Quadri- segmented solar cell module

Abstract

The application discloses a four-split solar cell module, which comprises two series-connected cell units, each of which comprises two parallel-connected cell series, the two cell series of each cell unit are collectively connected in parallel with a bypass diode, each cell series comprises two series-connected cell combinations, each cell combination comprises three parallel-connected cell strings, each cell string comprises N series-connected cell splits, N is greater than or equal to 2, the cell splits are obtained by equally dividing a solar cell along a first split line and a second split line, the first split line is perpendicular to a pair of edges of the solar cell, and the second split line is perpendicular to another pair of edges of the solar cell. The module of the application alleviates the current mismatch problem, reduces the use amount of a junction box and glue used for sealing the junction box. Under the condition that the system voltage is unchanged, more solar cell modules of the application can be connected in series in a photovoltaic array string, thereby reducing the use amount of inverters and lowering the BOS cost.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, specifically to a four-segment solar cell module. Background Technology

[0002] Current transport losses in a solar cell string are positively correlated with the square of the circuit current. Therefore, power losses in a solar cell module can be reduced by decreasing the circuit current.

[0003] In existing technologies, solar cell modules primarily utilize half-cell solar cells. A half-cell solar cell is obtained by uniformly cutting a full-cell solar cell along its middle. Compared to a single-cell solar cell, the photocurrent in a series circuit of two half-cell solar cells is reduced to half that of a full-cell solar cell. To further reduce current transmission losses in the cell string and increase module power, such as... Figure 1 In some existing technologies, a solar cell is divided into four equal segments along a direction perpendicular to the main grid. Compared to a half-cell cell, a four-segment cell can reduce the current to half that of a half-cell cell. However, in reality, the four segments of the cell do not generate equal currents during operation, leading to current mismatch problems in the series circuit.

[0004] Please refer to Figure 2 In existing technologies, quad-segment solar cell modules all use three bypass diodes connected in parallel to resist hot spots. Utility Model Content

[0005] This disclosure provides a solar cell module that solves the circuit mismatch problem of multi-segment solar cell modules and saves on junction boxes.

[0006] According to one aspect of this disclosure, a four-segment solar cell module is provided, comprising two series-connected cell units, each cell unit comprising two parallel-connected cell series, the two cell series of each cell unit being connected in parallel to a bypass diode, each cell series comprising two series-connected cell combinations, each cell combination comprising three parallel-connected cell strings, each cell string comprising N series-connected cell segments, N being greater than or equal to 2, the cell segments being obtained by dividing the solar cell into four equal parts along a first tangent line and a second tangent line, the first tangent line being perpendicular to one pair of sides of the solar cell, and the second tangent line being perpendicular to the other pair of sides of the solar cell.

[0007] The four-segment solar cell module of this embodiment is obtained by cutting a whole solar cell into four equal parts along a crosshair. Each segment has an equal cutting edge length, reducing the unevenness of current loss among the four segments, thus mitigating the current mismatch problem. The circuit structure of this embodiment's solar cell module has two parallel bypass diodes and requires two junction boxes, reducing the number of junction boxes and the amount of adhesive used to seal them compared to existing technologies. Furthermore, the inventors of this application have surprisingly discovered that for the same number and specifications of whole solar cells, the output voltage of this four-segment solar cell module is reduced by 1 / 3 compared to existing four-segment solar cell modules. Under the condition of a constant system voltage (e.g., 1500V), more solar cell modules of this application can be connected in series in the photovoltaic array string, thereby reducing the number of inverters required and lowering the balance of power (BOS). System cost.

[0008] In some embodiments, the solar cell module includes cell strings arranged in a 12-column × 2-row configuration. Each cell string extends along the column direction, and every three adjacent cell strings in the row direction form a cell combination. Every two adjacent cell combinations form a cell series. Two cell series arranged in the column direction form a cell unit. Each cell unit has end busbars at both ends. The end busbars connect two cell combinations in series within each cell series and connect three cell strings in parallel within each cell combination. A first intermediate busbar and a second intermediate busbar are provided between the two cell series in each cell unit. The first intermediate busbar and the second intermediate busbar connect three cell strings in parallel within the two cell combinations in the cell series, respectively. The two cell series in each cell unit share the first intermediate busbar and the second intermediate busbar. The two cell units share the second intermediate busbar, which connects the two cell units in series. Bypass diodes are connected between the first intermediate busbar and the second intermediate busbar.

