Photovoltaic modules

Abstract

The present invention discloses a photovoltaic module, comprising a first cover plate, a first packaging film, a battery layer, a second packaging film with a first hole, and a second cover plate with a second hole, which are stacked in sequence; the battery layer comprises a plurality of battery strings, the battery string comprises a first bus bar, and the first bus bar sequentially passes through the first hole and the second hole; the first bus bar comprises a first insulating strip on one side close to the second packaging film, and the first insulating strip does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located; the second packaging film comprises a first part and a second part, and the first part does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located, and the second part completely fills the second hole. In the first state of the photovoltaic module, the thickness of the first part is less than the thickness of the second part, and the first state is a state where the photovoltaic module is not laminated. The present invention can prevent the problem of battery string breakdown when the pulse voltage is high, and improve the reliability of the photovoltaic module.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and more specifically, to a photovoltaic module. Background Art

[0002] Solar power generation refers to a power generation method that directly converts light energy into electrical energy without going through a thermal process. It includes photovoltaic power generation, photochemical power generation, photoinduction power generation and photobiological power generation. Photovoltaic power generation is a direct power generation method that uses solar-grade semiconductor electronic devices to effectively absorb solar radiation energy and convert it into electrical energy. It is the mainstream of solar power generation today. In photochemical power generation, there are electrochemical photovoltaic cells, photoelectrolytic cells and photocatalytic cells. Currently, photovoltaic cells are used in practice.

[0003] Photovoltaic power generation systems are mainly composed of photovoltaic modules, batteries, controllers and inverters, among which solar cells are the key part of photovoltaic modules. Solar cells are mainly divided into two categories: crystalline silicon cells and thin-film cells. The former includes monocrystalline silicon cells and polycrystalline silicon cells, while the latter mainly includes amorphous silicon solar cells, copper indium gallium selenide solar cells and cadmium telluride solar cells.

[0004] In recent years, 2000V photovoltaic systems have appeared in the industry, which requires solar panels to pass the 2000V photovoltaic system standard test and a pulse voltage of up to 30KV, which can easily cause current photovoltaic panels to be broken down.

[0005] Therefore, there is an urgent need to provide a photovoltaic module that can prevent breakdown under higher pulse voltages. Summary of the invention

[0006] In view of this, the present invention provides a photovoltaic module to prevent breakdown under a relatively high pulse voltage.

[0007] The photovoltaic module provided by the present invention comprises a first cover plate, a first packaging film, a battery layer, a second packaging film, and a second cover plate stacked in sequence, wherein the second packaging film comprises a first hole, and the second cover plate comprises a second hole;

[0008] The battery sheet layer includes a plurality of battery strings, the battery string includes a first bus bar, and the first bus bar sequentially passes through the first hole and the second hole;

[0009] The first bus bar comprises a first insulating strip on one side close to the second packaging film, and the first insulating strip does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located;

[0010] The second packaging film includes a first portion and a second portion, the first portion does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located, and the second portion completely fills the second hole;

[0011] In the first state of the photovoltaic assembly, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the first portion is less than the thickness of the second portion. The first state is a state where the photovoltaic assembly is not laminated.

[0012] Optionally, the bulk resistance of the second part is not less than 10 17 Ohm cm.

[0013] Optionally, along a first direction, a width of the first insulating strip is greater than or equal to a width of the first bus bar, and the first direction is an extension direction of the battery string.

[0014] Optionally, along the first direction, the width of the first bus bar is m1, the width of the first insulating bar is m2, and 0≤m2-m1≤1mm.

[0015] Optionally, in the first state, the thickness of the first portion in a direction perpendicular to the plane where the first cover plate is located is h1, and the thickness of the second portion in a direction perpendicular to the plane where the first cover plate is located is h2, and h2=2h1.

[0016] Optionally, the material of the insulating strip includes polyetherimide.

[0017] Optionally, the battery string further includes a second bus bar, the second bus bar is located at a first edge and / or a second edge of the photovoltaic module, the first edge and the second edge are arranged opposite to each other along a first direction, and the first direction is an extension direction of the battery string;

[0018] The second bus bar further includes a second insulating strip on a side close to the second packaging film.

