WO2013098720A1

WO2013098720A1 - Automized system and method for making strings of cells of photovoltaic modules

Info

Publication number: WO2013098720A1
Application number: PCT/IB2012/057460
Authority: WO
Inventors: Dario Bernardi; Antonio Galiazzo; Javier Guidolin
Original assignee: 2Bg S.R.L.
Priority date: 2011-12-29
Filing date: 2012-12-19
Publication date: 2013-07-04
Also published as: ITPD20110416A1

Abstract

The invention relates to an automized system (1) for making strings of cells of photovoltaic modules, comprising: a conveyor belt 2 positioned along an alignment direction (X) of the cells; a first manipulator device 10 for positioning single cells in sequence at the input of the conveyor belt; a second manipulator device 20 suitable for positioning interconnection ribbons between cells; a device 30 for welding the ribbons to the cells. The system is characterised in that it comprises first means 40 of moving the welding device along the alignment direction X above the conveyor belt and by the fact of comprising at least one electronic control unit which manages the welding device and the first movement means in such a way that the welding device works by tracking along the alignment direction X the cells and the ribbons positioned on the conveyor belt kept in movement. The invention also relates to a method for making strings of cells of photovoltaic modules.

Description

DESCRIPTION

"AUTOMIZED SYSTEM AND METHOD FOR MAKING STRINGS OF CELLS

OF PHOTOVOLTAIC MODULES"

Field of application

[0001] The present invention relates to an automized system and method for making strings of cells of photovoltaic modules .

State of the art

[0002] In general, the production of a photovoltaic module envisages the following operating steps:

[0003] - electrically connecting individual photovoltaic cells in series to form strings;

[0004] - positioning several strings on a glass plate at a side of said plate covered with a film of adhesive polymer material (EVA) ;

[0005] - electrically interconnecting the strings at the ends to realise interconnection lines (buses) so as to form a photovoltaic module;

[0006] - completion of the module with the application of adhesive and protective sheets and lamination of the module;

[0007] - trimming of the edges of the module and attachment of the frames and of the box for the external electrical contacts;

[0008] - final testing. [0009] In particular, in the first operating step a string is made by aligning a predefined number of single cells along a direction of alignment. Electric interconnection tapes, known in the jargon as "ribbons", are suitably positioned between one cell and another. These operations are all performed in an automized manner.

[0010] Traditionally, an automized system for making strings of cells of photovoltaic modules is provided with a conveyor belt positioned along the alignment direction, on which the cells are aligned and the ribbons suitably positioned. More in detail, the system is provided with a first manipulator device suitable for catching a single cell from an adjacent warehouse and positioning it at the input of. the conveyor belt. Thanks to the movement of the conveyor belt the cells positioned thereon are progressively translated along the alignment direction so as to free space at the input for the positioning of new cells. The system is provided with a second manipulator device suitable for catching the ribbons from an adjacent warehouse and positioning them on the cells. The ribbons are positioned with a first portion placed over the cell which was last positioned on the conveyor belt and with a second portion, staggered from the first, resting on the conveyor belt, so as to receive thereon a new cell. The system is further provided with a welding device of the ribbons, which is positioned downstream of the input zone, i.e. downstream of the positioning zone of the cells and ribbons.

[0011] The welding device operates in a fixed position in relation to the conveyor belt; the first manipulator device is free to move transversally to the alignment direction i.e. transversally to the direction of movement of the conveyor belt; the second manipulator device is free to move along the alignment direction i.e. along the direction of movement of the conveyor belt.

^• [0012] Operatively, the conveyor belt is step-operated, i.e. with a sequence of stops and starts. The various positioning operations of the cell and ribbons and welding operations take place in fact with the conveyor belt at a standstill, that is to say the operations are performed in a discontinuous manner.

[0013] The intermittent functioning of the conveyor belt inevitably increases the downtime of the process. This negatively influences the productivity of the production process.

Presentation of the invention

[0014] Consequently, the purpose of the present invention is to overcome the drawbacks of the prior art mentioned above by making available an automized system and method for making strings of cells of photovoltaic modules which makes it possible to reduce the downtime of the process, increasing the productivity thereof.

