U.S. patent application number 17/272166 was filed with the patent office on 2021-07-08 for photovoltaic plant.
The applicant listed for this patent is TOTAL SA. Invention is credited to Valerick CASSAGNE, Frederic LEROY.
Application Number | 20210211093 17/272166 |
Document ID | / |
Family ID | 1000005495635 |
Filed Date | 2021-07-08 |
United States Patent
Application |
20210211093 |
Kind Code |
A1 |
CASSAGNE; Valerick ; et
al. |
July 8, 2021 |
PHOTOVOLTAIC PLANT
Abstract
The invention relates to a photovoltaic plant (100) comprising:
at least one photovoltaic module (1), including at least one
junction box (13) placed on a front face of the photovoltaic module
(1), via which face the solar rays enter, in proximity to a
peripheral edge (4) of said photovoltaic module (1), and at least
one DC current cable (15, 17) that conveys the current generated by
the at least one photovoltaic module (1), characterized in that it
furthermore comprises a protective sheath (5) that is placed, on
the front face of the photovoltaic module (1), encircling the
junction box (13) and the DC current cable (15, 17), said
protective sheath (5) having a cross-section the height of which
corresponds at least to the height of the junction box (13) and
including a window (57) that is located in the face of the
protective sheath (5) that makes contact with the photovoltaic
module (1), via which window the junction box (13) protrudes from
the protective sheath (5), and a closable longitudinal aperture
(51) allowing the junction box (13) and the DC current cable (15,
17) to be accessed.
Inventors: |
CASSAGNE; Valerick;
(Limours, FR) ; LEROY; Frederic; (Vincennes,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOTAL SA |
Courbevoie |
|
FR |
|
|
Family ID: |
1000005495635 |
Appl. No.: |
17/272166 |
Filed: |
August 30, 2019 |
PCT Filed: |
August 30, 2019 |
PCT NO: |
PCT/EP2019/073202 |
371 Date: |
February 26, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02S 40/36 20141201;
H02S 40/34 20141201; H01B 7/17 20130101 |
International
Class: |
H02S 40/36 20060101
H02S040/36; H02S 40/34 20060101 H02S040/34; H01B 7/17 20060101
H01B007/17 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2018 |
FR |
1857825 |
Claims
1. A photovoltaic plant for generating electrical energy
comprising: at least one photovoltaic module, including
photovoltaic cells connected to at least one junction box
positioned on a front face of the photovoltaic module, via which
face the solar rays enter, in proximity to a peripheral edge of
said photovoltaic module, at least one DC current cable that
conveys the current generated by the at least one photovoltaic
module, characterized in that it furthermore includes: a sheath,
fixed on the front face of the photovoltaic module, encircling the
junction box and the at least one DC current cable, intended to be
placed along the peripheral edge of the photovoltaic module close
to the junction box, said sheath having a cross-section whose
height corresponds at least to the height of the junction box and
including a window that is located in the face of the sheath that
makes contact with the photovoltaic module, via which window the
junction box protrudes into the sheath, and a closable longitudinal
aperture allowing the junction box and the at least one DC current
cable to be accessed.
2. The photovoltaic plant according to claim 1, characterized in
that the sheath is at least partially made from a polymer material
or from organic fibers, in particular from among the following:
EPDM, PVC or chlorofiber, a fluoropolymer, polysilicone, polyester,
polyamide, polypropylene, polyethylene, elasthane, aramid.
3. The photovoltaic plant according to claim 1, characterized in
that the closable longitudinal aperture is formed by two flaps
which are superimposed in the closed state of the closable
longitudinal aperture.
4. The photovoltaic plant according to claim 3, characterized in
that the flaps include strips, for one of textile loops, and for
the other of textile hooks, forming, when the flaps are
superimposed, a mechanical closure of the closable longitudinal
aperture.
5. The photovoltaic plant according to claim 1, characterized in
that the closable longitudinal aperture is formed by two flaps
including, at their free end, lips which are in contact in the
closed state of the closable longitudinal aperture.
6. The photovoltaic plant according to claim 1, characterized in
that the sheath includes a reinforcement forming elastic means
which brings the closable longitudinal aperture back into the
closed state in the absence of outside action.
