CN117716518A - Method and apparatus for wiring photovoltaic cells - Google Patents

Abstract

The present disclosure relates to methods and apparatus for wiring photovoltaic cells into strings of photovoltaic cells, and modules comprising strings of photovoltaic cells. The photovoltaic cells are typically arranged in a first direction and are electrically interconnected in series on their respective back sides by elongated wiring elements.

Description

Method and apparatus for wiring photovoltaic cells

Technical Field

The present disclosure relates to methods and apparatus for wiring photovoltaic cells into strings of photovoltaic cells, and modules comprising at least one string of photovoltaic cells.

Background

Photovoltaic cells having backside contacts have their electrodes on the backside (i.e., the side opposite the side facing primarily the sun). This type of photovoltaic cell provides excellent efficiency compared to conventional photovoltaic cells having their electrodes on the front and back sides. This is because the wiring elements required for electrically interconnecting the cells within the module partially shield the surface in front of the photovoltaic cells that receive the sunlight/radiation. For back side contact cells, no wiring element shields the front face, providing a larger surface to receive light.

However, electrically interconnecting a plurality of back contact cells in series into a string is not straightforward and should be done in an efficient manner in order to mass-produce photovoltaic modules comprising strings of these photovoltaic cells.

Several attempts are known from the prior art and are briefly discussed below.

EP3142156A1 published in the name of LG Electronics INC, 3 in 2017, relates to a solar cell module and a method for manufacturing the same. The solar cell module includes: a plurality of solar cells each including a semiconductor substrate and first and second electrodes each having a different polarity and extending in a first direction on a back surface of the semiconductor substrate; and a plurality of conductive lines extending in a second direction crossing the first direction on the back surface of the semiconductor substrate, connected to one of the first electrode and the second electrode by a conductive adhesive, and insulated from the other electrode by an insulating layer. The conductive adhesive includes a first adhesive layer connected to one electrode and a second adhesive layer positioned on the first adhesive layer and connected to the plurality of conductive lines.

WO2020069419A1, published in the name of Sunpower Corporation in month 4 of 2020, relates to a Photovoltaic (PV) string comprising solar cells with surrounding metal contact fingers. A method of coupling an electrically conductive connector to a solar cell with surrounding metal contact fingers. Furthermore, it relates to a solar cell comprising a first plurality of metal contact fingers and a second plurality of metal contact fingers interleaved with the first plurality of metal contact fingers, wherein at least one of the first plurality of metal contact fingers comprises a surrounding metal finger passing between a first edge of the solar cell and at least one contact pad.

Disclosure of Invention

As mentioned above, the photovoltaic cell having the back contact has excellent efficiency in converting light into electricity. Furthermore, modules comprising photovoltaic cells of this type are more aesthetically pleasing, as the wiring elements are typically not visible, as they are arranged on the back side of the module and thus not visible on the front side of the module. However, the electrical interconnection of the photovoltaic cells within the module should be performed in an efficient manner, and ideally the complexity of the production process and equipment should therefore be kept to a minimum.

To achieve this, a first aspect of the present disclosure is directed to a method for wiring photovoltaic cells into strings of electrically interconnected photovoltaic cells. The method comprises the step of arranging the first, second and third photovoltaic cells next to each other on the platform in a first direction. The second photovoltaic cell is disposed between the first photovoltaic cell and the third photovoltaic cell in a rotational orientation relative to the first photovoltaic cell and the third photovoltaic cell. Typically, the rotation is relative to a vertical rotation axis. This means that the first, second and third photovoltaic cells on the platform are each arranged with their back faces facing upwards or alternatively each facing downwards.

Typically, photovoltaic cells are arranged such that their optically active surfaces are in close proximity to each other. The optically active surface refers to a surface of a photovoltaic cell capable of receiving (solar) light/radiation and converting the light at least partially into electricity.

Good results are possible when two photovoltaic cells are arranged next to each other in a first direction with an overlap, preferably in the optically inactive area of the two photovoltaic cells. In some variations, the overlap may be between 0.1 and 0.6 millimeters, preferably about 0.3 millimeters, however, depending on the battery, the overlap may be adjustable. It is advantageous to arrange the photovoltaic cells with an overlap, because the strings of photovoltaic cells can be shortened in the first direction while having substantially optically identical surfaces.

Typically, the method further comprises the steps of: the first photovoltaic cell and the second photovoltaic cell are electrically interconnected in series on their respective back surfaces by at least one elongated wiring element in a first lateral position, and the second photovoltaic cell and the third photovoltaic cell are electrically interconnected in series on their respective back surfaces by at least one elongated wiring element in a first lateral position.

When electrically interconnecting photovoltaic cells arranged next to each other in a first direction with an overlap, the elongated wiring elements are typically not visible on the front face of the string. This allows for the manufacture of a more aesthetically pleasing module, as the light reflection through the elongated wiring elements is reduced and the module appears more uniform.

In order to achieve the desired efficiency in wiring the photovoltaic cells, the first lateral position and the second lateral position are offset relative to each other perpendicular to the first direction. This allows a substantially straight bridging of the respective at least one elongated wiring element between two adjacent photovoltaic cells.

