CN102246322A - Method for producing a photovoltaic module and photovoltaic module - Google Patents

Abstract

The invention relates to a method for producing a photovoltaic module having a plurality of solar cells which are each connected in a series circuit having two terminals. The terminals of a plurality of series circuits are aggregated to the connection device, and a plurality of terminals of the same polarity are connected to each other via transverse contact wires. These transverse contact conductors are guided alongside the solar cells above the front carrier glass and below the rear foil, the rear foil extending over the solar cells and the transverse contact conductors. The transverse contact wires are bent or folded together to a greater thickness away from the front-side carrier glass and are guided through cutouts in the rear-side film. Here, bent or folded transverse contact wires protrude above the backside film for later electrical connection.

Description

Method for manufacturing a photovoltaic module and photovoltaic module

technical field

The invention relates to a method according to the preamble of claim 1 for producing or electrically connecting a photovoltaic module having a plurality of solar cells and a photovoltaic module.

Background technique

When producing photovoltaic modules consisting of several solar cells, so-called strings or chains of several solar cells are often placed next to each other on a front carrier glass with a lamination film interposed, more precisely usually several Chains of such solar cells are placed next to each other. These chains are in contact longitudinally with the contact elements on the front and rear of the two poles of the electrical terminal, more precisely there are advantageously a plurality of such terminals on both the front and the rear. Distributed across the front side of the solar cell are transverse contact wires which are connected to the terminals on the front side and the rear side of the solar cell. These transverse contact wires are led together to a connection device to be installed subsequently, for example a so-called connection box. The connecting device is used for the electrical connection of the entire photovoltaic module. Another lamination film was then placed and finally a backside film was placed onto the solar cells. Thereafter the photovoltaic module is laminated and the connection device is then mounted as electrical contact to the transverse contact wires.

Lateral contact wires are now bent by 90° from the front edge of the solar cells and placed onto the backside of the solar cells for subsequent electrical connection to the connection means. For this purpose, the transverse contact wires have to be guided in a complex manner manually through the backside film on the back side of the solar cells and through the cutouts in the lamination film. This is disadvantageous.

Contents of the invention

The object underlying the present invention is to provide a method as described at the outset and a corresponding photovoltaic module with which the problems of the prior art can be eliminated and in particular an electrical connection to the photovoltaic module can be achieved A possibility that is simple to implement and well automated.

This object is achieved by a method with the features of claim 1 and a photovoltaic module with the features of claim 11 . Advantageous and preferred refinements of the invention are the subject matter of the further claims and are explained in greater detail below. Some of the features below are described only for the method or only for the photovoltaic module itself. However, these features should be applicable independently of both the method and the photovoltaic module. The wording of the claims is incorporated into the content of this description by express reference.

According to the invention, a plurality of terminals of the same polarity of the solar cell are connected to one another by transverse contact lines, and these transverse contact lines are guided beside or on the solar cell above the front-side carrier glass. In this case, the transverse contact conductors can advantageously be located on the carrier glass or on a laminating film directly on the carrier glass. In addition, these transverse contact wires are guided below the back film, which also runs over the solar cells. The transverse contact conductors are bent together or folded one above the other such that they have a greater thickness or a multiple of their own thickness corresponding to the fold and protrude from or protrude above the carrier glass. The bent regions of the transverse contact lines are guided through previously produced cutouts in the backside film—possibly also in the lamination film between the solar cells and the backside film. Due to the greater thickness, the lateral contact wires protrude above the backside film or above the surface of the backside film.

These folded or bent areas are advantageously still located within the interspace of the membrane, so that no additional movement or guidance of these folded or bent areas is required. The electrical connections mentioned above and still to be described in detail can then be easily carried out at these folded or bent regions. This can be achieved by bending or folding these transverse contact wires together, which protrude, so to speak, of their own accord above the surface of the rear foil and are well achievable for electrical connection.

