FIELD OF THE INVENTION

The present invention relates to the technical sector of concentrating photovoltaic modules. In particular, the invention relates to a plant and a method for fixing a secondary optical group in a photovoltaic partly-assembled photovoltaic module.

DESCRIPTION OF THE PRIOR ART

As is known, a concentrating photovoltaic module generally comprises: a box body comprising a bottom and lateral walls (constituted by aluminium sheets), the body of which identifies an upper opening, opposite the bottom; a glass sheet, positionable at the upper opening of the box body, for closing thereof; a plurality of primary optical groups (generally having a parabolic conformation), positioned internally of the box body for defining a row; each primary optical group is provided with a through-hole; a plurality of photovoltaic cells (for example high-efficiency), arranged internally of the box body, each at a through-hole of a primary optical group; a plurality of secondary optical groups (also generally parabolic in shape), fixed to the surface of the internal glass sheet of the box body so as to face a corresponding primary optical group; a plurality of electric circuits, each connected to a photovoltaic cell; a plurality of support bases, arranged internally of the box element and on each of which an electric circuit and a photovoltaic cell are fixed.

In detail, each primary optical group and the corresponding secondary optical group are reciprocally conformed and distanced so that a beam of solar rays emitted by the Sun towards the Earth which has entered the box body through the glass sheet is reflected by the primary optical group towards the secondary optical group. The secondary optical group reflects the solar ray beam and concentrates it at the photovoltaic cell.

For the performance of each photovoltaic cell, and therefore the whole photovoltaic module, it is fundamental that each primary and the corresponding secondary optical group are facing one another in the optimal way. In particular, it is necessary for the axes of the parabolas identified by the primary optical group and the corresponding secondary optical group to be aligned to one another. In this way, the photovoltaic cell arranged in the through-hole of the corresponding primary optical group receives, in the most direct way possible, the maximum quantity of solar rays.

The positioning of the secondary optical group with respect to the corresponding primary optical group is therefore fundamental.

This positioning has up to now been performed by an operative, who manually fixes the secondary optical groups on the glass sheet, once the primary optical groups and the corresponding photovoltaic cells have been predisposed in the box body. Following this operation, and after having applied sealant on the edge (210) of the box body which identifies the opening, the glass sheet is arranged on the opening of the box body in order to close it.

The main drawback of what has been described above is due to the fact that the glass sheet must have a certain amount of extra play with respect to the edge of the box body which identifies the opening on which it will have to be arranged: this is to enable the sealant used for the fixing of the glass sheet to the body to dilate following the high temperatures reached by the module during the functioning without risking the integrity of the glass sheet. This means that the dimensions of the glass sheet do not exactly correspond to those of the edge of the box body; the operative therefore cannot have an exact reference for the fixing of the secondary optical groups on the glass sheet which reference takes account also of the play of the glass sheet with respect to the edge of the box body.

Further, the mechanical perforating tolerances and the shape tolerances of the box body are normally much greater than the positioning precision necessary for correct functioning.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a solution which enables fixing a secondary optical group in a partly-assembled concentrating photovoltaic module so that the optical aspect of the secondary optical group is aligned to the optical axis of the primary optical group. In other words, the solution of the invention enables optimal fixing of the secondary optical group in a photovoltaic module.

The aim is attained with a solution according to claim 1 and claim 8.

The proposed solution advantageously enables optimal positioning of a secondary optical group in a partly-assembled concentrating photovoltaic module, i.e. so that once the concentrating photovoltaic module is assembled, the optical axis of the secondary optical group is aligned to the optical axis of the corresponding primary optical group.

