Photovoltaic module

Abstract

The application relates to the photovoltaic technical field and provides a photovoltaic module, which is at least beneficial to balancing the output performance of the photovoltaic module and improving the quality and use effect of the photovoltaic module. The photovoltaic module comprises the following: a first cell string group with a first sub-cell string and a second sub-cell string in series, the first sub-cell string comprises N cell pieces in series, the second sub-cell string comprises M cell pieces in series, wherein M and N are positive integers, and M is not equal to N; a second cell string group with a third sub-cell string and a fourth sub-cell string in series, the second cell string group is in series with the first cell string group, the third sub-cell string comprises X cell pieces in series, the fourth sub-cell string comprises Y cell pieces in series, wherein X and Y are positive integers, Y is not equal to X, and X+Y=M+N; a first diode, a second diode, a third diode and a fourth diode which are reversely connected in parallel with the first sub-cell string, the second sub-cell string, the third sub-cell string and the fourth sub-cell string respectively.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Technology

[0002] When photovoltaic (PV) modules installed outdoors are obstructed by dust, sand, bird droppings, or other contaminants, their output power will be reduced, and in severe cases, the modules will experience a hot spot effect. The hot spot effect refers to the phenomenon where defective cells in the PV module's series circuit, such as those that are obstructed, dirty, cracked, or have bubbles, act as a load, consuming the electrical energy generated by other cells and causing localized overheating. Severe hot spot effects can cause the modules to catch fire, resulting in irreversible and serious damage.

[0003] To prevent this from happening, a bypass diode is connected in parallel between the positive and negative terminals of a conventional photovoltaic module. When a cell experiences a hot spot effect and cannot generate electricity, it acts as a bypass, allowing the current generated by other cells to flow out through the diode, so that the photovoltaic system can continue to generate electricity and the power generation circuit will not be interrupted due to a problem with a single cell.

[0004] However, bypass diodes can easily lead to a significant drop in the power output of photovoltaic modules. Utility Model Content

[0005] This application provides a photovoltaic module that at least helps to balance the output performance of the photovoltaic module and improve its quality and performance.

[0006] According to some embodiments of this application, one aspect of this application provides a photovoltaic module, including: a first battery string group, the first battery string group including a first sub-cell string and a second sub-cell string arranged in series along a second direction, the first sub-cell string including N cells in series, the second sub-cell string including M cells in series, wherein M and N are both positive integers, and N≠M; a second battery string group, the second battery string group being connected in series with the first battery string group, and the first battery string group and the second battery string group being arranged along a first direction, the second battery string group including a third sub-cell string and a fourth sub-cell string arranged in series along the second direction. The third sub-cell string consists of X series-connected cells, and the fourth sub-cell string consists of Y series-connected cells, where X and Y are both positive integers, and X≠Y, X+Y=M+N; the first diode is connected in anti-parallel to the first sub-cell string; the second diode is connected in anti-parallel to the second sub-cell string, and the threshold voltage of the second diode is different from that of the first diode; the third diode is connected in anti-parallel to the third sub-cell string; and the fourth diode is connected in anti-parallel to the fourth sub-cell string, and the threshold voltage of the fourth diode is different from that of the third diode.

[0007] In some embodiments, M, N, X, and Y satisfy: 3≤M≤34; 3≤N≤34; 3≤X≤34; 3≤Y≤34; 12≤X+Y=M+N≤45; 6≤YX≤23; 6≤MN≤23.

[0008] In some embodiments, M, N, X, and Y also satisfy: X = N, Y = M.

[0009] In some embodiments, along the first direction, the distance L1 from any of the first diode, the second diode, the third diode, or the fourth diode to the edge of the photovoltaic module satisfies: L / 4 ≤ L1 ≤ L / 2, where L is the length of the photovoltaic module along the first direction.

[0010] In some embodiments, along the second direction, the distance W1 from any of the first diode, the second diode, the third diode, or the fourth diode to the edge of the photovoltaic module satisfies: W / 4 ≤ W1 ≤ W / 2, where W is the length of the photovoltaic module along the second direction.

