FR2964264A1 - PHOTOVOLTAIC INSTALLATION AND METHOD FOR DELIVERING ELECTRIC POWER EQUAL TO A PREDETERMINED VALUE. - Google Patents

Abstract

The invention relates to a photovoltaic installation comprising: - photovoltaic panels (2) configured to output a current and / or a DC voltage when subjected to incident solar radiation, and - a general generator (4), or an individual generator for each photovoltaic panel (2), having an internal resistance and delivering a current and / or an alternating electric voltage from the current and / or the DC voltage delivered by the photovoltaic panels (2), characterized in it further comprises, for the general generator (4), or for each individual generator (: - a means (6) for measuring the electric power delivered by the general generator (4), or the individual generator, and - a means setting (7) to adjust the impedance of the internal resistance of the general generator (4), or the individual generator, so that the power electrical supply delivered by said generator or said individual generator is equal to a predetermined value.

Description

PHOTOVOLTAIC INSTALLATION AND METHOD FOR DELIVERING ELECTRICAL POWER EQUAL TO A PREDETERMINED VALUE. Description Technical Field of the Invention The invention relates to a photovoltaic installation and a method for delivering an electric power equal to a predetermined value.

The invention relates to the technical field of facilities for the production of electricity and more particularly to photovoltaic installations intended to equip houses or industrial buildings.

20 State of the art. Photovoltaic installations (100) are known, as shown schematically in FIG. 1, allowing the production of electrical energy. These photovoltaic installations (100) generally comprise: photovoltaic panels (101) configured to deliver a current and / or a DC voltage when exposed to incident solar radiation, and a means (102) for supplying a current and / or an alternating electric voltage from the current and / or the DC voltage delivered by the photovoltaic panels. This means is connected to an electrical network of 10 - 2

distribution (103) so as to allow the resale of the current and / or the voltage produced to a third party company operating the distribution power grid.

These photovoltaic installations (100) are generally dimensioned so as to deliver an electric power equal to the maximum permissible legal power. For example, in France, for an individual, the maximum permissible legal power for a photovoltaic installation is 3 kilowatts peak (kWp).

However, the efficiency of a photovoltaic installation (100) fluctuates over time, various parameters being able to induce temporarily or irremediably losses of power resulting in the fall of the efficiency of said installation. In particular, it is possible to distinguish: the losses generated by the shadow formed on the photovoltaic panels (101) by an environment of the type of trees, mountains, walls, buildings, or the like, said shadow reducing the absorption surface of said photovoltaic panels, - losses caused by dust or dirt deposited on the surface of the photovoltaic panels (101) reducing the absorption of the latter; these losses can cause a decrease of 3% to 6% in the efficiency of the photovoltaic installation (100), - the angular or spectral losses, the photovoltaic panels (101) being spectrally and angularly selective, the variation of the solar spectrum and the tilting solar radiation during a day affects the current and / or voltage generated by said photovoltaic panels; these losses increase with the amount of dust and dirt deposited on the surface of said photovoltaic panels, - the losses by raising the temperature of the photovoltaic panels (101), the yield of said photovoltaic panels being able to fall by 0.4% per degree higher than their temperature Rated operating (in general 2964264 -3

25 ° C); the temperature of said photovoltaic panels depending on both the incident irradiation, the ambient temperature and the wind speed. In practice, the losses by temperature rise can reduce the efficiency of the photovoltaic system (100) from 5% to 14%. 5 - losses due to the aging of photovoltaic panels (102), their peak power decreasing over time by about 1% per year, 10% after 10 years and 20% after 20 years.

Therefore, the photovoltaic installation (100) initially dimensioned 10 to deliver an electric power equal to the maximum permissible legal power, will deliver from the first years of use significantly less power.

In view of this state of affairs, the main purpose of the invention is to provide a photovoltaic installation configured to deliver, in a constant manner over time, an electric power equal to the maximum permissible legal power.

The invention also aims to provide a photovoltaic installation of simple design, easy to use and inexpensive.

Disclosure of the invention. The solution proposed by the invention is a photovoltaic installation comprising: photovoltaic panels configured to deliver a current and / or a DC voltage when exposed to incident solar radiation, and a general generator, or an individual generator for each photovoltaic panel, having an internal resistance and delivering a current and / or 2964264

an alternating electric voltage from the current and / or the DC voltage delivered by the photovoltaic panels. This photovoltaic installation is remarkable in that it also comprises, for the general generator, or for each individual generator: a means for measuring the electric power delivered by the general generator, or the individual generator, and a means of setting to adjust the impedance of the internal resistance of the general generator, or the individual generator, so that the electrical power delivered by said general generator, or said individual generator, is equal to a predetermined value.

