Photovoltaic string module, photovoltaic array and photovoltaic power generation system

Abstract

The utility model provides a kind of photovoltaic module, photovoltaic array and photovoltaic power generation system, through multiple photovoltaic components are connected in series and then form module string, obtain a kind of photovoltaic module string by multiple module string parallel connection;On this basis, can be connected in parallel multiple above-mentioned photovoltaic module string, form a kind of photovoltaic array, the both ends of this kind of photovoltaic array are connected with specific target inverter through positive busbar and negative busbar respectively, and make the both ends of target inverter access power grid, to form photovoltaic power generation system;The photovoltaic module string, photovoltaic array and photovoltaic power generation system of this structure, even if the voltage of single photovoltaic component is promoted, also need not to meet the access requirement of inverter, and then reduce the number of photovoltaic component or additionally add the number of inverter, avoid the increase of inverter cost;To alleviate the situation of single block component voltage promotion, resulting in the technical problem of inverter utilization rate reduction and power generation cost increase.

Description

Technical Field

[0001] This utility model relates to the technical field of photovoltaic module applications, and in particular to a photovoltaic string module, a photovoltaic array, and a photovoltaic power generation system. Background Technology

[0002] With the rapid development of renewable energy technologies, solar photovoltaic (PV) power generation systems have been widely applied globally. As the core component of a PV power generation system, the electrical performance and connection method of PV modules directly affect the system's power generation efficiency and economic benefits. In current mainstream PV power plant designs, PV modules are typically connected in series, linking modules within a single maximum power point tracking (MPPT) loop to increase the DC voltage, enabling it to match the 1500V or 1000V input voltage requirements of centralized inverters. This series connection design is based on the standard electrical parameters of existing PV modules, particularly their operating voltage range.

[0003] In existing technologies, the positive and negative terminals of the photovoltaic (PV) string are directly connected to the corresponding DC input terminals of the inverter. The inverter converts DC to AC and generates electricity via grid connection. This technology requires that the total open-circuit voltage of the string be strictly controlled within the inverter's allowable input voltage range to ensure safe and stable system operation. When using new PV modules with higher output voltages, the voltage of individual modules increases. To avoid exceeding the inverter's maximum input voltage limit, the number of modules connected in series in a single MPPT must be reduced. While this adjustment meets voltage matching requirements, it leads to a decrease in the total module power connected to a single MPPT, thereby increasing the inverter's unit power cost. In large-scale PV power plants, inverter costs account for a significant proportion of the total system investment. This reduction in inverter utilization due to increased module voltage ultimately raises the overall power generation cost of the power plant, impacting the project's return on investment. Utility Model Content

[0004] The purpose of this invention is to provide a photovoltaic string module, a photovoltaic array, and a photovoltaic power generation system to alleviate the technical problems of reduced inverter utilization and increased power generation costs caused by increased voltage of a single module.

[0005] In a first aspect, this utility model provides a photovoltaic string module, comprising: Multiple strings connected in parallel; Each of the strings includes multiple photovoltaic modules connected in series; The photovoltaic module includes a battery and a reverse diode; Multiple batteries are connected in series, and a reverse diode is connected in parallel across the two ends of each battery.

[0006] Secondly, this utility model provides a photovoltaic array, including multiple photovoltaic string modules connected in parallel as described in the foregoing embodiments; The positive terminal of each photovoltaic string module is connected to the positive busbar, and the negative terminal of each photovoltaic string module is connected to the negative busbar.

[0007] In an optional implementation, a Y-type connecting wire is also included; One Y-shaped connecting line is used to connect the positive terminals of each photovoltaic string module in parallel and connect them to the positive busbar; the other Y-shaped connecting line is used to connect the negative terminals of each photovoltaic string module in parallel and connect them to the negative busbar.

[0008] In an optional implementation, a voltage stabilizer is also included; The positive terminal of the voltage stabilizer is connected to the positive busbar, and the negative terminal of the voltage stabilizer is connected to the negative busbar.

