Photovoltaic module and array system

Abstract

The application belongs to the technical field of photovoltaic systems, and particularly relates to a photovoltaic module and array system, which comprises a plurality of cell strings, each cell string comprising a plurality of cell units connected in series; each cell string is provided with bus bars at both ends for collecting the current at one end of the corresponding cell string; the plurality of cell strings are arranged in a head-to-tail splicing manner, so that in the two adjacent cell strings, the bus bar at the tail end of the former cell string is adjacent in space to the bus bar at the head end of the latter cell string; a pair of bus bars adjacent in space and belonging to the tail end of the former cell string and the head end of the latter cell string are electrically connected, so that the plurality of cell strings are connected in series to form a cell string group. The cell strings are arranged in a head-to-tail splicing manner inside the module, so that the bus bars at the head and tail ends of the adjacent cell strings are naturally close and welded, thereby being connected in series to form a high-voltage cell string group. The layout and connection of the conventional bus bars replace the independent 'jumper' conductors necessary for realizing the same circuit function in the traditional split module.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic system technology, specifically a photovoltaic module and array system. Background Technology

[0002] The statements in this section merely refer to the background art related to this invention and do not necessarily constitute prior art.

[0003] As the photovoltaic industry continues to pursue cost reduction and efficiency improvement, the size of silicon wafers and solar cells is constantly increasing (e.g., 182mm and 210mm have become mainstream). While larger cells increase module power, the short-circuit current they generate also increases significantly. According to Joule's law, the power loss caused by the resistance of the internal interconnects of the module is proportional to the square of the current, which leads to a sharp increase in the internal ohmic losses of traditional modules. This not only reduces the final system output efficiency but also significantly increases the risk of "hot spot effect" due to the concentration of heat loss, posing a serious challenge to the long-term reliability of the modules.

[0004] To address the aforementioned issues, existing technologies employ a "cell slicing scheme," which involves cutting a single, complete cell into multiple (e.g., 2, 3, 4, or 6) smaller cell units along a direction perpendicular to the main grid lines. Taking a "quarter-slice" cell as an example, its operating current can be reduced to one-quarter of the total cell current, thereby significantly reducing internal electrical losses at the source and mitigating the risk of hot spots. Therefore, slicing technology is considered a key technological path to achieving next-generation high-power, high-reliability components.

[0005] However, the electrical systems of existing power plants (including inverters, DC cables, fuses, etc.) are designed based on specific operating voltages (Voc / Vmp) and current ranges. When using quarter-cell batteries, although the current is reduced, the voltage of individual cell cells also decreases proportionally, causing the output voltage of the entire module to be unable to match that of traditional single-cell or two-cell modules.

[0006] To address the aforementioned compatibility issues, the current mainstream solution in the industry is to introduce additional, independent jumpers inside the module laminate to perform complex series-parallel connections on multiple low-voltage sub-strings formed by the series connection of segmented cells (for example, first connecting multiple sub-strings in parallel, and then connecting the parallel groups in series) in order to raise the module's output voltage to the level required by the system.

[0007] A jumper wire is essentially a long, extra conductor whose inherent resistance introduces significant additional Joule heat loss, offsetting some of the efficiency gains from the current reduction achieved through panelization. Furthermore, jumpers and their required insulating strips increase the variety and quantity of materials used, as well as the weight of the component, thus raising manufacturing costs.

[0008] Meanwhile, the installation of "jump wires" requires high-precision positioning and additional fixing fixtures, and the intersections must be strictly insulated, which significantly increases the complexity of the production process and the manufacturing cycle. Furthermore, insulation reliability is highly dependent on the quality of the lamination process, and long-term operation may pose a risk of short circuits due to material aging, affecting product reliability and lifespan. Moreover, the jump wire process differs greatly from traditional module production lines, requiring the addition of specialized equipment and modification of existing production lines, resulting in high costs for technology upgrades.

[0009] Furthermore, for asymmetric slicing schemes such as three-slice slicing, the required jumper layout is more complex and redundant in order to achieve effective diode bypass protection, which further amplifies all the above-mentioned disadvantages. Summary of the Invention

[0010] This invention provides a photovoltaic module and array system. Through a jumperless segmented cell module internal circuit design, the required series connection is achieved using a busbar layout, eliminating the power loss and process complexity caused by traditional jumpers. Simultaneously, by matching a system topology of "voltage doubling and sub-string parallel connection," the new high-efficiency segmented module can achieve plug-and-play compatibility without modifying existing power plant facilities, and leverage its advantages of low loss and high reliability.