[0015] A further purpose of the present invention is to provide an automized system for making strings of cells of photovoltaic modules which is operatively simple and efficient and at the same time simple and economical to set up.

Brief description of the drawings

[0016] The technical characteristics of the invention, according to the aforementioned purposes, are clearly evident from the contents of the following claims and the advantages of the same will be clearer from the detailed description which follows, made with reference to the appended drawings, showing one or more embodiments by way of non-limiting examples, wherein

[0017] - Figure 1 shows a perspective overall view of the automized system for making strings of cells of photovoltaic modules according to a preferred embodiment of the invention, illustrated with its components in a first operating configuration;

[0018] - Figure 2 shows an orthogonal view from above of the system illustrated in Figure 1;

[0019] - Figure 3 shows a perspective view of the automized system in Figure 1, illustrated with its components in a second operating configuration; [0020] - Figure 4 shows an orthogonal view from above of the system illustrated in Figure 3;

[0021] - Figure 5 shows an enlarged detail of the system in figure 3, contained in the circle V indicated therein and relative to a first manipulator device;

[0022] - Figure 6 shows a perspective view of the automized system in Figure 1, illustrated with its components in a third operating configuration; and

[0023] - Figure 7 shows an orthogonal view from above of the system illustrated in Figure 6.

Detailed description

[0024] With reference to the appended drawings, reference numeral.1 globally denotes an automized system for making strings of cells of photovoltaic modules according to the invention.

[0025] According to a general embodiment of the invention, the automized system 1 comprises:

[0026] - at least one conveyor belt 2 positioned along an alignment direction X of the cells, on which the cells and electric interconnection ribbons between cells are progressively positioned starting from an input end 2' of said belt;

[0027] - at least a first manipulator device 10 suitable for positioning single cells in sequence on the conveyor belt 2; [0028] - at least a second manipulator device 20 suitable for positioning interconnection ribbons between cells on the belt 2;

[0029] - at least one device 30 for welding the ribbons to the cells.

[0030] According to a first aspect of the invention, the system 1 comprises first means 40 of moving the welding device 30 along the alignment direction X above the conveyor belt 2.

[0031] According to a second aspect of the invention, as described further below in relation to the method of making strings of cells, the system 1 comprises at least one electronic control unit (not shown in the appended Figures) which manages the welding device 30 and the first movement means 40 in such a way that the welding device 30 works by tracking - along the alignment direction X - the cells and the ribbons positioned on the conveyor belt 2 kept in movement.

[0032] According to a preferred embodiment of the invention, the system 1 comprises second 50 and third means 60 of respectively moving the first 10 and the second manipulator device 20 at least along the alignment direction X above the conveyor belt 2. Operatively, the electronic control device also manages the two manipulator devices 10, 20 according to one or more predefined operating sequences in such a way that the two manipulator devices work by tracking the last cell positioned in terms of time on the conveyor belt kept in movement .

[0033] More in detail, as may be seen by comparing figures 4 and 7, the position adopted by the first manipulator device may vary along the alignment axis X. In other words, the single cell may be positioned on the conveyor belt at the input end 2' (see figure 4) or downstream of said input end (see figure 7) .

[0034] The expression "starting from an input end of the conveyor belt" relative to the positioning of the cells and ribbons should therefore be understood in the light of the above. The term "input end of the belt" refers to the end of the belt situated furthest upstream of the entire belt in the direction of advancement thereof. In other words, the positioning the cells and the ribbons may commence next to the input end, but may also continue further downstream depending on the needs to track the cells already positioned and therefore the speed of said belt .

[0035] According to an alternative embodiment of the invention (not illustrated in the appended Figures), the system 1 does not comprise means for moving the manipulator devices along the alignment axis X. In other words, from an operating point of view it is not envisaged that the manipulator devices for cells and ribbons track the conveyor belt. In fact, manipulators may be envisaged, for example of the carousel type, which position the cells and interconnection ribbons in a regular manner always and only at the input end, at a positioning rate suited to the advancement of the belt.