[0009] In an optional implementation, the number of voltage stabilizers is the same as the number of photovoltaic string modules connected in parallel.

[0010] Thirdly, this utility model provides a photovoltaic power generation system, including a photovoltaic array as described in any of the foregoing embodiments, and further including a target inverter; the photovoltaic array is connected to the target inverter, and the target inverter is connected to the power grid.

[0011] In an optional embodiment, the photovoltaic array is connected to the positive terminal of the target inverter via the positive busbar and to the negative terminal of the target inverter via the negative busbar.

[0012] In an optional implementation, the number of strings connected in parallel and the number of photovoltaic string modules connected in parallel are determined by the upper limit of the input current corresponding to the target inverter.

[0013] In an optional implementation, the number of photovoltaic modules connected in series is determined by the upper limit of the input voltage corresponding to the target inverter.

[0014] This utility model provides a photovoltaic string module, a photovoltaic array, and a photovoltaic power generation system. Multiple photovoltaic modules are connected in series to form a string, and these strings are then connected in parallel to obtain a photovoltaic string module. Based on this, multiple photovoltaic string modules can be connected in parallel to form a photovoltaic array. The two ends of this photovoltaic array are connected to a specific target inverter via positive and negative busbars, respectively, and the two ends of the target inverter are connected to the power grid to form a photovoltaic power generation system. With this structure, even if the voltage of a single photovoltaic module increases, there is no need to reduce the number of photovoltaic modules or add additional inverters to meet the inverter's connection requirements, thus avoiding increased inverter costs.

[0015] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.

[0016] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of a traditional photovoltaic array. Figure 2 A schematic diagram of the structure of a photovoltaic string module provided in an embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of a photovoltaic array provided in an embodiment of the present invention.

[0019] Icons: 100 - Photovoltaic module; 200 - Photovoltaic string module; 101 - Diode; 102 - Battery; 201 - String. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] For crystalline silicon TOPCon products, there are currently 4-chip products using a "parallel-series-parallel" circuit structure. This allows the output voltage and current to be adjusted to be close to that of the original 2-chip product, ensuring that the inverter cost does not increase. However, this circuit has high manufacturing difficulty and complex processes. Therefore, currently, a more advanced method is generally used. Figure 1 The photovoltaic array structure shown has each module as a photovoltaic component 100 and each dashed box as a string 201. Figure 1 An exemplary model is shown, consisting of a string 201 of 26 photovoltaic modules 100 connected in series, with the positive terminal of each string 201 connected to the positive busbar and the negative terminal of each string 201 connected to the negative busbar; however, if this series connection method is adopted, the inverter investment cost will double and the project return will be too low.

[0022] Based on this, the photovoltaic string module, photovoltaic array and photovoltaic power generation system provided by this utility model embodiment can be connected in series and parallel manner through strings, which solves the problem of excessive inverter investment when high voltage products, especially module products above 70V, are connected to the grid for power generation.

[0023] The following is a detailed description through examples.

[0024] Figure 2 This is a schematic diagram of the structure of a photovoltaic array provided in an embodiment of the present invention.

[0025] like Figure 2 As shown, the photovoltaic string module includes: multiple strings 201 connected in parallel, each string 201 including multiple photovoltaic modules 100 connected in series. Figure 2 An optional embodiment is shown, in which the photovoltaic string module may include two parallel strings 201, each string 201 consisting of 13 photovoltaic modules 100. In practical applications, the number of parallel strings 201 and the number of series photovoltaic modules 100 in each string 201 can be determined according to the actual situation of the photovoltaic string module, and are not limited to this. Figure 2 The situation is shown below.

[0026] This type of photovoltaic string module structure can meet the inverter access requirements without reducing the number of photovoltaic modules 100 connected in series when the voltage of each photovoltaic module 100 is increased, and it also does not require an additional inverter to meet the photovoltaic string module access requirements after the voltage of the photovoltaic modules 100 is increased.