[0011] In some embodiments, the photovoltaic module further includes: a first busbar connected to the end of the first sub-cell string away from the second sub-cell string, and connected to either the positive or negative output terminal of the photovoltaic module; a second busbar connected to the end of the second sub-cell string away from the first sub-cell string, and connected to the end of the third sub-cell string away from the fourth sub-cell string; a third busbar located between the first and second sub-cell strings, and connected to both the first and second sub-cell strings; a fourth busbar located between the third and fourth sub-cell strings, and connected to both the third and fourth sub-cell strings; and a fifth busbar connected to the end of the fourth sub-cell string away from the third sub-cell string, and connected to either the positive or negative output terminal of the photovoltaic module.

[0012] In some embodiments, there are multiple first sub-battery strings, the number of second sub-battery strings is equal to the number of first sub-battery strings, the multiple first sub-battery strings are connected in parallel through a first bus bar and a third bus bar, and the multiple second sub-battery strings are connected in parallel through a second bus bar and a third bus bar; there are multiple third sub-battery strings, the number of fourth sub-battery strings is equal to the number of third sub-battery strings, the multiple third sub-battery strings are connected in parallel through a second bus bar and a fourth bus bar, and the multiple fourth sub-battery strings are connected in parallel through a fourth bus bar and a fifth bus bar.

[0013] In some embodiments, the photovoltaic module further includes: a first jumper, the first jumper connecting a first busbar, a second busbar, and a third busbar; a first diode connected in series on the first jumper between the first busbar and the third busbar; and a second diode connected in series on the first jumper between the second busbar and the third busbar; wherein, in the direction from the first battery string group to the second battery string group, the first jumper is located between the penultimate first sub-cell string and the penultimate first sub-cell string; a second jumper, the second jumper connecting a second busbar, a fourth busbar, and a fifth busbar; a third diode connected in series on the second jumper between the second busbar and the fourth busbar; and a fourth diode connected in series on the second jumper between the fourth busbar and the fifth busbar; wherein, in the direction from the first battery string group to the second battery string group, the second jumper is located between the first fourth sub-cell string and the second fourth sub-cell string.

[0014] In some embodiments, a buffer pad is provided between the first jumper and the battery cell, and a buffer pad is provided between the second jumper and the battery cell. The width of the first jumper is smaller than the width of the buffer pad, and the width of the second jumper is smaller than the width of the buffer pad.

[0015] In some embodiments, the difference between the width of the buffer pad and the width of the first jumper is 2mm to 10mm; the difference between the width of the buffer pad and the width of the second jumper is 2mm to 10mm; and the thickness of the buffer pad is 0.05mm to 0.75mm.

[0016] In some embodiments, in the first and second battery string groups, the different battery cells have the same area.

[0017] The technical solution provided in this application has at least the following advantages:

[0018] In the photovoltaic module provided in this application embodiment, a first battery string group and a second battery string group are connected in series. The first battery string group includes a first sub-cell string and a second sub-cell string with different numbers of cells connected in series. The second battery string group includes a third sub-cell string and a fourth sub-cell string with different numbers of cells connected in series. The total number of cells connected in series in the first battery string group is the same as the total number of cells connected in series in the second battery string group, but the number of cells connected in series in each sub-cell string is different. In this way, the corresponding number of cells connected in series can be set according to the environment of different sub-cell strings in each group. Then, the threshold voltages of the corresponding first diode, second diode, third diode, and fourth diode can be selected according to the first sub-cell string, second sub-cell string, third sub-cell string, and fourth sub-cell string. This can avoid the unshaded cells being bypassed when the shading conditions of the cells in different areas are different, thereby avoiding excessive power reduction of the photovoltaic module and affecting the overall output performance of the photovoltaic module. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the circuit structure of a photovoltaic module in related technologies;

[0021] Figure 2 A schematic diagram of the circuit structure of a photovoltaic module provided in an embodiment of this application;

[0022] Figure 3 for Figure 2 The diagram shows the structural schematic of the photovoltaic module shown.

