SHADING SIMULATION DEVICE ON A PHOTOVOLTAIC PANEL

Abstract

A device (100) for simulating dynamic shading on at least one photovoltaic panel (200), comprising at least: - a film (104) intended to be moved relative to a front face (202) of the photovoltaic panel, at least a portion (106) of which is at least partially opaque and representative of a shading pattern intended to be projected onto the front face of the photovoltaic panel; - a device (108, 110) for guiding the film relative to the front face of the photovoltaic panel; - an actuation device (112, 114) configured to move the film relative to the front face of the photovoltaic panel. Figure 1 is shown for the abbreviated version.

Description

Title of the invention: DEVICE FOR SIMULATING SHADING ON A PHOTOVOLTAIC PANEL Technical field

[0001] The invention relates to the field of shading simulation on photovoltaic panels, with the aim of electrically characterizing these panels in such a configuration. STATE OF THE PRIOR ART

[0002] The study of partial shading of photovoltaic panels is an important issue in the architectural design of these panels. Indeed, when a shadow is projected onto a part of a photovoltaic panel, the photovoltaic cell(s) of this panel located in this shadow limit the output current of the entire chain of cells of the panel to which it belongs, in addition to being subject to rapid degradation linked to a strong reverse polarization at their terminals. Partial shading of a cell also generates localized heating on this cell, called a "hotspot", which is also responsible for degradation of the cell. Protection by "bypass" diode or by specific interconnection architectures are therefore necessary in order to avoid excessively rapid aging of the cells.

[0003] The partial shading patterns used depend on the application in which the photovoltaic module is integrated. Different scenarios are to be tested experimentally in order to verify the robustness of the module architecture according to exposure to partial shading, and to establish an aging protocol under shading.

[0004] A first way to simulate partial shading of a photovoltaic panel consists of using an opaque cover of variable size placed directly on the panel to be studied, and moving it manually. This method has the advantage of completely cutting off the incident light at the level of the cells masked by the cover, but does not allow for the creation of dynamically projected shading patterns, i.e. moving on the panel and / or changing shape and / or opacity. Manual intervention by an operator is therefore necessary for any modification of the protocol.

[0005] There are also systems using roll-up tarpaulins placed directly on the panel. With such systems, however, the number and complexity of possible shading patterns are very limited. Such systems are not suitable for simulating a shadow projection dynamically on the panel.

[0006] The document by H. Ziar et al., “Quantification of Shading Tolerability for Pho-tovoltaic Modules,” in IEEE Journal of Photovoltaics, vol. 7, no. 5, pp. 1390-1399, Sept. 2017, describes a partial shading device for a photovoltaic panel using opaque covers to create different shading patterns. However, the complexity of the shading patterns achievable with such equipment is very limited.

[0007] A second way to reduce the light intensity incident on a photovoltaic panel consists of directly varying the power of the lamps located above the module to be studied, as described in the document MA Al Mamun et al., “Experimental investigation of the effect of partial shading on photovoltaic performance”, June 2017, Renewable Power Generation, IET Volume ll (Issue 7), p. 912 - 921. By varying the electrical power sent to some of the lamps, it is possible to observe shading effects on the cells. The main disadvantage of this technique is the inability to obtain total darkness on part of the photovoltaic module given the propagation of the light beams and the lateral diffusion of the light coming from the lamps. This results in imprecise management of the shading patterns produced. Statement of the invention

[0008] An aim of the present invention is to propose a device for simulating dynamic shading on at least one photovoltaic panel which does not have the drawbacks of the existing devices described above.

[0009] For this, the present invention proposes a device for simulating dynamic shading on at least one photovoltaic panel, comprising at least: - a film intended to be moved opposite a front face of the photovoltaic panel, at least one part of which is at least partially opaque and representative of a shading pattern intended to be projected onto the front face of the photovoltaic panel; - a device for guiding the film with respect to the front face of the photovoltaic panel; - an actuating device configured to set the film in motion with respect to the front face of the photovoltaic panel.