[0019] Optionally, an orthographic projection area of ​​the second insulating strip on the first cover plate is greater than or equal to an orthographic projection area of ​​the second bus bar on the first cover plate.

[0020] Optionally, along the first direction, the width of the second insulating strip is greater than the width of the second bus bar;

[0021] And / or, along the second direction, the length of the second insulating strip is greater than the length of the second bus bar, and the second direction intersects with the first direction.

[0022] Optionally, the material of the second insulating strip is the same as that of the first insulating strip;

[0023] And / or, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the second insulating strip is the same as the thickness of the first insulating strip.

[0024] Compared with the prior art, the photovoltaic module provided by the present invention achieves at least the following beneficial effects:

[0025] The photovoltaic module of the present invention includes a first cover plate, a first packaging film, a battery layer, a second packaging film, and a second cover plate stacked in sequence. The first cover plate and the second cover plate can well protect the battery layer. The first packaging film and the second packaging film are located on both sides of the battery layer to prevent water and oxygen from entering and causing the battery string in the battery layer to fail. The battery layer includes a plurality of battery strings, and the battery string includes a first bus bar, which passes through the first hole and the second hole in sequence. The first bus bar serves as a conductive connection component and can conduct the current generated by the battery string to the junction box on the back of the photovoltaic module. In the related art, for a 2000V photovoltaic system, the pulse voltage is relatively large, and it is easy to break through the battery string from the position of the back plate hole, affecting the reliability of the photovoltaic module. In the present invention, the first bus bar includes a first insulating strip on one side close to the second packaging film. In a direction perpendicular to the plane where the first cover plate is located, the first insulating strip does not overlap with the second hole, and the first insulating strip plays an insulating role. When the pulse voltage is large, the first insulating strip can prevent leakage under the higher pulse voltage, and the first insulating strip does not overlap with the second hole, that is, the first insulating strip does not extend into the second hole, thereby ensuring the sealing of the second hole position; the second packaging film includes a first part and a second part, in a direction perpendicular to the plane where the first cover plate is located, the first part does not overlap with the second hole, and the second part completely fills the second hole. In the first state of the photovoltaic module, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the first part is less than the thickness of the second part. The first state is a state where the photovoltaic module is not laminated. Corresponding to the position of the second hole, the second packaging film is thickened. Before lamination, the thickness of the second part is greater than the thickness of the first part. After lamination, the second part can completely fill the second hole. Since the second packaging film also plays an insulating role, leakage can be further prevented when the voltage is too large and the battery string is broken down, thereby ensuring the reliability of the photovoltaic module.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0027] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0029] Figure 1 It is a schematic diagram of the planar structure of a photovoltaic module provided by the present invention;

[0030] Figure 2 yes Figure 1 A cross-section in the A-A' direction;

[0031] Figure 3 yes Figure 1 A cross-section in the B-B' direction;

[0032] Figure 4 It is a cross-sectional view of a photovoltaic module before lamination;

[0033] Figure 5 It is another cross-sectional view of the PV module when it is not laminated;

[0034] Figure 6 It is a schematic diagram of the planar structure of another photovoltaic module provided by the present invention;

[0035] Figure 7 is a planar relationship diagram of the first bus bar and the first insulating bar;

[0036] Figure 8 yes Figure 1 A cross-section in the C-C' direction;

[0037] Fig. 9 This is a schematic diagram of the planar structure of another photovoltaic module provided by the present invention. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0040] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , Figure 1is a schematic diagram of a planar structure of a photovoltaic module provided by the present invention, Figure 2 yes Figure 1 A cross-section along the A-A' direction, Figure 3 yes Figure 1 A cross-section along the B-B' direction, Figure 4 It is a cross-sectional view of a photovoltaic module before lamination. Figure 4 The cross-sectional view corresponds to Figure 1 The position of B-B' in Figure 5 This is another cross-sectional view of the photovoltaic module when it is not laminated. Figure 5 The cross-sectional view corresponds to Figure 1 The position of A-A' in the middle.