BRIEF DESCRIPTION OF THE DRAWINGS Specific embodiments of the invention and further advantages will be evidenced in the following description, with the aid of the appended tables of drawings, in which:

- figures 1 -10 illustrate ten perspective views of a plant according to the invention in different operating situations, and contextually different steps of the method of the invention;

- figure 1 a illustrates the detail of figure , in a larger-scale view; figure 2a illustrates detail b of figure 2, in a larger-scale view; - figure 3a illustrates detail c of figure 3, in a larger-scale view;

- figure 4a illustrates detail u of figure 4, in a larger-scale view;

- figure 5a illustrates detail x of figure 5, in a larger-scale view;

- figures 6a and 6b respectively illustrate detail y and detail v of figure 6, in larger-scale views;

- figure 7a illustrates detail w of figure 7, in a larger-scale view;

- figure 8a illustrates detail j of figure 8, in a larger-scale view;

- figure 9a illustrates detail k of figure 9, in a larger-scale view; and

- figure 10a illustrates detail h of figure 10, in a larger-scale view. DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to the appended tables of drawings, reference numeral (1 ) relates to a plant (1 ) for fixing a secondary optical group (20) in a partly- assembled concentrating photovoltaic module (2).

In particular, the partly-assembled (concentrating) photovoltaic module (2) comprises: a box body (21 ) comprising a bottom, lateral walls and an upper opening (A), opposite the bottom; a primary optical group (23), fixed internally of the box body and provided with a seating (not visible in the figures); a photovoltaic cell (not visible in the figures), fixed internally of the box body at the seating of the primary optical group (23); a sheet of transparent material (22) comprising a first surface (220) and a second surface (221 ) opposite the first surface (220), the sheet of transparent material (22) being positionable at the upper opening (A) of the box body (21 ), for closing the box body (21 ), so that the first surface (220) is facing the first optical group (23) and the second surface (221 ) is facing externally of the box body (21 ); a secondary optical group (20) fixable to the first surface (220) of the sheet of transparent material (22); a sealant substance (not visible in the figures), positionable along the edge (210) of the box body (21 ) which identifies the upper opening (A). In other words, in this case, the fact that the concentrating photovoltaic module (2) is partly assembled means that the secondary optical group (20) has not yet been fixed to the sheet of transparent material (22) and that the sealant has not yet been deposited along the edge (210) of the box body (21 ) which identifies the upper opening (A).

In particular, the plant (1 ) of the invention comprises: a frame (3) for restingly receiving the box body (21 ) (comprising, fixed internally thereof, the primary optical group (23) and the photovoltaic cell); and a supply line (F), for supplying the box body (21 ) onto the frame (3). The plant (1 ) further comprises a tilting element (4) solidly constrained to the frame (3) and predisposed such as: to intercept and retain the second surface (221 ) of the sheet of transparent material (22) positioned, in a supported configuration (S), at the upper opening (A) of the box body (21 ), with the first surface (220) facing the primary optical group (23) (see figures 3 and 3A); to enable retaining and tilting the sheet of transparent material (22) from the supported configuration (S) to a tilted configuration (T) in which the first surface (220) is facing towards an outside of the box body (21 ) see figures 4, 5, 4A, 5A); and to enable retaining and tilting of the sheet of transparent material (22) from the tilted configuration (T) to the supported configuration (S) (see figures 9, 9A).

The plant (1 ) further comprises at least a first manipulating organ (6), predisposed to: collect at least a secondary optical group (20) from a store (M1 ); apply gluing means (200) on the collected secondary optical group (20) (see for example figure 10A); fix the secondary optical group (20) on the first surface (220) of the sheet of transparent material (22) in the tilted configuration (T) thereof (see for example figures 7A, 8A).

The fixing of the secondary optical group (20) on the first surface (220) of the sheet of transparent material (22) is clearly enabled by the above-cited gluing means (200).

The plant (1 ) further comprises: means for applying the sealant substance (70) along the edge (210) of the box body (21 ) which identifies the upper opening (A) (see in particular figure 5A), so as to enable sealing the box body (21 ) with the sheet of transparent material (22) following the tilting of the sheet of transparent material (22) following tilting of the sheet of transparent material

(22) and the second optical group (20) fixed thereto from the tilted configuration (T) to the supported configuration (S); and at least a camera (5) arranged such as to detect an effective position of the primary optical group

(23) in the box body (21 );

The plant (1 ) also comprises processing means (not illustrated and comprising, obviously, a memory), predisposed for: receiving from the camera (5) information (i.e. data) concerning the effective position of the primary optical group (23) detected; calculating the displacement (i.e. the positioning error) between the effective position detected and the theoretical position of the primary optical group (23) in the box body (21 ); considering the theoretical position of the secondary optical group (20) with respect to the first surface (220) of the sheet of transparent material (22) and the displacement, calculating the correct position of the secondary optical group with respect to the first surface (220) of the sheet of transparent material (22) such that, following the tilting of the sheet of transparent material (22) and the secondary optical group (20) fixed thereto from the tilted configuration (T) to the supported configuration (S), the optical axis of the secondary optical group (20) is aligned to the optical axis of the primary optical group (23); and commanding the first manipulating organ (6) so as to fix the secondary optical group (20) at the correct position.