[0023] Figure 4 This application provides a schematic diagram of the structure of multiple photovoltaic module assemblies.

[0024] Explanation of reference numerals in the attached figures:

[0025] 101. Battery string; 102. Bypass diode; 200. Battery cell; 201. First battery string group; 202. Second battery string group; 211. First diode; 212. Second diode; 213. Third diode; 214. Fourth diode; 221. First sub-battery string; 222. Second sub-battery string; 223. Third sub-battery string; 224. Fourth sub-battery string; 231. First bus bar; 232. Second bus bar; 233. Third bus bar; 234. Fourth bus bar; 235. Fifth bus bar; 241. First jumper wire; 242. Second jumper wire; 250. Long wire. Detailed Implementation

[0026] As is known from the background technology, bypass diodes can easily lead to a significant drop in the power of photovoltaic modules.

[0027] Figure 1 This is a schematic diagram of the circuit structure of a photovoltaic module in related technologies.

[0028] Figure 1In the photovoltaic module shown, the battery string 101 includes multiple battery cells connected in series. The three battery strings 101 located above the bypass diode 102 are connected in series in sequence, the three battery strings 101 located below the bypass diode 102 are connected in series in sequence, and the battery strings 101 located on the upper and lower sides of the same bypass diode 102 are connected in parallel with each other.

[0029] When the output voltage of the battery string 101 is less than or equal to the forward threshold voltage of the bypass diode 102, the bypass diode will act as a bypass. For example, if the cells in region A of the photovoltaic module are shaded, such as by a tree, the cells in region A will act as a load, causing the output voltage of the battery string 101 above the bypass diode 102 to decrease. After the bypass diode 102 acts as a bypass, the unshaded cells in region B will also be short-circuited, resulting in a significant reduction in the overall power of the photovoltaic module and affecting its efficiency.

[0030] When the threshold voltage of the bypass diode 102 is large, the bypass diode 102 will bypass when a small number of cells in a battery string 101 are invalid, resulting in a serious reduction in the power of the photovoltaic module. When the threshold voltage of the bypass diode 102 is small, the bypass diode 102 will bypass when a large number of cells in the photovoltaic module are invalid, which can easily cause hot spot effect and cause irreversible serious damage to the photovoltaic module.

[0031] This application provides a photovoltaic module that at least helps to balance the output performance of the photovoltaic module and improve its quality and performance.

[0032] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0033] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0034] In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0037] In the description of the embodiments of this application, technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0038] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0039] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included.

[0040] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0041] The embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0042] Figure 2 A schematic diagram of the circuit structure of a photovoltaic module provided in an embodiment of this application; Figure 3 for Figure 2 The diagram shows the structure of the photovoltaic module.

[0043] refer to Figure 2 and Figure 3 The photovoltaic module provided in this application includes: a first battery string group 201, a second battery string group 202, a first diode 211, a second diode 212, a third diode 213, and a fourth diode 214. The first battery string group 201 and the second battery string group 202 are arranged along a first direction H.

[0044] The first battery string group 201 includes a first sub-battery string 221 and a second sub-battery string 222 connected in series. The first sub-battery string 221 and the second sub-battery string 222 are arranged along the second direction V. The first sub-battery string 221 includes N battery cells 200 connected in series, and the second sub-battery string 222 includes M battery cells 200 connected in series. M and N are both positive integers, and N≠M.

[0045] The second battery string group 202 is connected in series with the first battery string group 201. The second battery string group 202 includes a third sub-battery string 223 and a fourth sub-battery string 224 connected in series. The third sub-battery string 223 and the fourth sub-battery string 224 are arranged along the second direction V. The third sub-battery string 223 includes X battery cells 200 connected in series, and the fourth sub-battery string 224 includes Y battery cells 200 connected in series. Where X and Y are both positive integers, and X≠Y, X+Y=M+N.