[0009] In some implementations, N is equal to any one of 6, 9, 11, 12, and 13.

[0010] In some implementations, the front and back sides of the battery cells have electrode patterns, or only the back side.

[0011] In some implementations, the length L1 and width L2 of the solar cell satisfy 180mm≤L1≤212mm and 180mm≤L2≤212mm, respectively.

[0012] In some implementations, the width of the solar cell module is 1139±2mm, or the width of the solar cell module is 1308±2mm.

[0013] In some implementations, the solar cell module includes two junction boxes, with each bypass diode housed in one junction box. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This illustrates a four-part segmentation method in the prior art.

[0016] Figure 2 The equivalent circuit diagram of a quad-segment solar cell module in the prior art is shown.

[0017] Figure 3 The present disclosure illustrates the slicing method of the quadrature solar cells in a quadrature solar cell module in some examples.

[0018] Figure 4 A cell arrangement diagram of a quadrature solar cell module in some examples of this disclosure is shown.

[0019] Figure 5 Equivalent circuit diagrams of quad-segment solar cell modules in some examples of this disclosure are shown. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the present invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0023] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0024] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] The inventors of this application have discovered that the cause of circuit mismatch and EL brightness differences is the unequal power of each of the four segments. Although the existing four-segment design is geometrically equal, in reality, the power of the four segments is not equal; rather, the two smaller segments at the edges have higher power than the two smaller segments in the middle. The inventors have discovered the following reasons:

[0027] (1) The electrical properties of the monocrystalline silicon wafers used to prepare solar cells are unevenly distributed, resulting in unequal power distribution among the smaller wafers after geometric division. The silicon wafers used to prepare solar cells are obtained by cutting monocrystalline silicon rods. Monocrystalline silicon rods are produced by crystal pulling, and the process itself causes the minority carrier lifetime in the middle of the monocrystalline silicon rod to be shorter than that at the edge.

[0028] (2) The uneven distribution of electrical properties in the solar cell fabrication process leads to unequal power distribution among the individual cells after geometric division. During cell fabrication, minute variations in process conditions, such as non-uniform phosphorus diffusion in the diffusion process and differences in the contact resistance between the electrode and the silicon wafer during electrode fabrication, result in differences in minority carrier lifetime, series resistance, and other electrical parameters across different regions of the solar cell. The diffusion process also causes the sheet resistance in the middle to be higher than that at the edges. The minority carrier lifetime at the edges may be relatively longer, or the series resistance relatively smaller, allowing the two edge cells to collect and transport photogenerated carriers more effectively under the same illumination conditions, thus resulting in higher output power.

[0029] (3) The impact of the slitting process on the solar cells. The slitting operation of the solar cells will destroy the crystalline silicon integrity of the monocrystalline silicon and introduce a large number of defects on the cut surface. These defects will become recombination centers, resulting in power loss of the solar cells. The two middle cells each have two cut surfaces, while the two edge cells each have one cut surface. Therefore, the power loss of the two middle cells is greater than that of the two edge cells.

[0030] In view of this, a quad-segment solar cell module is provided according to the present disclosure.

[0031] The cells in a quadruple solar cell module are obtained by cutting the solar cell into four equal parts along a cross.

[0032] For example, the solar cells are rectangular or square. (e.g.) Figure 3 As shown, the solar cell is divided into four equal segments 6 along mutually orthogonal first tangent line D1 and second tangent line D2. The first tangent line D1 passes through the center of the solar cell and is perpendicular to one pair of opposite sides of the solar cell, while the second tangent line D2 passes through the center of the solar cell and is perpendicular to another pair of opposite sides of the solar cell. The four segments 6 obtained by dividing the cell along the first tangent line D1 and second tangent line D2 have equal cutting edge lengths, and each segment is allocated an equal size central region. This reduces the unevenness of current loss among the four segments 6, that is, it reduces the current difference between the segments 6, thereby alleviating the current mismatch problem.

[0033] For example, the solar cell can be a monocrystalline silicon or polycrystalline silicon solar cell, or a perovskite-silicon tandem solar cell. Specifically, the solar cell can be TOPCon (tunneling oxide passivated contact), HJT (heterojunction), or PERC (emitter and back passivated cell). Electrode patterns with different polarities can be simultaneously set on the surface of the solar cell; for example, the solar cell can be an IBC (interdigitated back contact) cell.