Thus, the photovoltaic system is capable of varying the impedance of the internal resistance of the general generator or of each individual generator as a function of the greater or lesser drops in the efficiency of the photovoltaic panels, so that the electric power delivered by the photovoltaic system is maintained equal to the maximum permissible legal power.

According to an advantageous characteristic of the invention making it possible to accurately, simply and quickly determine the electric power delivered by the general generator, or by each of said individual generators, the means for measuring the electric power is in the form of a wattmeter connected to said general generator, or said individual generator.

According to another advantageous characteristic of the invention enabling the photovoltaic installation to be reactive and self-managing, the internal resistance of the general generator or of each individual generator is in the form of one or more potentiometers. arranged on an electrical circuit, the or said potentiometers being each equipped with a movable cursor 30 between a position for which the impedance of said potentiometer is minimal and a position for which the impedance of said potentiometer is maximum. 2964264 -5

adjustment means is, for each potentiometer, in the form of a drive means configured to move the cursor of said potentiometer, said one or more drive means being controlled by a control unit. Indeed, the use of potentiometers, whose cursor is moved by a drive means controlled by a control unit, allows the photovoltaic system to modify quickly and automatically, in real time, the impedance of the potentiometers of the in order to regulate the electric power delivered by the photovoltaic installation.

According to yet another advantageous characteristic of the invention enabling the operation of each photovoltaic panel to be made autonomous, the photovoltaic installation comprises a control unit by means of adjustment dedicated to the displacement of the drive means of said adjustment means, said units commands being configured to communicate with each other, so as to move in a determined manner the cursor of each of said potentiometers.

According to yet another advantageous characteristic of the invention enabling the photovoltaic installation to be reactive and self-managing, the internal resistance of the general generator, or of each individual generator, is in the form of several resistors arranged on an electrical circuit, the adjustment means being in the form of switches arranged on said electrical circuit and configured to short circuit or not each of said resistors. In fact, the use of switches controlled by a control unit enables the photovoltaic installation to modify rapidly and automatically, in real time, the impedance of the internal resistance of the general generator, or of each individual generator so regulating the electrical power delivered by the photovoltaic installation.

According to yet another advantageous characteristic of the invention enabling the operation of each panel to be made autonomous.

photovoltaic, the installation comprises a control unit by means of adjustment dedicated to the control of the switches of said adjustment means, said control units being configured to interact with each other, so as to control the short circuit of a predetermined number of resistances. According to yet another advantageous feature of the invention making it possible to establish a map of the photovoltaic installation, the photovoltaic panels each include a control unit equipped with a radio wave dialogue means, each control unit being configured. to determine its position relative to said other control units as a function of the intensity of the radio signal received by each of said other control units.

According to yet another advantageous characteristic of the invention making it possible to sell to a third party the electricity delivered by the general generator, or the individual generators, the photovoltaic installation comprises means for connecting said general generator, or said individual generators, to an electrical distribution network.

Another aspect of the invention relates to a method for delivering, by means of photovoltaic panels, an electrical power, said photovoltaic panels delivering at the output a current and / or a continuous electrical voltage when they are subjected to an incident solar radiation, a general generator, or an individual generator for each photovoltaic panel, having an internal resistance and delivering a current and / or an alternating electric voltage from the current and / or the DC voltage delivered by said photovoltaic panels, wherein, for the general generator, or for each individual generator: - the electrical power delivered by the general generator, or the individual generator, is measured;

the impedance of the internal resistance of the general generator (4) or of the individual generator (4 ') is regulated so that the electric power delivered by the said general generator, or the said individual generator (4'), is equal to a predetermined value. Description of the figures. Other advantages and features of the invention will appear better on reading the description of a preferred embodiment which will follow, with reference to the appended drawings, carried out as indicative and non-limiting examples and in which: FIG. 1 schematically represents a photovoltaic installation of the prior art; FIG. 2 schematically represents a first exemplary embodiment of the photovoltaic system forming the subject of the invention; FIG. 3 schematically represents a second exemplary embodiment of FIG. The photovoltaic system object of the invention - Figure 4 schematically shows a first embodiment of a photovoltaic panel assembly and individual generator of the photovoltaic system object of the invention, - Figure 5 schematically shows a second example. of realization of a photovoltaic panel assembly and individual generator of the photovoltaic stallation object of the invention. 25