7. The photovoltaic plant according to claim 1, characterized in
that the sheath is made from an elastic material having a state of
least deformation in which the closable longitudinal aperture is in
the closed state.
8. The photovoltaic plant according to claim 1, characterized in
that the sheath is made in two parts: a bottom with an open
cross-section on the face opposite the photovoltaic module, bearing
the windows, and a cover closing the sheath by interlocking with
the bottom of open cross-section.
9. The photovoltaic plant according to claim 1 one of the preceding
claims, characterized in that the sheath has a rectangular
cross-section.
10. The photovoltaic plant according to claim 1, characterized in
that the sheath is made up of several longitudinal segments, a
segment being associated with a photovoltaic module and including a
window for the junction box of the photovoltaic module with which
it is associated.
11. The photovoltaic plant according to the preceding claim,
characterized in that each segment includes one end a thinner
portion intended to cooperate with a wider portion of an adjacent
segment.
12. The photovoltaic plant according to claim 1, characterized in
that the sheath is closed at least at one of its longitudinal ends
by a stopper having a shape which is complementary to the
cross-section of the sheath in the closed state of the closable
longitudinal aperture.
13. The photovoltaic plant according to the preceding claim,
characterized in that one of the stoppers includes at least one
passage for the at least one DC current cable.
14. The photovoltaic plant according to claim 1, characterized in
that the lower wall of the sheath in contact with a photovoltaic
module has at least one flow aperture for the flow of water falling
on the surface of the photovoltaic modules.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a photovoltaic plant,
converting solar radiation into electricity, and more particularly
relates to the protection of the cabling of such plants.
BACKGROUND OF THE INVENTION
[0002] Photovoltaic plants make it possible to supply renewable
electricity, without producing carbon dioxide and without consuming
fossil fuel. The only costs created by such a photovoltaic plant
for the user are the manufacturing cost, the installation cost and
the various upkeep costs.
[0003] The decrease in these costs makes photovoltaic energy
increasingly competitive when it is compared to the other modes of
electricity generation.
[0004] Manufacturing costs are reduced essentially by the design of
the photovoltaic modules of the plant: their manufacturing mode,
the materials used, the type of photovoltaic cells used, their
cabling, etc. The choice of the support structure of the modules,
its design and its dimensions also make it possible to reduce the
cost of the photovoltaic plant. To a lesser extent, the choice of
the cabling, its material and its arrangement also contributes to
reducing the purchase price.
[0005] At this time, it would be advantageous to better use the
surfaces of existing industrial or commercial buildings, in
particular by installing photovoltaic modules on the roofs thereof.
Indeed, for the operator of the building, generating electrical
energy can create additional revenue or savings and contribute to
favoring the economic exploitation of the building.
[0006] However, these commercial or industrial buildings are often
built for example with a metal or wooden framework which is sized
to just meet the technical constraints in terms of load in order to
support the roof with insulation as well as a snow load, for
example, depending on the construction region.
[0007] Now, it is not possible at this time to install certain
photovoltaic modules on the roofs of certain buildings due to the
weight of these modules, so as not to violate the technical
standards in force. Indeed, most of the known photovoltaic modules
generally have a glass front face and a metal support frame such
that a single photovoltaic panel often weighs more than 12 kg/m2,
or even 25 kg/m2 for some models. If the support structures
necessary for the installation of the photovoltaic modules are
added to this, the result is an additional load of 3 to 15
kg/m.sup.2 for a roof.
[0008] Thus, it is not possible to equip the large surfaces
currently available with photovoltaic modules, particularly old
buildings, due to their limited dimensioning in terms of load.
[0009] To address this drawback, lightweight or flexible
photovoltaic modules are known and encapsulated with laminated
resin having a lower production cost, which can be fixed directly
on the surface to be used.
[0010] Now, at this time, the cables connecting the photovoltaic
modules to one another as well as the junction boxes are generally
positioned on the rear face of the photovoltaic modules, and are
often integrated into raceways or ducts of a support structure of
the photovoltaic modules and thus protected from bad weather,
climate variations and UV radiation. Indeed, such protection is
necessary because the ultraviolet rays can for example make the
polymers porous and fragile.
[0011] Now, when the lightweight or flexible photovoltaic modules
are for example directly fixed on the roof of a commercial or
industrial building, all of the cabling and the junction boxes can
no longer be on the back side of the photovoltaic module, but must
rather be placed on the front and are therefore exposed to the bad
weather and the UV radiation.