The first manipulating organ (6) is therefore a high-precision manipulating organ. With reference to the accompanying figures, the first manipulating organ can comprise an arm (61 ) and gripping means (62) borne by the arm (61 ) (see, for example, figure 6B). Further, the first manipulating organ (6) can comprise a television camera (not illustrated) for detecting an effective presence of the gluing means (200) on the second optical group (20). Further, a probe device (63) (for example clearly visible in figures 8A, 6B), also borne by the arm (61 ), can be included to ensure the fixing of the secondary optical group (20) arranged on the first surface (220) of the sheet of transparent material (22).

The position of the sheet of transparent material (22) (which is preferably a sheet of glass) in the supported configuration (S) and the tilted configuration (T) is also obviously detected by the processing means.

The primary optical group (23) and the secondary optical group (20) preferably have: one thereof a parabolic conformation and the other thereof a hyperbolic conformation, and the photovoltaic cell is of the high-efficiency type.

The concentrating photovoltaic module (2) is for example of the solar-tracking type.

The proposed plant therefore advantageously guarantees the correct positioning of the secondary optical group (20) in the partly-assembled concentrating photovoltaic module (2), i.e. the positioning such that once the concentrating photovoltaic module has been assembled (and sealed), the optical axes of the second optical group (20) and the primary optical group (23) are perfectly aligned. This result could not, on the other hand, be absolutely guaranteed in the prior art, where the positioning of the secondary optical group (20) was manually performed by an operative. Apart from the imprecision connected with a manual operation and the defects present in the body and sheet of transparent material (for example imperfections of the edges of the sheet of transparent material), the major cause of an incorrect position of the secondary optical group was due to the mechanical imprecisions of the construction of the box body as well as to the fact that the sheet of transparent material must have a certain amount of play with respect to the edge of the box body defining the upper opening on which the sheet of transparent material must be arranged. This play has to be included in order to counter the thermal dilation to which the transparent material is subjected and also the sealant substance during the functioning of the photovoltaic module.

Thus, in the prior art, even when the operative was able to fix the secondary optical group in an ideal position on the sheet of transparent material, in the majority of cases this position was not the correct (i.e. optimal) one once the photovoltaic module was assembled. In fact, the positioning of the sheet of transparent material (with the secondary optical group fixed thereon) on the upper opening of the box body could not be realized with precision, due to the necessary amount of play between the sheet of transparent material and the edge of the box body which defines the upper opening thereof.

In the preferred embodiment of the invention, illustrated in the appended figures, the tilting element (4) comprises: a shaft (40), mobile rotatingly about an axis thereof; at least an arm (41 ), borne rigidly by the shaft (40); gripping means (42), borne by the arm (41). In particular, the gripping means (42) (which preferably comprise suckers subjected to an aspirating source) are able to: intercept and retain the second surface (221 ) of the sheet of transparent material (22) when the sheet is in the supported configuration (S); retaining the sheet of transparent material (22) when it is tilted from the supported configuration (S) thereof to the tilted configuration (T) thereof; and retain the sheet of transparent material (22) when it is tilted from the tilted configuration thereof (T) into the relative supported configuration (S) (see in detail figures 3A, 4A, 5A).

In this embodiment, the tilting of the sheet of transparent material (22) from the supported configuration (S) to the tilted configuration (T) and vice versa, is determined by the rotation of the arm (41 ) rotated by the shaft (40) (which is able to rotate for example by a 180 degree angle). The fact that the arm (41 ) is borne rigidly by the shaft (40) enables the sheet of transparent material (22) to be returned exactly into the supported configuration (S), from which it was collected.