Typically, the first, second and third photovoltaic cells are plate-shaped, each comprising a first edge and a second edge opposite the first edge, wherein the cells are arranged next to each other in a first direction along their first and second edges, respectively. In this context, the rotational orientation of the second photovoltaic cell is understood to mean that the first edge of the second photovoltaic cell faces the first edge of the third photovoltaic cell and the second edge of the second photovoltaic cell faces the second edge of the first photovoltaic cell. When the photovoltaic cells are arranged next to each other with an overlap, the edges of the photovoltaic cells in the area of the overlap are preferably parallel.

The overlapping portion of the first photovoltaic cell and the second photovoltaic cell may have the same overlapping stacking order as the overlapping portion of the second photovoltaic cell and the third photovoltaic cell. This can be described as a scaly overlap. However, the second photovoltaic cell may overlap the first photovoltaic cell and the third photovoltaic cell in the same manner. This can be described as a brick wall overlap.

In order to manufacture strings of photovoltaic cells of a desired length, the method preferably comprises the steps of: the first subsequent photovoltaic cells are arranged on the platform in a first direction next to the photovoltaic cells temporarily trailing in the string, and are electrically interconnected in series on their respective back sides in a first lateral position by at least one elongated wiring element in the first direction. Alternatively or additionally, a second subsequent photovoltaic cell is arranged on the platform in the first direction next to the photovoltaic cell temporarily trailing in the string, and the second subsequent photovoltaic cell and the photovoltaic cell temporarily trailing in the string are electrically interconnected in series on their respective back surfaces by at least one elongated wiring element in the first direction in a second lateral position. These steps can be understood as extending the intermediate string arranged on the platform by the first or second subsequent photovoltaic cell.

Preferably, the first subsequent photovoltaic cell and/or the second subsequent photovoltaic cell, respectively, are arranged next to the photovoltaic cell temporally trailing in the string in a rotated orientation such that at least one main conductor path of the first subsequent photovoltaic cell or the second subsequent photovoltaic cell is aligned with the main conductor path of opposite polarity of the photovoltaic cell temporally trailing in the string in the first direction.

Depending on the field of application, the step of extending the string by the first and second subsequent photovoltaic cells is performed in an alternating manner until a desired number of photovoltaic cells are electrically interconnected in series to form a string of a desired length (i.e., a desired number of cells).

For good results, the method comprises the steps of: at least one elongated wiring element is placed in a first lateral position in a first direction for electrically interconnecting a first subsequent photovoltaic cell and photovoltaic cells temporarily trailing in the string in series on their respective back surfaces. Furthermore, the method may comprise the steps of: at least one elongated wiring element is placed in the first direction in the second lateral position for electrically interconnecting the second photovoltaic cell and the photovoltaic cells temporarily trailing in the string in series on their respective back sides. In other words, the method comprises placing at least one elongated wiring element onto the platform in a first direction in the first lateral position or in the second lateral position.

During the manufacture of the string, the photovoltaic cells may be arranged on a platform and then the elongated wiring elements are placed on the photovoltaic cells. Alternatively or additionally, the elongated wiring element may be placed on a platform, and then the at least one photovoltaic cell may be arranged on the platform already carrying the at least one elongated wiring element.

According to an embodiment, the at least one elongated wire element is pulled in the first direction from the feeding means by the placement means, which placement means thereby moves relative to the platform. According to a design, the feeding device comprises several feeders configured to provide wiring material from one supply of each feeder to the placement device. The feeding device may further comprise a separating device configured to cut the quasi-continuous wire material into lengths.

The placement device may alternately pull at least one elongated wire element for placement in a first lateral position or in a second lateral position, however, the placement device may also pull at least two elongated wire elements simultaneously for placement of one in the first lateral position and the other in the second lateral position.

In some variations, the method includes gripping, by at least one first gripper arranged on a first gripper arm in a first lateral position, at least one elongated wiring element for placing the at least one elongated wiring element in the first lateral position. Furthermore, the method may comprise gripping the at least one elongated wiring element by at least a second gripper arranged on the first gripper arm or a separate second gripper arm in a second lateral position for placing the at least one elongated wiring element in the second lateral position.

Alternatively, the at least one first gripper acts as at least one second gripper by switching between a first lateral position to a second lateral position. In this case only one gripper arm is required, but additional gripper arms are also possible in order to increase the manufacturing speed.

For good performance, during placement, at least one elongated wiring element is cut in a first direction to be smaller than the length of two photovoltaic cells arranged next to each other in the first direction, in particular to be greater than the length of a single (differential) photovoltaic cell. This makes the cutting of redundant crossovers of the elongated wiring elements between photovoltaic cells as shown in the prior art obsolete. This is because the elongated wiring element, once placed, already has the desired length.

Depending on the field of application, only the first photovoltaic cell and the second photovoltaic cell are arranged on the platform. The third photovoltaic cell is omitted here (or at least initially omitted). In this case, the method comprises the steps of: the first photovoltaic cell is electrically contacted in the first direction by at least one elongated wiring element in the second lateral position. The at least one elongated wiring element typically extends beyond the first photovoltaic cell in a first direction to electrically interconnect to at least one end contact conductor or the like. Here, the method further comprises the steps of: the first photovoltaic cell and the second photovoltaic cell are electrically interconnected in series on their respective back surfaces in a first lateral position in a first direction by at least one elongated wiring element.

Depending on the application, at least one photovoltaic cell may comprise a plurality of individual portions. Good results are possible when at least one photovoltaic cell, in particular the first photovoltaic cell and/or the second photovoltaic cell and/or the third photovoltaic cell, comprises two separate half cells arranged next to each other in the first direction. Each half cell typically has a lower extension in the first direction than in the second direction, in particular about half the length of the full photovoltaic cell in the first direction compared to the full photovoltaic cell, and a similar width in the second direction.