[0046] The first diode 211 is connected in reverse parallel with the first sub-cell string 221.

[0047] The second diode 212 is connected in reverse parallel with the second sub-cell string 222, and the threshold voltage of the second diode 212 is different from the threshold voltage of the first diode 211.

[0048] The third diode 213 is connected in reverse parallel with the third sub-cell series 223.

[0049] The fourth diode 214 is connected in reverse parallel with the fourth sub-cell string 224. The threshold voltage of the fourth diode 214 is different from the threshold voltage of the third diode 213.

[0050] In the photovoltaic module provided in this application embodiment, a first battery string group 201 and a second battery string group 202 are connected in series. The first battery string group 201 includes a first sub-battery string 221 and a second sub-battery string 222 with different numbers of connected battery cells 200. The second battery string group 202 includes a third sub-battery string 223 and a fourth sub-battery string 224 with different numbers of connected battery cells 200. The total number of connected battery cells 200 in the first battery string group 201 is the same as the total number of connected battery cells 200 in the second battery string group 202, but the number of connected battery cells in the sub-battery strings in each group is different. In this way, the number of series-connected cells can be set according to the environment of different sub-cell strings in each group. Then, the threshold voltages of the first diode 211, second diode 212, third diode 213, and fourth diode 214 corresponding to the first sub-cell string 221, second sub-cell string 222, third sub-cell string 223, and fourth sub-cell string 224 can be selected. This can avoid the unshaded cells 200 being bypassed when the shading conditions of cells 200 in different areas are different, thereby avoiding excessive power reduction of the photovoltaic module and affecting the overall output performance of the photovoltaic module.

[0051] In some embodiments, the solar cell 200 can be any one of the following: PERC cell (Passivated Emitter and Rear Cell), PERT cell (Passivated Emitter and Rear Totally-diffused cell), TOPCon cell (Tunnel Oxide Passivated Contact), HIT / HJT cell (Heterojunction Technology), or BC cell (Back Contact). The BC cell includes IBC cell (Interdigitated Back Contact), HPBC cell (Hybrid Passivated Back Contact), TBC cell combining TOPCon (Tunnel Oxide Passivated Contact) and IBC technologies, or HBC cell combining HIT / HJT (Heterojunction Technology) and IBC technologies. It can also be other types of back contact cells.

[0052] In some embodiments, the solar cell 200 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0053] In some embodiments, the solar cell 200 can be a single cell, or it can be a segmented cell. A segmented cell refers to multiple independent cells obtained from a single cell through a cutting process. The current of a solar cell is proportional to the area of ​​the silicon wafer; large-size solar cells inevitably involve large currents. When solar cells are connected in series and packaged into a module, the power loss is proportional to the square of the current. To reduce the power loss caused by current, the fabricated large-size solar cell can be divided into two, three, or even five segments, and then packaged into a half-cell, one-third-cell, or even one-fifth-cell module.

[0054] In some embodiments, the different battery cells 200 in the first battery string group 201 and the second battery string group 202 have the same area. That is, the battery cells 200 in the first battery string group 201 and the second battery string group 202 are all from whole cells, or all from 2-cell cells, or all from 3-cell cells, or all from 5-cell cells. In this way, the power of the different battery cells 200 can be kept similar, which is beneficial to the overall power stability of the first battery string group 201 and the second battery string group 202.

[0055] Along the first direction H, the width of the solar cell 200 is 180mm to 216mm, for example, it can be 180mm, 185mm, 190mm, 193mm, 200mm, 207mm, 210mm or 216mm.

[0056] Along the second direction V, the width of the solar cell 200 is 180mm to 216mm, for example, it can be 180mm, 185mm, 190mm, 193mm, 200mm, 207mm, 210mm or 216mm.

[0057] In the first sub-cell string 221, the number M of the series-connected cells 200 can be a positive integer greater than or equal to 3 and less than or equal to 34, for example, it can be 3, 5, 8, 10, 13, 16, 19, 20, 24, 26, 28, 30, 32 or 34.