[0034] Please combine Figure 4 and Figure 5The quad-segment solar cell module includes two series-connected cell units 1. Each cell unit 1 includes two parallel-connected cell series 2. The two cell series 2 of each cell unit 1 are connected in parallel to a bypass diode 5. Each cell series 2 includes two series-connected cell combinations 3. Each cell combination 3 includes three parallel-connected cell strings 4. Each cell string 4 includes N series-connected cell segments 6, where N is greater than or equal to 2.

[0035] According to some exemplary embodiments of this disclosure, the circuit structure of the quad-cell solar cell module has two bypass diodes connected in parallel and requires two junction boxes, which reduces the number of junction boxes and the amount of adhesive used to seal the junction boxes compared to the prior art.

[0036] Furthermore, the inventors of this application have also discovered with surprise that, for the same number and specifications of whole cells, the output voltage of the quad-cell solar cell modules in some exemplary embodiments of this disclosure is reduced by 1 / 3 compared to the quad-cell solar cell modules of the prior art. With the system voltage (e.g., 1500V) remaining constant, more of the quad-cell solar cell modules of this application can be connected in series in the photovoltaic array, thereby reducing the number of inverters required and lowering the BOS (Balance of System) cost.

[0037] In some embodiments, the quad-segment solar cell module includes 12 columns × 2 rows of cell strings 4, each cell string 4 extending along the column direction Y. That is, there are 12 parallel cell strings 4 in the row direction X, all extending along the column direction Y. In the row direction X, every 3 adjacent cell strings 4 form a cell combination 3, so each row of the cell string array constructs 4 cell combinations 3. Every 2 adjacent cell combinations 3 form a cell series 2, that is, each row of the cell string array constructs 2 cell series 2. Two cell series 2 arranged in the column direction Y form a cell unit 1, that is, the 12 columns × 2 rows of cell strings 4 form two cell units 1. The size of the quad-segment solar cell module resulting from the parallel arrangement of 12 columns of cell strings 4 is substantially the same as that of solar cell modules in the prior art.

[0038] For example, each battery cell 1 has an end busbar 7 at both ends. The end busbar 7 connects two battery assemblies 3 in series within each battery series 2 and connects three battery strings 4 in parallel within each battery assembly 3. Specifically, the end busbar 7 extends along the row direction X. The same polarity of the three battery strings 4 in each battery assembly 3 is located at the same end, and the opposite polarity of the two battery assemblies 3 in the same battery series 2 is located at the same end. When the end busbar 7 is connected to the ends of each battery string 4 in the battery series 2, it can simultaneously connect two battery assemblies 3 in series within each battery series 2 and connect three battery strings 4 in parallel within each battery assembly 3.

[0039] For example, a first intermediate busbar 8 and a second intermediate busbar 9 are provided between the two battery series 2 of each battery cell 1. The first intermediate busbar 8 and the second intermediate busbar 9 connect the three battery strings 4 in the two battery combinations 3 of the battery series 2 in parallel, that is, the first intermediate busbar 8 connects the three battery strings 4 in one of the battery combinations 3 of the battery series 2 in parallel, and the second intermediate busbar 9 connects the three battery strings 4 in the other battery combination 3 of the same battery series in parallel. The two battery series 2 in each battery cell 1 share the first intermediate busbar 8 and the second intermediate busbar 9, and the two battery cells 1 share the second intermediate busbar 9. The second intermediate busbar 9 connects the two battery cells 1 in series, and a bypass diode 5 is connected between the first intermediate busbar 8 and the second intermediate busbar 9.

[0040] In some embodiments, the quad-cell solar cell module includes two junction boxes, each containing a bypass diode 5. The positive and negative terminals of the solar cell module are led out from the two junction boxes, respectively.

[0041] In some embodiments, N is equal to any one of 6, 9, 11, 12, and 13. Different values ​​of N can yield solar cell modules of different sizes and power.

[0042] In some embodiments, the front and back sides of the solar cell 6 may have electrode patterns, either simultaneously or only on the back side. The front side of the solar cell or cell may be the side facing solar radiation during operation, and the back side may be the side facing away from solar radiation during operation. Electrode patterns of different polarities of the solar cell may be respectively disposed on the front and back sides of the cell; for example, a positive electrode pattern may be disposed on the front side and a negative electrode pattern on the back side, or vice versa. Exemplarily, the solar cell may be a TOPCon (tunneling oxide passivated contact), HJT (heterojunction), or PERC (emitter and back passivated cell). Electrode patterns of different polarities of the solar cell may also be simultaneously disposed on the back side of the solar cell; exemplarily, the solar cell may be an IBC (interdigitated back contact) cell.