[0010] This device makes it possible to simulate partial or total shading on a photovoltaic panel, comprising one or more photovoltaic cells, and to project different shading scenarios dynamically without modifying the incident light source.

[0011] The device according to the invention allows the production of shading patterns which can be more complex than those which can be produced with fixed opaque covers.

[0012] The invention makes it possible to generate partial shading of at least one photovoltaic panel by a non-destructive method on the photovoltaic panel.

[0013] The invention does not require modification of the incident light source, this which may correspond to sunlight when the device is used outdoors or to that of a light source other than the sun when the device is used indoors.

[0014] Such a device can be used indoors or outdoors (for example in a solar power plant). It can be transported and its installation is easy.

[0015] The shadow(s) may be projected dynamically by the device, for example by simulating a linear movement speed relative to the photovoltaic panel.

[0016] The at least partially opaque part of the film can allow part of the incident light to pass through, for example between 0% and 80% of the light received at this part of the film.

[0017] A shadow projection is described as dynamic when the intensity and / or shape and / or position of the shadow changes over time during projection onto the photovoltaic panel.

[0018] The actuating device may comprise at least one motor or at least one cylinder.

[0019] In a first exemplary embodiment, the dynamic shading simulation device may be such that: - the actuating device comprises at least a first motor; - the guide device comprises first and second shafts around which the film is configured to be wound and unwound; - the first motor is coupled to the first shaft.

[0020] In this first embodiment, the actuating device may further comprise a second motor or an automatic winder, coupled to the second shaft.

[0021] In a second exemplary embodiment, the dynamic shading simulation device may be such that: - the actuating device comprises at least a first motor; - the guide device comprises first, second, third and fourth shafts; - the first motor is coupled to one of the first, second, third and fourth shafts; - the film forms an endless strip guided by the first, second, third and fourth shafts; - the first and second shafts are configured to guide the film opposite the front face of the photovoltaic panel, and the third and fourth shafts are configured to guide the film opposite a rear face, opposite the front face, of the photovoltaic panel.

[0022] In a third exemplary embodiment, the shading simulation device dynamic may be such that the guide device comprises side rails configured to guide the film in translation.

[0023] The film may comprise a layer of transparent material, and the at least partially opaque portion of the film may be formed by at least one at least partially opaque element disposed against the layer of transparent material and removably secured to the layer of transparent material. In this case, the pattern of the shadow or shadows projected onto the photovoltaic panel may be easily modified.

[0024] The dynamic shading simulation device may further comprise a frame to which the guidance device and the actuating device are secured.

[0025] In a first embodiment, the frame can form a support configured so that a rear face of the photovoltaic panel is arranged on the support.

[0026] In a second embodiment, the frame may comprise an opening configured to be arranged opposite the front face of the photovoltaic panel, and such that the film can be moved opposite the front face of the photovoltaic panel through the opening.

[0027] The dynamic shading simulation device may further comprise a light source configured to illuminate a first face of the film, and a second face of the film, opposite the first face, which may be intended to be moved opposite the front face of the photovoltaic panel.

[0028] The light source may be configured to emit light conforming to the AM 1.5 solar spectrum and / or with a power between 200 W / m2 and 2000 W / m2.

[0029] The shading simulation device may further comprise a current-voltage measuring device configured to measure the current-voltage characteristic of the photovoltaic panel.

[0030] The invention also relates to a method for characterizing at least one photovoltaic panel, comprising at least the following steps: - arranging a dynamic shading simulation device as described above and the photovoltaic panel such that the film of the dynamic shading simulation device is arranged opposite a front face of the photovoltaic panel; - set the film of the dynamic shading simulation device in motion; - measure the current-voltage characteristic of the photovoltaic panel by the current-voltage measuring device of the dynamic shading simulation device, simultaneously with the movement of the film of the dynamic shading simulation device.

