Solar panel comprising in particular a plurality of zones of electronic components connected to each other by a plurality of electrical cables.

Abstract

Solar panel comprising in particular a plurality of zones of electronic components connected to each other by a plurality of electrical cables.The present invention relates to a solar panel (10) comprising: - a base defining a front face and a rear face (18); - a plurality of photovoltaic cells (14); - a plurality of electronic component zones (20A,…,20N) arranged on the rear face of the base and connected to each other by a plurality of electrical cables (22); - a plurality of fastening devices (30A,…,30D, 32A,…,32D, 44A, 44B, 46A, 46B) for fastening the plurality of electrical cables to the rear face of the base; the panel (10) being characterized in that each fastening device comprises a U-shaped cross-section profile extending along a longitudinal axis (X), the profile having a flat base, a first lateral flank and a second lateral flank substantially orthogonal to the flat base, and an opening opposite the flat base. Figure for the abstract: Fig. 2.

Description

Title of the invention: Solar panel comprising in particular a plurality of zones of electronic components connected to each other by a plurality of electric cables. Technical field

[0001] The present invention relates to a solar panel comprising in particular a plurality of zones of electronic components connected to each other by a plurality of electrical cables.

[0002] The invention finds its application in particular in the space field. Thus, the solar panel according to the invention can be carried on board a spacecraft such as a satellite for example and constitutes a source of electrical power for such a craft. Prior art

[0003] Generally, the satellite comprises several solar panels, the assembly of which is called a solar generator, which are used to power at least some of the electrical devices of the satellite.

[0004] A solar panel generally comprises a base which defines a front face intended to be exposed to the Sun, called the sun face and a rear face opposite the front face also called the night face. The front face is provided with photovoltaic cells which are exposed to the Sun and are capable of generating electrical energy.

[0005] The rear face includes component areas, for example electronic, making it possible to recover the electrical energy generated by the cells and to route this energy to the electrical devices of the satellite.

[0006] The electronic component areas of the solar panel are notably connected to each other by a plurality of electrical cables.

[0007] The cables are generally electrically insulated from each other by suitable dielectric sheaths. They are also grouped into strands, or glued in a sheet on the surface of the panel with glue dots.

[0008] The routing of these cables on the rear face of the base is naturally done in a symmetrical and identical manner (we speak of uniqueness of wiring methodology).

[0009] According to this methodology, the glue points that allow each of the cables to be stuck to the rear face of the panel are aligned or sometimes even coincident between adjacent cables. The same applies to the cable direction change points, which are also aligned between adjacent cables. Thus, the cables are mounted identically on the solar panel.

[0010] During the operational phase of flight, it sometimes happens that faults appear in one or more cables.

[0011] These defects are due in particular to constraints of a mechanical, thermal nature and / or to aging of the materials due to the space environment (radiative dose, UV from the sun, thermal cycling in orbit) (possibly coupled together) which are exerted on the cables.

[0012] It was further noted that due to the uniqueness of the prior art wiring methodology, the stresses experienced by the panel were transferred identically to neighboring cables and thereby increased the probability of seeing an identical fault appear on two adjacent cables, at the same location on these cables.

[0013] These defects weaken the cable sheaths in particular by causing bare parts to appear (cracks) which expose the metallic core of the cables.

[0014] It is therefore understood that this considerably increases the risk of a short circuit, also known as an electric arc, occurring between different adjacent electrical cables. Such an electric arc can seriously damage, or even destroy, the solar panel. An arc can appear between bare parts when they are brought into contact by a plasma (naturally conductive) of origin, for example: an electrostatic discharge or the impact of a micrometeorite in the vicinity of the bare parts.

[0015] It has also been noted that gluing the cables to the rear face of the panel could increase the stresses on the cables. The same applies to other fixing principles (tightening on a bracket, etc.).

[0016] The aim of the present invention is to propose a solar panel in which the risk of an electric arc being established between different cables is considerably reduced. Statement of the invention

[0017] To this end, the invention relates to a solar panel comprising:

[0018] - a base being in contact with an ambient medium and defining a front face and a back side;

[0019] - a plurality of photovoltaic cells arranged on the front face of the base;

[0020] - a plurality of electronic component areas arranged on the rear face of the base and connected to each other by a plurality of electrical cables on which mechanical and thermal stresses can be exerted,

[0021] - A plurality of fastening devices for fastening the plurality of cables electrical on the rear face of the base;

[0022] each fixing device comprises a profile with a U-shaped cross-section, extending along a longitudinal axis, the profile comprising a flat sole, a first lateral flank and a second lateral flank substantially orthogonal to the flat sole, and an opening opposite the flat sole.