[0011] The first aspect of the present invention discloses a photovoltaic module, comprising: A battery string, having multiple strings, each battery string comprising multiple battery cells connected in series; Busbars are installed at both ends of each battery string to collect the current from one end of the corresponding battery string; Among them, multiple battery strings are arranged in a way that splices them together end to end, so that in two adjacent battery strings, the bus bar at the end of the previous battery string is spatially adjacent to the bus bar at the beginning of the next battery string. Electrical connections are made between a pair of adjacent busbars that belong to the tail end of the previous battery string and the head end of the next battery string, so that multiple battery strings are connected in series to form a battery string group.

[0012] Furthermore, the short side busbars on both sides of the module are folded back to the back of the battery string to increase the effective light-receiving area of ​​the module.

[0013] Furthermore, the battery unit is a segmented battery cell, which is cut from a whole solar cell, and the number of segments is 3, 4, 5 or 6.

[0014] Furthermore, the length of the busbar covers all the welding points of the interconnect strips (or interconnect bands) at one end of the corresponding battery string, and multiple busbars are arranged symmetrically in the component plane.

[0015] Furthermore, it also includes a junction box and a bypass diode, which is a Schottky diode or a switching diode, and has a reverse repetitive peak voltage ≥50V.

[0016] The battery string group is divided into multiple substrings, each substring having at least two battery strings connected in series; Each substring is connected in parallel with a bypass diode at both ends, and all bypass diodes are built into the junction box.

[0017] A second aspect of the present invention discloses a photovoltaic array system, comprising: Multiple photovoltaic modules; At least two sub-series branches, each with multiple photovoltaic modules connected in series; all sub-series branches are connected in parallel to form a power generation branch unit; The combiner box is electrically connected to at least one power generation branch unit.

[0018] Furthermore, the number of sub-series branches is at least two, and the two sub-series branches are connected in parallel to form a power generation branch unit.

[0019] Furthermore, the photovoltaic array system includes multiple power generation branch units, all of which are connected in parallel to the combiner box.

[0020] Furthermore, the power generation branch unit is connected to the combiner box via a multi-way combiner device (such as a three-way or four-way connector).

[0021] A third aspect of the present invention discloses a method for manufacturing a photovoltaic module, comprising the following steps: Battery string fabrication: Multiple segmented battery cells are connected in series and welded together using interconnecting strips (or interconnecting tapes) to form a battery string; End pre-busbars: At both ends of each battery string, busbars perpendicular to the interconnecting strips that connect all the battery cells are welded. Battery string splicing: Multiple battery strings with pre-connected ends are spliced ​​together end to end, so that the bus bar at the end of the previous battery string and the bus bar at the beginning of the next battery string are close to each other in space. Lateral connection: Direct welding or bridging welding of a pair of busbars that are close to each other in space and belong to the tail end of the previous battery string and the head end of the next battery string respectively. Lead wire welding: Weld lead wires to the busbars at both ends of the series-connected battery string and connect them to the junction box.

[0022] Furthermore, the welding is one of infrared welding, low-temperature welding, or lamination welding.

[0023] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: 1. By employing a circuit construction method of "end-to-end splicing" and "direct busbar welding," the independent "jump wire" conductor required in traditional solutions is eliminated. This eliminates the additional Joule heat loss caused by the jumper wire's own resistance, substantially improving the final output power and conversion efficiency of the module. By eliminating jumpers and their associated insulating strips, not only are the material costs and overall weight of the module reduced, but the internal packaging structure of the laminate is also simplified. This allows for the implementation of conventional string soldering and busbar welding processes, avoiding complex and error-prone steps such as high-precision jumper wire laying and insulation attachment. This significantly simplifies the production process, improves production efficiency and first-pass yield, and reduces the potential short-circuit risk due to insulation failure, enhancing the long-term reliability of the module. Simultaneously, it makes the manufacturing process highly compatible with traditional module production lines, eliminating the need for major modifications to existing mainstream production lines or investment in high-cost specialized equipment.

[0024] 2. The resulting photovoltaic array system adopts a "sub-series branch parallel" topology, enabling the total output voltage and current of the photovoltaic array to match existing power plants designed with traditional modules. It can be seamlessly integrated into existing power plants without replacing key system components such as inverters and cables.