[0031] Throughout the document, the term "on" is used without distinction of the orientation in space of the element to which this term relates. For example, in the characteristic "on a face of the first substrate", this face of the first substrate is not necessarily oriented upwards but may correspond to a face oriented in any direction. Furthermore, the arrangement of a first element on a second element must be understood as being able to correspond to the arrangement of the first element directly against the second element, without any intermediate element between the first and second elements, or as being able to correspond to the arrangement of the first element on the second element with one or more intermediate elements arranged between the first and second elements. Brief description of the drawings

[0032] The present invention will be better understood on reading the description of exemplary embodiments given purely for informational purposes and in no way limiting, with reference to the appended drawings in which: [Fig.l] and

[0033] [Fig.2] schematically represent a dynamic shading simulation device, object of the present invention, according to a first embodiment; [Fig.3] and [Fig.4] schematically represent a dynamic shading simulation device, object of the present invention, according to different variants of the first embodiment; [Fig.5] schematically represents a dynamic shading simulation device, object of the present invention, according to a second embodiment.

[0034] Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the transition from one figure to another.

[0035] The different parts represented in the figures are not necessarily on a uniform scale, in order to make the figures more readable.

[0036] The different possibilities (variants and embodiments) must be understood as not being mutually exclusive and can be combined with each other.

[0037] Detailed description of particular embodiments

[0038] An exemplary embodiment of a device 100 for simulating dynamic shading on at least one photovoltaic panel, or module, 200, according to a first embodiment, is described below in connection with Figures 1 and 2. In [Fig. 2], only a portion of the elements of the device 100 are shown. The device 100 can be used for any type of photovoltaic panel 200, i.e. comprising one or more photovoltaic cells based on semiconductors, organic materials, hybrids, etc.

[0039] The device 100 comprises a film 104, for example of rectangular shape, intended to be moved opposite a front face 202 of the photovoltaic panel 200. The face front 202 of the photovoltaic panel 200 corresponds to the face intended to receive the light from which the photovoltaic panel 200 produces electricity.

[0040] At least a portion of the film 104 is at least partially opaque and forms a pattern of one or more shadows intended to be projected onto the front face 202 of the photovoltaic panel 200. In the exemplary embodiment described, the film 104 is formed from a layer of transparent material, for example based on plastic, on which portions 106 of opaque material are secured. The shapes, patterns and degrees of opacity of these portions 106 are chosen as a function of the shadow patterns intended to be projected onto the front face 202 of the photovoltaic panel 200. In [Fig.l], the photovoltaic panel 200 is visible through the transparent portions of the film 104.

[0041] The material(s) of the film 104, i.e. of the transparent layer and of the portions 106 in the example described above, are chosen such that the film 104 has good mechanical strength and good resistance to UV and thermal radiation, for example such that it can withstand temperatures between 50°C and 80°C.

[0042] Advantageously, the portions 106 are secured to the layer of transparent material of the film 104 in a removable manner in order to be able to easily modify the shading pattern(s) projected onto the front face 202 of the photovoltaic panel 200. The attachment of the portions 106 to the layer of transparent material is for example ensured by an adhesive or by magnet.

[0043] Alternatively, it is also possible for the film 104 to comprise only one layer of material that includes one or more transparent portions and one or more at least partially opaque portions. In this case, the at least partially opaque portion(s) of the film 104 are not removable.

[0044] The device 100 also comprises a device for guiding the film 104 with respect to the front face 202 of the photovoltaic panel 200, as well as an actuation device configured to set the film 104 in motion with respect to the front face 202 of the photovoltaic panel 200. In the exemplary embodiment described, the guiding device corresponds to first and second shafts 108, 110 around which the film 104 is configured to be wound and unwound, and the actuation device corresponds to first and second motors 112, 114, the first motor 112 being coupled to the first shaft 108 and the second motor 114 being coupled to the second shaft 110. The motors 112, 114 are for example electric stepper motors with two directions of rotation, which makes it possible to simulate shading on the photovoltaic panel 200. moving in one or other of two opposite directions (parallel to the X axis in the example of figures 1 and 2).The rotation speed of the motors 112, 114 can be variable and programmable, which allows for example the device 100 to simulate a scrolling of shadows on the photo panel. voltaic 200 at different speeds, for example between 0 and 50 km / h, or even between 0 and 130 km / h.