[0012] It is therefore necessary to provide protection for the
cabling and the junction boxes which may be effective while
allowing easy installation or maintenance.
SUMMARY OF THE INVENTION
[0013] In order to at least partially address the aforementioned
problems, the invention relates to a photovoltaic plant for
generating electrical energy comprising: [0014] at least one
photovoltaic module, including photovoltaic cells connected to at
least one junction box positioned on a front face of the
photovoltaic module, via which face the solar rays enter, in
proximity to a peripheral edge of said photovoltaic module, [0015]
at least one DC current cable that conveys the current generated by
the at least one photovoltaic module, characterized in that it
furthermore includes: [0016] a protective sheath, fixed on the
front face of the photovoltaic module, encircling the junction box
and the at least one DC current cable, intended to be placed along
the peripheral edge of the photovoltaic module close to the at
least one junction box, said protective sheath having a
cross-section whose height corresponds at least to the height of
the junction box and including a window that is located in the face
of the protective sheath that makes contact with the photovoltaic
module, via which window the junction box protrudes into the
sheath, and a closable longitudinal aperture allowing the junction
box and the at least one DC current cable to be accessed.
[0017] The protective sheath forms additional protection for the
cables and the junction boxes. The closable longitudinal aperture
allows easy and quick access to the cables and to the junction
boxes, while it is easy to install. Since the cross-section of the
sheath approximately corresponds in terms of height to the junction
boxes, it further makes it possible to minimize the shade projected
by the sheath onto the photovoltaic cells.
[0018] The sheath protects the cables from water by decreasing the
quantity of water falling directly onto the cables, and by
preventing standing water. Indeed, the protective sheath guides the
water and promotes the flow thereof.
[0019] The photovoltaic plant according to the invention can
further include one or more of the following features, considered
alone or in combination.
[0020] The sheath can be at least partially made from a polymer
material or from organic fibers, in particular from among the
following: EPDM, PVC or chlorofiber, a fluoropolymer, polysilicone,
polyester, polyamide, polypropylene, polyethylene, elasthane,
aramid.
[0021] The closable longitudinal aperture can be formed by two
flaps which are superimposed in the closed state of the closable
longitudinal aperture.
[0022] The flaps can include strips, for one of textile loops, and
for the other of textile hooks, forming, when the flaps are
superimposed, a mechanical closure of the closable longitudinal
aperture.
[0023] The closable longitudinal aperture can be formed by two
flaps including, at their free end, lips which are in contact in
the closed state of the closable longitudinal aperture.
[0024] The protective sheath can include a reinforcement forming
elastic means which brings the closable longitudinal aperture back
into the closed state in the absence of outside action.
[0025] The protective sheath can be made from an elastic material
having a state of least deformation in which the closable
longitudinal aperture is in the closed state.
[0026] The protective sheath can be made in two parts: a bottom
with an open cross-section on the face opposite the photovoltaic
module, bearing the windows, and a cover closing the protective
sheath by interlocking with the bottom of the open
cross-section.
[0027] The protective sheath can have a rectangular
cross-section.
[0028] The protective sheath can be made up of several longitudinal
segments, a segment being associated with a photovoltaic module and
including a window for the junction box of the photovoltaic module
with which it is associated.
[0029] Each segment can include, at one end, a thinner portion
intended to cooperate with a wider portion of an adjacent
segment.
[0030] The protective sheath is closed at least at one of its
longitudinal ends by a stopper having a shape which is
complementary to the cross-section of the sheath in the closed
state of the closable longitudinal aperture.
[0031] One of the stoppers can include at least one passage for the
at least one DC current cable.
[0032] The lower wall of the protective sheath in contact with a
photovoltaic module can include at least one flow aperture for the
flow of rainwater falling on the surface of the photovoltaic
modules.