Especially when the elongated connection elements are heat welded to the respective back surfaces, the photovoltaic cells tend to bend, especially upwards from the platform. This deformation can be minimized by shortening the continuous extension of the photovoltaic cell in the first direction, since each half cell bends less than a full photovoltaic cell. The two individual half cells are preferably formed in pairs, so that the method described above can be applied without conditioning or with only minimal conditioning, since a pair of half cells can be regarded as one unit/one photovoltaic cell. In a preferred variant, the first, second and third photovoltaic cells and the first and second subsequent photovoltaic cells are formed as a pair of half cells, respectively. Typically, a pair of half cells is formed by dividing a full photovoltaic cell substantially perpendicular to its primary main conductor path into two separate half cells.

Similarly, as previously described for the full photovoltaic cell, each pair of half-cells (half-cells) may be arranged on the platform in an overlapping, adjacent or gapped manner.

A second aspect of the present disclosure is directed to an apparatus for wiring photovoltaic cells having a back side primary conductor path into strings of photovoltaic cells. The apparatus generally includes a platform configured to carry at least a first photovoltaic cell, a second photovoltaic cell, and a third photovoltaic cell disposed next to each other thereon in a first direction. The applicator for applying the elongated wiring element to the photovoltaic cell is typically arranged next to and/or above the platform. The applicator generally comprises a feeding device arranged to feed the elongated wiring element from the at least one supply to the placement device. The platform and the placement device are configured to move in a first direction relative to each other. For wiring the photovoltaic cells, the placement device is configured to place at least one elongated wiring element from the feeding device in a first lateral position in a first direction for electrically interconnecting a first photovoltaic cell and a second photovoltaic cell arranged next to each other on their back side in the first direction. Furthermore, the placement device is configured to place at least one elongated wiring element from the feeding device in a second lateral position in a first direction for electrically interconnecting a second photovoltaic cell and a third photovoltaic cell in series, which are arranged next to each other on their back side in the first direction.

The first lateral position and the second lateral position are preferably offset relative to each other perpendicular to the first direction.

This allows the plurality of photovoltaic cells to be electrically interconnected in a first direction by the substantially straight and parallel elongated wiring elements. Depending on the application, the placement device is configured to place a plurality of elongated wiring elements in the first lateral position and/or the second lateral position substantially simultaneously. The at least one elongated junction element interconnecting the first photovoltaic cell and the second photovoltaic cell in the first lateral position is preferably partially offset from the elongated junction element interconnecting the second photovoltaic cell and the third photovoltaic cell in the second lateral position.

To achieve good results, the supply arrangement is configured to arrange the subsequent photovoltaic cells on the platform such that the orientation of the subsequent photovoltaic cells rotates relative to the photovoltaic cells that are temporarily trailing in the string. As previously described, this allows for the arrangement of subsequent photovoltaic cells for the extended string, wherein each second photovoltaic cell is arranged on the platform in a rotated orientation.

The feeding means for feeding the elongated terminal elements are preferably arranged next to the platform, in particular next to the end of the platform in the first direction. This allows the platform to move the photovoltaic cells of the string that have been electrically interconnected in series in the first direction away from the feeding means. Here, the subsequent photovoltaic cells for the extended string are typically arranged on a platform next to the feeding means, since the distance the placement means pulls at least one elongated wiring element from the feeding means is minimized.

In a preferred variant, the placement device comprises at least a first gripper and at least a second gripper arranged laterally offset and configured to place the elongated wiring element in a first lateral position and in a second lateral position, respectively. Typically, at least one first gripper is arranged in a first lateral position and at least one second gripper is arranged in a second lateral position. However, the at least one first gripper may act as at least one second gripper by switching between a first lateral position and a second lateral position. The at least one first gripper and the at least one second gripper are each configured to grip and release the elongated wiring element, in particular by closing and opening the respective grippers. Typically, the at least one first gripper and the at least one second gripper grip the respective elongated wire element by an end section of the elongated wire element, which end section may protrude from the feeding means.

Preferably, the placement device comprises a gripper arm extending substantially perpendicular to the first direction in the lateral direction and having a set of first grippers and a set of second grippers attached thereto in an alternating manner in the second direction. The gripper is typically arranged to be movable over the platform.

Alternatively, the placement device may comprise a first gripper arm and a second gripper arm, each extending substantially perpendicular to the first direction in the second direction. In this case, the first gripper arm typically has a set of first grippers attached thereto, the set of first grippers being spaced apart from each other by a distance in the lateral direction, and the second gripper arm has a set of second grippers attached thereto, the set of second grippers being spaced apart from each other by a distance in the lateral direction. The first grippers are each arranged in a first lateral position, typically alternating in the lateral direction with the second grippers each correspondingly arranged in a second lateral position.

In a preferred variant, the platform comprises a conveyor, for example a conveyor belt, configured to transport the photovoltaic cells arranged thereon in a first direction.

For good performance, the apparatus comprises a control unit communicatively interconnected to the placement device for controlling the placement of the elongated wiring element. Preferably, the control unit is configured to control movement of the at least one gripper arm in the first direction. Typically, the control unit is further configured to control the at least one first gripper and the at least one second gripper, in particular in terms of gripping and releasing the elongated wire element. In some variations, the control unit is communicatively interconnected to the platform, in particular to the conveying device, for controlling the advancement of the photovoltaic cells arranged on the platform.

