A computer-implemented process to optimize the electricity production of a photovoltaic device and the resulting optimized photovoltaic power plant.

Abstract

The present invention relates to a computer-implemented method for optimizing the electricity production of a photovoltaic power plant comprising a plurality of electricity-producing units, the method comprising the following steps: - Obtaining a mathematical model of the photovoltaic power plant, - Calculating, for a given time, using the mathematical model and the position of the sun at that given time, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity-producing units, - Selecting, from this plurality of orientations, a specific orientation for each of the electricity-producing units that corresponds to a set of optimal positions for producing electricity by means of the photovoltaic power plant.and - Generate instructions so that the control systems direct each of the electricity production units towards their respective predetermined orientation. Figure from the summary: 6,

Description

Title of the invention: Computer-implemented method for optimizing the electricity production of a photovoltaic device and the photovoltaic power plant thus optimized. Scope of the invention

[0001] The invention relates to a computer-implemented method for optimizing the electricity production of a photovoltaic power plant, the photovoltaic power plant comprising a plurality of electricity production units, the electricity production units each being designed to change their orientation with respect to the sun, the electricity production units being connected to control means to control said orientation.

[0002] More specifically, the invention relates to a method for managing a photovoltaic power plant, such as an agrivoltaic power plant, in which the positioning of the photovoltaic panels can be controlled so as to optimize the overall electricity production of the plant during the day and throughout the year. According to one embodiment of the invention, the presence of shading on at least some of the photovoltaic panels can be taken into account to optimize said overall electricity production of the power plant. State of the art

[0003] In the prior art, it is known to use a backtracking system to optimize electricity production using photovoltaic panels. This backtracking system is designed for photovoltaic panels installed on regularly sloping terrain. This tracking system is not suitable for photovoltaic panels installed in a wave-like structure such as a canopy. According to the prior art, photovoltaic panels are, for example, fixed together on structures called "tables," a set of tables forming a photovoltaic power plant.

[0004] To optimize electricity production using photovoltaic panels, the panels are orientable to be positioned towards the sun. Typically, the panels are orientable using a tracking system to follow the sun's movement during the day and to adapt the orientation of the panels throughout the year.

[0005] Typically, the tables on which the photovoltaic panels are mounted are positioned in a first position, such as an essentially horizontal position. From said first position, the tables are oriented, using motors in the direction of the sun to maximize their electricity production.

[0006] To optimize electricity production from the tables placed closest to the sun, the tables must be rotated at an angle equal to the projected elevation of the sun. However, with such an orientation, it is possible that the tables closest to the sun may cast shadows on the photovoltaic panels of adjacent tables, resulting in a drop in electricity production.

[0007] To avoid such a drop in electricity production, according to the prior art, the tables preferably follow the movement imposed by backtracking, which consists of orienting the tables as much as possible towards the sun without casting shadows on each other.

[0008] A first drawback of known prior art solutions lies in the fact that the backtracking system as an input parameter only takes into account the avoidance of shadows on the solar panels. However, avoiding shadows does not necessarily maximize electricity production with the entire installation.

[0009] Furthermore, the backtracking system does not take into account either the specific connection of the cells that together form a photovoltaic panel or the effect of shading on some of these cells on the panel's electricity production. This means that the backtracking also does not take into account partial shading on some of the photovoltaic panels of a power plant and the effect of this shading on the overall electricity production of said power plant.

[0010] Another drawback, according to the prior art, is that point shadows, which can be created during the day, are also not taken into account during backtracking. These point shadows result, for example, from the presence of an object near the power plant, such as a pole or a tree. Point shadows can also be formed by structural elements of the power plant itself, such as cables or poles that are part of the plant's supporting structure, or other elements that are part of the plant's supporting structure or the immediate environment of the power plant. Preferably, the effect of such point shadows on the overall electricity production of a photovoltaic power plant should be controlled.

[0011] Therefore, in view of the above, it appears necessary to propose a solution allowing the optimized management of a photovoltaic power plant, such as an agrivoltaic power plant, in which the positioning of the tables can be controlled so as to optimize the overall electricity production of such a power plant during the day and the year. Object of the invention

[0012] The object of the present invention relates to a computer-implemented method for optimizing electricity production by means of a photovoltaic power plant, the photovoltaic power plant comprising a plurality of electricity production units, each of the electricity production units being adapted to modify its orientation relative to the sun in order to optimize its electricity production at all times, the electricity production units being connected to control means to control said orientation, the method comprising the following steps:

[0013] - Obtain a mathematical model of the photovoltaic power plant including the positions of the different electricity production units, the mutual distances between these units, the irradiance and the position of the sun relative to the photovoltaic power plant,

[0014] - Calculate, for a given moment, using the mathematical model and the position of the sun at that specific moment, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units, taking into account for each of the electricity production units their instantaneous orientation and their corresponding instantaneous electricity production,

[0015] - Select, from among this plurality of orientations, a specific orientation for each of the electricity production units that corresponds to a set of optimal positions, and

[0016] - Generate instructions so that the control means direct each of the electricity production units towards their respective determined orientation.