DESCRIPTION OF THE DRAWINGS
[0033] Other advantages and features will appear upon reading the
description of the invention, as well as the following figures,
among which:
[0034] FIG. 1 schematically shows a perspective view of a
photovoltaic plant according to the invention,
[0035] FIG. 2a separately shows a photovoltaic module of the plant
of FIG. 1, with its cabling visible and a two-pole junction
box,
[0036] FIG. 2b separately shows a photovoltaic module of the plant
of FIG. 1, with its cabling visible and two single-pole junction
boxes,
[0037] FIG. 2c separately shows a junction box and the DC current
cables associated therewith,
[0038] FIG. 3a, 3b are cross-sectional views of a lower portion of
the module of FIG. 2a with a sheath,
[0039] FIG. 4a schematically shows a perspective view of a sheath
for protecting the cabling of FIG. 2a,
[0040] FIG. 4b schematically shows a perspective view of a sheath
for protecting the cabling of FIG. 2b,
[0041] FIGS. 5 to 8 show cross-sections of different sheath
embodiments,
[0042] FIGS. 9 to 11 illustrate the installation of a plant
according to one embodiment of the invention,
[0043] FIGS. 12a and 12b illustrate a possibility for closing the
ends of the sheath with modular cabling,
[0044] FIGS. 13 and 14 illustrate a modular embodiment of the
sheath, in bottom view and cross-sectional view, respectively,
[0045] FIGS. 15 and 16 illustrate an embodiment with a flow
window.
[0046] In the figures, the identical elements are identified by the
same references.
DETAILED DESCRIPTION OF THE INVENTION
[0047] The following embodiments are examples. Although the
disclosure refers to one or several embodiments, this does not
necessarily mean that each reference relates to the same
embodiment, or that the features apply only to one single
embodiment. Simple features of various embodiments could also be
combined to provide other embodiments.
[0048] In the disclosure, some elements or parameters are indexed,
for example by the addition of the qualifier "first" or "second,"
"first," "next" or "last," or by a letter or a figure, etc. This
indexing seeks to differentiate the elements relative to one
another, and does not indicate any preferential order or chronology
for installation.
[0049] For example, in general, a photovoltaic module bears
reference number 1, whereas a specific photovoltaic module will be
designated by 1a, 1b or 1c.
[0050] FIG. 1 is a schematic illustration of the photovoltaic plant
100 according to the invention, in perspective view. The plant 100
of FIG. 1 for example includes three photovoltaic modules 1 (1a,
1b, 1c), connected to a network junction 3, for example a household
electrical grid, the public electrical grid or an accumulator.
[0051] The photovoltaic modules 1 are for example fixed directly on
a roof, a support structure or a heap. The modules 1 are for
example interconnected in series so as to form a string using DC
current cables 15, 17 conveying the current produced by each of the
modules 1 of the string to the network junction 3.
[0052] By convention, the first module 1a of the string is closest
to the network junction 3, and the last module 1c is the module
furthest from the network junction 3.
[0053] The three modules 1a, 1b, 1c are positioned horizontally
aligned, thus defining a longitudinal axis along which they are
connected in series or string. Along one of their peripheral edges,
in the present case their lower peripheral edge 4, a protective
sheath 5 extends longitudinally, here in particular rectilinear in
its longitudinal direction.
[0054] The protective sheath 5 encircles the DC current cables 15,
17 and the junction boxes 13. It extends parallel to the lower
peripheral edge 4 of the photovoltaic modules 1 along the entire
photovoltaic plant 100.
[0055] FIG. 2a separately shows a photovoltaic module 1, without
the protective sheath 5. The photovoltaic module 1 includes an
arrangement of photovoltaic cells 11, arranged in parallel rows and
connected by electrical contacts. The photovoltaic cells 11 are for
example flexible monocrystalline cells made from silicon, connected
by aluminum or silver contacts. The photovoltaic cells 11 can in
particular be laminated between two layers of encapsulating resin,
with a transparent protective layer on the front face, that is to
say, the face by which the sun's rays enter.
[0056] The module 1 includes a junction box 13, in the present
example a two-pole junction box, on its front face, near the lower
peripheral edge 4, with a substantially parallelepipedal shape, in
particular with rounded edges. The junction box 13 is connected to
the photovoltaic cells by electrical contacts, for example of the
same type as those connecting the cells 11 to one another.
[0057] Among the DC current cables 15, 17, it is possible to
distinguish: [0058] inter-module connection cables 15 connecting
two junction boxes 13 of two adjacent photovoltaic modules, for
example 1a and 1b or 1b and 1c, or the network junction 3 to the
junction box 13 of the first photovoltaic module 1a, [0059] a
return cable 17, which connects the junction box 13 of the last
photovoltaic module to the network junction 3, this return cable 17
running parallel to the connection cables 15 along the entire plant
in the protective sheath 5.