[0044] The photovoltaic module 100 of the present invention comprises a first cover plate 101, a first packaging film 102, a battery layer 103, a second packaging film 104, and a second cover plate 105 stacked in sequence, wherein the second packaging film 104 comprises a first hole 1041, and the second cover plate 105 comprises a second hole 1051; the battery layer 103 comprises a plurality of battery strings 20, and the battery string 20 comprises a first bus bar 40, and the first bus bar 40 sequentially passes through the first hole 1041 and the second hole 1051; the first bus bar 40 comprises a first insulating strip 50 on one side close to the second packaging film 104, and the first insulating strip 50 is perpendicular to the first insulating strip 50. In the direction of the plane where the first cover plate 101 is located, the first insulating strip 50 and the second hole 1051 do not overlap; the second packaging film 104 includes a first portion 104a and a second portion 104b, and in the direction perpendicular to the plane where the first cover plate 101 is located, the first portion 104a and the second hole 1051 do not overlap, and the second portion 104b completely fills the second hole 1051; in the first state of the photovoltaic component 100, in the direction perpendicular to the plane where the first cover plate 101 is located, the thickness of the first portion 104a is less than the thickness of the second portion 104b, and the first state is a state where the photovoltaic component 100 is not laminated.

[0045] Specifically, the first cover plate 101 and the second cover plate 105 can well protect the battery layer 103. Optionally, the first cover plate 101 and the second cover plate 105 can be transparent glass, or the first cover plate 101 is glass, and the second cover plate 105 is a back plate, and the back plate adopts a fluorine film / PET layer / inner coating structure design, and the middle PET layer determines the water vapor / air barrier of the back plate. The first packaging film 102 and the second packaging film 104 are respectively located on the first side and the second side of the battery layer 103, and the battery layer 103 is packaged. The main function is to protect the battery 21, prevent water and oxygen from entering and causing the battery string 20 in the battery layer 103 to fail, and package it into a photovoltaic module 100 that can output direct current. Of course, the first side and the second side are relative. For a single-sided module, the first side is the direct sunlight side, and the second side is the backlight side. For a double-sided module, the first side is the direct sunlight side, and the second side is the sunlight reflecting side.

[0046] The battery cell layer 103 includes a plurality of battery strings 20. There are many possible embodiments for arranging the battery strings 20. This embodiment only takes three strings and two parallels as an example for schematic illustration. There are three battery strings 20 connected in series on the upper and lower sides of the first bus bar 40. The three battery strings 20 on the upper side and the three battery strings 20 on the lower side are connected in parallel. The number of battery cells 21 in each battery string 20 is Figure 1 It is only a schematic illustration and is not specifically limited here. It should be noted that the arrangement of the battery string 20 can also be other ways, such as the battery cells 21 connected in series only communicate one battery string 20, of course, this is not specifically limited here. Optionally, there can be a certain interval between two adjacent battery cells 21, and the two adjacent battery cells 21 are electrically connected through the welding strip 30, and the end of the welding strip 30 is overlapped with the first bus bar 40 to achieve electrical connection.

[0047] like Figure 3 As shown, the second packaging film 104 includes a first hole 1041, the second cover plate 105 includes a second hole 1051, and the first bus bar 40 is bent once toward the second cover plate 105, and passes through the first hole 1041 of the second packaging film 104 and the second hole 1051 of the second cover plate 105 in sequence. The first bus bar 40 serves as a conductive connecting component and can conduct the current generated by the battery string to the junction box (not shown in the figure) on the back of the photovoltaic module 100.

[0048] In the related art, for a 2000V photovoltaic system, the pulse voltage is relatively large, and it is easy to break through the battery string from the position of the back plate hole (ie, the second hole 1051), affecting the reliability of the photovoltaic module.