Embodiments of the invention

With reference to FIGS. 2 and 3, the photovoltaic system (1) which is the subject of the invention comprises photovoltaic panels (2) configured to deliver a current and / or a DC voltage when they are produced.

are subject to incident solar radiation. The photovoltaic panels (2) are in the form of a plate of metal, plastic, or the like, on which are arranged side by side several photovoltaic cells (3). The photovoltaic panels (2) can be square, rectangular, hexagonal, circular, etc. Their surface can vary from 50 cm2 to several m2. An anti-reflective layer may be applied to the surface of the photovoltaic panels (2) so as to ensure good absorption of solar radiation. The photovoltaic panels (2) are intended to be installed, in series or in parallel, on supports fixed to the ground, on roofs, on walls, etc.

The photovoltaic cells (3) generally consist of semiconductors based on silicon (Si), cadmium sulphide (CdS), cadmium telluride (CdTe), etc. They are generally in the form of thin sheets, round or square, whose dimensions (side, diameter) vary from millimeters to several centimeters. These sheets are sandwiched between two metal contacts, for a thickness ranging from several microns to a few millimeters. Photovoltaic cells (3) can also be multi-junctions, that is to say be composed of different layers that convert different parts of the solar radiation spectrum and thus obtain better yields. The photovoltaic cells (3) can also combine layers of semiconducting polymers with silicon nanowires in the form of a 3 mm thick mat improving the absorption of incident solar radiation.

The photovoltaic cells (3) are connected together, in series or in parallel via an electrical circuit. As diagrammatically shown in FIGS. 4 and 5, by-pass diodes (14) can protect the photovoltaic cells (3) from overheating, individually or in groups. Indeed, when a photovoltaic cell (3) is partially or entirely in the shade, it delivers a quantity of current and / or voltage lower than that 2964264 -9

delivered by the other photovoltaic cells (3) without shadow. This difference in the amount of current and / or voltage induces overheating of the photovoltaic cell (3) in the shade, which can lead to its destruction. When the bypass diode (14) detects that a photovoltaic cell (3) is in the shade, said bypass diode disconnects from the electrical circuit said photovoltaic cell or the group of cells to which said photovoltaic cell is connected. In practice, a photovoltaic panel (2) comprises one to three bypass diodes (14), depending on its number of cells, but may include more.

Under the effect of incident solar radiation, the photovoltaic cells (3) and thus the photovoltaic panels (2) deliver electrical energy in the form of a current and / or a DC voltage. Thus, with reference to FIG. 2, and in such a way that this current and / or this electric voltage can be used for the supply of electrical appliances, such as household electrical appliances, computer equipment, or the like, the photovoltaic installation (1 ) also comprises a general generator (4) delivering a current and / or an alternating electric voltage from the current and / or the DC voltage delivered by the photovoltaic cells (3). As an alternative to the general generator, and as shown diagrammatically in FIG. 3, the photovoltaic installation (1) can comprise for each photovoltaic panel (2) an individual generator (4 ') delivering a current and / or an alternating electrical voltage to from the current and / or the DC voltage delivered by the photovoltaic cells (3). The general generator (4), or each of the individual generators (4 '), is in the form of a voltage or current inverter. It generally comprises a box of parallelepipedal, cylindrical or other shape, incorporating an electronic circuit having a bridge architecture and consisting of electronic switches such as insulated gate bipolar transistors (IGBTs), power transistors, thyristors, or others, as well as any other electronic components suitable for those skilled in the art. The general generator (4), or the individual generators (4 '), have an internal resistance formed by one or more components.

resistors (10 '), potentiometer (10), rheostat, thermistor, varistor, etc. The general generator (4), or the individual generators (4 '), can be equipped with an automatic means of decoupling the network. The latter is equipped with a mechanical or electronic switch enabling the general generator (4), or each of the individual generators (4 '), to disconnect instantaneously from the electrical network to which it is connected when a voltage drop occurs. A voltage drop may for example be due to a malfunction of the general generator (4), or the individual generator (4 '), photovoltaic cells (3), or any other means of the photovoltaic system (1). The general generator (4), or the individual generators (4 '), can also be equipped with a means of protection against current delivery and / or continuous electrical voltage so as to avoid deterioration of the downstream connected electrical devices. said general generator, or said individual generators. The general generator (4), or the individual generators (4 '), are advantageously connected to an electrical distribution network (5) so as to allow the resale of the current and / or the voltage produced to a third party operator said distribution power grid.

