Photovoltaic module comprises photovoltaic cells between glass substrates, provided with external connection terminals

Technical field of the invention

The invention relates to a photovoltaic module comprising a plurality of photovoltaic cells, arranged between glass substrates and connected in series by connecting conductors, and means for connecting the module with the outside.

State of the art

A photovoltaic cell is conventionally formed on a solid silicon substrate cut in the form of slices a few hundred microns thick. The substrate can be made of monocrystalline silicon, polycrystalline silicon or semiconductor layers deposited on a glass or ceramic substrate. It has on its surface a network of narrow electrodes, generally in silver or aluminum, intended to drain the current to one or more main electrodes 1 to a few millimeters in width, also in silver or aluminum.

Each cell supplies a current depending on the illumination at an electrical voltage which depends on the nature of the semiconductor and which is usually of the order of 0.45V to 0.65V for crystalline silicon. Voltages of 6V to several tens of volts are usually necessary to operate electrical devices, a photovoltaic module is generally formed by an assembly of several cells in series. A 40-cell module provides, for example, nearly 24 volts. Depending on the currents required, several cells can also be placed in parallel. A generator can then be produced by possibly adding accumulators, a voltage regulator, etc.

To manufacture a photovoltaic module, the cells are prepared, that is to say covered with a network of electrodes and connected to each other by metal conductors. The assembly thus formed is then placed between two sheets of polymer, themselves clamped between two glass substrates. The assembly is then heated to around 120 ° C to strongly soften the polymer, make it transparent and ensure the mechanical cohesion of the module.

In a known photovoltaic module 1, shown in FIG. 1, rear connection conductors 5 ′ associated with a first cell 2a are connected to the front connection conductors 5 associated with a second adjacent cell 2b. If the module has more than two cells, the rear link conductors of the second cell are then connected to the front link conductors of the next cell, all the cells thus being connected in series. In practice, a rear connecting conductor 5 ′ of a cell and the associated front connecting conductor 5 of the neighboring cell can be formed by the same conductor. The conductors (5 and 5 ') and the cells 2 can be surrounded by a layer of polymer material 6 arranged between two glass substrates, front 3 and rear 4. The end of a connecting conductor (5 and 5 ') of an end cell protrudes outside the module 1 and constitutes a connector 7 towards the outside. Such connectors degrade and oxidize over time. The degradation worsens the more the module is large and the current and voltage supplied by the module are important.

Object of the invention

The object of the invention is to remedy these drawbacks and, in particular, a connection of a photovoltaic module minimizing the problems of degradation and oxidation of the connectors connecting the module to the outside.

According to the invention, this object is achieved by the fact that the module's connection means with the outside comprise a connection terminal comprising a block of insulating material glued to one end of the module, so as to connect to a connector external to the at least one connector electrically connected to the connecting conductor associated with a cell arranged at the end of the module.

According to a preferred embodiment, the module comprises a sealing gasket made of mineral material, arranged between the two glass substrates, so as to delimit, inside the module, a sealed interior volume, in which the cells are arranged, the connector passing through the seal in a sealed manner.

According to a development of the invention, the connector ends with a female part of a flat connector arranged between the glass substrates outside the sealed volume, the outer connector being connected to the connector by a pin constituting the male part of the flat connector and ending in a female part integrated in an orifice of the block made of insulating material.

According to another development of the invention, the block of insulating material comprises two glass substrates enclosing several connectors, separated by glass plates, the whole being linked by a sealing glass.

Brief description of the drawings

Other advantages and characteristics will emerge more clearly from the description which will follow of particular embodiments of the invention given by way of non-limiting examples and shown in the accompanying drawings, in which:

FIG. 1 is a photovoltaic module according to the prior art.

FIGS. 2 to 4 and 8 represent different particular embodiments of w connection terminals of the module with the exterior according to the invention.

FIG. 5 represents a view in section along the axis AA of FIG. 4.

Figures 6 and 7 show a particular embodiment of a terminal for connecting the module with the outside, Figure 7 being a sectional view along the axis BB of Figure 6.

Description of particular embodiments.

The photovoltaic module 1 comprises metal connectors 11 intended to allow a connection of the module 1 with the outside. FIGS. 2 to 8 represent various embodiments of terminals 13 for connecting the module with the exterior each comprising a block of insulating material 15 glued to the end of the module 1, so as to connect external connectors to the connectors 11. In a preferred embodiment, the connectors 11 pass, in a sealed manner, a sealing gasket 12 made of mineral material, shown in FIGS. 2 to 5 and 8, which can be placed between the two glass substrates 3 and 4, so in delimiting, inside the module 1, a sealed interior volume in which the cells 2 are placed. The assembly can be baked at approximately 400 ° C. for approximately 10 minutes in order to effect the sealing.

In Figures 2 to 4 and 8, the connector 11 is electrically connected to a connecting conductor 5, associated with the cell 2 disposed at the end of the module 1, by a deformation of the end of the connecting conductor 5 exerting a pressure against the connector 11 to ensure contact. Optionally, the deformed end or the connector 11 can be tinned beforehand. Alternatively, a solder material, consisting of a small amount of tinning paste, can ensure their soldering during sealing.

