CN203339197U - Photovoltaic module - Google Patents

Abstract

In the photovoltaic module provided by the utility model, solar cells are connected in series into 6 battery strings with the same number of strings, and then the 6 battery strings are divided into 3 groups in pairs, and the strings in the group are connected in parallel, and the groups outside the group are connected in parallel. It is connected in series with the battery pack, and a set of bypass diodes is connected in parallel for each battery string. The output power of the photovoltaic module using the above circuit connection method is the same as that of the photovoltaic module in the prior art, and its maximum operating voltage is only half of that of the photovoltaic module in the prior art, and can be directly applied to an independent photovoltaic system with a lower DC side voltage. And compared with the photovoltaic modules in the prior art, the photovoltaic modules in the present invention can realize more kinds of DC side voltages through a series of series or parallel connections. Therefore, the photovoltaic module of the present invention can be applied to more types of independent photovoltaic systems on the premise of keeping the power density constant, and the application range is wider.

Description

A photovoltaic module

technical field

The utility model relates to the technical field of photovoltaics, in particular to a photovoltaic module.

Background technique

A solar cell is a semiconductor device that directly converts sunlight into electrical energy. Because it uses renewable sunlight and does not cause environmental pollution during use, solar cells have broad application prospects in today's energy shortages and increasingly severe environmental protection situations.

At present, solar cells that have been produced and used on a large scale include crystalline silicon cells and thin-film cells. Among them, crystalline silicon cells occupy more than 80% of the market share in the field of solar cell applications due to their mature production technology and high photoelectric conversion efficiency.

Since the crystalline silicon solar cell itself is fragile and easily corroded, if it is directly exposed to the atmosphere, its photoelectric conversion efficiency will decrease due to the influence of humidity, dust, acid rain, etc., and even damage and fail. Therefore, they must be packaged into photovoltaic modules before they can be put into use.

Common crystalline silicon photovoltaic modules mainly include: a laminate, a frame covering the periphery of the laminate, and a photovoltaic junction box arranged on the backlight surface of the laminate. Among them, the laminate mainly includes: a cell layer composed of multiple solar cells, a cover plate located on the light-receiving surface of the cell layer, a back sheet located on the backlight side of the cell layer, and bonding the cell layer and the cover plate, The EVA (ethylene-vinylacetate copolymer, ethylene-vinyl acetate copolymer) layer of the battery sheet and the back sheet.

To enable photovoltaic modules to stably supply power to users, they need to be integrated into a photovoltaic system. Common photovoltaic systems include grid-connected, off-grid and hybrid systems. As a kind of off-grid photovoltaic system, independent photovoltaic system is very suitable for small-scale household electricity consumption. At present, the DC side voltage of independent photovoltaic system generally has several types such as 12V, 24V, 48V, 110V and 220V.

In the actual application process, the following problems often occur: For a photovoltaic module, no matter what circuit connection method is used between the modules, there are still some problems that cannot meet the DC side voltage requirements of one or several independent photovoltaic systems. Possibly, photovoltaic modules have great limitations when applied in different types of independent photovoltaic systems.

Utility model content

The utility model provides a photovoltaic assembly to broaden the application range of the photovoltaic assembly in various types of independent photovoltaic systems.

In order to achieve the above object, the utility model provides the following technical solutions:

A photovoltaic module, comprising:

A laminate, the laminate comprising a battery sheet composed of multiple solar cells, a cover plate located on the light-receiving surface of the battery sheet, and a back sheet located on the backlight surface of the battery sheet, wherein the The battery sheet layer includes the first battery string to the sixth battery string arranged in parallel, the number of solar cells contained in each string of the first battery string to the sixth battery string is the same and connected in series, the first battery string The first battery string is connected in parallel with the second battery string to form a first group, the third battery string is connected in parallel with the fourth battery string to form a second group, the fifth battery string is connected in parallel with the sixth battery string to form a third group, and the first battery string is connected in parallel to form a third group. group, the second group and the third group are connected in series;

The photovoltaic junction box arranged on the backlight surface of the laminate, the photovoltaic junction box includes a first bypass diode group, a second bypass diode group and a third bypass diode group, the first bypass diode group, the second bypass diode group Each of the bypass diode group and the third bypass diode group includes at least one bypass diode, the first bypass diode group is connected in parallel with the first group, and the second bypass diode group is connected in parallel with the second group , the third bypass diode group is connected in parallel with the third group.