[0049] In the present invention, the first bus bar 40 includes a first insulating strip 50 on one side close to the second packaging film 104. In a direction perpendicular to the plane where the first cover plate 101 is located, the first insulating strip 50 does not overlap with the second hole 1051. The first insulating strip 50 plays an insulating role. When the pulse voltage is large, the first insulating strip 50 can prevent leakage under the high pulse voltage. Moreover, the first insulating strip 50 does not overlap with the second hole 1051, that is, the first insulating strip 50 does not extend into the second hole 1051. The first hole 1051 is 041 and the second hole 1051 only have the first bus bar 40. If the first insulating strip 50 extends into the first hole 1041 and the second hole 1051, when the second packaging film 104 is packaging the second hole 1051, the first insulating strip 50 needs to be bent into the second hole 1051, and the first insulating strip 50 is closer to the side wall of the second hole 1051, which will affect the sealing of the packaging. In this embodiment, the first insulating strip 50 and the second hole 1051 do not overlap, which can ensure the sealing of the second hole 1051. In addition, if the length of the first insulating strip 50 is equal to the length of the first bus bar 40 in the second direction Y, then the first bus bar 40 needs to be electrically connected to the junction box later, and the existence of the first insulating strip 50 will make the first bus bar 40 unable to be welded.

[0050] Combination Figure 3 The second packaging film 104 includes a first portion 104a and a second portion 104b. The first portion 104a and the second hole 1051 do not overlap in a direction perpendicular to the plane where the first cover plate 101 is located. The second portion 104b completely fills the second hole 1051, which can ensure the sealing of the second hole 1051. Figure 4 and Figure 5 In the first state of the photovoltaic module 100, in a direction perpendicular to the plane where the first cover plate 101 is located, the thickness h1 of the first portion 104a (refer to Figure 5 ) is smaller than the thickness h2 of the second portion 104b (refer to Figure 4 ), the first state is the state where the photovoltaic module 100 is not laminated. The second packaging film 104 is thickened at the position corresponding to the second hole 1051. Optionally, the second packaging film 104 can be thickened at the position corresponding to the entire first bus bar 40, which is convenient for manufacturing. Of course, the second packaging film 104 can also be thickened only at the position of the second hole 1051, which is not specifically limited here. Before lamination, the thickness of the second part 104b is greater than the thickness of the first part 104a. After lamination, the second part 104b can completely fill the second hole 1051. Since the second packaging film 104 also plays an insulating role, it can further prevent leakage when the voltage is too large and break down the battery string, thereby ensuring the reliability of the photovoltaic module.

[0051] In some optional embodiments, continue to refer to Figure 3 and Figure 4, the body resistance of the second portion 104b is not less than 10 17 Ohm cm.

[0052] The bulk resistance refers to the ratio of the voltage between the two ends of the material to the current passing through it. The smaller the bulk resistance, the smaller the resistance to the current, and the easier it is to be broken down by high voltage; the larger the bulk resistance, the greater the resistance to the current, the better the insulation performance, the more it can prevent voltage breakdown, and the less likely it is to be broken down by high voltage. Optionally, the bulk resistance of POE is generally larger than that of EVA, and the second part 104b can use POE.

[0053] Optionally, the bulk resistance of the second part 104b can be measured by a four-probe method using a four-probe tester. The four-probe method is a method based on the Wheatstone bridge principle, where four probes are arranged at a certain interval, two of which are used as current sources, and the other two probes are used as voltmeters. When the current source applies current to the second part 104b, a voltage drop is generated, thereby generating a voltage in the bridge. By measuring the voltage in the bridge, the bulk resistance of the second part can be calculated.

[0054] The steps for measuring body resistance can be as follows:

[0055] Cut a second sample of a cube with a side length of 1 cm;

[0056] Place the sample in the electrode holder;

[0057] Connect the four-probe tester to a regulated power supply and electrical measuring instruments;

[0058] Place the four-probe probe in contact with the sample, align the four probes (the 1st, 2nd, 3rd and 4th) in a straight line, and adjust the probe spacing to match the sample size;

[0059] Turn on the regulated power supply and apply current to the sample, that is, pass current I through the first and fourth probes, and a potential difference V is generated between the second and third probes;

[0060] Record the current value I, voltage value V and probe distance;

[0061] Calculate the bulk resistance of the sample.