[0060] The junction box 13 and the connection cable 15
advantageously include plugs and jacks which are complementary for
a quick assembly. The return cable 17 connects the positive pole of
the last junction box 13 to the positive pole of the network
junction 3.
[0061] The connection 15 and return cables 17 forming the DC
current cables 15, 17 can in particular be fixed by shape
cooperation to the poles that they connect, for example to the
complementary plug and jack means in order to allow quick
installation.
[0062] Other arrangements of DC current cables 15, 17 are, however,
also possible, in particular with a parallel connection of the
junction boxes 13. Such an interconnection of the junction boxes 13
makes it possible to favor the produced current to the detriment of
the supplied voltage.
[0063] Arrangements combining junction boxes 13 in parallel and in
series are also possible in order to adapt current and voltage at
the output of the photovoltaic plant.
[0064] Among possible variants, FIG. 2b separately shows a
photovoltaic module of the plant of FIG. 1, with its cabling
visible and two single-pole junction boxes 13-1 and 13-2 positioned
at the lateral ends of the peripheral edge 4.
[0065] One example of a single-pole or two-pole junction box 13 and
the DC current cables 15, 17 is shown in more detail in FIG. 2c. In
FIG. 2c, the junction box 13 is shown in perspective view. The
junction box 13 is parallelepipedal, with a connection cable 15
connected to it on each side perpendicular to the peripheral edge 4
along which it is positioned.
[0066] A separate return cable 17 extends on the side of the
junction box 13 facing the close peripheral edge 4. The return
cable 17 can alternatively be positioned on the side opposite the
junction box 13 or, in the context of a modular structure, be
combined with the connection cable 15, which then includes two
parallel lines. The junction box 13 here in particular includes a
hook 131 in order to keep the return cable 17 on its face oriented
toward the peripheral edge 4 along which it is positioned.
[0067] The module 1 further includes fixing means 19 (FIG. 2a), for
example piercings allowing screwing, hooking or quick fastening to
a dedicated support structure or bearings fixed to a roof or a
heap. According to other embodiments, the photovoltaic modules are
fixed by gluing on the support structure.
[0068] FIGS. 3a and 3b show a cross-sectional view of a first
embodiment of a protective sheath 5. This protective sheath 5 is
mounted and fixed so as to surround the junction box 13 and the
connection 15 and return cables 17.
[0069] In FIG. 3a, the section plane is the plane perpendicular to
the plane of the module and to the lower edge 4 of the module 1
passing through line A-A which is located to the left of a junction
box 13.
[0070] In FIG. 3b, the section plane is the plane perpendicular to
the plane of the module and to the lower edge of the module 1
passing through the line B-B which is located in the middle of the
junction box 13.
[0071] In this embodiment, the protective sheath 5 has a
rectangular cross-section, with a height corresponding at least or
exactly to the height of the junction box 13. It therefore contains
and encircles said junction box 13 as well as the connection 15 and
return cables 17, shown by their profile or their cross-section:
rectangular with rounded edges for the junction box 13, circular
for the cables 15, 17. The protective sheath 5 can be rigid or
flexible. It is for example at least partially made from polymer
material or from organic fibers, in particular from among the
following: EPDM, PVC or chlorofiber, a fluoropolymer, polysilicone,
polyester, polyamide, polypropylene, polyethylene, elasthane, or
even aramid. The protective sheath 5 can alternatively be made from
braided polyamide yarns. In particular, it does not need to be
completely tight, since its primary aim is to stop the ultraviolet
rays from the sun. On the contrary, partial tightness can even
reduce the accumulation of moisture for long periods.
[0072] If the protective sheath 5 is made from insulating polymers,
a destroyed yarn whose core is in contact with said protective
sheath 5 then does not make its manipulation or contact dangerous
for a human operator.
[0073] By adapting the height of the protective sheath 5 to that of
the junction box 13, the shadow projected by the protective sheath
5 onto the photovoltaic cells 11 is reduced, which makes it
possible to retain a high efficiency of the plant 100 despite an
installation of cable and junction boxes 13 on the front face of
the photovoltaic modules 1.