[0023] The configuration of the panel fixing device according to the invention, and in particular the presence of the lateral flanks, forms a barrier between the adjacent cables and makes it possible to prevent the stresses undergone by the panel from being transferred in an identical manner to neighboring cables and thereby reduces the probability of seeing an identical defect appear on two adjacent cables, at the same location on these cables.

[0024] According to other advantageous aspects of the invention, the panel comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0025] Each electric cable is fixed to the rear face of the base by means of at least one fixing device, each electric cable being arranged in the profile, between the lateral flanks of said at least one fixing device and being movable relative to said at least one fixing device.

[0026] Each fastening device comprises at least one retaining portion designed to hold the electrical cable in the profile.

[0027] Said at least one retaining portion is an elongation of an edge of a lateral flank which extends into the opening of the fixing device.

[0028] Each fixing device comprises two retaining portions.

[0029] The fixing devices are arranged on the rear face of the base so as to guide the corresponding electrical cables parallel to each other at least on a rectilinear guide portion along a guide axis.

[0030] At least some of the fixing devices form a group of fixing devices, the fixing devices of this group fixing different electric cables and being arranged in the rectilinear guide portion in parallel with respect to a fixing axis forming a non-zero angle with a guide axis.

[0031] At least some of the fixing devices form a group of fixing devices, the fixing devices of this group fixing different cables and being arranged in the rectilinear guide portion in a zigzag manner relative to a fixing axis forming a non-zero angle with the guide axis.

[0032] Spacecraft comprising a solar panel as previously described.

[0033] These characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings. Brief description of the drawings

[0034] [Fig.l] [Fig.l] is a schematic view of a solar panel according to the invention;

[0035] [Fig.2] [Fig.2] is a bottom view of the solar panel of [Fig.l];

[0036] [Fig.3] [Fig.3] is an isometric view of a fixing device according to the invention.

[0037] [Fig.4] [Fig.4] is an isometric view of several fixing devices according to the invention.

[0038] [Fig.5] [Fig.5] is a cross-sectional view of several fixing devices according to the invention. Description of the embodiments

[0039] [Fig.l] illustrates a solar panel 10 according to the present disclosure. The solar panel may be carried on board a spacecraft such as a satellite.

[0040] However, it must be understood that the solar panel according to the invention can be mounted on any mobile device other than a satellite or, in general, can be used independently of any mobile device, for example in a fixed configuration on the Earth's surface or on another planet (lunar rover, Martian rover, interplanetary probe, etc.).

[0041] With reference to [Fig.l], the solar panel 10 comprises a base 12 and a plurality of photovoltaic cells 14.

[0042] The base 12 is in contact with the ambient environment of the satellite which is then presented by a spatial environment devoid of atmosphere.

[0043] The base 12 is for example of substantially rectangular shape and defines a front face 16 oriented towards the Sun and a rear face 18 opposite the front face 16.

[0044] The cells 14 are arranged homogeneously on the front face 16 of the base 12, for example in two rows, each row comprising four cells 14. The invention is not limited to this number of cells.

[0045] The cells 14 are known per se and in particular make it possible to generate electrical energy when they are illuminated by the Sun.

[0046] The rear face 18 is illustrated in more detail in [Fig.2].

[0047] Thus, with reference to this figure, the rear face 18 comprises a plurality of component zones. These components make it possible to recover the electrical energy generated by the cells and to route this energy to the electrical devices of the satellite. For example, the rear face 18 comprises a plurality of electronic component zones 20A to 20N and a plurality of electrical cables 22 electrically connecting these electronic component zones 20A to 20N.

[0048] The cables 22 may be subjected to constraints of a mechanical or thermal nature, for example.

[0049] Thus, each constraint is chosen from the group including in particular:

[0050] - thermal expansion and cycling;

[0051] - mechanical stress, for example a bend exerted on a strand of cables;

[0052] - exposure to significant radiation doses;

[0053] - exposure to light (UV aging);

[0054] - electrostatic discharges and / or electric arcs etc.

[0055] One or more of these stresses combined simultaneously alter(s) the properties of the sheaths over time and weaken them. This generally results in a hardening of the sheath's dielectric, resulting in a lack of flexibility and cracking. It can also be a disintegration of the material itself due to irradiation from the environment which alters the chemical bonds, and which deteriorates or decomposes the material.

[0056] The electronic components are known per se and ensure in particular the operation of the solar panel 10.

[0057] In the present disclosure, each electronic component of the component areas 20A to 20N is a diode.

[0058] In other examples, each electronic component may be chosen for example from the group comprising in particular

[0059] - transistors;

[0060] - capacitors;

[0061] - control circuit;

[0062] - connectors, etc.

