ELECTRICAL ENERGY STORAGE MODULE FOR DEVICE FOR CONVERTING PHOTOVOLTAIC ENERGY INTO ELECTRICAL ENERGY

Abstract

The invention relates to an electrical energy storage module (120) of a device (10) for converting photovoltaic energy into electrical energy, said electrical energy storage module (120) being characterised in that it is designed to be detachably mounted on said device (10).

Claims

1. An electrical energy storage module of a device for converting photovoltaic energy into electrical energy, said device comprising at least one photovoltaic panel, said electrical energy storage module being configured to be removably mounted on said photovoltaic panel.

2. The storage module according to claim 1, said storage module being configured to be integrated in a device for converting photovoltaic energy into electrical energy.

3. The storage module according to claim 1, said storage module being configured to be mounted on the rear part of a device for converting photovoltaic energy into electrical energy.

4. The storage module according to claim 1, said storage module comprising fastening means on a photovoltaic panel of a device for converting photovoltaic energy into electrical energy.

5. The storage module according to claim 4, wherein the fastening means are fastening means by clamping, by blocking or by embedding.

6. The storage module according to claim 1, said storage module comprising means of adjustment enabling it to be fastened on photovoltaic panels of different dimensions.

7. The storage module according to claim 1, said storage module being in the form of a substantially flat plate.

8. The storage module according to claim 1, said storage module comprising insulation means for protecting it from high and low temperatures of a device for converting photovoltaic energy into electrical energy on which it is mounted.

9. The storage module according to claim 1, said storage module comprising heat dissipating means.

10. The storage module according to claim 1, said storage module comprising a plurality of storage cells connected together, in parallel or in series.

11. A device for converting photovoltaic energy into electrical energy, said device comprising at least one electrical energy storage module according to claims 1.

12. The device according to claim 11, said device comprising an internal inverter connected to the electrical energy storage unit.

13. The device according to claims 11, said device comprising a monitoring unit of the electrical energy storage module configured to protect it against shocks, short circuits, strong currents, surges and temperature elevations and/or to manage the storage and destocking of electrical energy by the electrical energy storage module.

14. The device according to claim 13, wherein said monitoring unit comprises a communication sub-unit configured to control the use of the electrical energy storage module and/or to remotely check the state of the storage module.

15. A system comprising a device for converting photovoltaic energy into electrical energy according to claim 14 and a terminal configured to communicate with said communication sub-unit by Power Line Carriers for controlling the monitoring unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG. 1 illustrates schematically an embodiment of a system according to the invention.

[0059] FIG. 2 is a rear view of an embodiment of a device for converting photovoltaic energy into electrical energy according to the invention.

[0060] FIG. 3a is a partially transparent view of the inner face of a first embodiment of a electrical energy storage module according to the invention.

[0061] FIG. 3b is a view of the outer face of a second embodiment of an electrical energy storage module according to the invention.

[0062] FIG. 4a is a partial sectional view of a first embodiment of a device according to the invention.

[0063] FIG. 4b is a partial sectional view of a second embodiment of a device according to the invention.

[0064] FIG. 5 illustrates a first implementation mode of the device according to the invention connected to an electrical network.

[0065] FIG. 6 illustrates a second implementation mode of the device according to the invention connected to an electrical network.

[0066] FIG. 7 illustrates a third implementation mode of the device according to the invention connected to an electrical network.

[0067] FIG. 8 illustrates a first implementation mode of the device according to the invention operating in isolated mode.

[0068] FIG. 9 illustrates a second implementation mode of the device according to the invention operating in isolated mode.

[0069] FIG. 10 illustrates a third implementation mode of the device according to the invention operating in isolated mode.

DETAILED DESCRIPTION

[0070] I. System 1

[0071] FIG. 1 illustrates schematically an embodiment of system 1 according to the invention. The system 1 comprises a device for converting photovoltaic energy into electrical energy 10 and a terminal 20.

[0072] A) Device 10

[0073] The device 10 according to the invention advantageously allows producing electrical energy from photovoltaic energy and storing it.

[0074] To this end, still in reference to FIG. 1, the device for converting photovoltaic energy into electrical energy 10 comprises a photovoltaic panel 110 and an electrical energy storage module 120.