[0062] Resistivity Among them, ρ is the resistivity, V is the voltage value, I is the current value, and C is the probe coefficient. S'1, S'2, and S'3 are the distance between the first and second probes, the distance between the second and third probes, and the distance between the third and fourth probes, respectively.

[0063] When S'1=S'2=S'3=1 mm, C=2π.

[0064] The current is I=C, ρ=V and can be directly read by a digital voltmeter.

[0065] The present invention increases the bulk resistance of the second portion 104b to be no less than 10 17 Ohm·cm, which can greatly increase the insulation of the second portion 104b, further preventing leakage and breakdown of the battery string when the voltage is too high, thereby ensuring the reliability of the photovoltaic module.

[0066] In some optional embodiments, continue to refer to Figure 1 And reference Figure 6 , Figure 6 It is a schematic diagram of the planar structure of another photovoltaic module provided by the present invention. Along the first direction X, the width of the first insulating strip 50 is greater than or equal to the width of the first bus bar 40 . The first direction X is the extension direction of the battery string 20 .

[0067] Figure 1 In the first direction X, the width of the first insulating strip 50 is equal to the width of the first bus bar 40. Figure 6 In the embodiment, along the first direction X, the width of the first insulating strip 50 is greater than the width of the first bus bar 40. Optionally, the width of the first insulating strip 50 and the width of the first bus bar 40 can be measured using a vernier caliper.

[0068] It can be understood that the first insulating strip 50 plays an insulating role. When the pulse voltage is large, the first insulating strip 50 can prevent leakage under the higher pulse voltage. Therefore, the width of the first insulating strip 50 along the first direction X is as large as possible, at least covering the first bus bar 40, so that the insulation effect is better. In this embodiment, along the first direction X, the width of the first insulating strip 50 is greater than or equal to the width of the first bus bar 40, so that the first bus bar 40 can be completely covered to improve the insulation effect.

[0069] In some optional embodiments, referring to Figure 7 , Figure 7 4 is a planar relationship diagram of the first bus bar and the first insulating strip. Along the first direction X, the width of the first bus bar 40 is m1, the width of the first insulating strip 50 is m2, and 0≤m2-m1≤1mm.

[0070] Figure 7 Only the case where the width of the first insulating strip 50 along the first direction X is greater than the width of the first bus bar 40 is shown. Of course, the width of the first insulating strip 50 along the first direction X may be equal to the width of the first bus bar 40 .

[0071] It is understandable that the larger the width of the first insulating strip 50 along the first direction X, the better. However, when the width of the first insulating strip 50 along the first direction X is too large, that is, the difference between m2 and m1 is too large, it will cause material waste. The part of the first insulating strip 50 along the first direction X that is larger than the first bus bar 40 has little effect on improving insulation and also increases material costs.

[0072] The difference between m2 and m1 can be 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm. Of course, the difference between m2 and m1 can also be other values, which are not specifically limited here.

[0073] In this embodiment, 0≤m2-m1≤1mm, which can ensure that the first insulating strip 50 completely covers the first bus bar 40 and improve the insulation effect without causing material waste and reducing material costs.

[0074] In some optional embodiments, continue to refer to Figure 4 and Figure 5 In the first state, the thickness of the first portion 104a in the direction perpendicular to the plane where the first cover plate 101 is located is h1, and the thickness of the second portion 104b in the direction perpendicular to the plane where the first cover plate 101 is located is h2, where h2=2h1. The thickness h2 of the second portion 104b is twice the thickness h1 of the first portion 104a. As described above, the second packaging film 104 plays a packaging role. For the position of the second hole 1051, the second packaging film 104 not only plays a role in packaging the second hole 1051, but the second packaging film 104 at the position of the second hole 1051 is also thicker in the present invention. By utilizing the insulation of the second packaging film 104, it is possible to further prevent leakage when the voltage is too large and breakdown of the battery string, thereby ensuring the reliability of the photovoltaic module. Therefore, the greater the thickness of the second portion 104b, the better. Of course, when the thickness of the second portion 104b is too large, the lamination process cannot compress it, resulting in an increase in the thickness of the photovoltaic module 100 at the position corresponding to the first bus bar 40, and also causing material waste. Therefore, the thickness of the second portion 104b must satisfy the above-mentioned packaging and improve the insulation effect, but it should not be too large to avoid increasing the thickness of the photovoltaic module 100 at a local position.