[0036] Advantageously, the movements along the alignment direction X of the two manipulator devices 10, 20 and of the welding device 30 are independent of each other. In particular, the movements of the welding device are independent of the movements of the two manipulators.

[0037] Preferably, the movements along the alignment direction X of the two manipulator devices 10, 20 and of the welding device 30 are co-ordinated with each other by the electronic unit to prevent interferences.

[0038] Preferably, the first 40, second 50 and third movement means 60 each comprise at least one first linear guide 41, 51, 61 parallel to the alignment axis X.

[0039] According to a preferred embodiment illustrated in the appended Figures, the first movement means 40 comprise only the aforesaid first linear guide 41. As may be seen in the appended Figures, the welding device 30 is positioned above the conveyor belt 2 and is moved parallel to the alignment axis X by means of said first guide 41. Preferably, such first guide 41 is scaled in such a way that the welding device 30 is movable between the input end 2' and the output end 2" of the belt 2.

[0040] According to a preferred embodiment illustrated in the appended Figures, the second movement means 50 comprise a second guide 52 transversal to the alignment axis X and therefore to the first guide 51. Advantageously, one of such guides is fixed and the other is translatable along the first so as to determine a two dimensional movement of the first manipulator device 10. In particular, the mobile guide (which in the embodiment illustrated in the appended Figures is in particular the second, transversal guide 52) is slidingly associated to the fixed guide (in the appended Figures the first, longitudinal guide 51) by means of a slide.

[0041] Advantageously, as may be seen in particular in figures 2 and 4, the first manipulator device 10 (i.e. the one for positioning the cells) is movable transversally to the alignment axis X by means of the second guide 52 (i.e. the transversal guide) between an operating position on the conveyor belt 2 and at least one position laterally external to the conveyor belt 2 where a cell . catching zone may be envisaged, indicated by reference numeral 70 in the appended Figures.

[0042] Advantageously, as may be seen in particular in Figure 2, the cell catching zone 70 comprises an intermediate support plane 71 on which the single cell is placed, ready for being caught by the first manipulator device 10. The system 1 is therefore provided with an auxiliary manipulator device 11 for keeping the intermediate surface continuously supplied with cells. Such auxiliary device 11 (also provided with its own means of movement 12) travels back and forth between the cell warehouse (not shown) and the intermediate support plane, so as to reduce the travel of the first device 10. Advantageously, the intermediate support plane 71 is moveable so as to simplify the movement of the first manipulator device 10.

[0043] According to a preferred embodiment illustrated in the appended Figures, the third movement means 60 comprise only the aforesaid first linear guide 61. As may be seen in the appended Figures, the second manipulator device 20 (i.e. the one for positioning the ribbons) is positioned above the conveyor belt 2 and is moved parallel to the alignment direction X, by means of said first guide 61. Preferably, such first guide 61 is scaled in such a way that the welding device 30 is movable between a position on the conveyor belt 2 corresponding to an intermediate section thereof (see Figure 7) and at least one position external to the conveyor belt, upstream of the input 2 ' where a ribbon catching zone may be envisaged, indicated by reference numeral 80 in the appended figures. Advantageously, a ribbon forming device (folding and cutting ; not shown in the appended Figures) starting from one or more reels of metal ribbons or a distributor of ready-made ribbon may be positioned in the ribbon catching zone.

[0044] Alternatively to the above, the conformation of the second and third movement means may be inverted, that is the first manipulator device movable only above the belt and the second manipulator device 20 moveable in two dimensions including externally to the belt 2, with corresponding inversion of the cell catching and ribbon catching zones. The need to position from two to more ribbons contemporarily, directing . them with their longitudinal axes parallel to the alignment axis X however, makes the configuration illustrated in the appended Figures preferable. From a plant design and management aspect it is in fact simpler and more efficient to catch the ribbons already directed parallel to the alignment axis X.

[0045] According to a preferred embodiment illustrated in the appended Figures, the linear guides 4,51,52,61 of the movement means are motorised guides with recirculating ball screw. In particular, the guides are provided with brushless electric motors 65.