In particular, in the supported configuration (S) the sheet of transparent material (22) is deconstrained for a brief time which is however sufficient for it to assume a stable position, in the light of any forces (due for example to the walls of the box body (21 ) possibly slightly deformed) which might tend to displace the sheet of transparent material (22) following fixing of the secondary optical group (20) thereon.

Obviously a plurality of arms (41 ) borne by the shaft (40) can be included (for example two, as illustrated in the figures).

In a further variant, not illustrated, the tilting element can be constituted by a manipulating organ, appropriately predisposed to carry out the above- described operations.

In the preferred illustrated embodiment, the camera (5) is aligned with the optical axis of the primary optical group (23) (see figure 7A).

In the preferred embodiment, the plant (1 ) further comprises a second manipulating organ (7) for collecting the sheet of transparent material (22) from a store (M2) and positioning it at the upper opening (A) of the box body

(21 ) , in the supported configuration (S) thereof (see figures 1A, 2A). In the accompanying figures of the drawings, the second manipulating organ (7) is arranged flanked to the first manipulating organ (6) (see for example figure 1 ).

With this variant, therefore, when the box body (21 ) reaches the frame (3) by means of the supply line (F), it is without the sheet of transparent material

(22) . The sheet of transparent material (22) can be for example in a store (M2) (the store (M2) for the sake of clarity being empty in figure 5 and full of sheets of transparent material (22) for example in figure 1A) where it is collected by the second manipulating organ (7) (comprising for example an arm (71 ) and gripping means (72), borne by the arm (71 )) at the second surface (221 ) thereof.

This variant advantageously prevents damage to and/or breakage of the sheet of transparent material (22) transported from the supply line (F) towards the frame (3).

The supply line (F) can for example comprise a plurality of conveyor belts.

In the preferred embodiment of the invention, illustrated in the figures, the second manipulating organ (7) comprises the means for applying the sealant substance (70) (for example silicone) along the edge (210) of the box body (21 ) which identifies the upper opening (A) thereof.

The plant (1 ) can further comprise supports (31 ) associated to the frame (3) and arranged such as to further support the sheet of transparent material (22) which in the relative tilted configuration (T). The supports (31 ) can be included as auxiliary to the tilting element (4), which is already alone able to retain the sheet of transparent material (22) in the tilted configuration (T). The supports can be constituted for example by abutments fixed to the frame (3) and dimensioned such as to abut the second surface (221) of the sheet of transparent material (22) when it is in the tilted configuration (T), thus supporting it (see for example figure 4A).

In a case where the partly-assembled concentrating photovoltaic module (2) comprises a plurality of primary optical groups (23) (for example eight) fixed in the box body (21 ) along at least a row, a plurality of corresponding photovoltaic cells each fixed to a seating of a primary optical group (23), a plurality of secondary optical groups (20), the frame (3) can comprise a slide (30) (to which the tilting element (4) is solidly constrained) so as to receive the box body (21 ) (to which, obviously, as specified above, the primary optical groups (23) and the corresponding photovoltaic cells are fixed).

In this embodiment (which is the one illustrated in the figures), the plant (1 ) further comprises an advancement line (L), comprising in turn: an entry station (L1 ) for receiving the box body (21 ) from the supply line (F); an exit station (L2) for conveying the box body (21 ) towards an exit line (Z), the box body (21 ) being sealed with the sheet of transparent material (22) and arranged on the slide (30). In particular, the slide (30) is step-movable along the advancement line (L) in an advancing direction (E) (indicated by an arrow for example in figure 1 ) from the entry station (L1 ) to the exit station (L2). The advancement line (L) and the exit line (Z) can each comprise for example a plurality of conveyor belts. This embodiment advantageously enables the first manipulating organ (6) to fix, one-by-one, the secondary optical groups (20) on the first surface (220) of the sheet of transparent material (22). Following the fixing of all the secondary optical groups (20) and the tilting of the sheet of transparent material (22) from the tilted configuration (T) to the supported configuration (S), the concentrating photovoltaic module (2) is assembled and can be evacuated towards an exit line (Z), to enable the processing of a further partly-assembled photovoltaic module along the advancement line (L).