[0017] According to one embodiment of the invention, the mathematical model includes parameters defining the area of ​​the photovoltaic power plant installation, such as latitude, longitude, altitude, orientation, and soil albedo.

[0018] According to one embodiment of the invention, the calculation step for the determined moment, using the mathematical model and the position of the sun at that determined moment, of the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units comprises:

[0019] a) Calculate, for a first orientation of the plurality of electricity production units, a first instantaneous electricity production of the photovoltaic power plant,

[0020] b) Modify the orientation of at least one first electricity generating unit of said plurality of electricity generating units to obtain a modified orientation of the plurality of electricity generating units,

[0021] c) Calculate, for the modified orientation of the plurality of electricity production units, a modified instantaneous electricity production of the photovoltaic power plant, and

[0022] d) Repeat steps b) and c) to obtain the instantaneous production of electricity from the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units.

[0023] According to one embodiment of the invention, the method further comprises:

[0024] - Quantify, using the mathematical model, the presence of at least one shadow created by at least one electricity generating unit on another electricity generating unit at the specified time, to identify a shaded electricity generating unit,

[0025] - Reduce, using the mathematical model, the estimated electricity production of said shaded electricity production unit, and

[0026] - Calculate, for this determined moment, using the mathematical model and the estimated reduced electricity production for the shaded electricity production unit, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units and

[0027] - Select, from this plurality of orientations, a specific orientation for each of the electricity production units which corresponds to an optimal position to produce electricity by means of the photovoltaic power plant at the determined time taking into account the estimated reduced electricity production for said shaded electricity production unit.

[0028] According to one embodiment of the invention, the mathematical model comprises parameters defining structural elements of the photovoltaic power plant and / or parameters defining objects in the vicinity of the photovoltaic power plant, the method further comprising:

[0029] - Quantify, using the mathematical model, the presence of at least one shadow created by a structural element of the photovoltaic power plant and / or an object near the photovoltaic power plant on an electricity production unit at a given time, to identify a shaded electricity production unit,

[0030] - Reduce, using the mathematical model, the estimated electricity production of said shaded electricity production module, and

[0031] - Calculate, for this determined moment, using the mathematical model and the estimated reduced electricity production for the shaded electricity production unit, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units, and

[0032] - Select, from among this plurality of orientations, a specific orientation for each of the electricity production units that corresponds to a set of optimal positions to produce electricity using the photovoltaic power plant at the determined time taking into account the estimated reduced electricity production for said shaded electricity production unit.

[0033] According to one embodiment of the invention, the estimated electricity production for the shaded electricity production unit is reduced in accordance with a mathematical function previously established using the electrical characteristics of said shaded module and its electrical connection.

[0034] According to a second aspect, the invention relates to a photovoltaic power plant for the production of electricity comprising:

[0035] - A plurality of electricity production units, the production units electricity generating units are each designed to change their orientation relative to the sun in order to optimize their electricity production at any given time, with the electricity generating units being connected to control systems to control said orientation.

[0036] - suitable computing means for hosting a mathematical model for the photovoltaic power plant including the positions of the different electricity production units, the mutual distances between these units, the irradiance and the position of the sun relative to the photovoltaic power plant, and adapted to calculate for a given moment, by means of the mathematical model and the actual position of the sun, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units, taking into account, for each of the electricity production units, their instantaneous orientation and their corresponding instantaneous electricity production, the calculation means being further adapted to the selection, among said plurality of orientations, of a given orientation for each of the electricity production units which corresponds to an optimal position for producing electricity by means of the photovoltaic power plant at the given moment,and to the generation of instructions for the control means, and,

[0037] - control means connected to the computing means and adapted to receive instructions for said computing means and to direct each of the electricity production units towards their respective determined orientation.

[0038] According to one embodiment of the invention, the photovoltaic power plant comprises at least one electricity production unit with a first module connected in parallel with at least one second adjacent module, the first and second modules comprising electricity-producing cells, the electricity production unit being provided with shunt diodes enabling the creation of a path for the electric current between an input and an output of the electricity production unit.

[0039] According to a third aspect, the invention relates to a computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement the process mentioned above.