[0058] In the second sub-cell string 222, the number N of the series-connected cells 200 can be a positive integer greater than or equal to 3 and less than or equal to 34, for example, it can be 3, 5, 8, 10, 13, 16, 19, 20, 24, 26, 28, 30, 32 or 34.

[0059] In the third sub-cell string 223, the number M of the series-connected cells 200 can be a positive integer greater than or equal to 3 and less than or equal to 34, for example, it can be 3, 5, 8, 10, 13, 16, 19, 20, 24, 26, 28, 30, 32 or 34.

[0060] In the fourth sub-cell string 224, the number N of the series-connected cells 200 can be a positive integer greater than or equal to 3 and less than or equal to 34, for example, it can be 3, 5, 8, 10, 13, 16, 19, 20, 24, 26, 28, 30, 32 or 34.

[0061] In some embodiments, M, N, X, and Y also satisfy the following relationships: 12≤X+Y=M+N≤45; 6≤YX≤23; 6≤MN≤23. That is, the number of series-connected cells 200 in a single battery string needs to be within an appropriate range, and the difference in the number of series-connected cells 200 between two sub-cell strings in different battery string groups needs to be within an appropriate range. This is to avoid an excessive number of series-connected cells 200 in a single sub-cell string, which would require a larger reverse breakdown voltage for the diode, increasing the cost of the diode. It also avoids the problem of a large number of short-circuited cells after the diode starts up, causing a significant reduction in the power of the module.

[0062] exist Figure 2 In this example, X equals N and Y equals M. In other embodiments, X may not equal N and Y may not equal M.

[0063] exist Figure 2 In this example, the number N of battery cells 200 connected in series in the first sub-battery string 221 is greater than the number M of battery cells 200 connected in series in the second sub-battery string 222. In other embodiments, the number N of battery cells connected in series in the first sub-battery string can be less than the number M of battery cells connected in series in the second sub-battery string.

[0064] exist Figure 2 In this example, the number X of battery cells 200 connected in series in the third sub-battery string 223 is less than the number Y of battery cells 200 connected in series in the fourth sub-battery string 224. In other embodiments, the number X of battery cells connected in series in the first sub-battery string can be greater than the number Y of battery cells connected in series in the fourth sub-battery string.

[0065] refer to Figure 3Along the first direction H, the distance L1 from any one of the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 to the edge of the photovoltaic module satisfies: L / 4≤L1≤L / 2, where L is the length L of the photovoltaic module along the first direction H.

[0066] In other words, the distance between the side of the first diode 211 furthest from the fourth diode 214 and the edge of the photovoltaic module is 1 / 4L to 1 / 2L; the distance between the side of the second diode 212 furthest from the third diode 213 and the edge of the photovoltaic module is 1 / 4L to 1 / 2L; the distance between the side of the third diode 213 furthest from the second diode 212 and the edge of the photovoltaic module is 1 / 4L to 1 / 2L; and the distance between the side of the fourth diode 214 furthest from the first diode 211 and the edge of the photovoltaic module is 1 / 4L to 1 / 2L. Thus, the appropriate distances between the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 and the edge of the photovoltaic module along the first direction X and along the first direction H avoid interference between the junction boxes corresponding to the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 and the edge of the photovoltaic module along the first direction H, preventing installation problems.

[0067] Continue to refer to Figure 3 Along the second direction V, the distance W1 from any of the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 to the edge of the photovoltaic module satisfies: W / 4≤W1≤W / 2, where W is the length W of the photovoltaic module along the second direction V.