[0025] 3. While keeping the total system current constant, the current flowing through each sub-branch of the photovoltaic array system is halved. According to Joule's law, this significantly reduces power loss on the DC cables and lowers the operating temperature rise of the connectors, thereby improving the overall system efficiency and operational safety of the photovoltaic power station.

[0026] 4. During the manufacturing stage, standardized steps such as "end pre-busing," "splicing," and "lateral connection" are used to stably and in batches produce component structures, ensuring product consistency. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 A schematic diagram of a component-level circuit structure provided for one or more embodiments of the present invention; Figure 2 This is a schematic diagram of a system-level photovoltaic array topology provided for one or more embodiments of the present invention. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] Terminology Explanation: Segmented solar cells: These refer to multiple small-area cell units cut from a standard whole solar cell along a specific direction (usually perpendicular to the main grid lines). For example, "quarter-cell" means dividing a single cell into four equal segments.

[0032] Interconnecting strip: A conductive strip used to connect the front and back electrodes of adjacent solar cells in series, usually made of tin-coated copper strip.

[0033] Busbar: In a battery string or assembly, a wide conductive strip used to collect and transmit current from multiple interconnecting bars, and its direction is usually perpendicular to the interconnecting bars.

[0034] Jumper wires: In existing segmented module technology, jumper wires are independent conductive strips that are laid separately and not directly connected to the cell electrodes in order to achieve circuit bridging or parallel connection at specific locations. They usually require insulation material and are a major component that causes losses and process complexity.

[0035] Lap welding busbar: An auxiliary welding strip used to connect two adjacent but not directly contacting busbars, achieving electrical connection by lap welding on it.

[0036] Battery string / battery string series / battery string unit: Multiple battery cells connected in series form a "battery string"; multiple battery strings connected end to end form a "battery string series"; multiple battery string series connected in parallel form a "battery string unit".

[0037] As described in the background section, existing technologies employ a "cell slicing scheme," which cuts a complete cell into multiple (e.g., 2, 3, 4, or 6) smaller cell units along a direction perpendicular to the main grid lines. Taking a "quadruple slice" as an example, its operating current can be reduced to one-quarter of the entire cell, thereby significantly reducing internal electrical losses at the source and mitigating the risk of hot spots. Therefore, slicing technology is considered a key technological path to achieving next-generation high-power, high-reliability components.

[0038] However, the electrical systems of existing power plants (including inverters, DC cables, fuses, etc.) are designed based on specific operating voltages (Voc / Vmp) and current ranges. When using quarter-cell batteries, although the current is reduced, the voltage of individual cell cells also decreases proportionally, causing the output voltage of the entire module to be unable to match that of traditional single-cell or two-cell modules.

[0039] To address the aforementioned compatibility issues, the current mainstream solution in the industry is to introduce additional, independent jumpers within the module laminate to create complex series-parallel connections between multiple low-voltage sub-strings formed by series-connected segmented cells (e.g., first connecting multiple sub-strings in parallel, then connecting the parallel groups in series), thereby boosting the module's output voltage to the level required by the system. For example, prior art such as published patent CN 119092579 A employs this type of jumper design.

[0040] A jumper wire is essentially a long, extra conductor whose inherent resistance introduces significant additional Joule heat loss, offsetting some of the efficiency gains from the current reduction achieved through panelization. Furthermore, jumpers and their required insulating strips increase the variety and quantity of materials used, as well as the weight of the component, thus raising manufacturing costs.

[0041] Meanwhile, the installation of "jump wires" requires high-precision positioning and additional fixing fixtures, and the intersections must be strictly insulated, which significantly increases the complexity of the production process and the manufacturing cycle. Furthermore, insulation reliability is highly dependent on the quality of the lamination process, and long-term operation may pose a risk of short circuits due to material aging, affecting product reliability and lifespan. Moreover, the jump wire process differs greatly from traditional module production lines, requiring the addition of specialized equipment and modification of existing production lines, resulting in high costs for technology upgrades.

[0042] Therefore, this solution provides a photovoltaic module and array system that utilizes a jumperless, segmented cell module internal circuit design and busbar layout to achieve the required series connection, eliminating the power loss and process complexity caused by traditional jumpers. Simultaneously, it matches a system topology of "voltage doubling and sub-string parallel connection," enabling the new high-efficiency segmented modules to achieve plug-and-play compatibility without modifying existing power plant facilities, while leveraging their advantages of low loss and high reliability.