[0074] The protective sheath 5 includes a longitudinal aperture 51
which preferably extends over its entire length and which is
closable. In the present example, this longitudinal aperture 51 is
positioned on its face opposite the module 1, here closed by a
first 53 and a second 55 flap. The first flap 53 folds down on the
second flap 55 in order to close said aperture 51. The flaps 53, 55
can in particular fold down into the position closing the closable
longitudinal aperture 51 under the action of a return to a state of
least deformation of the elastic material which makes up the
protective sheath 5. In addition or alternatively, the protective
sheath 5 can include an elastic reinforcement, for example made
from spring steel or elastic plastic, which forms elastic means
ensuring that the closable longitudinal aperture 51 returns to the
closed state in the absence of outside action.
[0075] The first flap 53 is then advantageously located on the top
side when the module 1 is considered inclined or vertical, in order
to allow a better discharge of rainwater outside the protective
sheath 5.
[0076] There is located, on the face of the protective sheath 5
located in contact with the front face of the photovoltaic module 1
in the mounted state, a window 57 for each junction box 13, at the
longitudinal positions of said junction boxes 13, by which the
junction boxes 13 protrude into the protective sheath 5. One such
window 57 is in particular visible only in FIG. 3b, corresponding
to a cross-section at the position of a junction box 13 and
therefore at the height of a window 57 and at the junction box 13
whose profile is visible in FIGS. 3a and 3b.
[0077] The protective sheath 5 can also be fixed on the front face
of the modules 1, for example by gluing, by screwing, by riveting
or by shape matching ("clipping").
[0078] The windows 57 and the closable longitudinal aperture 51 are
located on different faces, here opposite faces. The windows 57 in
particular have a shape and dimensions which correspond to the
junction boxes 13, so as to allow the passage in the protective
sheath 5. The closable longitudinal aperture 51 allows quick access
to the junction boxes 13 and to the cables 15, 17 contained and
protected by the protective sheath 5 in the closed state of said
closable longitudinal aperture 51.
[0079] The protective sheath 5 is shown in bottom perspective view
(from the location normally occupied by the photovoltaic module 1)
in FIG. 4a for modules shown in FIG. 2a and in FIG. 4b for the
modules shown in FIG. 2b.
[0080] FIG. 4a, respectively 4b in particular show that the windows
57, respectively 57-1 and 57-2, are positioned at a distance d
corresponding to the distance between two junction boxes 13
(two-pole), respectively 13-1 and 13-2 (single-pole), of two
successive modules 1 of the photovoltaic plant 100 (see FIG.
9).
[0081] The sheath 5 is in particular held by the interlocking of
the windows 57, respectively 57-1 and 57-2, on the junction boxes
13, respectively 13-1 and 13-2, and the passage of the cables 15
and 17 in the sheath 5.
[0082] FIGS. 5 to 8 illustrate alternative embodiments of a
closable longitudinal aperture 51, with a representation mode
similar to that of FIG. 3a, 3b.
[0083] In FIG. 5, the closable longitudinal aperture 51 is formed
by two flaps 53, 55, further including strips of loops 59 and
textile hooks 61, forming, in the closed state, a reversible
fastener of the "scratch" type.
[0084] In FIG. 6, the closable longitudinal aperture 51 is formed
by two flaps 53, 55 extended by two end lips 63, 65, respectively
at the free end of the first and the second flap 53, 55, in
compressed contact when said aperture 51 is in the closed
state.
[0085] In FIG. 7, the protective sheath is formed by two
longitudinal parts. It in particular includes a bottom 5a, with an
open cross-section on the face opposite the photovoltaic module 1,
and a cover 5b closing the protective sheath 5 by interlocking with
the bottom 5a of open cross-section which it closes.
[0086] In FIG. 8, the protective sheath 5 includes the closable
longitudinal aperture 51 on the face oriented toward the peripheral
edge 4, which can be advantageous when said peripheral edge 4 is a
lower edge: the flow of water through said aperture 51 is then
reduced, while the flow of water from the inside of the protective
sheath 5 is increased. Conversely, if the peripheral edge 4 is an
upper edge, the closable longitudinal aperture 51 can be positioned
on the opposite face, facing the photovoltaic cells 11.