[0027] Each photovoltaic module 100 includes a cell 102 and a reverse diode 101; multiple cells 102 are connected in series, and a reverse diode 101 is connected in parallel across the two ends of each cell 102. Figure 2 An optional embodiment is shown in which each photovoltaic module 100 may include three cells 102 connected in series, and a reverse diode 101 connected in parallel across each cell 102. In practical applications, the number of cells 102 connected in series and the number of diodes 101 connected in parallel can be determined according to the actual situation of the photovoltaic module 100, and are not limited to this. Figure 2 The situation is shown.

[0028] It should be noted that the photovoltaic module 100 in this application embodiment is mainly for high-voltage, low-current products, such as perovskite photovoltaic products with around 200V and thin-film photovoltaic products. This type of photovoltaic module 100 has the characteristics of high voltage and low current. For example, the open-circuit voltage Voc of this type of photovoltaic module 100 is more than twice that of existing photovoltaic products, and the short-circuit current Isc of this type of photovoltaic module 100 is only less than 1 / 2 of the short-circuit current of existing photovoltaic products.

[0029] Based on this, the photovoltaic string module in this application combines the differences in component current and voltage to connect the components in series and parallel. Thus, the number of inverters invested remains unchanged. Considering that the power of the 4-segment product is 10W higher, the cost per watt of each module in the project will be lower, ensuring that the maximum power point tracking (MPPT) power generation of the single-path module is maximized.

[0030] In some embodiments, such as Figure 3 As shown in the figure, this application embodiment also provides a photovoltaic array, including multiple photovoltaic string modules 200 connected in parallel as described in the above embodiment; the positive terminal of each photovoltaic string module 200 is connected to a positive busbar, and the negative terminal of each photovoltaic string module 200 is connected to a negative busbar.

[0031] in, Figure 3 Each dashed box in the figure represents the photovoltaic string module 200 described in the foregoing embodiment (e.g., Figure 2 As shown in the figure, this is another unit structure of photovoltaic array provided in the embodiments of this application. In practical applications, the number of parallel connections of this unit structure can be determined according to the actual situation of the photovoltaic array.

[0032] As an optional embodiment, the photovoltaic array further includes Y-type connecting lines, which may include two: one Y-type connecting line is used to connect the positive terminals of each photovoltaic string module 200 in parallel and connect it to the positive busbar; the other Y-type connecting line is used to connect the negative terminals of each photovoltaic string module 200 in parallel and connect it to the negative busbar. As another optional embodiment, the photovoltaic array may also use a voltage regulator to replace the Y-type connecting lines to achieve the above connection; the parallel connection positions of each photovoltaic string module 200 are combined using Y-type connecting lines or voltage regulators, and then the positive and negative terminals of the overall circuit of the photovoltaic array are connected to the positive and negative terminals of the busbar.

[0033] In practical applications, the photovoltaic array also includes a voltage stabilizer; the positive terminal of the voltage stabilizer is connected to the positive busbar, and the negative terminal of the voltage stabilizer is connected to the negative busbar. This voltage stabilizer is used to control the voltage differences among the parallel photovoltaic string modules 200, preventing uneven voltage matching caused by abnormal power generation from a single photovoltaic string module 200.

[0034] Based on this, in order to further optimize the potential problem of uneven voltage matching among the photovoltaic string modules 200, the number of voltage stabilizers can be set according to the number of photovoltaic string modules 200 connected in parallel, with one voltage stabilizer corresponding to each photovoltaic string module 200, so that the number of voltage stabilizers is consistent with the number of photovoltaic string modules 200 connected in parallel.

[0035] In a preferred embodiment of practical application, multiple photovoltaic modules are connected in series to form a string, and multiple strings are connected in parallel to obtain a photovoltaic string module. Based on this, multiple photovoltaic string modules can be connected in parallel to form a photovoltaic array. The two ends of this photovoltaic array are connected to a specific target inverter through a positive bus and a negative bus, respectively, and the two ends of the target inverter are connected to the power grid to form a photovoltaic power generation system. In this structure of photovoltaic string module, photovoltaic array and photovoltaic power generation system, even if the voltage of a single photovoltaic module increases, there is no need to reduce the number of photovoltaic modules or add additional inverters to meet the inverter's access requirements, thus avoiding an increase in inverter costs.