In order to measure the instantaneous electrical power producible by the photovoltaic installation (1), the latter also comprises, for the general generator (4), or for each individual generator (4 '), a means (6) for measuring the electric power delivered by said general generator, or said individual generator. In practice, for the general generator (4), or for each individual generator (4 '), this means (6) for measuring the electrical power is in the form of a power meter connected to said general generator, or to said individual generator . The wattmeter (s) are in the form of housings incorporating an electronic circuit provided with: an intensity sensor (ammeter) configured to measure the intensity delivered by the general generator (4), or the individual generator (4) to which he is connected, 2964264 -11-

a voltage sensor (voltmeter) configured to measure the voltage at the terminals of the general generator (4), or of the individual generator (4 ') to which it is connected, - a multiplier configured to calculate the value of the power 5 instantaneous electric delivered by the general generator (4), or the individual generator (4 ') to which it is connected by multiplying the value of the voltage measured by the value of the measured intensity, - and any other suitable electronic component to the skilled person.

Once the electric power delivered by the general generator (4) or the individual generators (4 ') is measured, the photovoltaic system (1) can adjust its output via a setting means (7) to adjust the impedance the internal resistance of said general generator, or said individual generators (4 '), so that the electric power supplied by said general generator, or said individual generator, is equal to a predetermined value. In practice, when the impedance of the internal resistance varies, the current and / or the alternating electric voltage delivered by the general generator (4), or the individual generators (4 '), varies, and it is thus possible to obtain an electric power equal to a determined value. For a general generator (4), this predetermined value is generally equal to the maximum permissible legal power, for example 3 kWp for a photovoltaic installation (1), in France, for an individual. For an individual generator (4 '), the predetermined value is generally equal to the permissible maximum permissible power divided by the number of individual generators (4') included in the photovoltaic system (1), for example 3 / n kWp for a photovoltaic installation (1) comprising "n" individual generators (4 '), in France, in an individual.

Thus, to deliver, by means of the photovoltaic panels (2), an electric power equal to the predetermined value, for the general generator (4), or for each individual generator (4 '): 2964264 -12-

the electrical power delivered by the general generator, or the individual generator, is measured; the impedance of the internal resistance of the general generator (4) or of the individual generator (4 ') is regulated so that the power the electric generator 5 delivered by said general generator, or said individual generator, is equal to a predetermined value.

According to a first exemplary embodiment shown in FIG. 4, the internal resistance of the general generator (4), or of each individual generator (4 '), is in the form of one or more potentiometers (10) arranged on a electrical circuit. The one or more potentiometers (10) are each equipped with a slider (11) movable between a minimum position for which the impedance of said potentiometer is minimal and a maximum position for which the impedance of said potentiometer is maximum. Each potentiometer 15 (10) may be rectilinear or rotatable, and its impedance may vary linearly, logarithmically or anti-logarithmically as the cursor (11) moves between the minimum and maximum positions. In practice, when the general generator (4), or the individual generators (4 '), comprise several potentiometers (10), the latter are arranged in series on the electrical circuit 20 so as to sum the ranges of impedance variation of said potentiometers.

The adjusting means (7) is then, for each potentiometer (10), in the form of a drive means (8) configured to move the slider (11) of said potentiometer. This drive means (8) may be in the form of a stepping motor, a linear motor or in any other form suitable to those skilled in the art. The driving means may be controlled by a control unit (9). The latter is generally in the form of an electronic box 30 incorporating a processor. The control unit (9) is connected via wire means (electrical cable, Ethernet, or other) or wireless means 2964264 -13-

(wifi, wimax, infrared, or other) by means (6) for measuring the electric power delivered by the general generator (4), or the individual generators (4 ') so as to recover the values of measured electrical powers. The control unit (9) is also connected to the drive means (8) by similar means so as to act on said drive means. The processor integrated in the box of the control unit (9) is configured to execute one or more computer programs. The computer program (s) are stored in a memory also integrated in the box and of the memory type register, mass memory, ROM, etc. The computer program is in the form of short sequences of instructions which, when executed in a precise order by the processor, allow: to determine, from the electrical power values measured for the general generator (4 ), or the individual generators (4 '), the value of the impedance of the internal resistance of said general generator, or said individual generators, so that the electric power delivered by said general generator, or said individual generator, equal to the predetermined value, - acting on the drive means (8) so as to adjust the value of the impedance of the internal resistance of the general generator (4), or of the individual generators (4 ') .