In an advantageous refinement of the invention, the transverse contact wires are folded over one another at least once, so that the thickness is thus at least doubled. It is particularly advantageous if the transverse contact wires are bent or folded two or three times one above the other. Multiple overlapping folds can be performed at least in part using crimp folds, whereby folds can be initiated from the ends of the transverse contact wires. However, this critically depends on the optimization of the folding fabrication technique. In this case, it can be provided in a further development of the invention that the transverse contact conductors also retain their approximately longitudinal orientation during folding and in the folded state, ie no lateral bending occurs. The number of overlapping folds also depends on the thickness of the laminating film and the backing film. As an advantageous thickness for the lamination film, one can start from about 0.4 mm and for the back film it can be somewhat smaller. The transverse contact wires, which are advantageously tinned wires, which can particularly advantageously consist of copper, can have a thickness of 0.3 mm to 0.5 mm. Thus, a sufficient height and a sufficient protrusion of the folded or bent regions above the membranes can be achieved with two or better three bends. The width of the lateral contact wires can be at least 3 mm, advantageously about 5 mm.

In an advantageous refinement of the invention, the transverse contact wires are guided close to the front edge of the preceding solar cell and in particular parallel to one another, as are the terminals of different polarity. It is particularly advantageous if the transverse contact conductors run on the narrow sides of the photovoltaic module, so that they can be kept shorter. Transversal contact wires of different polarity should have a distance of a few millimeters from each other.

In a further advantageous refinement of the invention, an individual connection device can be provided per photovoltaic module with a plurality of transverse contact conductor regions folded one above the other. If the photovoltaic module has, for example, six of the aforementioned solar cell strings, it is considered to be advantageous to provide two such connection devices. Alternatively a specific solar cell or string can be provided for each connecting device, or two connecting devices can be said to lie parallel to each other and be connected to all solar cells respectively.

For each connecting device, which in each case has two poles of a solar cell or its electrical connection, two folded regions of the transverse contact wires can advantageously be provided for each pole. These transverse contact wires can be guided to the connection device from the left and from the right. In this case, the folding regions can also be offset from one another so that they are spatially separated and cannot be confused. Thus, for example, the transverse contact lines which are connected to the front contacts of the solar cells can each run very close to the solar cells, and the other transverse contact lines are somewhat further away from the solar cells. The transverse contact conductors which are guided closer to the solar cell can be guided closer to one another than the other transverse contact conductors when they reach the connecting device from the left and right.

In a further embodiment of the invention, the cutouts are produced in the backside film, in particular also in the lamination film which is put on to the backside of the solar cell, before the placement, for example by stamping. These recesses advantageously have a rectangular or square shape. These recesses should be significantly larger in the case of the lamination film than the folded area itself of the transverse contact conductors in order to compensate for tolerances and in particular in the case of the lamination film to compensate for the area expansion. For example, the void can be about twice as long and multiple times as wide as the folded region. These voids in the backside film and lamination film should overlap each other.

The protruding portion of the bent or folded transverse contact wires above the top surface of the backside film should be at least 0.1 mm to 0.2 mm. A reliable electrical connection is thus possible, possibly even by press contacts in the connecting device. This is done after lamination of the photovoltaic modules. The connecting device can then be fastened to the carrier glass or to the edge of the edge profile connected thereto. It can also be fixed on the back film by gluing. For this purpose, the connection box can have, for example, a closable cover which is put on after the connection box has been fixed and the electrical connection to the transverse contact wires has been produced. The electrical connection of the connection device to the transverse contact conductors can be effected via the above-mentioned pressure contacts or similar. However, for reliable contact, soldering or welding is recommended to avoid contact problems later.

These and other features come from the description and drawings in addition to the claims, wherein each feature can be realized in the embodiments of the present invention and in other fields by itself or in multiple sub-combinations, and can constitute an advantageous And to the embodiments that are themselves capable of protection, rights to those embodiments are hereby claimed. The division of this application into sections and subheadings does not limit in general validity the statements made under those sections and subheadings.