[0043] In this solution, the component-level circuit structure, such as Figure 1 As shown, the battery string units are arranged in two rows, each row containing multiple battery strings connected end-to-end. Within each row, adjacent battery strings are directly or welded together via busbars at their ends; between adjacent rows, cross-row connection is achieved by horizontally welding busbars at corresponding positions.

[0044] Specifically, a pair of busbars located in the same lateral position (for example, the tail busbar of a battery string in the first column and the head busbar of the next battery string in the second column) are connected by welding, thereby connecting the two battery string units in series into a complete high-voltage battery string series.

[0045] Connect positive and negative leads to the junction box on the busbars at both ends of the circuit. This structure ultimately forms multiple "two-string-one-unit" sub-strings, which are then connected in series through the main busbar, with each sub-string connected in parallel to a bypass diode. The bypass diodes are Schottky diodes or switching diodes, with a reverse repetitive peak voltage ≥50V. The entire circuit consists only of solar cells, interconnects, busbars, and solder joints, without any independently laid jumpers.

[0046] In this solution, the above component-level circuit structure is implemented in the following way.

[0047] Battery string fabrication: Multiple segmented battery cells (taking four segments as an example) are connected in series and welded together by interconnecting strips to form a battery string.

[0048] End pre-bus: At both ends of each battery string, a bus bar perpendicular to it is welded to the interconnecting strip connecting all the battery cells. This bus bar collects all the current at one end of the battery string.

[0049] Battery string splicing: Multiple battery strings with completed end-to-end current charging are spliced ​​together end to end. At this time, the current charging bars of adjacent battery strings are close to each other in space, forming natural connection points.

[0050] The horizontal connection (the key to replacing jumpers) is as follows: Multiple batteries as described above are arranged in series side by side.

[0051] For the busbars located at the outermost ends between two adjacent columns, they can be directly aligned and welded, or a short section of the busbar can be added for bridging welding.

[0052] For the busbars located at the beginning and end of the battery string between two adjacent columns, direct welding or lap welding is also used for connection.

[0053] Lead wire soldering: Finally, lead wires are soldered at the beginning and end of the entire circuit network (i.e., on the start and end busbars of the outermost battery series) to connect to the junction box.

[0054] Through the above steps, the current collection and bridging are achieved entirely by the pre-designed busbar layout and direct soldering points, without the need for any separate "jump wires".

[0055] Regarding system-level photovoltaic array topology.

[0056] Because the quad-cell module prepared by this scheme has an output voltage (Voc) that is about twice that of a traditional half-cell module and an operating current (Isc) that is about half, in order to adapt to a photovoltaic branch originally designed as n traditional modules in series, this scheme splits the original branch into two parallel sub-branches, each of which is composed of n / 2 quad-cell modules proposed in the "module level" in series.

[0057] Voltage matching: Voltage of each sub-branch = (n / 2) (2 V_original) = n V_original is consistent with the total voltage of the original branch.

[0058] Current matching: Total current = 2 (I_original / 2) = I_original, which is consistent with the original branch current.

[0059] This array design achieves full compatibility in electrical parameters while enjoying the advantages of low loss and low hot spot risk due to low current.

[0060] Based on the above concept, the following is formed: Figure 2 The illustrated system-level photovoltaic array topology includes a DC combiner box and multiple identical power generation branch units connected in parallel. Each power generation branch is connected to the combiner box via corresponding wires. Each power generation branch contains multiple photovoltaic modules, whose positive and negative terminals are connected to terminal blocks via wires in a specific manner. Figure 2 In the diagram, each power generation branch is indicated by a green bar box representing the terminal block (which may also be other components that provide reliable, insulated mechanical connections and electrical parallel points).

[0061] Specifically, taking one branch as an example: this branch consists of four high-voltage segmented modules described in this solution, arranged in two rows, upper and lower. The negative terminals of the two modules in the upper row are connected in parallel to one end of the terminal block, and the positive terminals of the two modules in the lower row are connected in parallel to the other end of the terminal block. By achieving potential convergence at the terminal block, the total current of this branch is finally output to the combiner box through a wire.

[0062] This topology indicates that the entire photovoltaic array consists of multiple such parallel branches, each of which is composed of several high-voltage components connected in series. Its total output voltage is consistent with the original system design voltage, while the total output current is matched through the parallel connection of multiple branches, thereby achieving complete electrical compatibility with existing photovoltaic power generation systems.