Preferably, the number of solar cells contained in each of the first to sixth battery strings is 10.

Preferably, the number of solar cells contained in each of the first to sixth battery strings is 12.

Preferably, the first battery string is adjacent to the second battery string, the third battery string is adjacent to the fourth battery string, and the fifth battery string is adjacent to the sixth battery string.

Compared with the prior art, the technical solution provided by the utility model has at least the following advantages:

The photovoltaic module provided by the utility model does not change the number and arrangement of the solar cells of the photovoltaic module in the prior art, but changes the circuit connection method of the solar cells. Connect the solar cells in series to form 6 battery strings with the same number of strings, and then divide the 6 battery strings into 3 groups. The strings in the group are connected in parallel, and the groups outside the group are connected in series. A group of bypass diodes is connected in series and parallel with the battery pack. The output power of the photovoltaic module using the above circuit connection method is the same as that of the photovoltaic module with the same size and number of cells in the prior art and pure series connection between the cells, and its maximum operating voltage is only the maximum operating voltage of the photovoltaic module in the prior art Half of the voltage can be directly applied to an independent photovoltaic system with a lower voltage on the DC side, and compared with the photovoltaic modules in the prior art, the photovoltaic modules in the utility model can realize more kinds of photovoltaic modules through a series of series or parallel connections DC side voltage. Therefore, the photovoltaic module provided by the utility model can be applied to more types of independent photovoltaic systems on the premise of keeping the power density constant, and the application range is wider.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of the circuit connection method of a photovoltaic module with 60 solar cells provided by Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the connection between cells of a photovoltaic module with 60 solar cells provided by Embodiment 1 of the present invention.

Detailed ways

As mentioned in the background, the application of photovoltaic modules in various types of independent photovoltaic systems in the prior art has relatively large limitations. The inventor found through research that the main reason for this phenomenon is that the solar cells inside the conventional photovoltaic modules in the prior art are all connected in a pure series circuit. For this kind of photovoltaic module, its maximum operating voltage is the sum of the maximum operating voltages of all the cells it contains. For example, in a conventional photovoltaic module with 60 cells, the size of the cells is generally 156mm×156mm, and the maximum operating voltage of a single cell is about 0.5V, so its maximum operating voltage is 30V. Similarly, the maximum operating voltage of a photovoltaic module with 72 cells is 36V. The DC side voltage of an independent photovoltaic system generally has several types such as 12V, 24V, 48V, 110V, and 220V. Conventional photovoltaic modules are limited by their own maximum operating voltage, and their application range will be limited.

For example, the most commonly used photovoltaic module to realize an independent photovoltaic system is a photovoltaic module with 60 cells in a pure series circuit, but the maximum operating voltage of this photovoltaic module is generally around 30V, which cannot be applied to a DC side voltage of 12V. Independent photovoltaic system.

For another example, a photovoltaic module with 72 cells with a maximum operating voltage of 36V cannot reach a voltage of 48V no matter how it is designed in series or parallel, that is, it cannot be applied to an independent photovoltaic system with a DC side voltage of 48V.

Based on this, the utility model provides a photovoltaic module, including: a laminate, the laminate includes a cell layer composed of multiple solar cells, a cover plate located on the light-receiving surface of the cell layer, and The back plate located on the backlight side of the battery sheet, wherein the battery sheet includes first to sixth battery strings arranged in parallel, and each of the first battery string to the sixth battery string contains The number of solar cells is the same and connected in series, the first battery string and the second battery string are connected in parallel to form the first group, the third battery string and the fourth battery string are connected in parallel to form the second group, the fifth battery string A third group is formed in parallel with the sixth battery string, and the first group, the second group and the third group are connected in series; a photovoltaic junction box arranged on the backlight surface of the laminate, and the photovoltaic junction box includes a first bypass diode group, a second bypass diode group and a third bypass diode group, each of the first bypass diode group, the second bypass diode group and the third bypass diode group includes at least one bypass diode, and the first A set of bypass diodes is connected in parallel with the first set, the second set of bypass diodes is connected in parallel with the second set, and the third set of bypass diodes is connected in parallel with the third set.