The previously described embodiments of the method for wiring photovoltaic cells into strings disclose at the same time embodiments of the corresponding design of the device and vice versa. Embodiments of the described apparatus may be used to perform methods according to the present disclosure.

A third aspect of the present disclosure is directed to a photovoltaic module including a string of photovoltaic cells extending in a first direction. The string generally comprises at least a first, a second and a third plate-shaped photovoltaic cell arranged next to each other in a first direction.

The cells are generally disposed between the front and back sheets. Typically, the layers of the front sheet, the string or strings of photovoltaic cells and the back sheet are fixedly connected by at least one intermediate layer of a polymer such as EVA (ethylene vinyl acetate) (e.g. by means of lamination).

In a preferred variant, each photovoltaic cell comprises at least one positive main conductor path and at least one negative main conductor path, which respectively cross the back side of the respective photovoltaic cell substantially in parallel in the first direction. Typically, the at least one positive main conductor path is connected to the p-type semiconductor region by a number of positive contact fingers, and the at least one negative main conductor path is connected to the n-type semiconductor region by a number of negative contact fingers interleaved with the number of positive contact fingers. The at least one positive main conductor path and the at least one negative main conductor path may be regarded as electrodes of the respective photovoltaic cells.

For efficient electrical interconnection, the second photovoltaic cell is arranged in a rotational orientation relative to the first photovoltaic cell and the third photovoltaic cell between the first photovoltaic cell and the third photovoltaic cell such that a primary main conductor path of the second photovoltaic cell is aligned with a primary conductor path of opposite polarity of the first photovoltaic cell and the third photovoltaic cell. At least one elongated wiring element electrically interconnects the first photovoltaic cell and the second photovoltaic cell in series on their respective back sides in a first lateral position. Furthermore, at least one elongated wiring element electrically interconnects the second photovoltaic cell and the third photovoltaic cell in series on their respective back sides in the second lateral position. In this way, the positive primary conductor path of a photovoltaic cell may be electrically interconnected with the negative primary conductor path of a preceding photovoltaic cell or a subsequent photovoltaic cell (or vice versa).

Depending on the field of application, at least one string comprises only the first photovoltaic cell and the second photovoltaic cell, the third photovoltaic cell being omitted. This is typically the case for narrow photovoltaic modules used for example as roof tiles.

In a preferred variant, the string comprises a plurality of photovoltaic cells, wherein each second photovoltaic cell is rotated 180 degrees in the first direction, in particular about a vertical rotation axis. Good results can be achieved when each second photovoltaic cell in the first direction is interconnected to a preceding photovoltaic cell of the string by at least one elongated wiring element in a first lateral position, and to a subsequent photovoltaic cell of the string (or vice versa) by at least one elongated wiring element in a second lateral position.

In order to allow efficient electrical interconnection of each second rotating photovoltaic cell within the string, the at least one positive main conductor path and the at least one negative main conductor path are symmetrically arranged with respect to the rotation of the respective photovoltaic cell (in particular 180 degrees rotation about a vertical rotation axis). This allows for a substantially straight bridging of the elongated wiring elements electrically interconnecting the strings of photovoltaic cells in series.

Where the module comprises more than one string of photovoltaic cells arranged next to each other, in particular substantially parallel in a first direction, the strings are typically electrically interconnected in series by end contact conductors arranged next to the end and/or start of each string. Typically, to electrically interconnect two adjacent strings, one end contact conductor may extend along the end of one string and the beginning of an adjacent string. Preferably, the end contact conductors are electrically interconnected to photovoltaic cells that are either top or bottom in the string, respectively, by elongated wiring elements.

The elongated wire element has a substantially circular or rectangular cross section, depending on the field of application. The elongate wiring element may be at least one of: ribbons, particularly tin-plated copper ribbons; a wire rod; a fabric, preferably a woven fabric comprising conductive and insulating filaments.

In some variations, the elongated wiring element comprises an adhesive, in particular a conductive adhesive for fixedly connecting the elongated wiring element to the photovoltaic cell. In other variations, the elongated wiring element is configured to be soldered to the photovoltaic cell. In some other variations, an adhesive film or substrate or tape is used to fix the position of the elongated elements on the back side of the respective photovoltaic cells. In this case, it is possible to achieve a good electrical connection between the at least one elongated wiring element and the corresponding photovoltaic cell during subsequent lamination, in particular using low temperature solder.

It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operations of the disclosed concepts.

Drawings

The disclosure described herein will be understood more fully from the detailed description given herein below and from the accompanying drawings, which should not be taken as limiting the disclosure described in the appended claims. The drawings show the following:

Fig. 1 shows a first variation of an apparatus for wiring a photovoltaic cell according to the present disclosure;

fig. 2 shows: a) A first variant of a photovoltaic cell having a backside primary conductor path;

b) A second variant of a photovoltaic cell having a backside primary conductor path;

fig. 3 shows a first variation of a photovoltaic module according to the present disclosure;

fig. 4 shows a) to e) initial steps according to a first variant of the method of the present disclosure;

fig. 5 shows steps a) to e) of a first variant of the method according to the present disclosure;

fig. 6 shows a) to e) initial steps according to a second variant of the method of the present disclosure;

fig. 7 shows steps a) to e) according to a first variant of the method of the present disclosure;

fig. 8 shows steps a) to e) of a method according to the present disclosure performed by a first variant of the apparatus;

fig. 9 shows steps a) to e) of a method according to the present disclosure performed by a second variant of the apparatus;

fig. 10 shows a second variation of a photovoltaic module according to the present disclosure;

fig. 11 shows: a) A third variant of a photovoltaic cell having a backside primary conductor path; and

b) A fourth variation of a photovoltaic cell having a backside primary conductor path.