[0045] Advantageously, the shafts 108, 110 and the motors 112, 114 are used to keep the film 104 under tension so that the distance between the film 104 and the front face 202 of the photovoltaic panel 200 (distance parallel to the Z axis shown in FIGS. 1 and 2) is substantially constant, and for example equal to a few millimeters. In addition, the film 104 has for example a total length (dimension parallel to the X axis shown in FIGS. 1 and 2), that is to say when it is completely unrolled, of between 4 m and 30 m, or even more.

[0046] The device 100 further comprises a frame 116 to which the guide device, i.e. the shafts 108, 110, and the actuating device, i.e. the motors 112, 114, are secured. In the first embodiment, the frame 116 forms a support configured so that a rear face of the photovoltaic panel 200 is arranged on this support. This frame 116 corresponds for example to a stabilized table on which the photovoltaic panel 200 is intended to be placed. According to an exemplary embodiment, the support formed by the frame 116 can form a surface substantially parallel to the ground on which the photovoltaic panel 200 is intended to be arranged. The frame 116 may be mobile or fixed, and may support one or more photovoltaic panels 200. Other types of frame 116 are conceivable, whether the device 100 is used outdoors or indoors.

[0047] When the device 100 is intended to be used indoors, the device 100 further comprises a light source configured to illuminate a first face of the film 104 opposite that intended to be moved opposite the front face 202 of the photovoltaic panel 200. In the example of FIGS. 1 and 2, this light source is formed by several lamps 118 arranged above the film 104 so that the light emitted by the lamps 118 passes through the transparent parts of the film 104 and reaches the front face 202 of the photovoltaic panel 200, and that a portion of this light is blocked at least partially by the portions 106 to form the shadows on the front face 202 of the photovoltaic panel 200.

[0048] In an advantageous configuration, the light source is configured to emit light conforming to the AM 1.5 solar spectrum and / or with a power of between 200 W / m2 and 2000 W / m2, and for example equal to 1000 W / m2. According to an exemplary embodiment, the light source corresponds to one or more Xenon lamps 118 coupled to at least one filter (for example to form a class AAA solar simulator).

[0049] When the device 100 is intended to be used outdoors, the device 100 may not include the light source, and the light illuminating the photovoltaic panel 200 corresponds in this case to sunlight.

[0050] The device 100 further comprises a current-voltage measurement device 120, or IV measurement, configured to measure the current-voltage characteristic of the photovoltaic panel 200. The device 120 corresponds for example to a source and measurement unit (or SMU for “Source Measure Unit” in English) generating a voltage sweep at the terminals of the photovoltaic panel 200 in an interval between 0 V and Voc (open circuit voltage) and measuring the current of the photovoltaic panel 200 as a function of the applied voltage. The current-voltage characteristic of the photovoltaic panel 200 can then be plotted, which makes it possible to calculate the various intrinsic properties of the photovoltaic panel 200 such as for example its series / parallel resistance, the Voc, Isc (short-circuit current), the Fill Factor (Form Factor), etc. The device 120 can be controlled by a computer program on a computer connected by a communication cable.The program can start the current-voltage measurement continuously or at a regular time interval. This measurement can be processed in real time by a program in order to extract the different intrinsic parameters of the photovoltaic panel 200 as a function of the shading rate. The program can also control the actuating device (i.e. the motors 112, 114 in the example previously described) to set the film 104 in motion.

[0051] In an advantageous configuration, considering that the film 104 is unrolled above the photovoltaic panel 200 parallel to its length, the width (dimension along the Y axis shown in FIGS. 1 and 2) of the film 104 is greater than or equal to that of the photovoltaic panel 200 so that the shadow pattern(s) formed by the portion(s) 106 are projected onto all the photovoltaic cells of the panel 200. It is also conceivable that the width of the film 104 is greater than or equal to those of several photovoltaic panels 200 arranged next to each other, which makes it possible to simultaneously characterize several photovoltaic panels 200.