[0040] According to a fourth aspect, the invention relates to a computer-readable recording medium comprising instructions which, when executed by a computer, cause the computer to implement the method mentioned above. Brief description of the drawings

[0041] The purpose, object and features of the invention will become clearer upon reading the following description made with reference to the figures in which:

[0042] [Fig-1] shows an example of part of a photovoltaic power plant positioned above an agricultural plot, according to an embodiment of the invention;

[0043] [Fig.2] schematically shows tables of a photovoltaic power plant in a first position, essentially horizontal, according to the prior art;

[0044] [Fig.3] schematically shows the tables according to [Fig.2] in a second position, oriented towards the sun, according to the previous art;

[0045] [Fig.4] shows a two-dimensional geometric model of the shading of a table on an adjacent table, according to one embodiment of the invention;

[0046] [Fig.5] shows in graphic form an experimental validation of the irradiation model effective overall, according to an embodiment of the invention;

[0047] [Fig.6] shows the example of nine photovoltaic panels connected in series on a table, according to one embodiment of the invention;

[0048] [Fig.7] shows the wiring of the cells of the half-modules of a panel photovoltaic, according to an embodiment of the invention;

[0049] [Fig.8] shows the effective fraction for producing electricity from the radiation solar incident on a table as a function of the shaded linear fraction thereof, according to an embodiment of the invention. Detailed description of the invention

[0050] The detailed description below is intended to set out the invention in a sufficiently clear and complete manner, in particular by means of examples, but shall in no case be regarded as limiting the scope of protection to the particular embodiments and examples presented below.

[0051] In the following description, the term "set of optimal positions" is used. The term "set of optimal positions" refers to the set of orientations of the electricity generating units for which the calculated electricity production is the highest among all the tested sets of orientations. The "tested" orientations are the set of orientations identified and for which a performance calculation has been performed.

[0052] Figure 1 shows an example of part of a photovoltaic power plant 100 positioned above an agricultural plot. The photovoltaic power plant 100 comprises tables 10 on which photovoltaic panels 30 are fixed. The tables 10 are suspended from a set of cables stretched above the agricultural plot 20. The cable set comprises upper cables 51 and lower cables 52, mutually connected by means of turnbuckles 53. The upper cables 51 and the lower cables 52 are, at their respective ends, fixed to the upper ends of the poles 40. The poles 40 supporting these cables 51 and 52 are, for example, about 8 m high and are spaced, for example, about 27 m apart, allowing the passage of most agricultural machinery. At their upper ends, the 40 posts are connected using the 4L crossbeams

[0053] The photovoltaic power plant 100 according to [Fig. 1] is an example of an "agrivoltaic" power plant. Such a photovoltaic power plant is defined as an electricity production installation using the sun's radiant energy, whose photovoltaic panels are located on an agricultural plot where they allow for the maintenance or sustainable development of agricultural production.

[0054] In the example of [Fig.1], the photovoltaic panels 30 are fixed on the tables 10 in series of nine panels 30 per table 10.

[0055] One of the key factors for the efficiency of a photovoltaic power plant 100 according to [Fig. 1] is the optimization of light sharing, which is necessary both for the growth of the plants on the agricultural plot 20 and for electricity production using the photovoltaic panels 30. To ensure this sharing while maximizing energy production, the photovoltaic panels 30 are typically oriented and mounted on motors that allow them to rotate from East to West around a North-South axis. Thanks to this orientation and mounting, the photovoltaic panels 30 can optimally track the sun's movement throughout the day and throughout the year. The tables 10 are fixed to the upper cables 51 by means of fasteners that allow the tables 10 to rotate relative to the cables 51. These fasteners include motors adapted to receive instructions regarding the best orientation of the tables.The opposing fixings of each table 10 form an axis of rotation for the table 10 in question.

[0056] The fixings of the tables 10 to the cables 51 include, for example, cradles (not shown in [Fig. 1]). Said cradles are adapted to be fixed on one side to the cables 51 and, on the other side, to provide seats for receiving the opposite ends of the tables 10.

[0057] In the photovoltaic industry and in the context of this description, the use of actuators to correctly position the panels 30 relative to the position of the sun is called solar tracking.

[0058] To enable assembly, as described above, the posts 40 are typically positioned in an East-West direction so as to allow the cables 51, 52 to extend in an essentially East-West direction and to orient the tables 10 with their respective axes of rotation in the North-South direction.

[0059] Figures 2 and 3 schematically illustrate the concept of backtracking according to the prior art. In this example, the sun is positioned to the left of the images and has a projected elevation of 20° in the image plane.

[0060] According to [Fig. 2], the tables 10 are positioned essentially horizontally in a first position. From the first position as shown in [Fig. 2], the tables 10 are oriented, using the motors (not shown in Figures 2 and 3), towards the sun to maximize their electricity production.

[0061] To optimize the electricity production of the table shown on the left of [Fig. 3], the tables 10 must be rotated by an angle of 20°, thanks to the projected elevation of the sun in this example. However, with such an orientation, the photovoltaic panels of the adjacent tables 10 shade each other, resulting in a drop in electricity production. The presence of shadows is shown in [Fig. 3] by means of the shaded areas.

[0062] To avoid such a drop in production, according to the prior art, the tables 10 preferably follow the backtracking behavior of orienting themselves as much as possible towards the sun without casting shadows on each other.

[0063] In view of the above observations, a first consideration is that Figures 2 and 3 clearly show that backtracking is calculated relatively easily for tables 10 all located at the same altitude. On the other hand, the situation is more complex with tables 10 mounted on cables 51, 52 as in the example of [Fig. 1].