For example, if a photovoltaic installation (1) comprising twenty photovoltaic panels (2) each delivering a maximum electrical power equal to 200 Wc, the photovoltaic installation can then deliver a maximum electrical power equal to 4 kWp. However, the maximum permissible legal power for a photovoltaic installation (1), in France, for an individual is equal to 3 kWp.

For a photovoltaic system (1) comprising a general generator (4), the impedance of the internal resistance of said general generator is 2964264 - 14 -

regulated so as to reduce the electrical power delivered by the photovoltaic panels (2) and to obtain an electric power delivered by said general generator equal to 3 kWp.

For a photovoltaic installation (1) comprising individual generators (4 '), the impedance of the internal resistance of each of said individual generators is adjusted so as to decrease the electrical power delivered by the photovoltaic panels (2) and to obtain a electrical power delivered by each of said individual generators equal to 150 Wc 10 (3000Wc / 20). However, it can happen that a photovoltaic panel (2) undergoes losses such that the maximum power delivered by said panel is less than the predetermined value. Therefore, for each of the other photovoltaic panels (2), the impedance of the internal resistance of each of the associated individual generators (4 ') is adjusted to compensate for these losses. Using the previous example of a photovoltaic installation (1) comprising twenty photovoltaic panels (2), if one of said photovoltaic panels delivers a power only equal to 55 Wc, then, for each of the other photovoltaic panels (2), the impedance of the internal resistance of each of the individual generators (4 ') associated is set so that said associated individual generators (4') deliver a power equal to 155 Wc.

As shown in FIG. 2, and when the photovoltaic installation (1) comprising individual generators (4 '), said photovoltaic installation can comprise comprises a control unit (9) by control means (7) dedicated to the control driving means (8) of said adjusting means. In this case, the control units being configured to communicate with each other, so as to move in a determined manner the slider (11) of each of the potentiometers 30 (10), in order to obtain an electric power delivered by the general generator ( 4), or the individual generators (4 '), equal to the predetermined value. This 2964264 -15-

dialogue is in the form of an exchange of information between the various control units (9), said information comprising codes or pieces of code and information on the power delivered by the photovoltaic panels (3) of each of the photovoltaic panels (2). The dialogue can be via wired connectors or via a wireless link such as WiFi, Mimo, infrared, etc. Each control unit (9) analyzes the information it receives so as to determine, depending on the power delivered the general generator (4), or the individual generators (4 '), the value of the impedance of the resistance internal of said general generator, or said 10 individual generators, via the drive means (8) of the adjusting means (7) that it controls.

In practice, the control units (9) are electrically powered by an auxiliary power supply circuit, but they can also be integrated with the photovoltaic panels (2) and be directly electrically powered by said photovoltaic panels. In the latter case, when the photovoltaic panels (2) suffer losses, said photovoltaic panels can deliver a current and / or a voltage zero or insufficient to supply electricity to the control unit (9) integrated. These losses can for example be due to a malfunction of the photovoltaic cells (3), the fact that said photovoltaic cells are in the shade, the fact that the photovoltaic panel (2) is disconnected or removed from the installation, etc. The other control units (9) of the photovoltaic installation (1) then detect the absence of dialogue with this control unit (9), and adapt their dialogue so as to determine, according to the power delivered by the photovoltaic panels (2) operating, the value of the impedance of the internal resistance of each of the individual generators (4 ') associated with said photovoltaic panels operating. 2964264 -16-

Furthermore, when the photovoltaic panels (2) each include a control unit (9), and said control units are equipped with radio wave dialogue means, each control unit can be configured to determine its position by relative to said other control units as a function of the intensity of the radio signal received by each of said other control units. It is thus possible for the control units to establish a mapping of the photovoltaic installation (1) as a function of the intensity of the radio signal emitted by each control unit. Mapping of the photovoltaic system (1) means that it is possible to determine the position of the control units (9) relative to each other, and therefore to determine the position of the photovoltaic panels ( 2) relative to each other. Therefore, the control units can detect whether one of the photovoltaic panels (2) is moved or removed. This detection can in particular be useful to prevent theft. The control units (9) can then be connected to an audible, visual, or other alarm that said control units trigger when they detect the displacement or removal of one of the photovoltaic panels (2).