[0046] According to an alternative embodiment not illustrated in the appended Figures, the movement means may be composed entirely or in part of robotised arms. In particular, the second movement means 50 (i.e. those for moving the first manipulator device) may consist of a robotised arm.

[0047] Alternatively to the linear guides with recirculating ball screw other mechanical devices may be used, such as pistons or toothed racks for example.

[0048] The welding device 30 may be of any type suitable for the purpose. In particular, it may be an infrared, ultrasound or laser welding device.

[0049] The first manipulator device 10, for positioning the cells, is preferably of the suction cup type. However other devices suitable for the purpose may also be used, [0050] The second manipulator device 20, for positioning the ribbons, is preferably of the pincer type, as shown in the appended Figures. In particular, such second device 20 is composed of a wing 21, connected to a sliding slide 22 (associated to the linear guide 61 positioned to the side of the belt 2) in cantilever way to move above the conveyor belt 2. A plurality of automized gripping pincers 23 project from the wing 21, distributed transversally to the alignment axis X. Each pincer 23 is designed to catch and transport a single ribbon. Alternatively, other devices suitable for the purpose may also be used,

[0051] The method for making strings of cells of photovoltaic modules according to the invention is now described.

[0052] The method comprises a step a) of arranging a system 1 for making strings of cells of photovoltaic modules comprising :

[0053] - at least a conveyor belt 2 positioned along an alignment direction X of the cells, on which the cells and electric interconnection ribbons are progressively positioned starting from an input end 2';

[0054] - at least a first manipulator device 10 suitable for positioning single cells in sequence at the input of the conveyor belt;

[0055] - at least a second manipulator device 20 suitable for positioning interconnection ribbons between cells on the belt 2;

[0056] - at least a device for welding the ribbons to the cells;

[0057] - first means 40 of moving the welding device 30 along the alignment direction X above the conveyor belt

2'·

[0058] - an electronic control unit which manages the welding device 30 and the first movement means 40.

[0059] In particular, in the arranging step a) a system 1 according to the invention, as described above, may be arranged .

[0060] The method envisages a step b) of keeping the conveyor belt 2 in movement along the alignment axis X, preferably with a direction of advancement from the input to the output. Due to the movement of advancement of the conveyor belt the cells positioned thereon ^' are progressively translated along the alignment direction so as to free space for the positioning of new cells. Preferably, the belt 2 is kept in movement for the entire process of making the string. The speed of advancement of the belt may be constant or variable according to oneor more speed profiles.

[0061] The method further comprises the following steps:

[0062] c) positioning single cells aligning them on the moving conveyor belt 2 by means of the first manipulator device 10;

[0063] d) positioning ribbons on the belt 2 between each cell by means of the second manipulator device 20;

[0064] e) welding the ribbons to the cells by means of the welding device (30) .

[0065] Preferably, the welding is performed on groups of a predefined number of cells. This is related to the dimensions of the welding device i.e. to the number of cell's which can be simultaneously treated by said device.

[0066] The steps c) of positioning the cells and d) of the positioning the ribbons, as well as the step e) of welding are repeated depending on the number of cells which are to form the string.

[0067] The method comprises for each welding step e) a step f) of moving the welding device along the alignment axis X by means of the first movement means 40 in such a way that the welding device 30 tracks a group of cells to be welded with the conveyor belt 2 moving.

[0068] Operatively, the electronic control unit manages the movement of the welding device 30 in relation to the speed of the belt 2 and to the position of the group of cells on the belt.

[0069] Each welding step e) is conducted during a respective moving step f) . Operatively, the welding device 30 moves in such a way as to position itself above the group of cells to be welded, adjusting its speed of movement to the speed of the belt. The moving step f) may therefore comprise a transition sub-step during which the device moves with ^'speeds different in absolute value and direction compared to the speed of the belt to reach the objective i.e. group of cells to be welded. During the movement step f) , the speed of the welding device 30 may therefore be variable. In particular, the device 30 may also be subject to rearward movements in relation to the direction of advancement of the belt.