The photovoltaic module provided by the utility model does not change the number and arrangement of the solar cells of the photovoltaic module in the prior art, but changes the circuit connection method of the solar cells. Connect the solar cells in series to form 6 battery strings with the same number of strings, and then divide the 6 battery strings into 3 groups. The strings in the group are connected in parallel, and the groups outside the group are connected in series. A group of bypass diodes is connected in series and parallel with the battery pack. The output power of the photovoltaic module using the above circuit connection method is the same as that of the photovoltaic module with the same size and number of cells in the prior art and pure series connection between the cells, and its maximum operating voltage is only the maximum operating voltage of the photovoltaic module in the prior art Half of the voltage can be directly applied to an independent photovoltaic system with a lower voltage on the DC side, and compared with the photovoltaic modules in the prior art, the photovoltaic modules in the utility model can realize more types through a series of series or parallel connections the DC side voltage. Therefore, the photovoltaic module provided by the utility model can be applied to more types of independent photovoltaic systems on the premise of keeping the power density (that is, the power per unit area) unchanged, and the application range is wider.

The above is the core idea of the utility model. In order to make the above purpose, features and advantages of the utility model more obvious and easy to understand, the specific implementation of the utility model will be described in detail below in conjunction with the accompanying drawings.

In the following description, a lot of specific details have been set forth in order to fully understand the utility model, but the utility model can also be implemented in other ways that are different from those described here, and those skilled in the art can do so without violating the connotation of the utility model. Under the circumstances, similar promotion is done, so the utility model is not limited by the specific embodiments disclosed below.

Secondly, the utility model is described in detail in conjunction with the schematic diagram. When describing the embodiment of the utility model in detail, for the convenience of explanation, the cross-sectional view showing the structure of the device will not be partially enlarged according to the general scale, and the schematic diagram is only an example, and it will not be described here. The protection scope of the utility model should be limited. In addition, the three-dimensional space dimensions of length, width and depth should be included in actual production.

Embodiment one

This embodiment provides a photovoltaic module with 60 solar cells, that is, the number of solar cells contained in each of the first battery string to the sixth battery string in the photovoltaic module is 10. As shown in Figure 1, the first battery string 101 and the second battery string 102 are connected in parallel. Since the first battery string 101 and the second battery string 102 are composed of 10 battery slices connected in series, it is assumed that the maximum operating voltage of one battery slice is U , then the voltage at both ends of the branch formed by the parallel connection of the first battery string 101 and the second battery string 102 is 10U; similarly, the voltage at both ends of the branch formed by the parallel connection of the third battery string 103 and the fourth battery string 104 is 10U , the voltage across the branch formed by the parallel connection of the fifth battery string 105 and the sixth battery string 106 is 10U. The above 6 strings of battery strings are connected in parallel and the 3 branches are connected in series with each other, so the maximum working voltage of the entire photovoltaic module (that is, between ports 11 and 12) is 30U.

However, if the cells are connected in pure series in the prior art, the maximum operating voltage of a photovoltaic module with 60 cells in the prior art is the sum of the voltages at both ends of all cells, which is 60U. It can be seen that this implementation The maximum working voltage of the photovoltaic module with 60 cells in the example is half of the maximum working voltage of the photovoltaic module with 60 cells in the prior art.

If the solar cell is a conventional solar cell with a size of 156mm×156mm, a short-circuit current of 8-9A, and a maximum operating voltage of 0.5V, then U=0.5V, and the photovoltaic power of 60 cells using the above-mentioned circuit connection method The maximum working voltage of the module is 15V, while the maximum working voltage of the photovoltaic module with 60 cells in the prior art is 30V.

In addition, the first bypass diode group 107 is connected in parallel at both ends of the branch formed by the parallel connection of the first battery string 101 and the second battery string 102, and the two ends of the branch formed by the parallel connection of the third battery string 103 and the fourth battery string 104 A second bypass diode group 108 is connected in parallel, and a third bypass diode group 109 is connected in parallel at both ends of the branch formed by the parallel connection of the fifth battery string 105 and the sixth battery string 106 . When one or several cells of the photovoltaic module are blocked and the hot spot effect occurs, the bypass diode connected in parallel with the branch where the cells are shaded will be turned on, so that the branch where the cells are shaded will stop working In order to avoid damage caused by local overheating of photovoltaic modules caused by the shaded cells as loads that consume electric energy and generate heat. The number of bypass diodes included in the first bypass diode group 107 , the second bypass diode group 108 and the third bypass diode group 109 for preventing the hot spot effect should not be less than one.