The step is preferably equal to an interaxis (i.e. the distance) between optical axes of two adjacent primary optical groups (23) in the box body (21 ). Clearly, in a case where there is also the second manipulating organ (7), the advancement line (L) enables a partly-assembled concentrating photovoltaic module (2) to be processed first by the second manipulating organ (7) and then by the first manipulating organ (6).

In an embodiment of the invention, each each primary optical group (23) fixed in the box body (21) exhibits at least a reference indicator in a respective surface proximal to a bottom of the box body (21 ) (i.e. the surface opposite the one which receives and reflects the solar rays, once the concentrating photovoltaic module is in use). Further, the box body (21 ) comprises at least a hole facing the reference indicator. Further, the camera (5) is arranged below the slide (30); the slide (30) comprising at least a through-opening (300) (see figure 10A), predisposed to enable the camera (5) to detect the reference indicator. In this way, the position of the primary optical group (23) is detected directly by the camera (5).

Obviously a plurality of through-openings (300) can be included in the slide (30) (as in the case illustrated in figure 10A), for example equal to the number of primary optical groups (23) present in the box body (21 ).

The reference indicator (or indicators) can be for example constituted by the centring (and fixing) means described in international publication WO2013156929 in the name of the same Applicant. As described in the above-cited document, the centring means can be constituted for example by pins, which project (in a variant of the invention) from the surface of the primary optical group (23) proximal to the box body (21 ) (defined above). The above-mentioned holes in the box body (21 ) in this case are constituted by suitable seatings for receiving the pins.

In a case where the means are already present, there is advantageously no need to have any reference indicator on the primary optical group (23).

Alternatively a reference indicator (or more than one) can be included exclusively so as to be detected by the camera (5) (for example an exclusively visual reference indicator, without the function of fixing and centring as described above).

In a further variant, the seating of each primary optical group consists in a through-hole, and each partly-assembled concentrating photovoltaic module (2) further comprises at least a support base for supporting the photovoltaic cell with a first surface (so that the photovoltaic cell on the first surface faces the secondary optical group (20) once the concentrating photovoltaic module (2) has been assembled). In particular, each base is fixed at the through-hole of a primary optical group (23). Each base (not visible in the appended figures) comprises, in a respective second surface, opposite the first surface, and projecting below the primary optical group (23), at least a reference indicator. Further, the box body (21 ) comprises at least a hole (not visible in the appended figures) facing the reference, and the camera (5) is arranged below the slide (30).

Further, the slide (30) comprises at least a through-opening (300), predisposed to enable the camera (5) to detect the reference. In this way, the position of the primary optical group (23) is identified indirectly starting from the position of the support base detected by means of the reference indicator (obviously where the positioning of the support base is known). In this case too, a plurality of through-openings (300) can be included in the slide (30). For example, a projecting element (for example a pin) can be present, included in the second surface of the support base (for example centrally thereof).

In the preferred embodiment, the television camera (5) is aligned with the reference of the support base.

In the two embodiments described above, the fact that the television camera (5) is arranged below the slide (30) advantageously means that problematic light and reflection play is avoided, which would occur if the television camera (5) were arranged above the slide (due to the fact that highly-reflective optical systems are present). The television camera (5), with the specification described in the two latter variants, can therefore detect the position of each primary optical group (23) in a particularly precise way.

Further, in this way the performance of each photovoltaic cell is maximised; indeed there is not interference between the reference indicator and the reflective surface (i.e. the surface predisposed for receiving and reflecting the solar rays once the concentrating photovoltaic module (2) is in use) of the primary optical group (23): including a reference indicator at the reflective surface would clearly mean reducing the performance of the corresponding photovoltaic cell and therefore the overall performance of the concentrating phototovoltaic module (2). The two above-described variants can also be included in the same way with the frame (3) fixed in the place of the slide (30) (with a single primary optical group (23) and a single second optical group (20).

In the accompanying the figures, the partly-assembled concentrating photovoltaic module (2) further comprises a device for conveying the solar rays (8) from the secondary optical group (20) to the photovoltaic cell, fixed in the box body (21 ), so as to enable the box body (21 ) to receive the greatest possible quantity of solar rays (clearly visible for example in figures 4A and 5A).