[0075] Optionally, the first portion 104 a and the second portion 104 b of the second packaging film 104 may also be measured by a vernier caliper.

[0076] In this embodiment, h2=2h1, and the second hole 1051 can be completely filled after lamination, meeting the packaging requirements and improving the insulation effect. The position of the second part 104b can be compressed during lamination without increasing the thickness of the photovoltaic component 100 corresponding to the position of the first bus bar 40.

[0077] In some optional embodiments, continue to refer to Figure 3 , the material of the insulating strip includes polyetherimide.

[0078] Polyimide (abbreviated as PI) refers to a type of polymer containing an imide ring (-CO-NR-CO-) on the main chain. It is one of the organic polymer materials with the best comprehensive performance. It is resistant to high temperatures of over 400°C and has high insulation performance. Its dielectric constant is 4.0 at 10 Hz and its dielectric loss is only 0.004 to 0.007. It can effectively prevent the battery cell 21 from being broken down when the voltage is too large. In addition, polyimide is a flexible material and does not hinder the bending of the first bus bar 40.

[0079] In some optional embodiments, continue to refer to Figure 1 and Figure 6 ,as well as Figure 8 , Figure 8 yes Figure 1 A cross-sectional view taken along the C-C' direction, the battery string further includes a second bus bar 60, the second bus bar 60 is located at the first edge 1001 and / or the second edge 1002 of the photovoltaic module 100, the first edge 1001 and the second edge 1002 are arranged opposite to each other along a first direction X, and the first direction X is the extension direction of the battery string 20;

[0080] The second bus bar 60 further includes a second insulating strip 70 on a side close to the second packaging film 104 .

[0081] Understandably, Figure 1 and Figure 6 1 shows that both the first edge 1001 and the second edge 1002 of the photovoltaic module 100 include a second bus bar 60, where the second bus bar 60 is used to connect two adjacent battery strings along the second direction Y. In some optional embodiments, the second bus bar 60 may be provided only on the first edge 1001 or the second edge 1002, which is not specifically limited here.

[0082] For a 2000V photovoltaic system, the pulse voltage is relatively large, and it is easy to break down the battery string at the position of the second bus bar 60, affecting the reliability of the photovoltaic module.

[0083] Optionally, the material of the second insulating strip 70 may be the same as that of the first insulating strip 50 , such as polyimide (PI). Polyimide has high insulation and certain flexibility.

[0084] Reference Figure 8 The second bus bar 60 also includes a second insulating strip 70 on one side close to the second packaging film 104. The second insulating strip 70 has insulating properties and can prevent leakage at the position of the second bus bar 60 under a higher pulse voltage, thereby further improving the reliability of the photovoltaic module.

[0085] In some optional embodiments, continue to refer to Figure 1 and reference Fig. 9 , Fig. 9 It is a schematic diagram of the planar structure of another photovoltaic assembly provided by the present invention, and the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than or equal to the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101 .

[0086] Figure 1 FIG. 4 shows a case where the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is equal to the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101. Fig. 9 The orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is larger than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101 . Fig. 9 , the first edge 1001 and the second edge 1002 of the photovoltaic module 100 both include the second bus bar 60, and the first edge 1001 and the second edge 1002 of the photovoltaic module 100 both include the second insulating strip 70. Fig. 9 It is also shown in the figure that along the first direction X, the width of the first insulating strip 50 is greater than the width of the first bus bar 40, which is not specifically limited here.