[0087] A protective sheath 5 as previously described in particular
is lightweight, makes it possible to cover and protect the DC
current cables 15, 17, the connectors 18 (not visible in FIG. 8) as
well as the junction boxes 13, while allowing easy and quick access
to the latter during upkeep or an inspection of the condition of
the components of the photovoltaic plant 100.
[0088] FIGS. 9 to 11 and 12a, 12b illustrate the method for
installing the photovoltaic plant 100, for example on a roof or on
inclined terrain.
[0089] The first step shown in FIG. 9 is the aligned positioning of
the photovoltaic modules 1, with a gap e between two consecutive
modules (e in particular being able to be zero) ensuring a distance
d between the junction boxes 13 of two consecutive photovoltaic
modules 1. The photovoltaic modules 1 are in particular fixed by
their fixing means 19 to the support (here the roof or inclined
terrain), using screws, fasteners or hooks or by gluing.
[0090] The second step shown in FIG. 10 is the arrangement and the
fixing of the protective sheath 5 along the peripheral edges 4
aligned near the junction boxes 13, with said junction boxes 13
protruding in the windows 57. The protective sheath 5 can in
particular be fixed by gluing. In the case of FIG. 10, the
protective sheath 5 is level with a row of fixing means 19 of the
modules 1, and can therefore be fixed by the latter.
[0091] The third step is the connection of the photovoltaic modules
1 to one another and to the DC current network junction or to the
power converter 3, using the DC current cables 15 and 17. To this
end, the connection cables 15 are positioned between the successive
junction boxes 13 of the modules 1a, 1b, 1c of the string, for
example, the first junction box 13 being connected by its negative
pole to a negative pole of the network junction 3, and the return
cable 17 is positioned between the positive pole of the last
junction box 13 and the positive pole of the network junction
3.
[0092] The closable longitudinal aperture 51 is then closed again,
and plant is priest to operate.
[0093] During an inspection or upkeep, an operator needs only to
open the closable longitudinal aperture 51 in order to access the
DC current cables 15, 17 and the junction boxes 13, for example to
inspect the condition of the equipment items or to measure the
voltage across the terminals of a junction box 13 in order to
determine which segment of DC current cable 15, 17 or which
photovoltaic module 1 must be replaced.
[0094] In order to more completely close the volume delimited by
the protective sheath 5, in particular with respect to outside
objects (leaves, gravel, insects and animals, etc.), stoppers 71,
73 with a cross-section corresponding to that of the protective
sheath 5 in the closed state can be positioned and fixed at the
longitudinal ends of the protective sheath 5, as shown in FIG. 12a,
12b. Advantageously, these stoppers 71, 73 include cable passages,
connections to other ducts or raceways or outlets or plugs for the
DC current cables 15, 17. They can in particular be glued, stapled
or sewn to the ends.
[0095] In the context of a modular structure, with quick and easy
assembly, the connection 15 and return cables 17 are provided with
connectors 18, for example plugs and outlets which are
interconnected and which thus maintain electrical contact, in
particular by shape cooperation. In particular, the connectors 18
can connect the DC current cable portions 15, 17 reversibly, in
order to allow quick replacement.
[0096] In the case of FIG. 12a, a portion of the DC current cables
15, 17 is fixedly connected to the junction boxes 13, and
connectors are provided between the consecutive junction boxes
13.
[0097] In the case of FIG. 12b, the connectors are integrated into
the junction boxes 13, in particular in the form of female outlets
flush at the sides of said junction boxes 13, so as to maintain a
rectangular contour allowing the insertion of the junction boxes 13
into the windows 57, which in turn are rectangular.
[0098] The DC current cables 15, 17 and the junction boxes 13 are
then connected by the connectors 18 simply, quickly and reversibly.
The assembly of the plant 100 is then quicker and potentially less
expensive, while the maintenance and in particular the replacement
of components (module 1a, 1b, cable segment, etc.) is then
simplified.
[0099] Alternatively, the ends of the protective sheath 5 can be
sewn around the DC current cables 15, 17.
