WO2009122456A1

WO2009122456A1 - System to connect photovoltaic panels

Info

Publication number: WO2009122456A1
Application number: PCT/IT2009/000097
Authority: WO
Inventors: Enzo Mauri; Dario Solcia; Mirko Despini; Federico Crippa
Original assignee: Compel Electronics S.P.A.
Priority date: 2008-04-02
Filing date: 2009-03-13
Publication date: 2009-10-08
Also published as: ITMI20080569A1

Abstract

The invention concerns a system to inter-connect photovoltaic panels by means of junction boxes having a containment body (CFSC) and a cover (L), with self-locking fasteners (Z) on the longitudinal sides and with a protection on the upper transversal side. From the bottom of said body (CFSC) protrude two longitudinal protuberances (El, E2) having supports for the immovable fixation thereto of connectors and cables, while on the back face of same body there are grooves for a silicone better charge. The system consents automatic operations of mountings, of tests and of silicone charges.

Description

SYSTEM TO CONNECT PHOTOVOLTAIC PANELS.

BACKGROUNG OF THE INVENTION

The present invention concerns systems to inter-connect solar photovoltaic panels, substantially comprising: - junction box; - connectors; - cables; - diodes; and - similar components.

The invention results principally from the coordination of measures, provisions, selections of materials and their forms, so to obtain total effects superior to the sum of the contributions of the single combined elements.

PRIOR ART

The solar energy production systems are undergoing technological developments and commercial diffusion, which increase with exponential rates (also because of the oil prices).

Besides the panels, the "Core" of said systems resides "in primis" in the interconnection devices, in particular in the boxes for the panel junctions as well as in the internal and external connections through connectors and cables.

Consequently this field is becoming a crowded field of patents concerning, above all, small improvements which, even if at a first glance could appear as lacking a high inventive level, in the practice they result, nevertheless, as improvement carrying elements, and produce technical progress whereby they still have patentability merits.

Exemplarily, in the introductory part of the recent International Patent Publication

WO2008/000101 a long patent documentation is mentioned and adeguately commented, comprising a series of Titles such as the European Patent Publications EP n° 999601, n°

1605554, n° 1501133, the German Patent Publication DE n° 102005044939, n°

202005018884 Ul, the Patents US n° 6.582.249 and Japanese n° 2022359389. However said WO2008/000101 concerns a junction box substantially comprising two portions, a superior one and an inferior one; said upper portion (cover, lid) can be overturned and has inner projecting self-locking fasteners to house a plate.

Additionally also EP 1502426 can be cited as it describes a box wedged within translucent plates, the coupling conductor ends extending between the photovoltaic elements partially supported by stiffening organs in contact with the pins.

US Patent n° 7.291.036 claims a junction box comprising a cover (with a plate coated with a thermally conductive material and with locking elements), and a printed circuit plate having a first face carrying diodes and a second face with laminar elements and with clip elements.

German Patent Publication 1020060112665 refers to a box with a plurality of laminas and a by-pass diode thermally in contact with said laminas.

All the above mentioned Patent proposals have surely undeniable merits however the fact must be admitted that the up-to-now available devices are not exempt of lacunae (both individually or in combination).

SUMMARY OF THE INVENTION

First object of the present invention is to provide a system which eliminates at least the major ones of said lacunae and shows a happy combination of measures which can result into a "maximum maximorum" of performances and economy.

An other object is to provide a system which, by relying on an advanced junction box, is characterized by a high "automaticity, in particular in the steps of mounting, of test, of adhesive charge etc..

A further object of the present invention is to provide methods which consent to bring about said automaticities without the intervention of additional specific means. The main characteristics of the invention are recited in the claims which are at the end of this description but have to be also considered herewith incorporated.