[0064] With reference to [Fig.1], of the six tables 10 hung between each pair of consecutive poles 40, the two tables 10 closest to the poles will be at the highest altitudes and those located in the center of the cables 51, 52 at the lowest altitudes.

[0065] The height differences of the six tables 10 located along the cables 51, 52 mean that the creation of shaded surfaces of the tables 10 on neighboring tables 10 is different for the tables 10 according to their position in a row of tables 10 and also according to the time of day and / or the time of year and according to the tracking angle taken by said tables 10.

[0066] A second consideration is that the prior art backtracking system only takes into account the setting of the photovoltaic power plant 100 with shadow avoidance as the sole input parameter. However, this does not automatically lead to the maximization of the power plant's electricity production. photovoltaic 100. Moreover, such a setting does not take into account the presence of point shadows on a table 10. Such point shadows may be linked to the presence of a tall object, such as a tree for example next to one of the tables 10. Such an object could create a shadow on one or more tables, for example, for part of the day.

[0067] It should also be noted that, in the structure of the photovoltaic power plant 100 according to [Fig. 1], the tables 10 are fixed in a structure comprising elements such as posts 40, crossbeams 41, cradles, and cables 51, 52. This type of construction creates the risk of point shadows cast by constituent elements of the photovoltaic power plant 100 itself. Furthermore, it should be noted that the risk of point shadows cast by constituent elements of the power plant itself is much greater for an agrivoltaic power plant of the type according to [Fig. 1] than in standard photovoltaic power plants with panels directly fixed to the ground.

[0068] The object of the invention is to propose a method of managing a photovoltaic power plant, such as an agrivoltaic power plant and such a power plant, in which the positioning of the tables 10 can be controlled so as to optimize the overall electricity production for the entire installation.

[0069] Initially, the invention relates to a computer-implemented method for optimizing the electricity production of a photovoltaic power plant 100, wherein the photovoltaic power plant 100 comprises a plurality of electricity-producing units, such as photovoltaic panels 30. Each of these electricity-producing units is designed to change its orientation relative to the sun in order to optimize its electricity production at all times. To allow an operator to control this orientation, the electricity-producing units are connected to control means.

[0070] The process according to the invention comprises several steps.

[0071] To begin with, it is necessary to obtain a mathematical model of the photovoltaic power plant 100 including the positions of the different electricity production units 30, the mutual distances between these units 30, the irradiance and the position of the sun with respect to the photovoltaic power plant 100.

[0072] Next, we must calculate, for a given moment, using the mathematical model and the position of the sun at that given moment, the electricity production of the photovoltaic power plant 100 for a plurality of orientations for each of said plurality of electricity production units 30. For these calculations, the user must take into account for each of the electricity production units 30 their instantaneous orientation and their corresponding instantaneous electricity production.

[0073] In a subsequent step, one must select, from among this plurality of orientations, a specific orientation for each of the electricity production units 30 which corresponds to a set of optimal positions for producing electricity by means of the photovoltaic power plant 100.

[0074] Using the previous steps, the method according to the invention makes it possible to generate instructions so that the control means orient each of the electricity production units towards their respective determined orientations.

[0075] The technical effect of the method according to the invention is that at any time, the instantaneous production for all possible positions of the photovoltaic panels 30 and of all relative positions of the photovoltaic panels 30 is known, so that the user knows the ideal orientation of all the photovoltaic panels 30 to maximize the electricity production of the whole photovoltaic power plant 100.

[0076] One of the advantages of the invention lies in the fact that the presence of one or more photovoltaic panels 30 partially in the shade can be accepted, provided that the total electricity production of the photovoltaic power plant 100 is maximized.

[0077] As indicated above, the mathematical model of the photovoltaic power plant 100 according to the invention includes the positions of the different electricity production units 30. According to one embodiment of the invention, the mathematical model includes parameters defining the area of ​​the implantation of the photovoltaic power plant 100, such as latitude, longitude, altitude, orientation, and soil albedo.

[0078] It should be noted that three types of inputs are used for the modeling.

[0079] The first type of input relates to shadows. These inputs include parameters concerning: - tables (dimensions, dynamic spatial coordinates), - other objects casting shadows (their dimensions, their static spatial coordinates), - the position of the sun (elevation, azimuth) and - tracking angles.

[0080] These inputs are processed using mathematical functions to obtain the shaded fraction of the photovoltaic tables 30.

[0081] The second type of input relates to light. These inputs include parameters concerning:

[0082] - the site (latitude, longitude, altitude, orientation, albedo, IAM),

[0083] - horizontal irradiation data (GHI, BHI, DHI),

[0084] - the tracking angles, and

[0085] - the Earth-Sun distance.

[0086] These inputs are processed using mathematical functions to obtain the direct, diffuse and reflected irradiances on the inclined plane of the tracking modules (BTI, DTI, RTI).