Description of drawings

Embodiments of the invention are shown schematically in the drawings and explained in more detail below. In the attached picture:

1 shows an oblique view from below of a solar cell with transverse contact wires which are bent several times one above the other in their end regions,

Figure 2 shows a top view of the device from Figure 1 from the rear, and

FIG. 3 shows a side view of exactly these folded end regions of the transverse contact wires.

Detailed ways

FIG. 1 shows in an oblique view from below how a plurality of solar cells 11 are provided, for example two such solar cells. These solar cells have front contacts 12 on the front side 13, as is generally known. Distributed above the front contacts 12 are common contacts 15 formed from flat wires, which protrude slightly beyond the side edges of the solar cells 11 . In FIG. 1 , the solar cells 11 are provided in so-called strings in the direction of the common contact 15 , that is to say for example six to ten solar cells 11 are connected in a chain. Several of these strings—for example four or six—are again arranged next to one another.

The lateral contact wires 17 run in front of the solar cell 11 , wherein the lateral contact wires 17 a run very close to the solar cell 11 , for example at a distance of a few millimeters. The transverse contact conductors 17b run parallel to the transverse contact conductors 17a and are in particular configured identically, wherein the transverse contact conductors 17b are at a distance of a few millimeters from the transverse contact conductors 17a.

At the illustrated ends of the transverse contact wires 17 there are provided folded areas 19 a and 19 b , which are explained in more detail with reference to FIG. 3 . These folding regions form, so to speak, the ends of the transverse contact wires. It can also be appreciated that the ends or folded regions 19a of the transverse contact wires 17a are much closer to each other than the folded regions 19b of the transverse contact wires 17b.

It can be seen from FIGS. 1 and 2 that the common contact piece 15 is preferably connected and contacted with the transverse contact wire 17 a by welding or welding. Thus, it is thus possible to provide, so to speak, into two electrical terminals of these solar cells 11 via a transverse contact line 17a connected to the left and right with the further common contact 15 of the front contact 12 of the solar cells 11 one of. The rear contacts on the solar cells 11 are not shown, which extend to slightly further-running transverse contact conductors 17 b and are electrically connected or welded to these transverse contact conductors 17 b. However, this is easily conceivable and achievable for professionals.

It can also be seen from the plan view from FIG. 2 how the front edge of the lamination film 24 protrudes slightly beyond the transverse contact conductors 17 b and thus covers these transverse contact conductors 17 b well. This front edge of the lamination film 24 corresponds to the front edge of the carrier glass 22 shown in FIG. membrane. This can be said to be the side edge of the entire finished photovoltaic module 30 , the assembly of which is shown schematically in FIG. 3 .

In particular, FIG. 2 also shows how rear-side film 26 is provided with cutouts 27 before it is placed on the rear side of solar cell 11 and over lateral contact lines 17 . Recesses 27 a are here somewhat farther from the side edge and closer to each other than recesses 27 b. As can be appreciated from FIG. 3 , a lamination film 24 and a back film 26 are placed to the back of these solar cells 11 , wherein the lamination film 24 also has a void corresponding to the back film 26 . When placed according to FIG. 3 , the fold area 19 a protrudes through the recess 27 a in the rear film 26 and the corresponding recess in the lamination film 24 . Likewise, the folded area 19b protrudes through the interstices 27b of the lamination film 24 and the backside film 26 . As can be appreciated from Figure 2, it is possible to provide that the void 27 is slightly larger than the folded area 19, but not much larger.

It can be seen from FIG. 3 that the transverse contact conductor 17 is folded three times at the fold region 19 , that is to say has four times its thickness. The folding takes place in such a way that the end regions of the transverse contact wires are laid on top of each other twice with a length of, for example, one to two centimeters and are then folded inward away from the ends. As explained at the outset, other folds or bends are also possible. Advantageously, all folding areas 19 have the same height. A uniform folding process can thus be carried out and thus the electrical connection means can be configured identically in each case, which, although not shown here, can easily be realized by a skilled person.