[0070] According to a particularly preferred embodiment, the system 1 comprises second 50 and third means 60 of respectively moving the first 10 and the second manipulator device 20 at least along the alignment direction X above the conveyor belt 2.

[0071] In particular, according to the aforesaid preferred embodiment, for each positioning step c) of a single cell the method comprises a step g) of moving the first manipulator device 10 along the alignment axis X by means of the second movement means 50, in such a way that the first device 10 tracks the last cell positioned on the conveyor belt 2 in terms of time.

[0072] Preferably, each . step c) of positioning a single cell is conducted during a respective step g) of moving.

[0073] Again, according to the aforesaid preferred embodiment, for each positioning step d) of the interconnection ribbons between two single cells the method further comprises a step h) of moving the second manipulator device 20 along the alignment axis X by means of the third movement devices 60, in such a way that the second device 20 tracks the last cell positioned on the conveyor belt in terms of time. [0074] Preferably, each step d) of positioning ribbons is conducted during a respective step h) of moving.

[0075] Operatively, the electronic control unit manages the movement of the two manipulator devices 10 and 20 in relation to the speed of the belt and to the position on the belt of the last cell placed on the belt in terms of time .

[0076] More in detail, the manipulator devices 10 and 20 move so as to reach the last cell positioned on the belt in terms of time. After reaching the cell, the manipulator device 10, 20 adjust its speed of movement to the speed of the belt, for a sufficient length of time to complete the positioning operation of the cell or of the ribbons. The moving steps g) and h) may therefore comprise transition sub-steps during which the device moves with speeds different in absolute value and direction compared to the speed of the belt to reach the objective i.e. the last cell positioned. During such movement steps g) and h) , the speed of the manipulator devices 10, 20 may therefore be variable. In particular, the devices may also be subject to rearward movements in relation to the direction of advancement of the belt.

[0077] More in detail, the control unit manages the movements of the welding device and of the two manipulator devices according to the tracking logic previously described depending on the advancement speed values of the conveyor belt and on the spatial coordinates of the cells already positioned on the belt. Preferably, the spatial co-ordinates of the cells already positioned and especially of the last cell placed in terms of time, are calculated by interpolation processes, using suitable calculation algorithms.

[0078] The invention makes it possible to achieve several advantages, in part already described.

[0079] The system and method for making strings of cells of photovoltaic modules according to the present invention makes it possible to avoid intermittent functioning of the conveyor belt. The invention thereby permits operating with the belt in continuous- movement, even at variable speeds. This makes it possible to considerably reduce process downtime compared to traditional systems.

[0080] The automized management of the operations entrusted to an electronic control unit, which implements appropriate control and management logics, makes it possible to prevent a loss of precision in the positioning of the cells/ribbons and in welding, thereby guaranteeing high quality of the final product.

[0081] The automized system for making strings of cells of photovoltaic modules according to the invention is, in addition, operatively simple and efficient, while also being simple and economical to set up, especially in the case in which motorised linear guides are used (in particular with recirculating ball screw) as movement means of the manipulator devices and/or of the welding device.

[0082] The invention thus conceived thereby achieves the intended purposes .

[0083] Obviously, . its practical embodiments may assume forms and configurations different from those described while remaining within the sphere of protection of the invention.

[0084] In addition, all the elements may be replaced with technically equivalent elements and the dimensions, shapes and material used may be varied as needed.

Claims

1. Automized system for making strings of cells of photovoltaic modules, comprising:

- at least one conveyor belt (2) positioned along an alignment direction (X) of the cells, on which the cells and electric interconnection ribbons between cells are progressively positioned starting from an input end (2');

- at least a first manipulator device (10) suitable for positioning single cells in sequence on the conveyor belt;

- at least a second manipulator device (20) suitable for positioning -interconnection ribbons between cells on the belt (2);

- at least one device (30) for welding the ribbons to the cells;

characterised in that it comprises first means (40) of moving the welding device (30) along the alignment direction (X) above the conveyor belt (2) and characterised by the fact of comprising at least one electronic control unit which manages the welding device (30) and the first movement means (40) in such a way that the welding device (30) works by tracking along the alignment direction (X) the cells and the ribbons positioned on the conveyor belt (2) kept in movement.