Detailed Description

Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, wherein some, but not all, of the features are shown. Indeed, the embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, like reference numerals will be used to refer to like parts or features.

Fig. 1 shows a first variant of the device 14 for wiring a photovoltaic cell 1 according to the present disclosure, while fig. 2 a) and 2 b) show a first variant and a second variant of a photovoltaic cell 1 with a back side main conductor path 7. As shown in fig. 3, these photovoltaic cells 1 are electrically interconnected into a string 2 for manufacturing a photovoltaic module 18 according to a first variant of the present disclosure. Fig. 4 a) to 4 e) and 5 a) to 5 e) show steps of a first variant of the method according to the present disclosure, while fig. 6 a) to 6 e) and 7 a) to 7 e) show steps of a second variant of the method according to the present disclosure. In fig. 8 a) to 8 e) and 9 a) to 9 e), detailed views of a first variant and a second variant of the placement device (8) performing the steps of the method are shown, respectively. Fig. 11 a) and 11 b) show a third and a fourth variant of a photovoltaic cell 1 having a rear main conductor path 7 and comprising two separate half cells 24. As shown in fig. 10, these photovoltaic cells 1 are electrically interconnected into a string 2 for manufacturing a photovoltaic module 18 according to the present disclosure.

Visible in fig. 1 is a device 14 for wiring photovoltaic cells 1 having a back side main conductor path 7 into strings 2 of photovoltaic cells 1. The apparatus 14 typically comprises a platform 3, which platform 3 has a conveyor 3.1, which conveyor 3.1 is used for transporting photovoltaic cells 1 arranged next to each other thereon in a first direction x in the first direction x. In the first variant shown, the apparatus 14 further comprises an applicator 15, which applicator 15 comprises the feeding means 9 and the placement means 8.

For wiring the photovoltaic cells 1, the placement device 8 is configured to place at least one elongated wiring element 5.1 from the feeding device 9 in a first lateral position (direction y) in a first direction x for electrically interconnecting a first photovoltaic cell 1.1 and a second photovoltaic cell 1.2, which first photovoltaic cell 1.1 and second photovoltaic cell 1.2 are arranged next to each other in the first direction x on their back sides 4. Furthermore, the placement device 8 is configured to place at least one elongated wiring element 5.2 from the feeding device 9 in a second lateral position in the first direction x for electrically interconnecting a second photovoltaic cell 1.2 and a third photovoltaic cell 1.3, which second photovoltaic cell 1.2 and third photovoltaic cell 1.3 are arranged next to each other on their back side 4 in the first direction x. The elongated wiring element may be placed directly on the platform or on the photovoltaic cells 1 arranged on the platform.

As can be seen in fig. 1, the apparatus 14 may further comprise a supply arrangement 17 arranged next to the placement device 8, which supply arrangement 17 is configured to supply the photovoltaic cells 1 to the placement device 8. In the variant shown, the supply arrangement 17 comprises a reservoir 17.1 for storing the photovoltaic cells 1, an alignment device 17.3 for aligning at least one photovoltaic cell 1 to a predetermined position, and an arrangement device 17.2 for arranging the photovoltaic cells on the platform 3.

Fig. 2 shows two variants of photovoltaic cells 1, said photovoltaic cells 1 having a main conductor path 7 arranged on their rear face 4. In fig. 2 a), a first variant of a photovoltaic cell is shown, comprising twelve main conductor paths 7 arranged substantially equidistantly spaced from each other in the lateral direction y. Each main conductor path 7 substantially spans the total length of the back surface 4 in the first direction x. In the variant shown, there are six positive main conductor paths 7.1 and six negative main conductor paths 7.2 arranged alternately. In the second variant shown in fig. 2 b), the main conductor paths 7 are not arranged equidistant from each other in the lateral direction y. In both variants, the positive main conductor paths 7.1 are each electrically connected to the p-type semiconductor region 19 by means of a number of positive contact fingers 20. The negative main conductor path 7.2 is electrically connected to the n-type semiconductor region 21 by a number of negative contact fingers 22 interleaved with the positive contact fingers 20.

Fig. 11a and 11b show a similar photovoltaic cell 1, wherein the first variant shown in fig. 2 a) corresponds to the third variant shown in fig. 11a, and the second variant shown in fig. 2 b) corresponds to the fourth variant shown in fig. 11 b. However, the variants of photovoltaic cell 1 shown in fig. 11 each comprise two separate half-cells 24. Typically, such a pair of half cells 24 is formed by dividing a full photovoltaic cell 1 substantially perpendicular to its main conductor path 7.1, main conductor path 7.2 into two separate half cells 24.