[0043] In some embodiments, the quad-cell solar cell module further includes a front cover, a rear cover, and an encapsulant, with the cell string array sealed between the front and rear covers by the encapsulant.

[0044] In some embodiments, the length L1 and width L2 of the solar cell satisfy 180mm≤L1≤212mm and 180mm≤L2≤212mm, respectively. For example, the length L1 of the solar cell can be 182.2mm and the width L2 can be 183.75mm; or, the length L1 can be 182mm and the width L2 can be 210mm; or, the length L1 can be L1=210mm and the width L2 can be 210mm.

[0045] In some embodiments, the width of the quadrature solar cell module is 1139±2 mm, or the width of the quadrature solar cell module is 1308±2 mm. The width direction can be the row direction X of the cell string array. According to the general cell string spacing in the art, in related technologies, for a solar cell with a side length of 182 mm, the width of a solar cell module with 6 rows of cell strings is generally about 1134 mm, while for a solar cell with a side length of 210 mm, the width of a solar cell module with 6 rows of cell strings is generally about 1303 mm. According to the general cell string spacing, this disclosure has 12 rows of cell strings composed of quadrature cell segments. Although this increases the number of cell string segments, the width of the solar cell module only increases by a few millimeters, and will not have a significant negative impact on the packaging and power density of the solar cell module.

[0046] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A quad-cell solar cell module, characterized in that, It includes two series-connected battery units (1), each battery unit (1) includes two parallel-connected battery series (2), the two battery series (2) of each battery unit (1) are connected in parallel to a bypass diode (5), each battery series (2) includes two sets of series-connected battery combinations (3), each set of battery combinations (3) includes three parallel-connected battery strings (4), each battery string (4) includes N series-connected battery segments (6), N is greater than or equal to 2, the battery segments (6) are obtained by dividing the solar cell into four equal parts along the first tangent line (D1) and the second tangent line (D2), the first tangent line (D1) is perpendicular to one pair of sides of the solar cell, and the second tangent line (D2) is perpendicular to the other pair of sides of the solar cell.

2. The quad-segment solar cell module according to claim 1, characterized in that, The solar cell module includes 12 columns × 2 rows of cell strings (4), each cell string (4) extending along the column direction. Every 3 adjacent cell strings (4) in the row direction form a cell combination (3), and every 2 adjacent cell combinations (3) form a cell series (2). Two cell series (2) arranged in the column direction form a cell unit (1). Each of the battery cells (1) is provided with end busbars (7) at both ends. The end busbars (7) connect two battery combinations (3) in series within each battery series (2) and connect three battery strings (4) in parallel within each battery combination (3). A first intermediate busbar (8) and a second intermediate busbar (9) are provided between the two battery series (2) of each battery cell (1). The first intermediate busbar (8) and the second intermediate busbar (9) respectively connect the three battery strings (4) in the two battery combinations (3) in the battery series (2) in parallel. The two battery series (2) in each battery cell (1) share the first intermediate busbar (8) and the second intermediate busbar (9). The two battery cells (1) share the second intermediate busbar (9). The second intermediate busbar (9) connects the two battery cells (1) in series. A bypass diode (5) is connected between the first intermediate busbar (8) and the second intermediate busbar (9).

3. The quad-segment solar cell module according to claim 1, characterized in that, N is any one of 6, 9, 11, 12, and 13.

4. The quad-segment solar cell module according to claim 1, characterized in that, The battery segment (6) has electrode patterns on both the front and back sides, or only on the back side.

5. The quad-segment solar cell module according to claim 1, characterized in that, The length L1 and width L2 of the solar cell satisfy 180mm≤L1≤212mm and 180mm≤L2≤212mm, respectively.

6. The quad-segment solar cell module according to claim 2, characterized in that, The width of the solar cell module is 1139±2mm, or the width of the solar cell module is 1308±2mm.

7. The quad-segment solar cell module according to claim 2, characterized in that, It includes two junction boxes, with each of the bypass diodes (5) disposed in one junction box.

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