After all the invention can be looked at as a combination of critical measures, each one having its own specific effect, said measures being however so coordinated to produce at least one effect above the sum of said single effects, what results in the realization of a total performance of high efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features of the invention will more clearly appear from the detailed description of the (illustrative and not limitative) embodiment shown in the accompanying drawings, in which:

- figure 1 is an exploded perspective view of the system according of the invention;

- figure 2 is a top perspective view of the system of the invention, its cover being closed;

- figures 3 and 4 are perspective views on the lateral portions of the box containing body, said portions extending beyond the cover surface;

- figure 5 is a bottom view of the silicone containing slot;

- figure 6 is a partially perspective top view of the sole containment zone of the circuitry, and shows, as an example, the diodes relieved from the box internal face;

- figure 6A is a perspective view from below of the inner face LI of the detached cover L, on the face of which is provided a stiffening ribbing NE facing the edge B carrying the self-locking fasteners Z₅ said edge B having a height lower than that of NE; and

- figure 7 is a flow chart of the mounting preferred process of the panel Box.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT In the accompanying drawings, in particular in the exploded perspective of fig. 1, in the top view of fig. 2 (the cover or lid being closed), in the partially top perspective of fig. 3 (view on the left side of the box with closed lid) and of fig. 4 (view on the right side), a junction box (S) according to the invention is shown, which comprises: i) - a lower body which forms the circuitry containment space CFSC, in particular diodes Dl, D2 and D3 (said D3 being extracted from the bottom as it is not visible in fig. 1, whereas it is well visible in fig. 6A) and the related series of springs MI, M2, M3; ii) - a gasket GUA (reproducing the rectangular conformation of said containment space CFSC); and iii) - a cover or lid L. Said body CFSC has a containment surface substantially equal to the surface of cover L as for instance defined by the two lateral longitudinal body sides FLLl and FLL2 and by the two transversal sides LTF (frontal) and LTP (posterior); in the case shown in the drawings the body CFSC is rectangular and consequently also the Hd L is rectangular. Obviously quadrangular, circular, polygonal forms are possible.

According to a first feature of the invention, the bottom of said body CFSC extends beyond the cover limits; in particular from said two lateral longitudinal body sides (corresponding to FLLl and FLL2), two protuberances El and E2 project towards the outside whereas from the transversal posterior side (corresponding to LTP) protrudes a third protuberance E3, the couple of said longitudinal protuberances having areas and functionality different from those of said protuberance E3.

Significantly said protrusions El and E2 forming the longitudinal body sides have the function to house, each, a connector (male) CM and a cable CA.S (on El), respectively a female connector CF with its cable CA.D (on E2). On the contrary the transversal protuberance E3 is not occupied by electronic components but has the particular function to prolong (extend) a slot CAV. si for the adhesive (preferably, silicone Si) acting to fix the glue on the inferior internal face of CFSC to the photovoltaic panel (not shown), as it will be better seen when figures 6A and 7 will be illustrated.

Therefore, according to invention, a connector couple (male CM and female CF) with the relevant longitudinally aligned cables is utilized externally to the containment body CFSC, said connectors CM-CF and cables CAS-CAD being immovably fixed to the expansions El-

E2 through, preferably, the hooked supports FAS and FAD which exert holding forces directly on the surface of said connectors and cables inter united by form constraint.

Indeed said hooked supports are made of plastic-elastomeric material having good elastic memory.

On the front face FF of said containment body there are holes to insert therein the ring nuts

Gh. s and Gh. d associated to said cables, as well as the osmotic valve Vo.

The circuitry, substantially the diodes Dl, D2 and D3 is located within the containment space

CFSC (diode D3 being represented as extracted in fig. 1 but well visible in its working position in fig. 6) together with their Pins, bridges and rises SCA in order to detach them from the containment body bottom FO and to place them exactly on a same transversal line.

Besides said diodes D1-D3 and the bridges SCA, in fig. 6 are shown also the springs MI-M4, their coverings C Mo4, and the junction box laminae LA1-LA4 to which are fixed the terminals of the panel (not shown).

The gasket GUA is located in the groove GO between said two internal walls of body CFSC.

This part of the box gasket can be considered substantially conventional whereby no further details and explanations seem necessary.

Said gasket GUA embedded in said groove GO substantially on the top of the most internal well Pi and the intermediate wall 25 of the containment body CFSC contributes to the automatic embedding of cover L in the body CFSC which, to this end, is provided with a second groove or deep slot GO' formed by said intermediate wall 25 and the outer wall Pe in which are made the "pockets or niches" SLl₅ SL2 (SL3, SL4) in which the lid self-locking fasteners or clips Z1-Z4 are inserted.