A first variant of the photovoltaic module 18 visible in fig. 3 comprises two strings 2 each having four photovoltaic cells 1. The strings 2 are electrically interconnected in series via a common end contact conductor 23 extending in the lateral direction y along the respective end sections of the two strings 2. Within each string 2, each second photovoltaic cell 1 in the first direction x is turned 180 degrees (i.e. a vertical rotation axis, which is perpendicular to the first direction x and the lateral direction y). This allows for a substantially straight connection of two adjacent photovoltaic cells 1 by the elongated connection element 5.1, 5.2.

In contrast, the second variant of the photovoltaic module 18 visible in fig. 10 comprises two strings 2 each having four photovoltaic cells 1. Each of the photovoltaic cells 1 comprises two individual half cells 24 arranged next to each other in the first direction x. Each half cell 24 typically has a length of about half in the first direction x and a similar width in the second direction y, as compared to the full photovoltaic cell 1.

In a first variant of the method according to the present disclosure, as shown in fig. 4 and 5, the elongated wiring element 5.1 and the elongated wiring element 5.2 are placed on the platform 3 and the photovoltaic cells 1.1, 1.2 are then arranged onto the platform 3 carrying the elongated wiring element by the supply arrangement 17. Typically, a set of substantially parallel elongated wiring elements 5.2, 5.1 is placed on the conveyor means 3.1 of the platform, then the subsequent photovoltaic cells are arranged thereon, and finally the conveyor means 3.1 is moved in the first direction x by approximately the length of one photovoltaic cell 1. This routine is repeated until the desired number of photovoltaic cells are interconnected.

The electrical interconnection of the elongated wiring elements 5 with the respective main conductor paths may be done directly on the platform 3 by means of an adhesive applied to the elongated wiring elements 5 or by means of soldering.

In fig. 6 and 7, the sequence of steps is exchanged compared to fig. 4 and 5, wherein the photovoltaic cell 1 is first arranged on the platform 3 and the elongated wiring element 5.1, the elongated wiring element 5.2 is then placed on the photovoltaic cell 1.

The placement of the elongated wire element 5.1, 5.2 is shown in fig. 8 and 9, wherein in fig. 8 the placement device 8 comprises a first gripper arm 12, which first gripper arm 12 is arranged movable in a first direction over the platform 3. A set of first grippers 10 is arranged alternately with a set of second grippers 11 on a first gripper arm 12 on the first gripper arm 12. In order to place a set of elongated wire elements 5.2 in the second lateral position, as shown in fig. 8 a), the first gripper arms 12 are moved to a position next to the feeding means 9, so that the second grippers 11 can grip the ends of the wire material, respectively, by closing the respective second grippers 11. Thereafter, the first gripper arm 12 is moved away from the feeding device 9, and thereby the wiring material is pulled out from the feeding device 9. Before reaching the intermediate terminal (terminal) position of the first gripper arm in the first direction x, the wire material is cut to a length such that the elongated wire element 5.2 can be placed by releasing the grip of the second gripper 11. Thereafter, the conveyor 3.1 advances in the first direction x by approximately the length of the photovoltaic cell 1 in the first direction x. Next, as shown in fig. 8 b), the first gripper arm 12 is moved back to the feeding means 9 in the first direction so that the first gripper 10 can grip the end of the wiring material. Thereafter, the first gripper arm 12 is moved away from the feeding device 9 in the first direction x, whereby the wiring material is pulled out of the feeding device 9. In the next intermediate end position of the first gripper arm 12, as can be seen in fig. 8 c), the first gripper 10 is releasing the pulled-out elongated connection element 5 in the first lateral position. Next, the conveyor 3.1 is advanced in the first direction x.

This step is repeated in fig. 8 d) and 8 e) for placing a set of parallel elongated wire elements 5.2 in the second lateral position.

In contrast, as shown in fig. 9 a) to 9 e), the second variant of the placement device 8 comprises an additional second gripper arm 13, which second gripper arm 13 has a set of second grippers 11 arranged thereon. This allows independent movement of the set of first grippers 10 and the set of second grippers 11, thereby allowing substantially simultaneous placement of the elongated wiring element 5.1, 5.2 in the first and second lateral positions.

Of course (Rather), the words used in the specification are words of description Rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure.

Tag list

1. Photovoltaic cell

1.1 First photovoltaic cell

1.2 Second photovoltaic cell

1.3 Third photovoltaic cell

2 (photovoltaic cell) string

3. Platform

3.1 Conveying device

4. Back surface

5. Elongated wiring element

5.1 Elongated wiring element (in a first lateral position)

5.2 Elongated wiring element (in second lateral position)

6. Subsequent photovoltaic cell

6.1 First subsequent photovoltaic cell

6.2 Second subsequent photovoltaic cell

7. Main conductor path

7.1 Positive electrode main conductor path

7.2 Negative electrode main conductor path

8. Placement device

9. Feeding device

10. First clamp holder

11. Second clamp holder

12. First gripper arm

13. Second gripper arm

14. Apparatus and method for controlling the operation of a device

15. Applicator

16 Supply (of elongate wire elements)

17 Supply arrangement (of photovoltaic cells)

17.1 Storage (of photovoltaic cells)

17.2 arrangement (robot)

17.3 Alignment device

18. Photovoltaic module

19 P-type semiconductor region

20. Positive electrode contact finger

21 N-type semiconductor region

22. Negative contact finger

23 end contact conductor

24 Half-cells (of photovoltaic cells).

Claims (20)