[0087] The third type of input relates to electricity production. These inputs include parameters concerning: - the results concerning the aforementioned shadows (Shaded Fraction), - the results concerning light (BTI, DTI, RTI), and - the electrical wiring of the 100 photovoltaic power plant.

[0088] These inputs are processed using mathematical functions to obtain the instantaneous, simulated electricity production.

[0089] In an optimization phase, said results concerning instantaneous electricity production, simulated together with possible backtracking parameters (that is to say the set of possible values ​​for which we seek the optimal combination) are used to obtain optimal backtracking parameters and the percentage gain in expected electricity production together with an indication of the distribution of expected gains as a function of the parameters.

[0090] To identify the optimal orientation of all the photovoltaic panels 30, iterative calculations may be used, wherein the calculation step for the determined time, using the mathematical model and the position of the sun at that determined time, of the electricity production of the photovoltaic power plant 100 for a plurality of orientations for each of said plurality of electricity production units comprises:

[0091] a) Calculate, for a first orientation of the plurality of electricity production units, a first instantaneous electricity production of the photovoltaic power plant 100,

[0092] b) Modify the orientation of at least a first electricity generating unit 30 of said plurality of electricity generating units to obtain a modified orientation of the plurality of electricity generating units,

[0093] c) Calculate, for the modified orientation of the plurality of electricity production units, a modified instantaneous electricity production of the photovoltaic power plant 100, and

[0094] d) Repeat steps b) and c) to obtain the instantaneous production of electricity from the photovoltaic power plant 100 for a plurality of orientations for each of said plurality of electricity production units.

[0095] According to one embodiment of the invention, a two-dimensional geometric model is used to quantify the shaded fraction of each table 10 of a photovoltaic power plant, such as an agrivoltaic power plant, as a function of time, related to the presence of neighboring tables 10. In a second step, this model is coupled with a The system combines the actual altitude data for each table with angular decomposition models of solar radiation to produce, as a function of time, an estimate of the effective global tilted irradiance received by each table. In English, the term Global Tilted Irradiance, or GTI, is used to refer to this effective global irradiance received by each table.

[0096] A two-dimensional geometric model of the shading of a table on an adjacent table has been developed and is shown by reference to [Fig.4]. In this model, the tables, represented by lines of length a, separated by a distance b, a height Ah and inclined at angles [31 and

[32] with respect to the horizontal, are illuminated by a sun whose elevation projected into the plane orthogonal to the tables is denoted y.

[0097] In [Fig.4] we call: - y(t) the projection of the solar elevation onto the plane orthogonal to the tables at o. 9 - [31(t) and |32(t) the angles of the tables with respect to the horizontal in ° (0° to horizontal, 90° vertical); - the height of the tables in m; - b the inter-table distance in m; and - Ah, the difference in height between the rotation axes of the tables in meters.

[0098] The quantity y depends on the elevation e and the azimuth a of the sun as well as the angular offset of the plane orthogonal to the modules co by the formula:

[0099] [Math.l] tan e tan y = ---:--—-

[0100] The solar elevation and azimuth data required to calculate the quantity y come from the PVLIB2 package used with the Python language. According to this model, the shaded distance d^ on a table is written:

[0101] [Math.2] | i* 4__ —____________ _

[0102] It is finally possible to relate this distance to the length of the table and limit the result between 0 and 100% to obtain a shaded fraction of the tables using the formula:

[0103] [Math.3] Al U = £00 * 0, msn „ 1 J |

[0104] The two-dimensional approximation results in a linear and not surface shaded fraction.

[0105] The outputs of this model are curves representing the shaded fraction of tables as a function of time. The presence or absence of shade depends essentially on the relative heights of the tables 10. When a neighboring table 10 is at an altitude at least equal to that of the measured table 10, it can cast a shadow on it.

[0106] Regarding the presence of point shading for a photovoltaic power plant, such as an agrivoltaic power plant, it is noted that the presence of this type of shading depends on the environmental factors of a power plant, such as the presence of tall objects such as trees, etc.

[0107] From the shading model presented above, field data and inter-table shading it is possible to generate an efficient GTI model.

[0108] According to the invention, the calculation to identify the optimal orientations for photovoltaic panels 30, taking into account the possible presence of shadows, comprises the following steps:

[0109] - Quantify, using the mathematical model, the presence of at least one shadow created by at least one electricity production unit 30 on another electricity production unit 30 at the specified time, to identify a shaded electricity production unit 30,

[0110] - Reduce, using the mathematical model, the estimated electricity production of said shaded electricity production unit 30, and

[0111] - Calculate, for this determined moment, using the mathematical model and the estimated reduced electricity production for the shaded electricity production unit 30, the electricity production of the photovoltaic power plant 100 for a plurality of orientations for each of said plurality of electricity production units and

[0112] - Select, from among this plurality of orientations, a specific orientation for each of the electricity production units 30 which corresponds to an optimal position for producing electricity by means of the photovoltaic power plant 100 at the determined time taking into account the estimated reduced electricity production for said shaded electricity production unit 30.