[0068] In other words, the distance between the side of the first diode 211 furthest from the second diode 212 and the edge of the photovoltaic module is 1 / 4W to 1 / 2W; the distance between the side of the second diode 212 furthest from the first diode 211 and the edge of the photovoltaic module is 1 / 4W to 1 / 2W; the distance between the side of the third diode 213 furthest from the fourth diode 214 and the edge of the photovoltaic module is 1 / 4W to 1 / 2W; and the distance between the side of the fourth diode 214 furthest from the third diode 213 and the edge of the photovoltaic module is 1 / 4W to 1 / 2W. Thus, the appropriate distances between the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 and the edge of the photovoltaic module along the second direction V prevent interference between the junction boxes corresponding to the first diode 211, the second diode 212, the third diode 213, or the fourth diode 214 and the edge of the photovoltaic module along the second direction V, thus avoiding installation problems.

[0069] refer to Figure 2 and Figure 3The photovoltaic module also includes: a first busbar 231, a second busbar 232, a third busbar 233, a fourth busbar 234, and a fifth busbar 235. The first busbar 231 is connected to the end of the first sub-cell string 221 away from the second sub-cell string 222, and is connected to either the positive or negative output terminal of the photovoltaic module; the second busbar 232 is connected to the end of the second sub-cell string 222 away from the first sub-cell string 221, and is connected to the end of the third sub-cell string 223 away from the fourth sub-cell string 224; the third busbar 233 is located between the first sub-cell string 221 and the second sub-cell string 222, and is connected to both the first and second sub-cell strings 221; the fourth busbar 234 is located between the third sub-cell string 223 and the fourth sub-cell string 224, and is connected to both the third and fourth sub-cell strings 223; the fifth busbar 235 is connected to the end of the fourth sub-cell string 224 away from the third sub-cell string 223, and is connected to either the positive or negative output terminal of the photovoltaic module.

[0070] Continue to refer to Figure 2 and Figure 3 The number of first sub-battery strings 221 can be multiple. The number of second sub-battery strings 222 is equal to the number of first sub-battery strings 221. Multiple first sub-battery strings 221 are connected in parallel through a first bus bar 231 and a third bus bar 233. Multiple second sub-battery strings 222 are connected in parallel through a second bus bar 232 and a third bus bar 233. The number of third sub-battery strings 223 can be multiple. The number of fourth sub-battery strings 224 is equal to the number of third sub-battery strings 223. Multiple third sub-battery strings 223 are connected in parallel through a second bus bar 232 and a fourth bus bar 234. Multiple fourth sub-battery strings 224 are connected in parallel through a fourth bus bar 234 and a fifth bus bar 235.

[0071] exist Figure 2 In the example, the number of the first sub-battery string 221 and the second sub-battery string 222 are both 3, and the number of the third sub-battery string 223 and the fourth sub-battery string 224 are both 3.

[0072] In other embodiments, the number of the first sub-battery string may not be equal to the number of the fourth or third sub-battery string. For example, the number of the first and second sub-battery strings may both be 2, and the number of the third and fourth sub-battery strings may both be 4; or, the number of the first and second sub-battery strings may both be 5, and the number of the third and fourth sub-battery strings may both be 2.

[0073] Continue to refer to Figure 2 and Figure 3The photovoltaic module also includes: a first jumper 241 and a second jumper 242. The first jumper 241 connects the first busbar 231, the second busbar 232 and the third busbar 233. A first diode 211 is connected in series on the first jumper 241 between the first busbar 231 and the third busbar 233, and a second diode 212 is connected in series on the first jumper 241 between the second busbar 232 and the third busbar 233. The second jumper 242 connects the second busbar 232, the fourth busbar 234 and the fifth busbar 235. A third diode 213 is connected in series on the second jumper 242 between the second busbar 232 and the fourth busbar 234, and a fourth diode 214 is connected in series on the second jumper 242 between the fourth busbar 234 and the fifth busbar 235.

[0074] Figure 4 This application provides a schematic diagram of the structure of multiple photovoltaic module assemblies.