[0052] It is also possible to use a device 100 whose film 104 has a width less than that of the photovoltaic panel 200, the shadow pattern(s) in this case being projected onto only a portion of the photovoltaic cells of the photovoltaic panel 200.

[0053] In another configuration, the device 100 may comprise several films 104 each intended to be set in motion above at least one part of an associated photovoltaic panel 200 or several photovoltaic panels 200, or each intended to be set in motion on a part of the same photovoltaic panel 200.

[0054] In the embodiment described above, the film 104 is set in motion such that it winds around one of the shafts 108, 110 and unwinds from the other of the shafts 108, 110. trees 108, 110. Thus, in this exemplary embodiment, the film 104 always remains above the photovoltaic panel 200, which makes it possible to use the device 100 even when elements, for example pipes, are located under the photovoltaic panel 200.

[0055] In the embodiment described above, the device 100 comprises two motors 112, 114 each coupled to one of the shafts 108, 110. Alternatively, the device 100 may comprise a single motor coupled to one of the two shafts 108, 110, the other shaft being coupled to an automatic winder type device ensuring the winding of the film 104 around this other shaft.

[0056] In a variant shown in [Fig. 3], the device 100 comprises, in addition to the first and second shafts 108, 110, third and fourth shafts 122, 124 cooperating to guide the film 104 which forms an endless strip guided by the shafts 108, 110, 122, 124. In this variant, the first and second shafts 108, 110 are configured to guide the film 104 opposite the front face 202 of the photovoltaic panel 200, and the third and fourth shafts 122, 124 are configured to guide the film 104 opposite a rear face, opposite the front face, of the photovoltaic panel 200. In this variant, the length of the film 104 is for example between 4 m and 10 m.

[0057] In the exemplary embodiment shown in [Fig. 3], the device 100 comprises a single motor 112 which is coupled to the first shaft 108. It is however possible for the device 100 to comprise one or more other motors coupled to one or more of the other shafts 110, 122, 124.

[0058] In another variant shown in [Fig. 4], the device 100 does not include shafts for guiding the film 104, but lateral rails 126 configured to guide the film 104 in translation above the front face 202 of the photovoltaic panel 200. In addition, in the example shown in [Fig. 4], the film 104 is set in motion not by motors rotating one or more shafts, but by one or more jacks 128 guiding the film 104 in translation in the rails 126.

[0059] An exemplary embodiment of a device 100 for simulating shading on at least one photovoltaic panel, or module 200, according to a second embodiment, is described below in connection with [Fig.5].

[0060] In this second embodiment, the device 100 is intended to be used outdoors, and does not include the lamps 118. The shadow(s) are projected onto the photovoltaic panel 200 using the sunlight which passes through the film 104.

[0061] Furthermore, in this second embodiment, the frame 116 comprises an opening (not visible in [Fig. 5]) configured to be arranged opposite the front face 202 of the photovoltaic panel 200, and so that the film 104 can be set in motion opposite the front face 202 of the photovoltaic panel 200 through the opening.

[0062] Finally, in the example shown in [Fig. 5], the photovoltaic panel 200 is not arranged parallel to the ground. The frame 116 is inclined such that the film 104 can be moved parallel to the front face 202 of the photovoltaic panel 200.

[0063] To characterize the photovoltaic panel 200, whatever the embodiment or variant of the device 100, the following steps can be implemented: - arranging the device 100 and the photovoltaic panel 200 such that the film 104 of the device 100 is arranged opposite a front face 202 of the photovoltaic panel 200; - setting in motion the film 104 of the device 100; - measuring the current-voltage characteristic of the photovoltaic panel 200 by the current-voltage measuring device 120 of the device 100, simultaneously with the movement of the film 104 of the device 100.