[0113] According to the invention, it is possible that the mathematical model may include parameters defining structural elements of the photovoltaic power plant 100 and / or parameters defining objects in the vicinity of the photovoltaic power plant 100. The process further includes:

[0114] - Quantify, using the mathematical model, the presence of at least one shadow created by a structural element of the photovoltaic power plant 100 and / or an object near the photovoltaic power plant 100 on an electricity production unit 30 at the determined time, to identify a shaded electricity production unit 30,

[0115] - Reduce, using the mathematical model, the estimated electricity production of said shaded 30 electricity production module, and

[0116] - Calculate, for this determined moment, using the mathematical model and the estimated reduced electricity production for the shaded electricity production unit 30, the electricity production of the photovoltaic power plant 100 for a plurality of orientations for each of said plurality of electricity production units 30, and

[0117] - Select, from among this plurality of orientations, a specific orientation for each of the electricity production units 30 which corresponds to an optimal position for producing electricity by means of the photovoltaic power plant 100 at the determined time taking into account the estimated reduced electricity production for said shaded electricity production unit 30.

[0118] Figure 5 shows an experimental validation of the efficient GTI model. The electricity production of a portion of the photovoltaic power plant 100 is illustrated by the black curve labeled "Production". The dashed "Unshaded" and dashed "Model" curves represent, respectively, the output of the efficient GTI model assuming a perfectly clear sky without shading and with the shading calculated for the tables studied. These curves are multiplied by a constant so that their scale coincides with that of the electricity production.

[0119] As shown in [Fig. 5], in the afternoon, the studied tables 10 are not shaded. The three curves coincide. During the day, the tables 10 are not shaded, the blue and red curves are identical, and their variation does not accurately reproduce that of the black production curve. This can be explained by a sky that was possibly not perfectly clear (around 12:00) as well as by suboptimal processing of reflected radiation and an unmodeled GTI on the back face.

[0120] In the morning, tables 10 are shaded. The production curve in black then deviates significantly from the blue "unshaded" curve. The objective of the modeling (red curve) is to reproduce as accurately as possible the variations in production during shaded periods.

[0121] In the case shown in [Fig. 5], a good modeling of the shading effect is observed. The same result was obtained for other tables 10 of the power plant Photovoltaic 100, for other clear days in spring and summer. We can therefore conclude that the modeling allows us to understand, reproduce, and predict table-to-table shading on the photovoltaic power plant.

[0122] In addition to the possibility, described above, of calculating and predicting in advance the presence of shadows on the solar panels, it is possible, according to the invention, to equip the solar installation with sensors enabling the determination of the presence of shadows on the basis of a measured reduction in electricity production, during the use of the solar installation.

[0123] An important factor in modeling the electricity production of a photovoltaic power plant, such as an agrivoltaic power plant, is the way in which the different photovoltaic panels 30 are electrically connected. Indeed, when several photovoltaic panels 30 are connected in series, the same current flows through them. This common current is equal to the current flowing through the element in said series with the lowest current.

[0124] To explain the influence of the connection of the photovoltaic panels 30, reference is made to figures 6 and 7.

[0125] The way in which the photovoltaic panels 30 are wired and arranged in relation to the shading is important for modeling their electricity production. Figure 6 shows the example where a total of nine photovoltaic panels 30 are connected in series per table 10. The photovoltaic panels 30 are arranged vertically.

[0126] Each 30 photovoltaic panel is divided into two half-modules with a first module 31 which forms the upper part of the photovoltaic panel 30 and a second module 32 which forms the lower part of the photovoltaic panel 30. Each half-module 31, 32 is composed of 36 photovoltaic cells, for a total of 72 cells per panel 30.

[0127] Figure 7 shows that half-module 31 and half-module 32 are wired electrically in parallel. Each third of the cells in a half-module 31 is wired in series with a corresponding third of the cells in a half-module 32. This type of connection means that the current flowing through the photovoltaic panels 30 is equal to the sum of the current flowing through the cell with the lowest current in half-module 31 and the cell with the lowest current in half-module 32. In [Fig. 7], the path of the current through the photovoltaic cells is schematically shown with reference numeral 70. The current 70 flows from an input 71 to an output 72.

[0128] If a table 10 has nine photovoltaic panels 30 wired in series, as in the example shown in [Fig.6], this implies that the current flowing through the table 10 is equal to the module 30 which has the sum of the current flowing through the half-module 31 and the half-module 32 which has the lowest current in the table 10.

[0129] With reference to Figures 3 and 6, it is easy to imagine that the shading on the half-modules 31 and 32 of the panels 30 of the same table 10 is not necessarily equally distributed. The half-modules 32, forming the lower part of the panels 30, are, in the examples of Figures 3 and 6, at least partially covered, while the half-modules 31 of the same panels 30 are not covered.

[0130] Indeed, when the shading is not equally distributed over the nine panels 30 of a table 10, the series connection of the panels 30 implies that the current flowing in the table 10 is limited by the panels 30 and in particular by the most shaded half-modules 32.

