Photovoltaic module for reducing current loss based on cell subdivision and circuit thereof
By subdividing the solar cells into multiple segments and rationally designing the solder strips and busbars, the problems of increased current and material costs caused by large-size solar cells were solved, thus realizing the design of a photovoltaic module with low loss and high power generation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- EGING PHOTOVOLTAIC TECHNOLOGY CO LTD
- Filing Date
- 2025-04-22
- Publication Date
- 2026-05-01
AI Technical Summary
The application of large-size solar cells leads to an increase in the internal current of photovoltaic modules, which increases current loss and the risk of heat generation. At the same time, the increase in the diameter of the solder ribbon and the thickness of the encapsulation film increases material costs and shading effect, affecting the photoelectric conversion efficiency of the modules.
The battery cells are subdivided into multiple segments and connected in series by solder strips. Copper strips with a plating protection are used as solder strips and busbars. A reasonable busbar structure is designed to match the current, and battery strings and circuit matrices are constructed to reduce the current and solder strip cross-sectional area within a single battery string.
It reduces current loss, decreases component heating risk and material costs, and improves power generation output efficiency and photoelectric conversion efficiency.
Smart Images
Figure CN224192350U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic module technology, specifically a photovoltaic module and its circuit based on cell subdivision to reduce current loss. Background Technology
[0002] In the field of photovoltaic power generation, photovoltaic modules, as core components, directly affect energy conversion efficiency and system operational stability through their structural design. Traditional photovoltaic modules typically use whole cells or two-cell cells connected in series to form a cell string with specific voltage and current output. However, with the continuous advancement of photovoltaic technology, cell sizes are trending towards larger dimensions. While this evolution increases module power density, it also brings a series of technical challenges.
[0003] Specifically, the use of larger solar cells leads to a significant increase in the current of a single cell string. This increased current not only exacerbates current losses within the module but also significantly increases the risk of overheating during module operation.
[0004] To address the challenges posed by increased current, current technologies require a corresponding increase in the diameter of the solder ribbon to enhance its current-carrying capacity and ensure effective current transmission. However, increasing the ribbon diameter directly leads to a rise in the amount of ribbon used, increasing material costs and increasing the ribbon's coverage area on the cell surface, thus exacerbating the shading effect and further impacting the module's photoelectric conversion efficiency. Simultaneously, to accommodate the thicker ribbon and ensure module encapsulation reliability, the encapsulation film thickness must be increased to provide sufficient insulation protection and stress buffering. This increased film thickness further raises material costs. Summary of the Invention
[0005] To address the technical problems in the background art, this utility model discloses a photovoltaic module and its circuit based on cell subdivision to reduce current loss.
[0006] This utility model provides a photovoltaic module based on cell segmentation to reduce current loss, including a cell string, which is composed of multiple cells segmented and connected in series with solder strips;
[0007] Solar cell slicing is achieved by uniformly cutting solar cells along the fine grid direction and the main grid direction;
[0008] The solar cell is divided into 4a solar cell segments, where a is a natural number greater than 0;
[0009] The electrodes in the battery cell slabs are printed as independent areas;
[0010] The solar cells are connected in series by solder strips.
[0011] The current of the solar cell is set as I, and the current of each solar cell segment is set as I1, where I1 = I / 4a. The cross-sectional area of the solder ribbon is proportional to the current of the cell string. Therefore, the beneficial effects of the above settings are: 1. By dividing the solar cell into multiple segments, the current in a single cell string is reduced, which reduces current loss, significantly reduces the risk of module overheating, and results in higher power output; 2. By dividing the solar cell into multiple segments, the current in a single cell string is reduced, and the cross-sectional area of the solder ribbon is reduced, thereby reducing the cross-sectional area of the interconnecting strips of the series-connected cell strings, which can reduce the material cost of the module.
[0012] The specific connection structure of the welding strip is as follows: the welding strip connects the positive electrode of one of the battery cell segments to the negative electrode of the battery cell segment that is longitudinally adjacent to it.
[0013] Furthermore, the substrate of the solder strip is a copper strip, and a plating layer is provided on the outer side of the copper strip; the plating layer is one of tin-lead, tin-bismuth, tin-indium, tin-lead-indium, tin-lead-bismuth, or tin-bismuth-silver. The plating layer is used to protect the copper strip and increase the solderability of the busbar.
[0014] The battery strings are connected by busbars. The specific structure of the busbars is as follows: the outer ends of the battery strings are connected by multiple spaced first busbars; adjacent battery strings are connected by spaced second and third busbars; the second busbars are located on both sides, and the third busbars are located between the second busbars.
[0015] Furthermore, the base material of the first, second, and third busbars is copper strip, with a tin-lead alloy plating on the surface. The tin-lead alloy is used to protect the copper strip and increase the solderability of the busbars.