Claims

Claims

1. Device (100) for simulating dynamic shading on at least one photovoltaic panel (200) formed of photovoltaic cells, comprising at least: - a film (104) intended to be moved opposite a front face (202) of the photovoltaic panel (200), at least one part (106) of which is at least partially opaque and representative of a shading pattern intended to be projected onto the front face (202) of the photovoltaic panel (200); - a device (108, 110, 122, 124, 126) for guiding the film (104) with respect to the front face (202) of the photovoltaic panel (200); - an actuating device (112, 114, 128) configured to set the film (104) in motion with respect to the front face (202) of the photovoltaic panel (200) and at least several photovoltaic cells of this photovoltaic panel (200).

2. A dynamic shading simulation device (100) according to claim 1, wherein the actuating device comprises at least one motor (112, 114) or at least one cylinder (128).

3. A dynamic shading simulation device (100) according to claim 2, wherein: - the actuating device comprises at least a first motor (112); - the guiding device comprises first and second shafts (108, 110) around which the film (104) is configured to be wound and unwound; - the first motor (112) is coupled to the first shaft (108).

4. A dynamic shading simulation device (100) according to claim 3, wherein the actuator further comprises a second motor (114) or an automatic winder, coupled to the second shaft (110).

5. A dynamic shading simulation device (100) according to claim 2, wherein: - the actuating device comprises at least a first motor (112); - the guiding device comprises first, second, third and fourth shafts (108, 110, 122, 124); - the first motor (112) is coupled to one of the first, second, third and fourth shafts (108, 110, 122, 124); - the film (104) forms an endless strip guided by the first, second, third and fourth shafts (108, 110, 122, 124); - the first and second shafts (108, 110) are configured to guide the film (104) opposite the front face (202) of the photovoltaic panel (200), and the third and fourth shafts (122, 124) are configured to guide the film (104) opposite a rear face, opposite the front face (202), of the photovoltaic panel (200).

6. A dynamic shading simulation device (100) according to claim 2, wherein the guide device comprises side rails (126) configured to guide the film (104) in translation.

7. Dynamic shading simulation device (100) according to one of the preceding claims, in which the film (104) comprises a layer of transparent material, and the at least partially opaque part of the film is formed by at least one at least partially opaque element (106) arranged against the layer of transparent material and secured to the layer of transparent material in a removable manner.

8. A dynamic shading simulation device (100) according to one of the preceding claims, further comprising a frame (116) to which the guide device (108, 110, 122, 124, 126) and the actuating device (112, 114, 128) are secured.

9. A dynamic shading simulation device (100) according to claim 8, wherein the frame (116) forms a support configured so that a rear face of the photovoltaic panel (200) is arranged on the support.

10. A dynamic shading simulation device (100) according to claim 8, wherein the frame (116) comprises an opening configured to be arranged opposite the front face (202) of the photovoltaic panel (200), and such that the film (104) can be set in motion opposite the front face (202) of the photovoltaic panel (200) through the opening.

11. Device (100) for dynamic shading simulation according to one of the preceding claims, further comprising a light source (118) configured to illuminate a first face of the film (104), and in which a second face of the film (104), opposite the first face, is intended to be moved opposite the front face (202) of the photovoltaic panel (200).

12. A dynamic shading simulation device (100) according to claim 1 indication 11, wherein the light source (118) is configured to emit light conforming to the AM 1.5 solar spectrum and / or with a power between 200 W / m2 and 2000 W / m2.

13. Dynamic shading simulation device (100) according to one of the preceding claims, further comprising a current-voltage measuring device (120) configured to measure the current-voltage characteristic of the photovoltaic panel (200).

14. Method for characterizing at least one photovoltaic panel (200), comprising at least the following steps: - arranging a dynamic shading simulation device (100) according to claim 13 and the photovoltaic panel (200) such that the film (104) of the dynamic shading simulation device (100) is arranged opposite a front face (202) of the photovoltaic panel (200); - setting in motion the film (104) of the dynamic shading simulation device (100); - measuring the current-voltage characteristic of the photovoltaic panel (200) by the current-voltage measuring device (120) of the dynamic shading simulation device (100), simultaneously with the movement of the film (104) of the dynamic shading simulation device (100).

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