[0036] In some embodiments, this application also provides a photovoltaic power generation system, including a photovoltaic array as described above, and a target inverter; the photovoltaic array is connected to the target inverter, and the target inverter is connected to the power grid.

[0037] Specifically, based on the number of photovoltaic modules in the photovoltaic array and the voltage requirements of individual photovoltaic modules, the model and quantity of several target inverters are determined, as well as the maximum input voltage (upper limit of input voltage) and the maximum input current (upper limit of input current) on the DC side of each target inverter. The target inverter can be understood as an inverter that can meet the input requirements of this photovoltaic array, thereby realizing photovoltaic grid connection.

[0038] In practical applications, the photovoltaic array is connected to the positive terminal of the target inverter via a positive busbar and to the negative terminal of the target inverter via a negative busbar.

[0039] It should be noted that the number of parallel-connected strings and the number of parallel-connected photovoltaic string modules in the photovoltaic array in the foregoing embodiments are determined by the upper limit of the input current corresponding to the target inverter; and the number of series-connected photovoltaic modules in the photovoltaic array in the foregoing embodiments is determined by the upper limit of the input voltage corresponding to the target inverter.

[0040] The number of circuits in the parallel-connected photovoltaic string modules and the number of photovoltaic modules connected in series are set accordingly, with the rated power of the target inverter per string as the upper limit.

[0041] The photovoltaic power generation system provided in this embodiment of the present invention has the same technical features as the photovoltaic array and photovoltaic string module provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0042] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0043] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0045] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0046] In addition, in the various embodiments of this utility model, each functional unit can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0047] Finally, it should be noted that the above-described embodiments are merely specific implementations of this utility model, used to illustrate the technical solutions of this utility model, and not to limit it. The protection scope of this utility model is not limited thereto. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this utility model. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be covered within the protection scope of this utility model.

Claims

1. A photovoltaic string module, characterized in that, include: Multiple strings connected in parallel; Each of the strings includes multiple photovoltaic modules connected in series; The photovoltaic module includes a battery and a reverse diode; Multiple batteries are connected in series, and a reverse diode is connected in parallel across the two ends of each battery.

2. A photovoltaic array, characterized in that, Includes multiple photovoltaic string modules as described in claim 1 connected in parallel; The positive terminal of each photovoltaic string module is connected to the positive busbar, and the negative terminal of each photovoltaic string module is connected to the negative busbar.

3. The photovoltaic array according to claim 2, characterized in that, It also includes Y-type connecting cables; One Y-shaped connecting line is used to connect the positive terminals of each photovoltaic string module in parallel and connect them to the positive busbar; the other Y-shaped connecting line is used to connect the negative terminals of each photovoltaic string module in parallel and connect them to the negative busbar.

4. The photovoltaic array according to claim 2, characterized in that, It also includes voltage stabilizers; The positive terminal of the voltage stabilizer is connected to the positive busbar, and the negative terminal of the voltage stabilizer is connected to the negative busbar.

5. The photovoltaic array according to claim 4, characterized in that, The number of voltage stabilizers is the same as the number of photovoltaic string modules connected in parallel.

6. A photovoltaic power generation system, characterized in that, The photovoltaic array, as described in any one of claims 2-5, further includes a target inverter; the photovoltaic array is connected to the target inverter, and the target inverter is connected to the power grid.

7. The photovoltaic power generation system according to claim 6, characterized in that, The photovoltaic array is connected to the positive terminal of the target inverter via the positive busbar and to the negative terminal of the target inverter via the negative busbar.

8. The photovoltaic power generation system according to claim 6, characterized in that, The number of strings connected in parallel and the number of photovoltaic string modules connected in parallel are determined by the upper limit of the input current corresponding to the target inverter.

9. The photovoltaic power generation system according to claim 6, characterized in that, The number of photovoltaic modules connected in series is determined by the upper limit of the input voltage corresponding to the target inverter.

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