In an embodiment variant not shown, the photovoltaic installation (1) may, however, comprise a global control unit (9) configured to control the drive means (8) of all the adjustment means (7). In this case the control unit (9) is connected to all the means (6) for measuring the electrical power delivered by the individual generators (4 '). From the electrical power values measured by the means (6), the control unit (9) is able to determine for each photovoltaic panel (2) the value of the impedance of the internal resistance of each of the generators. individual (4 ') associated with said photovoltaic panels via the drive means (8) of the adjustment means (7) that it controls. 2964264 -17-

According to a second exemplary embodiment shown in FIG. 5, the internal resistance of the general generator (4) or of each individual generator (4 ') is in the form of several resistors (10') arranged on an electric circuit. The adjusting means (7) is in the form of switches (8 ') arranged on said electric circuit. The switches (8 ') configured to short-circuit each of said resistors (10') or not so as to obtain a desired impedance value. The switches (8 ') may be in the form of mechanical switches as shown diagrammatically in FIG. 5, or in the form of electronic switches such as insulated gate bipolar transistors (IGBTs), power transistors, thyristors, etc.

The switches (8 ') can be controlled by a control unit (9). The latter is generally in the form of an electronic box incorporating a processor. The control unit (9) is connected via wire means (electrical cable, Ethernet, or other) or wireless means (wifi, wimax, infrared, or other) by means (6) for measuring the electrical power delivered by generator (4), or the individual generators (4 ') so as to recover the measured electrical power values. It is also connected to the switches (8 ') by similar means so as to act on said switches. The processor integrated in the box of the control unit (9) is configured to execute one or more computer programs. The computer program (s) are stored in a memory also integrated in the box and the memory type register, mass memory, read-only memory, etc. The computer program is in the form of short sequences of instructions which, when executed in a precise order by the processor, allow: - to determine, from the electrical power values measured for the general generator (4) , or the individual generators (4 '), the value of the impedance of the internal resistance of said general generator, or said individual generators, so that the electric power delivered

by said general generator, or said individual generator, being equal to the predetermined value, - acting on the switches (8 ') so as to adjust the value of the impedance of the internal resistance of the general generator (4), or individual generators (4 ').

The determination and adjustment of the impedance of the internal resistance of the general generator (4), or of the individual generators (4 '), during a lossless or operationless operation, is carried out in a manner similar to that described in FIG. the first embodiment.

As shown in FIG. 2, and when photovoltaic installation (1) comprising individual generators (4 '), said photovoltaic installation can comprise a control unit (9) by setting means (7) dedicated to the control of the switches ( 8 ') of said adjusting means. As in the previous embodiment, the control units (9) can be configured to communicate with each other, so as to control the short circuit of a determined number of resistors (10 '), in order to obtain a electric power delivered by said general generator, or said individual generators, equal to the predetermined value. This dialogue is of the same form as previously mentioned. In practice, each control unit (9) analyzes the information it receives in order to control the short circuit of a given number of resistors (10 '), via the switches (8') of the adjustment means (7). that he commands. The control units (9) can also be electrically powered by an auxiliary power supply circuit, or be integrated with the photovoltaic panels (2) and be directly electrically powered by said photovoltaic panels. As previously 30, the control units (9) of the photovoltaic system (1) can detect the absence of a dialogue with one of the control units (9).

when the photovoltaic panel (2) to which it is integrated malfunctions. Similarly, the control units (9) adapt their dialogue so as to determine, according to the power delivered by the photovoltaic panels (2) operating, the new number of resistors (10 ') to be short-circuited for each individual generator (4 ') associated with functioning photovoltaic panels.

As before when the control units (9) are equipped with radio wave dialogue means, each control unit (9) can be configured to determine its position with respect to said other control units as a function of the control unit. intensity of the radio signal received by each of said other control units. Similarly, the control units (9) can detect whether one of the photovoltaic panels (2) is moved or removed. In an alternative embodiment not shown, however, the installation may comprise a global control unit (9) configured to control the switches (8 ') of all the adjustment means (7). In this case the control unit (9) is connected to all the means (6) 20 for measuring the electrical power delivered by the individual generators (4 '). From the electric power values measured by the means (6), the control unit (9) is able to determine for each photovoltaic panel (2), the number of resistors (10 ') to be short-circuited for each generator individual (4 '), via the switches (8') of the adjusting means (7) 25 that it controls.