[0075] Typically, diodes are located inside a junction box, which is connected to jumpers via leads. Therefore, the position of the jumpers corresponds to the position of the junction box. (Refer to the reference.) Figure 3 and Figure 4 In the direction from the first battery string group 201 to the second battery string group 202, the first jumper 241 is located between the penultimate first sub-cell string 221 and the penultimate first sub-cell string 221, and the second jumper 242 is located between the first fourth sub-cell string 224 and the second fourth sub-cell string 224. Thus, when two photovoltaic modules are arranged vertically and connected in series via a long conductor 250, the distance between the first jumper 241 in one photovoltaic module and the second jumper 242 in the other photovoltaic module can be relatively short, thereby shortening the length of the long conductor 250 and saving on its usage cost. Furthermore, placing the first jumper 241 and the second jumper 242 between the gaps in the battery strings avoids leakage caused by direct contact between the jumper and the battery cells; for double-glass modules, placing the first jumper 241 and the second jumper 242 between the gaps in the battery strings also prevents the jumper from shading the back of the photovoltaic module.

[0076] In some embodiments, a buffer pad (not shown in the figure) may be provided between the first jumper 241 and the battery cell 200, and a buffer pad (not shown in the figure) may be provided between the second jumper 242 and the battery cell 200. The buffer pad can insulate the jumper from the battery cell 200 to ensure that no leakage occurs between the jumper and the battery cell 200 in the event of jumper misalignment, and the buffer pad can also act as a stress buffer to prevent the jumper from causing the battery cell to crack.

[0077] The width of the first jumper 241 can be smaller than the width of the buffer pad. The difference between the width of the buffer pad and the width of the first jumper 241 can be 2mm to 10mm, for example, it can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0078] The width of the second jumper 242 can be smaller than the width of the buffer pad. The difference between the width of the buffer pad and the width of the second jumper 242 can be 2mm to 10mm, for example, it can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0079] The thickness of the buffer pad can be 0.05mm to 0.75mm, for example, it can be 0.05mm, 0.06mm, 0.08mm, 0.1mm, 0.3mm, 0.5mm, 0.7mm or 0.75mm.

[0080] In the photovoltaic module provided in this application embodiment, a first battery string group 201 and a second battery string group 202 are connected in series. The first battery string group 201 includes a first sub-battery string 221 and a second sub-battery string 222 with different numbers of connected battery cells 200. The second battery string group 202 includes a third sub-battery string 223 and a fourth sub-battery string 224 with different numbers of connected battery cells 200. The total number of connected battery cells 200 in the first battery string group 201 is the same as the total number of connected battery cells 200 in the second battery string group 202, but the number of connected battery cells in the sub-battery strings in each group is different. In this way, the number of series-connected cells can be set according to the environment of different sub-cell strings in each group. Then, the threshold voltages of the first diode 211, second diode 212, third diode 213, and fourth diode 214 corresponding to the first sub-cell string 221, second sub-cell string 222, third sub-cell string 223, and fourth sub-cell string 224 can be selected. This can avoid the unshaded cells 200 being bypassed when the shading conditions of cells 200 in different areas are different, thereby avoiding excessive power reduction of the photovoltaic module and affecting the overall output performance of the photovoltaic module.

[0081] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: The first battery string group includes a first sub-battery string and a second sub-battery string arranged in series along a second direction. The first sub-battery string includes N battery cells connected in series, and the second sub-battery string includes M battery cells connected in series, where M and N are both positive integers, and M≠N. The second battery string group is connected in series with the first battery string group, and the first battery string group and the second battery string group are arranged along a first direction. The second battery string group includes a third sub-battery string and a fourth sub-battery string connected in series and arranged along the second direction. The third sub-battery string includes X battery cells connected in series, and the fourth sub-battery string includes Y battery cells connected in series, where X and Y are both positive integers, and X≠Y, X+Y=M+N; The first diode is connected in reverse parallel with the first sub-cell series; The second diode is connected in reverse parallel with the second sub-cell string, and the threshold voltage of the second diode is different from that of the first diode. The third diode is connected in reverse parallel with the third sub-cell; The fourth diode is connected in reverse parallel with the fourth sub-cell string, and the threshold voltage of the fourth diode is different from that of the third diode.