The cover new embodiment according to the invention is shown in its top view of figures 1 and 2 and its plan view of fig. 6. On the superior external face LS it is possible to see: - a rectangle 10 for the possible insertion of the client name and for the creation of an internal step (26) as well as; - three small rectangles for the indication of the technical data. The already mentioned four self-locking fasteners Zl, Z2, Z3, Z4 (each one with its hook ZlR, Z2B etc.) protrude downwardly from the longitudinal lateral sides FLLl and FLL2. An expansion Cvo protrudes downwardly from the transversal frontal side LTF in order to protect the osmotic valve Vo facing the corresponding front side of body CFSC. On the internal face LI of cover L (see fig, 6 A which is a bottom, planar view of the Hd of fig. 1) there is a rib NE which extends frontally along the whole more external edge B which is there is however less high than said rib NE. In the perspective view (fig. 5) of the bottom FIFO of body CFSC (180° turned over fig. 1) a feature of the invention is shown, consisting in that a long groove or slot CAV. Si for the glue or adhesive(preferably silicone) to fix said bottom FIFO to preformed zones of the voltaic panel (not shown) is now made along the edges of the expansions El, E2, E3 to extend clockwise (for instance) from O to 0'. This extended groove CAV. si has the advantage to strongly increase the zone of contact between silicone SI (dashed in fig. 5) poured from a dispenser or tube (not shown) without dressing-off or trimmings, i.e. outputs from groove CAV. si, whereby gradients of silicone concentrations are avoided.

Surprisingly the functions of the expansions El and E2 are no more restricted to those of support (external to body CFSC) of connectors CM-CF and cables CA. S -CAS.D but now said El and E2 act also to substantially increase the length of the relevant groove CAV. si (in cooperation with the path on E3) by increasing thereby the uniform quality and distribution of the glue as well the life of the fixation of the box to the panel, and by eliminating outputs of the silicone on the panel, which result any way in a loss of material and moreover request boring operations of detachment.

This represents therefore an additional effect. Moreover the mounting of bottom FIFO of the box to/on the panel can be carried out automatically. Conventionally it took place with the aid of a pneumatic arm which carried the box in correspondence of the panel, or by means of a vice or pliers which seized the box inserting a multi-tech fork below said box. This movement was generally made difficult by the casual presence on the path, of mobile connectors and cables, not immovably fixed.

As, according to a feature of the invention, connectors and cables are now stationary constrained to the expansions El and E2, i.e. are in well indicated fixed positions, the movement of the box towards and on the panel can be automized and be thereby quicker and more precise.

Also the electric test of the box is now made automatically and consists in the verification that there is (or not) energy production by simply exposing the upper face of a panel to an ad hoc light source. To this end a robot can be used which inserts two probes in the connectors CM and CF and detects the correct or incorrect current flow.

Normally the probe insertion and detachment at the beginning and end of a test are carried out manually with precautions which cause sensitive time losses. Moreover cables and probes have to be returned to their place at each detachment.

According to a further advantageous feature of the invention, as the connectors CM and CF are now immovably constrained in a fixed position on the expansions El and E2, the robot can now automatically and precisely insert said probes in the fixed connectors and easily disconnect them at the end of the test. On the basis of the stable positioning and fixation of the connectors to the expansions El and E2 it has been possible to study and bring about ad hoc connectors, housings and hooks of high compatibility so to realize, already with the sole aid of the form constraints, automatic, fast and safety, mountings and demountings, as it can be intuitively understood from the accompanying drawings.

After all with the adoption of the connector and cable displacements outside the containment body CFSC, and with their stable fixation to the expansions El and E2 the invention succeeds to advantageously obtain at least the two additional effects of the automatic test and mounting.

As it will be seen also from the phase IV of the following flow-chart, the cover opening is necessary to connect the panel terminals to the laminas of the box circuitry. In the above description, dispensers, arms robots etc. have been mentioned and defined as "per se known" without referring to Prior Patents and Technical-Scientific Publications. This is simply justified by the fact that adequate information concerning photovoltaic panels, junction box, robot, arms, dispensers and their utilization systems and methods are abundantly present on Internet.

Fig. 7 shows a flow-chart of a preferred process to apply the system of the invention on a photovoltaic panel. It is true that the box in question are generally provided open, i.e. with box cover L removed, it is however convenient to start also from the case of a closed box, whereby step 1 refers to the box opening by lifting up said lid L from the containment body

(CFSC).