1. A method for wiring photovoltaic cells (1) into strings (2) of electrically interconnected photovoltaic cells (1), the method comprising the steps of:

a. -arranging a first photovoltaic cell (1.1), a second photovoltaic cell (1.2) and a third photovoltaic cell (1.3) next to each other on a platform (3) in a first direction (x), wherein the second photovoltaic cell (1.2) is arranged in a rotational orientation relative to the first photovoltaic cell (1.1) and the third photovoltaic cell (1.3) between the first photovoltaic cell (1.1) and the third photovoltaic cell (1.3);

b. electrically interconnecting the first photovoltaic cell (1.1) and the second photovoltaic cell (1.2) in series on their respective back surfaces (4) in a first lateral position in the first direction (x) by means of at least one elongated wiring element (5.1);

c. -electrically interconnecting the second photovoltaic cell (1.2) and the third photovoltaic cell (1.3) in series on their respective back faces (4) in a second lateral position in the first direction (x) by means of at least one elongated wiring element (5.2); wherein the method comprises the steps of

d. The first and second lateral positions are offset relative to each other perpendicular to the first direction (x).

2. The method according to claim 1, wherein the method comprises the steps of:

a. -arranging a first subsequent photovoltaic cell (6.1) next to the photovoltaic cell (1) temporarily trailing in the string (2) on the platform (3) in the first direction (x), and-electrically interconnecting the first subsequent photovoltaic cell (6.1) and the photovoltaic cell (1) temporarily trailing in the string (2) in series on their respective back faces (4) by means of at least one elongated wiring element (5) in the first lateral position in the first direction (x); and/or

b. -arranging a second subsequent photovoltaic cell (6.2) next to the photovoltaic cell (1) temporarily trailing in the string (2) on the platform (3) in the first direction (x), and-electrically interconnecting the second subsequent photovoltaic cell (6.2) and the photovoltaic cell (1) temporarily trailing in the string (2) in series on their respective back faces (4) by means of at least one elongated wiring element (5) in the first direction (x) in the second lateral position.

3. The method according to at least one of the preceding claims, wherein the first subsequent photovoltaic cell (6.1) and/or the second subsequent photovoltaic cell (6.2), respectively, are arranged next to the photovoltaic cell (1) temporarily trailing in the string (2) in a rotational orientation such that at least one main conductor path (7) of the first subsequent photovoltaic cell or the second subsequent photovoltaic cell (6.2) is aligned in the first direction (x) with a main conductor path (7) of opposite polarity of the photovoltaic cell (1) temporarily trailing in the string (2).

4. Method according to at least one of the preceding claims, wherein the method comprises placing at least one elongated wiring element (5) onto the platform (3) in the first direction (x) in the first lateral position or in the second lateral position.

5. Method according to at least one of the preceding claims, wherein the at least one elongated wiring element (5) is pulled from a feeding device (9) in the first direction (x) by a placement device (8), the placement device (8) thereby being moved relative to the platform (3).

6. The method according to claim 5, wherein the method comprises:

a. Gripping at least one elongated wiring element (5) by means of at least one first gripper (10) arranged in said first lateral position on a first gripper arm (12) for placing said at least one elongated wiring element (5) in said first lateral position; and

b. -gripping at least one elongated wiring element (5) by means of at least a second gripper (11) arranged in said second lateral position on said first gripper arm (12) or a separate second gripper arm (13) for placing said at least one elongated wiring element (5) in said second lateral position.

7. Method according to claim 6, wherein the at least one first gripper (10) acts as the at least one second gripper (11) by switching between the first lateral position to the second lateral position.

8. The method according to at least one of the preceding claims, wherein during the placing, the at least one elongated wiring element (5) is cut in the first direction (x) to a length smaller than two photovoltaic cells (1) arranged next to each other in the first direction (x), in particular to a length larger than a single photovoltaic cell (1).

9. The method according to at least one of the preceding claims, wherein only a first photovoltaic cell (1.1) and a second photovoltaic cell (1.2) are arranged on the platform (3), and the method comprises the steps of:

a. electrically contacting the first photovoltaic cell (1.1) in the second lateral position in the first direction (x) by means of at least one elongated wiring element (5.2); and

b. -electrically interconnecting the first photovoltaic cell (1.1) and the second photovoltaic cell (1.2) in series on their respective back surfaces (4) in the first lateral position in the first direction (x) by means of at least one elongated wiring element (5.1).

10. The method according to at least one of the preceding claims, wherein at least one of the photovoltaic cells (1), in particular the first photovoltaic cell (1.1) and/or the second photovoltaic cell (1.2) and/or the third photovoltaic cell (1.3), comprises two individual half cells (24) arranged next to each other in the first direction (x).

11. An apparatus (14) for wiring photovoltaic cells (1) having a backside main conductor path (7) into strings (2) of photovoltaic cells (1), the apparatus (14) comprising:

a. -a platform (3), the platform (3) being configured to carry at least a first photovoltaic cell (1.1), a second photovoltaic cell (1.2) and a third photovoltaic cell (1.3) arranged next to each other thereon in a first direction (x);

b. An applicator (15), the applicator (15) being for applying an elongated wiring element (5) to a photovoltaic cell (1), the applicator comprising:

i. -a feeding device (9), the feeding device (9) being arranged to feed an elongated wiring element (5) from at least one supply (16)