The cell layer connected according to the above circuit connection method is shown in Figure 2, which is the same as the cell arrangement of the photovoltaic module with 60 cells in the prior art, and the 60 solar cells are arranged in 6 columns and 10 rows. 10 battery slices in each column are connected in series to form 6 battery strings, which are the first battery string 201, the second battery string 202, the third battery string 203, the fourth battery string 204, the fifth battery string 205, and the sixth battery string. String 206. The first battery string 201 and the second battery string 202 are connected in parallel to form the first group 21, the third battery string 203 and the fourth battery string 204 are connected in parallel to form the second group 22, and the fifth battery string 205 and the sixth battery string 206 are connected in parallel to form the first group 21. Three sets of 23.

The positive pole of the first group 21 is introduced into the A terminal in the junction box by the bus bar aa' (not shown in the figure), and the negative pole of the first group 21 is introduced into the B terminal in the junction box by the bus bar bb' (not shown in the figure). shown), a first bypass diode group including at least one bypass diode is arranged between the A terminal and the B terminal; the anode of the second group 22 is introduced into the B terminal in the junction box by the bus bar bb', the first The negative electrodes of the two groups 22 are introduced into the C terminal (not shown in the figure) in the junction box by the bus bar cc', and a second bypass diode group including at least one bypass diode is arranged between the B terminal and the C terminal ; The positive pole of the third group 23 is introduced into the C terminal in the junction box by the bus bar cc', the negative pole of the third group 23 is introduced into the D terminal (not shown in the figure) in the junction box by the bus bar dd', and the C terminal A third bypass diode set including at least one bypass diode is disposed between the post and the D post. Terminal A is used as the positive output terminal of the photovoltaic module, and terminal D is used as the negative output terminal of the photovoltaic module to output the module current.

In addition, the intersection 1 of the bus bars aa' and cc', the intersection 2 of the bus bars cc' and bb', the intersections 3 and 4 of the bus bars dd' and bb', and each bus bar and solar cell The contact parts of the chip need to be separated by isolation strips with good electrical insulation (such as EPE: an insulating material composed of EVA+PET+EVA three-layer materials, where PET is the abbreviation of polyethylene terephthalate) to prevent current short circuit.

In order to simplify the bus bars for circuit connection and avoid unnecessary increase in workload, it is preferable in this embodiment to make the first battery string 201 and the second battery string 202 adjacent, and the third battery string 203 and The fourth battery string 204 is adjacent, the fifth battery string 205 and the sixth battery string 206 are adjacent, and it is more preferable that the first battery string 201 to the sixth battery string 206 are arranged sequentially as shown in the figure.

It should be noted that this embodiment only uses the arrangement of the first battery string 201 to the sixth battery string 206 as an example for illustration, and the first battery string 201 to the sixth battery string 206 are just names and do not represent actual sort order.

If in order to build a low-voltage independent photovoltaic system with a DC side voltage of 12V, the following methods are adopted: keep the pure series circuit connection and the size of the photovoltaic module with 60 cells unchanged, reduce the number of cells in the photovoltaic module, and make a single photovoltaic module The maximum operating voltage is reduced to achieve a DC side voltage of 12V. However, this method reduces the power output of a single original 60-cell photovoltaic module, that is, reduces its power per unit area, and increases the power generation cost per unit area of the photovoltaic system.

In order to keep the power density of the module unchanged as much as possible, the size of the photovoltaic module can be reduced while reducing the number of cells, that is, to make a photovoltaic module with a number of cells less than 60 and a size smaller than the original 60 cells. size of. Although this kind of photovoltaic module can still reduce the maximum working voltage of a single module, and its power density is higher than the above-mentioned photovoltaic module that simply reduces the number of cells, but because the spacing between the cells in the photovoltaic module is kept at 2 mm ~ 3 mm, The string spacing between the battery strings is 3mm to 4.5mm, and the distance between the battery slices and the edge of the cover plate is also regulated by the standard (in order to ensure electrical safety, the edge distance cannot be lower than the specified minimum value), so even if the number of battery slices is reduced At the same time, the module size is reduced to produce smaller-sized photovoltaic modules, and its power density is still lower than that of the original 60-cell photovoltaic module. And the use of small-sized photovoltaic modules will inevitably increase the cost. Simply put, if a 250W photovoltaic module is made into two 125W photovoltaic modules, the various materials used must be more expensive than a 250W photovoltaic module. If there are many, the corresponding labor cost will also increase.

