / n.

6. The photovoltaic module according to claim 1, characterized in that, A portion of the plurality of first battery strings is arranged along a first direction, another portion of the plurality of first battery strings is arranged along a first direction, and the portion of the plurality of first battery strings and the other portion of the plurality of first battery strings are arranged symmetrically along a second direction; Multiple second battery strings are symmetrically arranged along the second direction, and the first direction and the second direction are perpendicular.

7. The photovoltaic module according to claim 6, characterized in that, The plurality of the first battery strings include: Multiple first substrings are arranged at intervals along a first direction, and multiple first substrings are arranged in parallel. Multiple second substrings are arranged at intervals along a first direction, multiple second substrings are arranged in parallel, and multiple first substrings and multiple second substrings are arranged opposite each other along a second direction.

8. The photovoltaic module according to claim 6, characterized in that, The second battery string includes at least a plurality of battery columns, which are arranged along a first direction and connected in series. The multiple battery columns corresponding to the multiple second battery strings are respectively arranged opposite to each other along the second direction.

9. The photovoltaic module according to any one of claims 1-8, characterized in that, Also includes: A first busbar is disposed along a second direction in the middle region of the first battery cell and the second battery cell. The first battery cell and the second battery cell are symmetrically arranged about the first busbar. The first battery string and the second battery string are respectively connected to the first busbar.

10. The photovoltaic module according to claim 9, characterized in that, Also includes: The first diode is disposed on the first busbar and is connected in reverse parallel between two second battery strings arranged opposite each other along the second direction.

11. The photovoltaic module according to claim 9, characterized in that, Also includes: Multiple second busbars are respectively disposed at both ends of the first battery cell along the second direction, and the second busbars are respectively connected to multiple first battery strings at both ends of the first battery cell.

12. The photovoltaic module according to claim 11, characterized in that, The first battery cell comprises multiple cells arranged along a first direction. The photovoltaic module further includes: The third busbar is disposed between two adjacent first battery cells, and its two ends are connected to a plurality of second busbars and the first busbar respectively along the second direction.

13. The photovoltaic module according to claim 12, characterized in that, Also includes: The second diode is disposed on the first busbar and is connected in parallel in the opposite direction to one of the plurality of first battery cells. A third diode is disposed on the first busbar and is connected in reverse parallel with another of the plurality of first battery cells; The second diode and the third diode are disposed on both sides of the third busbar along the first direction.

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