[0100] In the context of a modular structure, not requiring any
cutting of a particular length of protective sheath 5, said
protective sheath 5 can be made up of several longitudinal segments
5c, 5d, etc., a longitudinal segment 5c, 5d for example being
associated with a photovoltaic module 1 and including a window 57
(or two windows 57-1 and 57-2). Such a protective sheath 5 is shown
in FIGS. 13 and 14.
[0101] Each segment 5c, 5d includes, at one end, a thinner portion
intended to cooperate with a wider portion of the following or
preceding segment in the string. FIG. 14 is a perspective view from
below (similar to FIG. 4). Each protective sheath 5c, 5d then has a
total length d when it is interlocked in the adjacent segment 5d,
5c. The interlocking of the sheaths can also be done by conical
shapes or flanges or also by elastic deformation of the mouths.
[0102] In FIG. 14, the segments are shown in cross-section, so as
to make visible a thinner portion 67 of the considered segment 5c,
which is interlocked in the end of the adjacent segment 5d during
the installation of the plant 100.
[0103] Alternatively, the protective sheath 5 can assume a
continuous form, for example the form of an unwinding roller when
it is flexible enough (braided polymer yarns or a polymer
membrane), and in particular without the windows 57. For the
installation of the plant 100, it is then necessary to cut, on the
one hand, the required length of protective sheath 5, and on the
other hand, the windows 57 in the appropriate locations. Although
it requires more steps, this installation method provides greater
freedom regarding the arrangement of the modules 1.
[0104] Since the lightweight modules are often installed in the
direction of the inclined part of the roofs or the heap, the
electrical connections and sheaths will be located perpendicular to
the incline and therefore can provide a dam for the flow of
rainwater. FIGS. 15 and 16 illustrate one embodiment of a
protective sheath 5 and photovoltaic plant 100 in which the
protective sheath 5 includes flow apertures 21, passing through the
protective sheath 5 in the direction perpendicular to its
longitudinal axis, at its lower surface (that which is against the
photovoltaic module 1).
[0105] In the embodiment of FIG. 15, the lower wall of the
protective sheath 5, that which is positioned against the
photovoltaic modules 1a, 1b and which forms a bottom of said
protective sheath 5, is bowed between the junction boxes 13, while
the photovoltaic modules 1a, 1b are rectilinear. Thus, flow
apertures 21 allow the flow of rainwater falling on the surface of
the considered photovoltaic module 1a, 1b.
[0106] Around the windows 57 through which the junction boxes 13
are inserted, connected by the DC current cable 15, the protective
sheath 5 includes frames 23, in the form of a flat rectilinear
portion of the bottom of the protective sheath 5 positioned against
the photovoltaic module 1. The frames 23 encircle the windows 57,
and are parallel to the photovoltaic module 1a, 1b of the junction
box 13 which they encircle.
[0107] At the frames 23, the protective sheath 5 can be glued on
the module 1. Alternatively, the protective sheath 5 can be
screwed, riveted or stapled at the frame 23 against the
photovoltaic module 1a, 1b.
[0108] In the embodiment of FIG. 16, the protective sheath 5
includes several bowed portions each delimiting a flow aperture 21
between two successive junction boxes 13.
[0109] The flow apertures 21 thus make it possible to avoid
standing water at the junction boxes 13, and thus reduce soiling at
the sheath 5 and of its content.
[0110] The protective sheath 5 can also be non-rectilinear in its
longitudinal direction, which is easily obtained using a protective
sheath 5 made from braided yarns of polyamide, polyethylene or
polyvinyl (or other polymers), for example in order to connect
nonaligned modules 1 (for example in the case of a curved
heap).
[0111] The cross-section of the protective sheath 5 can also be
different from a rectangle; for example when it is made from
braided polymer yarns or from polymer membrane, it will have an
ovaloid cross-section.
[0112] The protective sheath 5 makes it possible to prevent the
stagnation and accumulation of water at the DC current cables 15,
17 by encouraging the discharge thereof.
[0113] The addition of the protective sheath 5 therefore makes it
possible to increase the life expectancy in the operating state of
the photovoltaic plant 100 by protecting the DC current cables 15,
17, the connectors 18 (FIG. 12a, 12b) and the junction boxes 13 of
the junction modules 1 on the front face. It is easy and quick to
install, while it can be made from inexpensive materials, thus
representing a low extra cost. It therefore contributes to making
photovoltaic energy more efficient and competitive.
* * * * *