In FIG. 2, an external connector, formed by a conductive wire 16, is connected in the block of insulating material 15, to one end of a connector 11 penetrating into the block of insulating material 15. The insulating material may be a material. polymer. The connector 11 can be a strip with a thickness between 50 and δΟΟμιτι, typically 300μηη, and a width between 1 and 100 mm, typically 4mm. The connector 11 passes through the sealing gasket 12 in a sealed manner and it is connected on the one hand to the connecting conductor 5 inside the module and on the other hand to the conductive wire 16 outside the module. The connection zone between the connector 11 and the conductive wire 16 is covered with a resin or a polymer, for example of epoxy type, constituting the block 15, which is bonded to the glass substrates 3 and 4. This resin or this polymer can be molded. The advantages are the absence of unwelded contacts, the absence of mechanical stress during the manufacture of the module and during its subsequent connection, a great simplicity of the process since the soldering between the connector 11 and the conductor wire 16 can be carried out during the module sealing operation. In addition, module protection diodes can be transferred outside the module (on the conductive wire 16), which allows easy maintenance.

The connectors 11 are preferably made of a material chosen from the group comprising copper, stainless steel, titanium and iron-nickel alloys, in particular an iron-nickel alloy comprising 48% nickel (FeNi-48). Preferably, the material of the connectors 11 is a metal or an alloy whose coefficient of thermal expansion is close to that of the substrates, such as FeNi-48. The connectors can also be tinned, gold-plated or nickel-plated.

The connector 11 shown in FIG. 3 ends with a female part 17 of a flat connector arranged between the glass substrates 3 and 4 outside the sealed volume. An external connector is connected to the connector 11 by a pin constituting the male part 18 of the flat connector and ending in a female part 19 integrated in an orifice of the block 15. The sealing gasket 12 is disposed at a certain distance from the end of the module, corresponding to the length of the male part 18 of the flat connector projecting from the block 15. The female part 19 is intended to be connected to an additional male connector. inserted into the hole in block 15. As before, the connector 11 can be formed by a strip with a thickness between 50 and δΟΟμιτι, typically 300gm, and with a width between 1 and 100mm, typically 4mm. The blade ends, at one end, with the female part 17. The block of insulating material 15 is preferably made of polymer material or of resin. A block of insulating material 15 can group together several connectors 11, the female part 19 serving to connect the connectors 11 corresponding to an external male connector inserted into a common orifice of the block 15.

In an alternative embodiment (not shown), the sealing gasket 12 is arranged at the end of the module and the female parts 17 of the connectors 11 are arranged at the end of the glass substrates 3 and 4 outside the sealed volume. The female parts 17 and the male parts 18 can then have larger dimensions.

In another particular embodiment, shown in Figures 4 and 5, at least one connector 11, substantially L-shaped, penetrates, forming a right angle 20, into the block of insulating material 15. Ends 11 'of the connectors 11 are arranged on the wall of a cylindrical opening 21 of the terminal 13. This cylindrical opening constitutes, with the ends 11 ', a female part intended to cooperate with an external connector introduced into the opening. The block of insulating material 15 is preferably made of glass and sealed to the substrate 3 and 4. The terminal 13 can be produced by high temperature molding of a vitreous compound around the ends of the connectors 11. The outer connector 13 is formed. then placed at the periphery of the substrates 3 and 4 during the module assembly operation and welded to the substrates 3 and 4 by means of a sealing glass, for example identical to the material constituting the sealing joint 12.

A particular variant embodiment of terminal 13 of FIGS. 4 and 5 is shown in FIGS. 6 and 7. The block of insulating material 15 of terminal 13 comprises two glass substrates 22 and 23 enclosing several connectors 11, separated by strips 24. glass, the assembly being linked by a sealing glass 25. The glass slides typically have a thickness of between 0.1mm and 0.5mm.

In FIG. 8, the connector 11 ends at its outer end, with a flexible part 26, making a spring, integrated in the block of insulating material 15 and coming into contact with a contact zone 27, arranged at the periphery of a orifice of the block 15 and intended to be connected to an external male connector introduced into the orifice. The flexible part 26 and the connector 11 can be gilded. The block of insulating material 15 can be made of polymer material or resin and glued against the glass substrates 3 and 4. Several springs 26 can be connected to a common terminal 13 comprising a single orifice.

The means for connecting the photovoltaic module with the exterior described above are suitable for modules supplying a current between 1 A to 10 A and a voltage between 1 V to 60 V.

The invention is not limited to the particular embodiments shown.

In particular, the connectors 11 can be connected to the connecting conductors 5 of any type of photovoltaic module. The connecting conductors 5 can, in particular, be arranged either on either side of a cell or on the same side of the cell, more particularly on the rear face of the cell in the case where the positive and negative poles of a cell are brought back to the rear face thereof.