2. The photovoltaic module according to claim 1, characterized in that, M, N, X, and Y satisfy the following conditions: 3≤M≤34; 3≤N≤34; 3≤X≤34; 3≤Y≤34; 12≤X+Y=M+N≤45; 6≤YX≤23; 6≤MN≤23.

3. The photovoltaic module according to claim 2, characterized in that, M, N, X, and Y also satisfy: X = N, Y = M.

4. The photovoltaic module according to claim 1, characterized in that, Along the first direction, the distance L1 from any of the first diode, the second diode, the third diode, or the fourth diode to the edge of the photovoltaic module satisfies: L / 4 ≤ L1 ≤ L / 2, where L is the length of the photovoltaic module along the first direction.

5. The photovoltaic module according to claim 1 or 4, characterized in that, Along the second direction, the distance W1 from any of the first diode, the second diode, the third diode, or the fourth diode to the edge of the photovoltaic module satisfies: W / 4 ≤ W1 ≤ W / 2, where W is the length of the photovoltaic module along the second direction.

6. The photovoltaic module according to claim 1, characterized in that, Also includes: The first busbar is connected to the end of the first sub-cell string away from the second sub-cell string, and is connected to either the positive output terminal or the negative output terminal of the photovoltaic module. The second busbar is connected to the end of the second sub-battery string away from the first sub-battery string, and is also connected to the end of the third sub-battery string away from the fourth sub-battery string. The third busbar is located between the first sub-battery string and the second sub-battery string, and connects the first sub-battery string and the second sub-battery string; A fourth busbar is located between the third sub-battery string and the fourth sub-battery string, and connects the third sub-battery string and the fourth sub-battery string; The fifth busbar is connected to the end of the fourth sub-cell string away from the third sub-cell string, and is connected to either the positive or negative output terminal of the photovoltaic module.

7. The photovoltaic module according to claim 6, characterized in that, The number of first sub-battery strings is multiple, the number of second sub-battery strings is equal to the number of first sub-battery strings, the multiple first sub-battery strings are connected in parallel through the first bus bar and the third bus bar, and the multiple second sub-battery strings are connected in parallel through the second bus bar and the third bus bar; The number of the third sub-battery strings is multiple, and the number of the fourth sub-battery strings is equal to the number of the third sub-battery strings. The multiple third sub-battery strings are connected in parallel through the second bus bar and the fourth bus bar, and the multiple fourth sub-battery strings are connected in parallel through the fourth bus bar and the fifth bus bar.

8. The photovoltaic module according to claim 7, characterized in that, Also includes: A first jumper is connected to the first busbar, the second busbar, and the third busbar. A first diode is connected in series on the first jumper between the first busbar and the third busbar, and a second diode is connected in series on the first jumper between the second busbar and the third busbar. The first jumper is located between the penultimate first sub-battery string and the penultimate first sub-battery string in the direction from the first battery string group to the second battery string group. The second jumper connects the second busbar, the fourth busbar, and the fifth busbar. The third diode is connected in series on the second jumper between the second busbar and the fourth busbar, and the fourth diode is connected in series on the second jumper between the fourth busbar and the fifth busbar. The second jumper is located between the first fourth sub-battery string and the second fourth sub-battery string in the direction from the first battery string group to the second battery string group.

9. The photovoltaic module according to claim 8, characterized in that, A buffer pad is provided between the first jumper and the battery cell, and a buffer pad is provided between the second jumper and the battery cell. The width of the first jumper is smaller than the width of the buffer pad, and the width of the second jumper is smaller than the width of the buffer pad.

10. The photovoltaic module according to claim 9, characterized in that, The width difference between the buffer pad and the width of the first jumper is 2mm to 10mm; the width difference between the buffer pad and the width of the second jumper is 2mm to 10mm; the thickness of the buffer pad is 0.05mm to 0.75mm.

11. The photovoltaic module according to claim 1, characterized in that, In the first battery string group and the second battery string group, the different battery cells have the same area.

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