Compared with the photovoltaic module with 60 cells in the prior art, the photovoltaic module provided by the utility model has the same size, the number and specifications of the cells used, and only the circuit connection mode between the cells is changed. , so the total output power of the photovoltaic module in the utility model remains unchanged, that is, the power density per unit area remains unchanged, and the cost will not increase. The change of the connection mode of the battery slices makes the maximum working voltage of the photovoltaic module of the utility model become half of that of the prior art: 15V. With the photovoltaic controller, the photovoltaic module of the utility model can be operated under the premise that the power density and cost remain unchanged. Next, it is directly applied to an independent photovoltaic system with a DC side voltage of 12V, which broadens the application range of photovoltaic modules with 60 cells.

Embodiment two

Based on the core idea of the present utility model, this embodiment provides a photovoltaic module with 72 solar cells, that is, the solar cells contained in each string of the first battery string to the sixth battery string in the photovoltaic module The number is 12 pieces. The connection mode between the cells is the same as that in the first embodiment, which is still connected in series, then in parallel and then in series. The only difference is the number of solar cells in each string of the first battery string to the sixth battery string.

In the prior art, the maximum operating voltage of a photovoltaic module with 72 cells in pure series connection is about 36V, and no matter what kind of electrical connection it goes through, it cannot achieve a voltage of 48V. That is to say, the 72 cells in the prior art Photovoltaic modules cannot be applied to independent photovoltaic systems with a DC side voltage of 48V.

The photovoltaic module provided by this embodiment has the same size and the number of cells as the photovoltaic module with 72 cells in the prior art, and what is changed is the connection mode between the solar cells, which is not used in this embodiment. The traditional pure series connection adopts the same circuit connection method as that of the first embodiment, so that the maximum operating voltage drop of the photovoltaic module in this embodiment is about 18V. The voltage of these three photovoltaic modules connected in series is about 54V, and with a suitable photovoltaic controller, it can be directly applied to a photovoltaic system with a DC side of 48V on the premise of maintaining power density and not increasing costs, so that 72 pieces Photovoltaic modules with cells have a wider range of applications.

It should be noted that this utility model only takes photovoltaic modules with 60 cells and 72 cells as an example for illustration, similarly there are other photovoltaic modules of various specifications that can use the circuit connection provided by the utility model In this way, the maximum operating voltage of the module is reduced to half, thereby broadening the application range in various types of independent photovoltaic systems.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the scope of the technical solution of the utility model, can use the method and technical content disclosed above to make many possible changes and modifications to the technical solution of the utility model, or modify it into an equivalent change, etc. effective example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical proposal of the present invention.

Claims (4)

1. A photovoltaic module, characterized in that, comprising: A laminate, the laminate comprising a battery sheet composed of multiple solar cells, a cover plate located on the light-receiving surface of the battery sheet, and a back sheet located on the backlight surface of the battery sheet, wherein the The battery sheet layer includes the first battery string to the sixth battery string arranged in parallel, the number of solar cells contained in each string of the first battery string to the sixth battery string is the same and connected in series, the first battery string The first battery string is connected in parallel with the second battery string to form a first group, the third battery string is connected in parallel with the fourth battery string to form a second group, the fifth battery string is connected in parallel with the sixth battery string to form a third group, and the first battery string is connected in parallel to form a third group. group, the second group and the third group are connected in series; The photovoltaic junction box arranged on the backlight surface of the laminate, the photovoltaic junction box includes a first bypass diode group, a second bypass diode group and a third bypass diode group, the first bypass diode group, the second bypass diode group Each of the bypass diode group and the third bypass diode group includes at least one bypass diode, the first bypass diode group is connected in parallel with the first group, and the second bypass diode group is connected in parallel with the second group , the third bypass diode group is connected in parallel with the third group. 2 . The photovoltaic module according to claim 1 , wherein the number of solar cells contained in each of the first battery string to the sixth battery string is 10. 3 . 3 . The photovoltaic module according to claim 1 , wherein the number of solar cells contained in each of the first battery string to the sixth battery string is 12. 4 . 4. The photovoltaic module according to claim 1, wherein the first battery string is adjacent to the second battery string, the third battery string is adjacent to the fourth battery string, and the fifth battery string is Adjacent to the sixth battery string.

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