[0063] For the photovoltaic modules proposed in this solution, by eliminating the additional "jump wire" conductor with inherent resistance, the Joule heat loss caused by the jump wire resistance is eliminated, thereby improving the final output power and conversion efficiency of the module and fully realizing the potential of slab technology to reduce internal losses.

[0064] In the specific hardware structure, jumpers and matching insulating strips are eliminated, reducing the types and quantities of specialized materials and lowering the manufacturing cost and overall weight of the modules. This makes the corresponding welding process closer to traditional methods, eliminating complex steps such as high-precision jumper laying, positioning, and insulation attachment, thus improving production cycle time and efficiency. This reduces the risk of short circuits due to insulation failure in the final photovoltaic system, improving long-term product reliability. Simultaneously, the manufacturing process is highly compatible with existing mainstream string-and-layer production lines, allowing for rapid switching from traditional modules to high-efficiency sectionalized modules without major modifications to existing production lines or investment in high-cost specialized equipment.

[0065] The resulting photovoltaic array system leverages the doubling of output voltage from segmented modules, employing a "two shorter sub-branches in parallel" design instead of the original "one long branch in series." This ensures the new array's total output voltage and current are identical to the original system design parameters, allowing for plug-and-play application in existing photovoltaic power plants without requiring inverter, cable, or protection device adjustments, thus ensuring electrical compatibility with existing power plants. Furthermore, while maintaining the same total system current, the current flowing through each sub-branch is halved, resulting in lower operating temperatures for modules and connectors, and enhanced system safety and long-term reliability.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photovoltaic module, characterized in that, include: A battery string, having multiple strings, each battery string comprising multiple battery cells connected in series; Busbars are installed at both ends of each battery string to collect the current from one end of the corresponding battery string; Among them, multiple battery strings are arranged in a way that splices them together end to end, so that in two adjacent battery strings, the bus bar at the end of the previous battery string is spatially adjacent to the bus bar at the beginning of the next battery string. Electrical connections are made between a pair of adjacent busbars that belong to the tail end of the previous battery string and the head end of the next battery string, so that multiple battery strings are connected in series to form a battery string group.

2. A photovoltaic module as described in claim 1, characterized in that, The battery unit is a segmented battery cell, which is cut from a whole solar cell, and the number of segments is at least one of 3, 4, 5 or 6.

3. A photovoltaic module as described in claim 1, characterized in that, The length of the busbar covers all the welding points of the interconnecting bars at one end of the corresponding battery string, and the multiple busbars are arranged symmetrically in the component plane.

4. A photovoltaic module as described in claim 1, characterized in that, It also includes junction boxes and bypass diodes; The battery string group is divided into multiple substrings, each substring having at least two battery strings connected in series; Each substring is connected in parallel with a bypass diode at both ends, and all bypass diodes are built into the junction box.

5. A photovoltaic array system, characterized in that, include: Multiple photovoltaic modules as described in any one of claims 1-4; At least two sub-series branches, each with multiple photovoltaic modules connected in series; all sub-series branches are connected in parallel to form a power generation branch unit; The combiner box is electrically connected to at least one power generation branch unit.

6. A photovoltaic array system as described in claim 1, characterized in that, The number of sub-series branches is at least two, and the two sub-series branches are connected in parallel to form a power generation branch unit.

7. A photovoltaic array system as described in claim 1, characterized in that, The photovoltaic array system includes multiple power generation branch units, all of which are connected in parallel to the combiner box.

8. A photovoltaic array system as described in claim 1, characterized in that, The power generation branch unit is connected to the combiner box via a multi-channel combiner device.

9. A method for manufacturing a photovoltaic module, used to manufacture a photovoltaic module as described in any one of claims 1-4, characterized in that, Includes the following steps: Battery string fabrication: Multiple segmented battery cells are connected in series and welded together using interconnecting strips to form a battery string; End pre-busbars: At both ends of each battery string, busbars perpendicular to the interconnecting strips that connect all the battery cells are welded. Battery string splicing: Multiple battery strings with pre-connected ends are spliced ​​together end to end, so that the bus bar at the end of the previous battery string and the bus bar at the beginning of the next battery string are close to each other in space. Lateral connection: Direct welding or bridging welding of a pair of busbars that are close to each other in space and belong to the tail end of the previous battery string and the head end of the next battery string respectively. Lead wire welding: Weld lead wires to the busbars at both ends of the series-connected battery string and connect them to the junction box.

10. A method for manufacturing a photovoltaic module as described in claim 9, characterized in that, The welding is one of infrared welding, low-temperature welding, or lamination welding.

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