[0016] Furthermore, the first busbar is arranged linearly; one end of the second busbar is bent; and both ends of the third busbar are bent. Specifically, the bending angles are 90° for both the second and third busbars. This arrangement connects the bent portions to the junction box, leading the internal circuitry to the outside of the photovoltaic module; the bending length matches the junction box structure design, ensuring sufficient welding area between the busbars and the terminals.
[0017] The cross-sectional area of the busbar is matched with the current. The first busbar is the current path after two battery strings are connected in series and parallel. The current is relatively small, so its cross-sectional area is also relatively small. The second and third busbars are the current path after four battery strings are connected in series and parallel. The current is relatively large, so their cross-sectional areas are also relatively large. To ensure that the busbars are matched with the current, specifically: the width of the second and third busbars is 6-10mm and the thickness is 0.15-0.5mm; the width of the first busbar is 4-6mm and the thickness is 0.15-0.5mm.
[0018] This utility model also provides a photovoltaic module circuit based on cell subdivision to reduce current loss, including a cell string;
[0019] One end of the battery string is led out as the positive terminal, and the other end is led out as the negative terminal;
[0020] Each pair of battery strings is connected in series and parallel to form the first battery matrix;
[0021] Two first battery matrices are connected in series to form a second battery matrix;
[0022] Two second battery matrices are connected in parallel to form a third battery matrix;
[0023] Several third-generation battery arrays connected in series;
[0024] Each third cell matrix has a diode connected in parallel.
[0025] The beneficial effects of this utility model are: 1. By dividing the battery cells into multiple parts, the current in a single battery string is reduced, which can reduce current loss, significantly reduce the risk of module overheating, and achieve higher power output; 2. By dividing the battery cells into multiple parts, the current in a single battery string is reduced, the cross-sectional area of the solder strip is reduced, thereby reducing the cross-sectional area of the interconnecting strip of the series battery strings, which can reduce the material cost of the module. Attached Figure Description
[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0027] Figure 1 This is the circuit diagram of this utility model;
[0028] Figure 2 This is a schematic diagram of the battery cell cutting pattern;
[0029] Figure 3 This is a schematic diagram of the cell segmentation process;
[0030] Figure 4 This is a schematic diagram of the busbar installation structure;
[0031] Figure 5 This is a top view of the busbar;
[0032] Figure 6 This is a schematic diagram of a battery cell assembly composed of battery cell segments in the embodiment;
[0033] In the diagram: 1. Battery string; 2. Battery cell segment; 3. Solder ribbon; 4. Battery cell; 6. First busbar; 7. Second busbar; 8. Third busbar; 9. First battery matrix; 10. Second battery matrix; 11. Third battery matrix; 12. Diode. Detailed Implementation
[0034] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.
[0035] This utility model discloses a photovoltaic module that reduces current loss based on cell subdivision, including a cell string 1, a busbar, and a diode 12. Its circuit diagram is as follows: Figure 1 As shown, one end of battery string 1 is the positive terminal, and the other end is the negative terminal. Every two battery strings 1 are connected in parallel to form a first battery matrix 9, that is, every two battery strings 1 are connected with their positive terminals connected to each other and their negative terminals connected to each other. Every two first battery matrices 9 are connected in series to form a second battery matrix 10. Every two second battery matrices 10 are connected in parallel to form a third battery matrix 11. Each third battery matrix 11 is connected in parallel with a diode 12. Any number of third battery matrices 11 are connected in series, and each third battery matrix 11 is connected in parallel with a diode 12.
[0036] like Figure 6 As shown, the battery string 1 is composed of multiple battery cells 2 connected in series by solder strips 3. In this embodiment, n=72. Figure 3 As shown, the solar cell slice 2 is formed by uniformly cutting the solar cell 4 along the fine grid direction and the main grid direction; the solar cell 4 is cut into 4a solar cell slices 2, where a is a natural number greater than 0, and in this embodiment a=1. The cutting process is as follows: the electrodes in the solar cell slice 2 are printed as independent areas, and then laser-cut. The solar cell slices 2 are connected in series by solder ribbons 3, which connect the positive electrode of one solar cell slice 2 to the negative electrode of the solar cell slice 2 that is longitudinally adjacent to it.
[0037] The substrate of solder strip 3 is a copper strip, and a plating layer is provided on the outer side of the copper strip; the plating layer is one of tin-lead, tin-bismuth, tin-indium, tin-lead-indium, tin-lead-bismuth, or tin-bismuth-silver. The plating layer is used to protect the copper strip and increase the solderability of the busbar.
[0038] The specific structure of the bus bar is as follows: Figure 2 , Figure 4 and Figure 5 As shown, the upper and lower ends of the battery string 1 are connected by three spaced-apart first busbars 6; the longitudinally adjacent battery strings 1 are connected by spaced-apart second busbars 7 and third busbars 8; there are two second busbars 7 located on both sides, and two third busbars 8 located between the second busbars 7.
[0039] The base material of the first busbar 6, the second busbar 7, and the third busbar 8 is copper strip, with a tin-lead alloy plating on the surface. The tin-lead alloy is used to protect the copper strip and increase the solderability of the busbar.