[0087] The second insulating strip 70 plays an insulating role. When the pulse voltage is relatively large, the second insulating strip 70 can prevent leakage under the relatively high pulse voltage. Therefore, the larger the area of ​​the second insulating strip 70, the better. At least the second bus bar 60 is covered, so that the insulation effect is better. In this embodiment, the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than or equal to the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101, so that the second bus bar 60 can be completely covered, thereby improving the insulation effect.

[0088] In some optional embodiments, with continued reference to 9 , along the first direction X, the width of the second insulating strip 70 is greater than the width of the second bus bar 60 ;

[0089] And / or, along the second direction Y, the length of the second insulating bar 70 is greater than the length of the second bus bar 60 , and the second direction Y intersects with the first direction X.

[0090] Optionally, the width of the second insulating strip 70 and the width of the second bus bar 60 may be measured by a vernier caliper; the length of the second insulating strip 70 and the length of the second bus bar 60 may also be measured by a vernier caliper.

[0091] Specifically, the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is larger than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101, which may include the following situations:

[0092] 1. Along the first direction X, the width of the second insulating strip 70 is greater than the width of the second bus bar 60, and along the second direction Y, the length of the second insulating strip 70 is equal to the length of the second bus bar 60, thereby ensuring that the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101;

[0093] 2. Along the first direction X, the width of the second insulating strip 70 is equal to the width of the second bus bar 60, and along the second direction Y, the length of the second insulating strip 70 is greater than the length of the second bus bar 60, thereby ensuring that the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101;

[0094] 3. Along the first direction X, the width of the second insulating strip 70 is greater than the width of the second bus bar 60 , and along the second direction Y, the length of the second insulating strip 70 is greater than the length of the second bus bar 60 , thereby ensuring that the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101 .

[0095] Fig. 9 Herein, only the example that the width of the second insulating strip 70 is greater than the width of the second bus bar 60 along the first direction X and the length of the second insulating strip 70 is greater than the length of the second bus bar 60 along the second direction Y is used for schematic illustration.

[0096] Along the first direction X, the width of the second insulating strip 70 is greater than the width of the second bus bar 60; and / or, along the second direction Y, the length of the second insulating strip 70 is greater than the length of the second bus bar 60, thereby ensuring that the orthographic projection area of ​​the second insulating strip 70 on the first cover plate 101 is greater than the orthographic projection area of ​​the second bus bar 60 on the first cover plate 101, so that the second insulating strip 70 can completely cover the second bus bar 60, thereby improving the insulation effect.

[0097] In some optional embodiments, continue to refer to Figure 3 and Figure 8 , the material of the second insulating strip 70 is the same as the material of the first insulating strip 50;

[0098] And / or, in a direction perpendicular to the plane where the first cover plate 101 is located, the thickness of the second insulating strip 70 is the same as the thickness of the first insulating strip 50 .

[0099] It can be understood that the material of the second insulating strip 70 can be the same as that of the first insulating strip 50, which can save the trouble of selecting materials. For example, polyimide can be used. Polyimide has high insulation properties and can improve the insulation properties of the photovoltaic module 100. Polyimide also has a certain flexibility and does not affect the bending of the second bus bar 60 during the lamination process.

[0100] Optionally, in a direction perpendicular to the plane where the first cover plate 101 is located, the thickness of the second insulating strip 70 is the same as the thickness of the first insulating strip 50 , so that after lamination, the uniformity of the overall thickness of the photovoltaic module 100 can be ensured.

[0101] It can be seen from the above embodiments that the photovoltaic module provided by the present invention achieves at least the following beneficial effects:

[0102] The photovoltaic module of the present invention includes a first cover plate, a first packaging film, a battery layer, a second packaging film, and a second cover plate stacked in sequence. The first cover plate and the second cover plate can well protect the battery layer. The first packaging film and the second packaging film are located on both sides of the battery layer to prevent water and oxygen from entering and causing the battery string in the battery layer to fail. The battery layer includes a plurality of battery strings, and the battery string includes a first bus bar, which passes through the first hole and the second hole in sequence. The first bus bar serves as a conductive connection component and can conduct the current generated by the battery string to the junction box on the back of the photovoltaic module. In the related art, for a 2000V photovoltaic system, the pulse voltage is relatively large, and it is easy to break through the battery string from the position of the back plate hole, affecting the reliability of the photovoltaic module. In the present invention, the first bus bar includes a first insulating strip on one side close to the second packaging film. In a direction perpendicular to the plane where the first cover plate is located, the first insulating strip does not overlap with the second hole, and the first insulating strip plays an insulating role. When the pulse voltage is large, the first insulating strip can prevent leakage under the higher pulse voltage, and the first insulating strip does not overlap with the second hole, that is, the first insulating strip does not extend into the second hole, thereby ensuring the sealing of the second hole position; the second packaging film includes a first part and a second part, in a direction perpendicular to the plane where the first cover plate is located, the first part does not overlap with the second hole, and the second part completely fills the second hole. In the first state of the photovoltaic module, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the first part is less than the thickness of the second part. The first state is a state where the photovoltaic module is not laminated. Corresponding to the position of the second hole, the second packaging film is thickened. Before lamination, the thickness of the second part is greater than the thickness of the first part. After lamination, the second part can completely fill the second hole. Since the second packaging film also plays an insulating role, leakage can be further prevented when the voltage is too large and the battery string is broken down, thereby ensuring the reliability of the photovoltaic module.

[0103] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A photovoltaic module, characterized in that: It includes a first cover plate, a first packaging film, a battery layer, a second packaging film, and a second cover plate stacked in sequence, wherein the second packaging film includes a first hole, and the second cover plate includes a second hole; The battery sheet layer includes a plurality of battery strings, the battery string includes a first bus bar, and the first bus bar sequentially passes through the first hole and the second hole; The first bus bar includes a first insulating strip on one side close to the second packaging film, and the first insulating strip does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located; along a first direction, the width of the first insulating strip is greater than or equal to the width of the first bus bar, and the first direction is the extension direction of the battery string; The second packaging film includes a first portion and a second portion, the first portion does not overlap with the second hole in a direction perpendicular to the plane where the first cover plate is located, and the second portion completely fills the second hole; In the first state of the photovoltaic assembly, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the first portion is less than the thickness of the second portion. The first state is a state where the photovoltaic assembly is not laminated.

2. The photovoltaic module according to claim 1, characterized in that: The body resistance of the second part is not less than 10 17 Ohm cm.

3. The photovoltaic module according to claim 1, characterized in that: Along the first direction, the width of the first bus bar is m1, the width of the first insulating strip is m2, and 0≤m2-m1≤1mm.

4. The photovoltaic module according to claim 1, characterized in that: In the first state, the thickness of the first portion in a direction perpendicular to the plane where the first cover plate is located is h1, and the thickness of the second portion in a direction perpendicular to the plane where the first cover plate is located is h2, where h2=2h1.

5. The photovoltaic module according to claim 1, characterized in that: The material of the insulating strip includes polyetherimide.

6. The photovoltaic module according to claim 1, characterized in that: The battery string further includes a second bus bar, the second bus bar is located at a first edge and / or a second edge of the photovoltaic module, the first edge and the second edge are arranged opposite to each other along a first direction, and the first direction is an extension direction of the battery string; The second bus bar further includes a second insulating strip on a side close to the second packaging film.

7. The photovoltaic module according to claim 6, characterized in that: An orthographic projection area of ​​the second insulating strip on the first cover plate is greater than or equal to an orthographic projection area of ​​the second bus bar on the first cover plate.

8. The photovoltaic module according to claim 7, characterized in that: Along the first direction, the width of the second insulating strip is greater than the width of the second bus bar; And / or, along a second direction, the length of the second insulating strip is greater than the length of the second bus bar, and the second direction intersects with the first direction.

9. The photovoltaic module according to claim 6, characterized in that: The material of the second insulating strip is the same as that of the first insulating strip; And / or, in a direction perpendicular to the plane where the first cover plate is located, the thickness of the second insulating strip is the same as the thickness of the first insulating strip.

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