-a placement device (8), the platform (3) and the placement device (8) being configured to move relative to each other in the first direction (x), and the placement device (8) being configured to 1 place at least one elongated wiring element (5) from the feeding device (9) in a first lateral position in the first direction (x) for electrically interconnecting a first photovoltaic cell (1.1) and a second photovoltaic cell (1.2), the first photovoltaic cell (1.1) and the second photovoltaic cell (1.2) being arranged next to each other in the first direction (x) on their back sides (4),

2. -placing at least one elongated wiring element (5) from the feeding device (9) in a second lateral position in the first direction (x) for electrically interconnecting the second photovoltaic cell (1.2) and a third photovoltaic cell (1.3) in series, the second photovoltaic cell (1.2) and the third photovoltaic cell (1.3) being arranged next to each other in the first direction (x) on their back faces (4); wherein the method comprises the steps of

3. The first and second lateral positions are offset relative to each other perpendicular to the first direction (x).

12. The apparatus (14) according to claim 11, wherein a supply arrangement (17) is configured to arrange a subsequent photovoltaic cell (6.1, 6.2) on the platform (3) such that an orientation of the subsequent photovoltaic cell (6.1, 6.2) is rotated relative to the photovoltaic cell (1) temporarily trailing in the string (2).

13. The apparatus (14) according to at least one of the preceding claims 11 to 12, wherein the placement device (8) comprises at least a first gripper (10) and at least a second gripper (11) arranged laterally offset and configured to place an elongated wiring element (5) in the first and second lateral position, respectively.

14. The device (14) according to at least one of the preceding claims 11 to 13, wherein the placement means (8) comprises a gripper arm (12), which gripper arm (12) extends substantially perpendicular to the first direction (x) in a lateral direction (y) and has a set of first grippers (10) and a set of second grippers (11) attached to the gripper arm (12) in an alternating manner in the second direction (y).

15. The device (14) according to at least one of the preceding claims 11 to 13, wherein the placement means (8) comprises a first gripper arm (12) and a second gripper arm (13), the first gripper arm (12) and the second gripper arm (13) each extending in a second direction (y) substantially perpendicular to the first direction (x),

a. the first gripper arm (12) has a set of first grippers (10) attached thereto, the set of first grippers (10) being spaced apart from each other in the lateral direction (y); and is also provided with

b. The second gripper arm (13) has a set of second grippers (11) attached thereto, the set of second grippers (11) being spaced apart from each other in the lateral direction (y).

16. A photovoltaic module (18) comprising a string (2) of photovoltaic cells (1) extending in a first direction (x), the string (2) comprising

a. At least a first (1.1), a second (1.2) and a third (1.3) plate-shaped photovoltaic cell arranged next to each other in the first direction (x), each photovoltaic cell (1,1.1,1.2,1.3) comprising

i. -at least one positive main conductor path (7.1) and at least one negative main conductor path (7.2) each crossing the back surface (4) of the respective photovoltaic cell (1) substantially in parallel in the first direction (x), the at least one positive main conductor path (7.1) being connected to the p-type semiconductor region (19) by a number of positive contact fingers (20), and the at least one negative main conductor path (7.2) being connected to the n-type semiconductor region (21) by a number of negative contact fingers (22) interleaved with the number of positive contact fingers (20); wherein the method comprises the steps of

-the second photovoltaic cell (1.2) is arranged in a rotational orientation between the first photovoltaic cell (1.1) and the third photovoltaic cell (1.3) with respect to the first photovoltaic cell (1.1) and the third photovoltaic cell (1.3) such that the main conductor path (7.1, 7.2) of the second photovoltaic cell (1.2) is aligned with the main conductor path (7.2,7.1) of opposite polarity of the first photovoltaic cell (1.1) and the third photovoltaic cell (1.3); and

b. -at least one elongated wiring element (5), said at least one elongated wiring element (5) electrically interconnecting said first photovoltaic cell (1.1) and said second photovoltaic cell (1.2) in series on their respective back faces (4) in a first lateral position; and

c. at least one elongated wiring element (5), said at least one elongated wiring element (5) electrically interconnecting said second photovoltaic cell (1.2) and said third photovoltaic cell (1.3) in series on their respective back faces (4) in a second lateral position.

17. The photovoltaic module (18) according to claim 16, wherein the string (2) comprises a plurality of photovoltaic cells (1), the plurality of photovoltaic cells (1) being arranged to rotate each second photovoltaic cell (1.2) 180 degrees in the first direction (x), in particular about a vertical rotation axis (z).

18. The photovoltaic module (18) according to at least one of the preceding claims 16 to 17, wherein each second photovoltaic cell (1.2) in the first direction (x) is interconnected to a preceding photovoltaic cell (1) of the string (2) by at least one elongated wiring element (5) in the first lateral position and to a subsequent photovoltaic cell (1) of the string (2) by at least one elongated wiring element (5) in the second lateral position, or vice versa.

19. The photovoltaic module (18) according to at least one of the preceding claims 16 to 18, wherein the at least one positive main conductor path (7.1) and the at least one negative main conductor path (7.2) are arranged symmetrically with respect to the rotation of the respective photovoltaic cell (1), in particular 180 degrees around a vertical rotation axis (z).

20. Photovoltaic module (18) according to at least one of the preceding claims 16 to 19, wherein at least one of the photovoltaic cells (1), in particular the first photovoltaic cell (1.1) and/or the second photovoltaic cell (1.2) and/or the third photovoltaic cell (1.3), comprises two individual half cells (24) arranged next to each other in the first direction (x).