2. System according to claim 1, comprising second (50) and third (60) means for respectively moving the first (10) and second (20) manipulator device (20) at least along the alignment direction (X) above the conveyor belt (2), the electronic control device also managing the activity of the two manipulator devices (10,20) according to one or more predefined operating sequences in such a way that the two manipulator devices work by tracking the last cell positioned in terms of time on the conveyor belt kept in movement.

3. System according to claim 2, wherein the movements along the alignment direction (X) of the two manipulator devices (10, 20) and of the welding device (30) are independent of each other.

4. System according to claim 2 or 3, wherein the movements along the alignment direction (X) of the two manipulator devices (10, 20) and of the welding device (30) are co-ordinated with each other to prevent interferences .

5. System according to one or more of the previous claims, wherein the first, second and third movement means (40, 50, 6^'0) each comprise at least a first linear guide (41, 51, 61) parallel to the alignment axis (X) .

6. System according to one or more of the previous claims, wherein the welding device (30) is positioned above the conveyor belt (2) and is preferably movable between the input end (2') and the output end (2") of the belt parallel to the alignment axis (X) , preferably by means of said first linear guide (41) .

7. System according to one or more of the previous claims, wherein the second movement means (50) comprise a second guide (52) transversal to the alignment axis (X) , of such two guides one being fixed and the other being translatable along the first one, so as to determine a two dimensional movement of the first manipulator device (10).

8. System according to claim 7, wherein said first manipulator device (10) is movable transversally to the alignment axis (X) by means of said second guide (52) between a position on the conveyor belt (2) and at least one position laterally external to the conveyor belt (2) where a cell catching zone may be envisaged.

9. System according to one or more of the claims from 2 to 8, wherein said second manipulator device (10) is movable along the alignment axis (X) by means of said third movement means (60) between a position on the conveyor belt (2) and at least one position external to the conveyor belt (2), upstream of the input end (2') where a ribbon catching zone may be envisaged.

10. System according to one or more of the claims from 5 to 9, wherein said linear guides are motorised guides with recirculating ball screw.

11. Method of making strings of cells for photovoltaic modules, comprising the following steps:

a) arranging a system (1) for making strings of cells for photovoltaic modules according to one or more of the previous claims :

b) keeping the conveyor belt in movement (2) along the alignment axis (X) ;

c) positioning single cells aligning them on the moving conveyor belt (2) by means of the first manipulator device (10) ;

d) positioning ribbons on the belt (2) between each cell by means of the second manipulator device 20;

e) welding the ribbons to the cells by means of the welding device (30), the welding being performed on groups of a predefined number of cells;

the method comprising for each welding step e) a step f) of moving the welding device along the alignment axis (X) by means of the first movement means (40) in such a way that the welding device (30) tracks a group of cells to be welded with the conveyor belt (2) moving, the electronic control unit managing the movement of the welding device (30) in relation to the speed of the belt (2) and the position of the group of cells on the belt, each welding step e) being conducted during a respective moving step f ) .

12. Method according to claim 11 wherein said system comprises second (50) and third (60) means for respectively moving the first (10) and second (20) manipulator device (20) along the alignment direction (X) above the conveyor belt (2), the method comprising:

- for_> each positioning step c) of a single cell a step g) of moving the first manipulator device (10) along the alignment axis (X) by means of the second movement means (50), in such a way that the first device (10) tracks the last cell positioned on the conveyor belt (2) in terms of time, each step c) of positioning a single cell being conducted during a respective step g) of moving;

- for each positioning step d) of the interconnection ribbons between two single cells a step h) of moving the second manipulator device (20) along the alignment axis (X) by means of the third movement devices (60), in such a way that the second device (20) tracks the last cell positioned on the conveyor belt (2) in terms of time, each step d) of positioning ribbons being conducted during a respective step h) of moving;

the electronic control unit managing the movement of the two manipulator devices in relation to the speed of the belt and the position on the belt of the last cell placed on the belt in terms of time.