[0131] To optimize electricity production, if at least a sufficiently large portion of the surface of said second half-module 32 is shaded, said second half-module 32 must be independent of the first half-module 31 to allow the first half-module 31 to produce electricity without being impeded by the current from the second half-module 32, which is shaded. This is why photovoltaic panels 30 equipped with two half-modules are sold commercially.

[0132] In [Fig.7], in addition to the half-modules seen previously, electrical shunts 60 also allow for more optimal current flow in the event of shading on a part of the module on the left or right side of module 30. If shading is present on the left side of module 30, then the leftmost electrical shunt 60 will become conductive and will allow the current coming from the right side not to be hindered by the shaded cells on the left side of module 30.

[0133] In the present invention, the specific capacity of the photovoltaic panels 30 to have one or more independent half-modules and the presence of electrical shunts 60 is used optimally in the presence of inevitable shading on part of the power plant for various reasons.

[0134] The current flowing in the photovoltaic panel 30, before the shunt is equal to the current flowing in the left part at least partially covered by a shadow and after the shunt the current is equal to the current flowing in the right part of the module 30, not covered by a shadow.

[0135] In the present invention, this parameter is used to calculate the optimal orientation of the photovoltaic panels 30. When the calculations show that one or more half-modules are shaded, the electricity production using these half-modules will be much lower than that of the unshaded half-module. The optimal orientation can then be calculated for the rest of the installation. In practice, it may well be necessary, in order to optimize the overall electricity production of the photovoltaic power plant 100, to accept that the production of some of the photovoltaic panels or the production of one or more half-modules will be very low due to shading. In other words, the calculations may to show that in order to optimize the production of the entire photovoltaic power plant it is better to "sacrifice" the potential electricity production of a part of the 30 photovoltaic panels and / or the potential electricity production of one or more half-modules of the photovoltaic power plant.

[0136] It can be seen that the type of wiring described above justifies the linear approximation described with reference to [Fig. 4], above. The linear shaded fraction is defined as the ratio between the maximum shadow height on a table 10 and the height of the table 10. For example, in [Fig. 6] it can be seen that the maximum shadow height, indicated by the shaded area over the entire table 10, is approximately 25%.

[0137] Taking this into consideration, a model of the useful radiation fraction for electrical generation received by table 10 as a function of the shaded linear fraction of the latter has been developed. This model is shown in [Fig.8].

[0138] Figure 8 shows the effective fraction for electricity production of solar radiation incident on a table 10 as a function of its linear shaded fraction. As long as the cells positioned at the bottom of the panels 30 are not completely shaded, the effective fraction of the radiation decreases linearly with the shaded fraction. In the example of Figures 7 and 8, each panel 30 is composed of 24 cells in its height. This means that the cells positioned at the bottom of the panels 30 are not completely shaded if the linear fraction is less than the threshold value of 1 / 24 ≈ 4% shading of the panel 30.

[0139] As shown in [Fig.8], beyond the threshold value of 1 / 24 of shading and up to the top of the lower half-module 32, as at least one cell of the half-module is completely shaded, the whole of the lower half-module 32 is lost and the effective fraction of the radiation received by table 10 is equal to that received by the upper half-module 31, i.e. 50%.

[0140] The same evolution described above for the lower half-module 32 occurs for the upper half-module 31, while the shading extends to the top of the panels 30 of the table 10.

[0141] With reference to the foregoing, it should also be noted that according to the invention, one or more tables 10 can be placed in series and together form a "string". In order to optimize the electricity production of the entire photovoltaic power plant 100, calculations using the mathematical model may show that the production of a string or a part of the string must be sacrificed to optimize the total electricity production of the photovoltaic power plant 100. From the foregoing, it is clear that according to the invention, an ideal orientation of the panels can be calculated to produce electricity at any time of day and at any time of year.

[0142] In addition to the description of the use of the invention to optimize the optimal production of electricity using the photovoltaic power plant 100, it is noted that the result of the calculations and the orientation of the photovoltaic panels 30 can, among other things, allow the user to obtain the following resulting control modes: Time tracking, Zero-shadow tracking, Tracking optimized by half-module, and Mixed tracking.

[0143] Furthermore, according to the invention described above, the use of the mathematical model allows, at the user's choice, the control of electricity production.

[0144] The embodiments described above are given as examples only.