The invention also relates to a method for fixing a secondary optical group (20) in a partly-assembled concentrating photovoltaic module (2). As previously mentioned, the photovoltaic module (2) comprises: a box body (21 ) comprising a bottom, lateral walls and an upper opening (A), opposite the bottom; a primary optical group (23), fixed internally of the box body and provided with a seating; a photovoltaic cell (not visible in the figures), fixed internally of the box body at the seating of the primary optical group (23); a sheet of transparent material (22) comprising a first surface (220) and a second surface (221 ) opposite the first surface (220), the sheet of transparent material being positionable at the upper opening (A) of the box body (21 ), for closing the box body (21 ), so that the first surface (220) is facing the first optical group (23) and the second surface (221 ) is facing externally of the box body (21 ); a secondary optical group (20) fixable to the first surface (220) of the sheet of transparent material (22); a sealant substance, positionable along the edge (210) of the box body (21 ) which identifies the upper opening (A). In particular, the method comprises steps of: a) supplying the box body (21 ), in which the primary optical group (23) and the photovoltaic cell are fixed, to a work station; b) positioning the sheet of transparent material (22) at the upper opening (A) of the box body (21 ) in a supported configuration (S), with the first surface (220) facing the primary optical group (23) (see figures 2, 2A); c) following steps a) and b), intercepting and retaining the second surface (221 ) of the sheet of transparent material (22) in the supported configuration (S) (see figures 3, 3A); d) tilting the sheet of transparent material (22) from the supported configuration (S) to a tilted configuration (T), wherein the first surface (220) is facing externally of the box body (21 ) (see figure 4A); e) applying a sealant substance along the edge (210) of the box body (21 ) which identifies the upper opening (A) (see figure 5A); f) detecting an effective position of the primary optical group (23) in the box body (21 ); g) calculating a displacement between the effective position detected and the theoretical position of the primary optical group (23) in the box body (21 ); h) calculating, considering the theoretical position of the secondary optical group (20) and the displacement, the correct position of the secondary optical group with respect to the first surface (220) of the sheet of transparent material (22) such that once the sheet of transparent material (22) is tilted and the secondary optical group (20) fixed thereto from the tilted configuration (T) to the supported configuration (S), the optical axis of the secondary optical group (20) is aligned to the optical axis of the primary optical group (23); i) applying gluing means (200) on the secondary optical group (20) and fixing the second optical group (20) at the correct position (see figure 6B); and, following the above steps, a step of: j) tilting the sheet of transparent material (22) from the tilted position to the rest position (see figure 9A).. The last step enables sealing the box body (21 ) with the sheet of transparent material (22), i.e. it enables assembly of the concentrating photovoltaic module (2). With the method of the present invention, therefore, it is possible to guarantee correct positioning of a secondary optical group (20) in a partly-assembled concentrating photovoltaic module (2). By correct positioning is meant a positioning such that once the concentrating photovoltaic module has been fully assembled the optical axis of the secondary optical group (20) is aligned to the optical axis of the primary group (23). In other words, maximum efficiency of each photovoltaic cell arranged internally of the box body (21 ) is guaranteed, and the maximum efficiency of the concentrating photovoltaic module (2) in its entirety is also ensured.

In the preferred embodiment of the invention, the step step of positioning the sheet of transparent material (22) at the upper opening (A) of the box body (21 ) is done following the step of supplying the box body (21 ), in which the primary optical group (23) and the photovoltaic cell are fixed, to a work station. This embodiment prevents possible damage to the sheet of transparent material (22) during the relative supply towards the work station.

Clearly the described method can be carried out also in the presence of a plurality of primary optical groups (23) in the box body (21 ), a plurality of photovoltaic cells and a plurality of corresponding secondary optical groups (20). In the latter case, the step of tilting the sheet of transparent material (22) from the tilted configuration (T) to the supported configuration (S) is carried out when all the secondary optical groups (20) have been fixed on the first surface (220) of the sheet of transparent material (22).

The above-described method can be actuated for example with the above- described plant (1 ), or with any other plant or system able to carry out the above-listed steps.