It can be seen precisely from the figure how after the transverse contact wires 17 have been folded into folded areas 19 these folded areas 19 protrude according to FIG. The voids 27 of the overlamination film 24 and the back film 26 and how these folded areas 19 protrude above the top surface of the back film 26 due to the height of the back film 26 . After lamination of the photovoltaic module 30 , these folded regions 19 of the transverse contact wires 17 also still protrude and can be easily electrically connected as basically explained at the outset.

To this end, it is also immaterial whether a single such connection array with folding regions 19 or, for example, two or three such connection arrays are provided in the finished photovoltaic module. This depends on the structural form and electrical power of the photovoltaic modules.

Claims (13)

1. A method for producing or electrically connecting a photovoltaic module having a plurality of solar cells, at least two of which are each connected in a series circuit, wherein the series circuit has two terminals , and wherein the terminals of a plurality of series circuits are assembled to a connecting device, characterized in that a plurality of terminals of the same polarity are connected to each other via transverse contact wires which are connected under the rear film above the front carrier glass Guided next to the solar cells, with the back film running over the solar cells and the transverse contact wires, wherein the transverse contact wires are bent or folded together to a greater thickness away from the front carrier glass and guided through cutouts in the back film and protrude over the over the backside film for later electrical connections. 2. The method as claimed in claim 1, characterized in that the transverse contact wires are folded on top of each other at least once, preferably twice, wherein multiple folds are carried out on top of each other, in particular with crimp folding. 3. The method as claimed in claim 1 or 2, characterized in that the transverse contact wires are guided close to the front edge of the preceding solar cell and in particular parallel to one another, preferably at a distance of a few millimeters from one another. 4. The method as claimed in one of the preceding claims, characterized in that the cutouts are produced in the backside film before the backside film is placed over the solar cells, preferably by stamping. 5. A method according to claim 4, characterized in that said void has a rectangular shape. 6. Method according to one of the preceding claims, characterized in that the folded transverse contact wires are also guided through the gaps in the adhesive or lamination film which is placed between the solar cell and the Between the backing films, preferably the voids in the adhesive or laminated film coincide with the voids in the backing film when placed one above the other. 7. The method according to one of the preceding claims, characterized in that the backside film, in particular together with the adhesive or lamination film according to claim 6, is held below the bent or folded transverse contact conductors so that these transverse contact conductors are slightly protruding above the top surface of the back film, preferably with a protruding portion of at least 0.1 mm to 0.2 mm above the top surface of the back film. 8. The method according to one of the preceding claims, characterized in that a lamination step is carried out after placing the backside film, and the electrical connection of the connection means to the transverse contact wires, in particular the common wiring, is then carried out by connection, in particular welding Electrical connection of terminals of different polarity in the box. 9 . The method according to claim 8 , characterized in that firstly the connection to the connection device is made and then the connection box is fastened, in particular glued, to the photovoltaic module. 10. The method according to one of the preceding claims, characterized in that a plurality of electrical terminals are provided close to one another, in particular two terminals per identical terminal pole, each having a transverse contact wire, In this case, connection terminals of different polarities are preferably arranged offset from one another. 11. A photovoltaic module, in particular produced by a method according to one of the preceding claims, comprising a plurality of solar cells, at least two of which are connected in series in each case, wherein all Said series circuit has two connection terminals, and wherein the connection terminals of a plurality of series circuits are assembled to a connecting device, characterized in that a plurality of connection terminals of the same polarity are connected to each other by transverse contact wires, which are connected at The underside of the back film is guided next to the solar cells above the front carrier glass, wherein the back film runs over the solar cells and the transverse contact wires, wherein the transverse contact wires are bent or folded together to a greater thickness away from the front carrier glass and are guided through through cutouts in the backside film and protrude above the backside film for electrical connection. 12. Photovoltaic module according to claim 11, characterized in that the transverse contact wires are tinned wires, preferably made of copper. 13. Photovoltaic module according to claim 11 or 12, characterized in that the transverse contact conductor is a flat conductor having a width of at least 3 mm, in particular approximately 5 mm, wherein the transverse contact conductor preferably has a thickness of 0.3 mm to 0.4 mm.

Images