As explained above, this regulated electric power and delivered by the general generator (4), or the individual generators (4 '), is generally intended to be sold to a third party operating an electrical distribution network (5). Thus, the photovoltaic installation (1) comprises a means for connecting the general generator (4), or the generators 2964264 - 20 -

individual generators (4 ') to the electrical distribution network (5). This means is generally in the form of an electric meter configured to measure the amount of current and / or voltage delivered to the electrical distribution network (5). The electric meter is generally in the form of a box incorporating electronic or electromechanical components. It may comprise a mechanical or digital display for quantifying the electrical power delivered to the distribution grid (5) by the general generator (4), or the individual generators (4 '). Thus quantified, the electric power can be billed and sold.

Claims (9)

REVENDICATIONS1. Photovoltaic installation comprising: - photovoltaic panels (2) configured to output a current and / or a DC voltage when subjected to incident solar radiation, and - a general generator (4), or an individual generator ( 4 ') for each photovoltaic panel (2), having an internal resistance and delivering a current and / or an alternating electric voltage from the current and / or the DC voltage delivered by the photovoltaic panels (2), characterized in that it further comprises, for the general generator (4), or for each individual generator (4 '): - means (6) for measuring the electric power delivered by the general generator (4), or the individual generator ( 4 '), and - setting means (7) for adjusting the impedance of the internal resistance of the general generator (4), or of the individual generator (4'), so that the electrical power said generator or said individual generator is equal to a predetermined value. Photovoltaic plant according to claim 1, in which, for the general generator (4), or for each individual generator (4 '), the means (6) for measuring the electrical power is in the form of a connected power meter. audit generator, or individual generator. 3. Photovoltaic installation according to one of claims 1 or 2, wherein the internal resistance of the general generator (4) or each individual generator (4 ') is in the form of one or more potentiometers (10). arranged on an electric circuit, the one or more potentiometers being each equipped with a slider (11) movable between a position for which the impedance of said potentiometer is minimal and a position for which the impedance of said potentiometer is maximum, and wherein the adjusting means (7) is, for each potentiometer (10), in the form of a driving means (8) configured to move the slider (11) of said potentiometer, said one or more means of drive being controlled by a control unit (9). 4. Photovoltaic installation according to claim 3, characterized in that it comprises a control unit (9) by adjusting means (7) dedicated to the displacement of the drive means (8) of said adjustment means, said control units (8) commands being configured to communicate with each other, so as to move in a determined manner the cursor (11) of each of the potentiometers (10). 15 5. Photovoltaic installation according to one of claims 1 or 2, wherein the internal resistance of the general generator (4), or each individual generator (4 '), is in the form of several resistors (10') arranged on an electrical circuit, and wherein the adjusting means (7) is in the form of switches (8 ') arranged on said electrical circuit and configured to short circuit or not each of said resistors. 6. Photovoltaic installation according to claim 5, characterized in that it comprises a control unit (9) by adjusting means (7) dedicated to controlling the switches (8 ') of said adjusting means, said control units being configured to communicate with each other, so as to control the short circuit of a determined number of resistors (10 '). 30 2964264 - 23 - Photovoltaic plant according to one of Claims 3 to 6, in which the photovoltaic panels (2) each incorporate a control unit (9) equipped with a radio wave dialogue means, each control unit being configured. to determine its position relative to said other control units as a function of the intensity of the radio signal received by each of said other control units. Photovoltaic plant according to any one of claims 3 to 7, characterized in that it comprises means for connecting the general generator (4), or the individual generators (4 '), to an electrical distribution network ( 5). 9. A method for delivering, by means of photovoltaic panels (2), an electric power, said photovoltaic panels (2) delivering at output a current and / or a continuous electrical voltage when they are subjected to incident solar radiation, a general generator (4), or an individual generator for each photovoltaic panel (2), comprising an internal resistor and delivering a current 20 and / or an alternating electric voltage from the current and / or the DC voltage delivered by said panels photovoltaic cells, in which, for the general generator, or for each individual generator: - the electrical power delivered by the general generator, or the individual generator, is measured; - the impedance of the internal resistance of the general generator (4) is regulated , or of the individual generator (4 '), so that the electric power delivered by said general generator, or led it individual generator (4 '), equal to a predetermined value. 30