[0063] Holes through which the wiring passes to be connected to the solar cells on the front face or even the solar cells themselves can also be considered as electronic components. Indeed, the constraints are not exclusive to the rear face of the solar panel but can also be applied to the front face, for example at the level of the cables which are connected to the solar cells and which are therefore glued to the front face of the solar panel. Also, the risk of danger is predominant on the rear face but is not exclusive to this face.

[0064] The cables 22 connect these different zones of electronic components 20A to 20N according to their functionality and according to methods known per se.

[0065] Generally speaking, the term “cable” means any wire conducting current or electrical signals. The electrical currents are, for example, used to power one or other of the electronic component zones 20A to 20N. According to the present invention, the cables are single or unitary wires.

[0066] The cables also serve to transport the current, called light current, generated by the solar cells exposed to sunlight which constitute the energy source of the spacecraft. This current is used to power the various equipment and / or charge the satellite's batteries; this is called photovoltaic power.

[0067] As illustrated in [Fig.3], each cable 22 has a sheath 23 allowing it to be electrically insulated from the other cables 22.

[0068] Each cable 22 is fixed to the rear face 18 by means of at least one fixing device.

[0069] A fastening device 30A of the plurality of fastening devices is illustrated more specifically in [Fig. 3]. The fastening device comprises a U-shaped cross-section profile 300 having a planar sole 310, a first and second lateral flank 320, 330 and an opening 340.

[0070] The flat sole 310 of the profile 300 extends along a longitudinal axis “X”. The first lateral flank 320 and the second lateral flank 330 each extend from the flat sole 310 and are substantially orthogonal to the flat sole 310, the opening 340 is opposite the flat sole 310.

[0071] The flat sole 310 and the two lateral flanks 320, 330 form a passage in the profile 300. This passage is intended to receive a cable from the plurality of cables of the panel. For example, the passage has a shape complementary to that of the cable. In the present disclosure, the passage has a circular force.

[0072] The fixing device is fixed to the rear face 18 for example by gluing.

[0073] A cable 22 of the plurality of cables is arranged in the profile 300, in the passage formed between the first and second lateral flanks 320, 330 of the fixing device. The cable 22 is movable relative to the fixing device 30A. For example, the cable can slide in the fixing device. The cable is held in the fixing device without excessive stress, without imposing a fixed point on the cable as a glue point would do.

[0074] In a non-visible embodiment, the fixing device comprises an adapter, such as a rigid or foam wedge, or a small hoop, arranged in the passage of the profile which is intended to adapt any type of cable in the fixing device.

[0075] For example, the fixing device extends over a portion of the cable equal to 5 mm.

[0076] According to one embodiment, the fixing device 30A comprises at least one retaining portion. The retaining portion is designed to hold the cable in the passage of the profile and prevent a cable 22 from exiting the profile 300.

[0077] In the present disclosure, the retaining portion is an elongation 322, 332 of an edge of a lateral flank 320, 330 which extends into the opening 340 of the fixing device 30A.

[0078] In the present disclosure, the fixing device 30A comprises two retaining portions 322, 332, each retaining portion being an elongation 322, 332 of an edge of a lateral flank 320, 330 which extends into the opening 340 of the fixing device 30A.

[0079] The retaining portions 322, 332 of the fixing devices are particularly visible in [Fig.5].

[0080] In an embodiment not shown, the two retaining portions overlap so as to close the opening of the passage.

[0081] For ease of reading, only a few fixing devices 30A to 30D, 32A to 32D, 44A and 44B, and 46A and 46B are shown in [Fig. 2]. Fixing devices may for example be arranged every 30 cm on the rear face 18.

[0082] The fixing devices 30A to 30D, 32A to 32D, 44A and 44B, and 46A and 46B are arranged so as to guide the corresponding cables 22 along the rear face 18 between different areas of electronic components 20A to 20N.

[0083] In [Fig.2], two rectilinear guide portions 33a and 33b following guide axes XI and X2 respectively are shown.

[0084] Thus, as can be seen in [Fig.2], during this routing, at least some of the cables 22 are guided parallel to each other at least on a rectilinear guide portion along a guide axis.

[0085] Furthermore, during routing, at least some of the cables 22 are guided so that their routing direction changes at direction change points. Four direction change points 34A, 34B and 36A, 36B are shown in [Fig.2],

[0086] In the example of [Fig.2], at least some of the fixing devices (30A,.. .,30D) form a group of fixing devices, fixing different cables, arranged in the rectilinear guide portion 33a in parallel with respect to a fixing axis “Y1” forming a non-zero angle with a guide axis “XI”.