Claims

1. Demands A computer-implemented method for optimizing the electricity production of a photovoltaic power plant, the photovoltaic power plant comprising a plurality of electricity production units, each electricity production unit being designed to modify its orientation relative to the sun in order to optimize its electricity production at all times, the electricity production units being connected to control means to control said orientation, the method comprising the following steps: - Obtain a mathematical model of the photovoltaic power plant including the positions of the different electricity production units, the mutual distances between these units, the irradiance and the position of the sun relative to the photovoltaic power plant, - Calculate, for a given moment, using the mathematical model and the position of the sun at that given moment, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units, taking into account for each of the electricity production units their instantaneous orientation and their corresponding instantaneous electricity production, - Select, from this plurality of orientations, a specific orientation for each of the electricity production units that corresponds to a set of optimal positions for producing electricity using the photovoltaic power plant at the given time, and - Generate instructions so that the control systems direct each of the electricity production units towards their respective predetermined orientation, the method further comprising: - Quantify, using the mathematical model, the presence of at least one shadow cast by at least one electricity generating unit on another electricity generating unit at a given time, in order to identify a shaded electricity generating unit, - Reduce, using the mathematical model, the estimated electricity production of said shaded electricity generating unit, and - Calculate, for this determined moment, using the mathematical model and the reduced estimated electricity production for the shaded electricity production unit, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units and - Select, from this plurality of orientations, a determined orientation for each of the electricity production units which corresponds to a set of optimal positions for producing electricity using the photovoltaic power plant at the determined moment taking into account the reduced estimated electricity production for said shaded electricity production unit.

2. A method according to claim 1, wherein the mathematical model includes parameters defining the area of ​​the photovoltaic power plant installation, such as latitude, longitude, altitude, orientation, and soil albedo.

3. A method according to claim 1 or 2, wherein the calculation step for the specified time, using the mathematical model and the position of the sun at that specified time, of the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity-producing units comprises: a) Calculating, for a first orientation of the plurality of electricity-producing units, a first instantaneous electricity production of the photovoltaic power plant, b) Modifying the orientation of at least a first electricity-producing unit of said plurality of electricity-producing units to obtain a modified orientation of the plurality of electricity-producing units, c) Calculating, for the modified orientation of the plurality of electricity-producing units, a modified instantaneous electricity production of the photovoltaic power plant,and d) Repeat steps b) and c) to obtain the instantaneous electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units.

4. A method according to any one of the preceding claims, wherein the mathematical model comprises parameters defining structural elements of the photovoltaic power plant and / or parameters defining objects near the photovoltaic power plant, the method further comprising: - Quantifying, using the mathematical model, the presence of at least one shadow cast by a structural element of the photovoltaic power plant and / or an object near the photovoltaic power plant on an electricity production unit at a given time, in order to identify a shaded electricity production unit, - Reducing, using the mathematical model, the estimated electricity production of said shaded electricity production module, and - Calculating, for this given time, using the mathematical model and the reduced estimated electricity production for the shaded electricity production unit, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units,and - Select, from among this plurality of orientations, a specific orientation for each of the electricity production units that corresponds to an optimal position for producing electricity by means of the photovoltaic power plant at the specified time, taking into account the estimated reduced electricity production for said shaded electricity production unit.

5. A method according to claim 3 or 4, wherein the estimated electricity production for the shaded electricity production unit is reduced in accordance with a mathematical function previously established using the electrical characteristics of said shaded module and its electrical connection.

6. A photovoltaic power plant for the production of electricity comprising: - A plurality of electricity-producing units, each electricity-producing unit being designed to modify its orientation relative to the sun in order to optimize its electricity production at all times, the electricity-producing units being connected to control means to control said orientation, - computing means adapted to host a mathematical model for the photovoltaic power plant comprising the positions of the different electricity production units, the mutual distances between these units, the irradiance and the position of the sun relative to the photovoltaic power plant, and adapted to calculate for a given moment, using the mathematical model and the actual position of the sun, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units, taking into account, for each of the electricity production units, their instantaneous orientation and their corresponding instantaneous electricity production, the calculation means being further adapted to the selection, among said plurality of orientations, of a given orientation for each of the electricity production units which corresponds to an optimal position for producing electricity by means of the photovoltaic power plant at the given moment,and to the generation of instructions for the control means, the computing means being further adapted for: - Quantify, using the mathematical model, the presence of at least one shadow cast by at least one electricity generating unit on another electricity generating unit at a given time, in order to identify a shaded electricity generating unit, - Reduce, using the mathematical model, the estimated electricity production of said shaded electricity generating unit, and - Calculate, for this given moment, using the mathematical model and the estimated reduced electricity production for the shaded electricity production unit, the electricity production of the photovoltaic power plant for a plurality of orientations for each of said plurality of electricity production units and - Select, from this plurality of orientations, a specific orientation for each of the electricity production units that corresponds to a set of optimal positions for producing electricity by means of the photovoltaic power plant at the specified time, taking into account the estimated reduced electricity production for said shaded electricity production unit, and - control means connected to the computing means and adapted to receive instructions from said computing means and to orient each of the electricity production units towards their respective determined orientation.

7. Photovoltaic power plant according to claim 6, comprising at least one power generation unit with a first module connected in parallel with at least one second adjacent module, and wherein the first and second modules comprise power generation cells, the power generation unit being provided with shunt diodes enabling the creation of a path for electric current between an input and an output of the power generation unit.

8. Product computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the method according to any one of claims 1 Q

9. a J. Computer-readable recording medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 1 to 5.

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