[0040] The first busbar 6 is arranged linearly;
[0041] Because the cross-sectional area of the busbars is matched to the current, the first busbar 6 is the current path for two battery strings connected in parallel (string 1), which has a relatively small current and a relatively small cross-sectional area. The second busbar 7 and the third busbar 8 are the current paths for four battery strings connected in parallel (string 1), which have a larger current and a relatively larger cross-sectional area. To ensure the busbars are matched to the current, specifically: the width of the second busbar 7 and the third busbar 8 is 6-10mm, and the thickness is 0.15-0.5mm; the width of the first busbar 6 is 4-6mm, and the thickness is 0.15-0.5mm. The second busbar 7 and the third busbar 8 also serve as internal circuit lead-out functions; therefore, one end of the second busbar 7 is bent at 90°; both ends of the third busbar 8 are bent at 90°. This configuration allows the bent portions to connect to the junction box, leading the internal circuit to the outside of the photovoltaic module. The bending length matches the junction box structure design, ensuring the welding area between the busbars and the terminals.
[0042] The current of cell 4 is set as I, the current of cell segment 2 is I1, I1=I / 4; the current of the first cell matrix 9 is I2=2×I1, the current of the second cell matrix 10 is I3=I2=2×I1, and the current of the third cell matrix 11 is I4=2×I3=4×I1=I. Therefore, it does not affect the number of photovoltaic systems installed.
[0043] The cross-sectional area of the solder strip 3 is proportional to the current of the battery string 1. Therefore, the advantages of the above setting are: 1. By dividing the battery cell 4 into multiple parts, the current in a single battery string 1 is reduced, which can reduce current loss, significantly reduce the risk of module overheating, and achieve higher power output; 2. By dividing the battery cell 4 into multiple parts, the current in a single battery string 1 is reduced, the cross-sectional area of the solder strip 3 is reduced, thereby reducing the cross-sectional area of the interconnecting strip of the series battery string 1, which can reduce the cost of module materials.
[0044] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A photovoltaic module based on battery slice sub-division to reduce current loss, characterized by: Includes a battery string (1), which is formed by connecting multiple battery cells (2) in series with solder strips (3); The battery cell slab (2) is formed by uniformly cutting the battery cell (4) along the fine grid direction and the main grid direction; The battery cell (4) is divided into 4a battery cell segments (2), where a is a natural number greater than 0; The electrode printing in the battery cell segment (2) is an independent area.
2. The photovoltaic module based on battery piece subdivision to reduce current loss according to claim 1, characterized in that: The welding strip (3) connects the positive electrode of one of the battery cell segments (2) and the negative electrode of the battery cell segment (2) that is longitudinally adjacent to it.
3. The photovoltaic module of claim 2, wherein: The substrate of the welding strip (3) is a copper strip, and a plating layer is provided on the outer side of the copper strip; The coating is one of tin-lead, tin-bismuth, tin-indium, tin-lead-indium, tin-lead-bismuth, or tin-bismuth-silver.
4. A photovoltaic module for reducing current loss based on cell subdivision according to claim 1, characterized in that: The battery string (1) is connected by a busbar; The outer ends of the battery string (1) are connected by multiple spaced first busbars (6); Adjacent battery strings (1) are connected by a second busbar (7) and a third busbar (8) arranged at intervals; The second busbar (7) is located on both sides, and the third busbar (8) is located between the second busbar (7).
5. A photovoltaic module for reducing current loss based on cell subdivision according to claim 4, characterized in that: The base material of the first busbar (6), the second busbar (7) and the third busbar (8) is copper strip, and the surface is plated with tin-lead alloy.
6. The photovoltaic module of claim 5, wherein: The first busbar (6) is arranged linearly; one end of the second busbar (7) is bent; both ends of the third busbar (8) are bent.
7. A photovoltaic module for reducing current loss based on cell subdivision according to claim 6, characterized in that: The second busbar (7) and the third busbar (8) are both bent at 90°.
8. The photovoltaic module of claim 7, wherein: The width of the second busbar (7) and the third busbar (8) is 6-10 mm, and the thickness is 0.15-0.5 mm; The width of the first busbar (6) is 4-6 mm and the thickness is 0.15-0.5 mm.
9. A photovoltaic module circuit based on cell subdivision to reduce current loss, employing the photovoltaic module based on cell subdivision to reduce current loss as described in any one of claims 4-8, characterized in that: One end of the battery string (1) is led out as the positive electrode, and the other end is led out as the negative electrode; Every two strings of the battery (1) are connected in parallel to form a first battery matrix (9); Two of the first battery matrices (9) are connected in series to form a second battery matrix (10). Every two second battery matrices (10) are connected in parallel to form a third battery matrix (11). Several of the third battery arrays (11) are connected in series; Each of the third battery arrays (11) is connected in parallel with a diode (12).