[0087] Figures 3 and 4 are enlarged views of this embodiment in which three fixing devices (30A, 30B, 30C) arranged parallel to each other are shown.

[0088] In the present disclosure, the fixing devices are joined to each other.

[0089] According to one embodiment, the fixing devices are glued to each other by clipping.

[0090] According to one embodiment, the fixing devices are formed in a single piece as illustrated in [Fig.5].

[0091] In one embodiment, the fixing devices are separate from each other.

[0092] In the example of [Fig.2], at least some of the fixing devices 32A,...,32D form a group of fixing devices which each fix a different cable 22. These fixing devices 32A,...,32D are arranged in the rectilinear guide portion 33b in a zigzag manner relative to a fixing axis “Y2” forming a non-zero angle with the guide axis “X2”.

[0093] According to an embodiment not shown, a portion of a fixing device may be opposite a portion of a second fixing device.

[0094] This configuration makes it possible to limit cable vibrations.

[0095] In the example of [Fig.2], at least some of the fixing devices 44A, 44B, 46A, 46B comprise a first portion 50 extending in a first direction and a second portion 60, extending from the first portion in a second direction, inclined relative to the first direction so as to follow the change in routing direction of the cables.

[0096] By "a second direction inclined relative to the first direction" is meant that the second portion of the steering device extends from the first portion of the steering device with an inclination of between 80° and 100°, preferably between 85° and 95°, even more preferably with an inclination equal to 90°.

[0097] These fixing devices make it possible to fix the cable portions 22 which are guided so that their routing direction changes at direction change points 34A, 34B and 36A, 36B.

[0098] In the example of [Fig.2], a device for fixing a cable extends in a first direction and another device for fixing the same cable extends in a second direction, inclined relative to the first direction so as to follow the change in routing direction of the cables.

[0099] Thanks to the panel fixing devices according to the invention, the lateral flanks make it possible to form barriers between the adjacent cables. But this configuration also makes it possible to prevent the stresses undergone by the panel from being transferred in an identical manner to neighboring cables and thereby reduces the probability of seeing an identical defect appear on two adjacent cables, at the same location on these cables.

Claims

Claims

1. Solar panel (10) comprising: - a base (12) being in contact with an ambient medium and defining a front face (16) and a rear face (18); - a plurality of photovoltaic cells (14) arranged on the front face (16) of the base (12); - a plurality of electronic component zones (20A,...,20N) arranged on the rear face (18) of the base (12) and connected to each other by a plurality of electrical cables (22) on which stresses of a mechanical or thermal nature can be exerted, - A plurality of fixing devices (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B, 47A, 47B) intended to fix the plurality of electrical cables (22) on the rear face (18) of the base (12); the panel (10) being characterized in that each fixing device (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B) comprises a profile (300) with a U-shaped cross-section, extending along a longitudinal axis (X), the profile (300) comprising a flat sole (310), a first lateral flank (320) and a second lateral flank (330) substantially orthogonal to the flat sole (310), and an opening (340) opposite the flat sole (310), each electric cable (22) being fixed to the rear face (18) of the base (12) by means of at least one fixing device (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B), each electric cable (22) being arranged in the profile (300), between the lateral flanks (320, 330) of said at least one fixing device (30A,.. .,30D, 32A,.. .,32D, 44A, 44B, 46A, 46B) and being movable relative to said at least one fixing device (30A,.. .,30D, 32A,...,32D, 44A, 44B, 46A, 46B), at least some of the fixing devices (44A, 44B, 46A, 46B) comprising a first portion (50) extending in a first direction and a second portion (60), extending from the first portion in a second direction, inclined relative to the first direction.

2. Solar panel (10) according to claim 1, characterized in that each fixing device (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B) comprises at least one retaining portion (322, 332) designed to hold the electric cable (22) in the profile (300).

3. Solar panel (10) according to the preceding claim, characterized in that said at least one retaining portion (322, 332) is an elongation of an edge of a lateral flank (320, 330) which extends into the opening (310) of the fixing device (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B).

4. Solar panel (10) according to the preceding claim, characterized in that each fixing device (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B) comprises two retaining portions (322, 332).

5. Solar panel (10) according to claim 1 characterized in that the fixing devices (30A,...,30D, 32A,...,32D, 44A, 44B, 46A, 46B) are arranged on the rear face (18) of the base (12) so as to guide the corresponding electrical cables (22) parallel to each other at least on a rectilinear guide portion (33a, 33b) along a guide axis (XI, X2).

6. Spacecraft comprising a solar panel (10) according to one of the preceding claims.

Images