Step II emphasizes that the box movement is now automatic because of the elimination

(according to the invention) of the conventional obstacles due to the casual (and not foreseeable) presence of connectors CM, CF and cables CAs-CA.D not immovably fixed, whereby, whereas the box of the Prior Art had to be moved with the aid of lifting means and therefore it was long and uncomfortable, now the box automatic movement is quick comfortable, safe and precise. In step III the automatic deposition of the adhesive (preferably silicone) in the long groove CAV. si made without discontinuity in the three expansions El, E2 and E3 of the bottom FO substantially equal to the area covered by lid L. As it can be better seen from fig. 5 (plan prospective view on the external face of bottom FI-FO of the central containment space CFSC) said groove CAV extends (clockwise) on a long continuous path on said expansion from point O to point O' whereby, the adoption, according to a feature of the invention, of said protuberances El - E2 - E3 produces, in addition to the effect of advantageous sits for connectors and cables fixed outside movement paths, also a beneficial synergic effect on the seal and immobility of the box on the panel; this effect is undoubtedly an additional unpredictable effect.

The automatic positioning of the junction box on the panel pre-prepared zone is carried without problems in the step V. The adhesive setting or hardening takes place in step VI. The box closure is carried out in step VII by applying over said box the cover which clips firmly the whole system with the aid of said self-locking fasteners Z1-Z4 and of the form constraint between cover and containment body. Step VI and VII can even be inverted. For scruple of illustrative clarity the invention has been described by referring to the embodiment shown (as a non limitative example) in the accompanying drawings; obviously additions, modifications, substitutions and the like can be applied to said embodiment, which if were found in the reach of mean technician of this field, are to be considered as comprised and falling in the scope of the present invention.

Claims

1) System for the interconnection of solar photovoltaic panels, comprising: - junction boxes, covers, connectors, cables, diodes, supports and similar components, characterized in that the box (S) has a central body to form containment space (CFSC) having a surface corresponding to the cover (L) area, and at least three protuberances (El, E2, E3) protruding from the bottom towards the outside, on two of these protuberances (El, E2) being immovably fixed a male connector (CM) on side (El), and, on side (E2) a female connector (CF), as well as cables (CA. S. CA.D) longitudinally aligned with the axes of said connectors, so to render automatic the operations of testing, mounting and adhesive charge.

2) System according to claim 1, characterized in that at least one (E3) of said protrusions projecting from the bottom of said body (CFSC) is made on one of the transversal sides of said body.

3) System according to claim 1, wherein said cover (L) having the same surface of body (CFSC) is provided with self-locking fastener (Z) projecting downwardly and located on the cover (L) longitudinal sides.

4) System according to claim 1, wherein "niches" (SL1-SL4) for the reception of the cover fasteners are made on the longitudinal sides of said body (CFSC).

5) System according to claim 3, wherein on at least one transversal side of said cover is made a downwardly protrusion to protect the osmotic valve (Vo) located on the anterior front of body (CFSC).

6) System according to claim 1, wherein on the internal or back face of the cover are made: - central step (26); - a first vertical rib (NE) which is facing and is as long as the most external edge (B) of said cover, and shows a height superior to that of said edge (B), as well as a second low rib (NE') projecting from the bottom to form a groove (GO")

7) System according to claim 1, wherein at the top of body (CFSC) there are interstice walls (Pi, 25, Pe) which form a first interstice or hollow space for embedding therein a gasket (GUA), and a second groove ( GO') in the most external wall of which are formed said niches for the self-locking fasteners in the phase of the automatic closure of cover (L) on the body (CFSC).

8) System according to claim 7, wherein on the external wall of the bottom of body (CFSC) a slot (CAV. si) is made for the easily controlled charge of the silicone adhesive, said slot interesting also the more peripheral zone of the lateral expansions (El and E2) as well as the back face of the posterior protuberance (E3) so to strongly increase the extension and the capacity of the silicone, so to facilitate the filling without escapes of said silicone and so to increase the life of the adhesive fixation of the box on the panel.

9) Method for mounting on photovoltaic panels junction boxes with movable lid, according to claim 1 to 8 , wherein: - the containment body (CFSC) is open by lifting up cover (L); - the box is automatically moved; - an adhesive in particular a silicone is automatically filled in the groove or slot running along the edges of protuberances (E1-E3); - connecting the panel terminal to the laminas of the diodes in the body (CFSC) while the cover is detached; - automatically positioning said closed box on the panel predisposed zones; - letting the silicone to harden; - carrying out the electric automatic test, and closing the cover.