[0075] The device according to the invention may be connected to an electrical network 30 (FIGS. 5 to 7) or operate in isolation by being connected directly to an electrical energy consuming unit 40, such as, for example, an apartment building (FIGS. 8 to 10).

[0076] The photovoltaic panel 110 comprises a plurality of photovoltaic cells 112 in the form of a substantially flat plate of low thickness, as known to those skilled in the art, and a photovoltaic module 114.

[0077] In an embodiment illustrated in FIG. 4a, the photovoltaic panel 110 further comprises a frame 116 placed around said plate, for example, made of aluminum, on which the electrical energy storage module 120 is mounted. Alternatively, as illustrated in FIG. 4b, the electrical energy storage module 120 may be mounted directly on the plate.

[0078] The plurality of photovoltaic cells 112 is configured to collect photovoltaic energy, for example solar energy, as known to those skilled in the art. A standard type solar panel may, for example, comprise sixty photovoltaic cells 112.

[0079] The photovoltaic module 114 is configured to generate electrical energy from photovoltaic energy collected by the plurality of photovoltaic cells 112 and to provide said electrical energy to the electrical energy storage module 120 and/or to the electrical network 30 and/or to an electrical energy consuming unit 40.

[0080] The device 10 further comprises an internal inverter 130 connected to the electrical energy storage module 120 and configured to convert the direct current stored in the storage module 120 into usable alternating current to power a variety of common electrical loads. Such internal inverter 130 may be a grid inverter in the electric network 30, for example a micro-inverter.

[0081] The device also comprises a management unit 140 of the electrical energy storage module 120 configured to protect it against significant shocks, short circuits, strong currents, surges and excessive temperature elevations and/or to manage the storage or destocking of electrical energy by the electrical energy storage module 120.

[0082] To this end, the management unit 140 is connected, on the one hand, to the photovoltaic module 114 and, on the other hand, to the electrical energy storage module 120 and to the internal inverter 130.

[0083] The management unit 140 may be mounted on the photovoltaic panel 110, for example, above or next to the electrical energy storage module 120.

[0084] In this example, the management unit 140 is further configured to equalize the plurality of storage cells 128 (with reference to FIG. 3a) of the electrical energy storage module 120 by putting them in parallel during their period of inactivity.

[0085] The management unit 140 comprises at least one indicator of the load state of the electrical energy storage module 120 such as, for example, one or more Light Emitting Diodes (LEDs).

[0086] In the illustrated embodiment, the management unit 140 of the electrical energy storage module 120 comprises a communication sub-unit 142 configured to control the use of the electrical energy storage module 120, particularly so as to provide the electrical energy stored by the storage module 120 to an electrical network 30, and/or to remotely check the state of the storage module 120.

[0087] Such communication sub-unit 142 may be configured to communicate with a terminal 20 of a link L1 which can be wired or wireless, for example by Power Line Carrier (PLC).

[0088] B) Electrical energy storage module 120

[0089] The electrical energy storage module 120 is configured to be removably mounted on the device for converting photovoltaic energy into electrical energy 10.

[0090] In the two embodiments illustrated in FIGS. 3a to 4b, the electrical energy storage module 120 is in the form of a substantially flat plate of small thickness, for example inferior to 40 mm, and in particular lower than the thickness of the photovoltaic panel 110, thereby advantageously integrating the storage module 120 to the device for converting photovoltaic energy into electrical energy 10 without the storage module 120 protruding from the photovoltaic panel 110.

[0091] For example, the width of the storage module 120 may be between 100 and 500 mm and its length may be between 500 and 2000 mm.

[0092] As illustrated in FIGS. 4a and 4b, the electrical energy storage module 120 comprises an inner face FI arranged to be disposed in line with the rear side 12 of the photovoltaic panel 110, and an outer face FE opposite said inner face FI.

[0093] To this end, still in reference to FIGS. 4a and 4h, the electrical energy storage module 120 comprises means for fastening it to the photovoltaic panel 110.

[0094] In the example of FIG. 4a, the photovoltaic panel 110 comprises a frame 116 and the electrical energy storage module 120 is mounted on said frame 116 by means of blades or fastening tabs 121a and a system of screws and nuts 121b. Such fastening means especially allow mounting the electrical energy storage module 120 by embedding, by blocking or by clamping on different types of photovoltaic panels.

[0095] Such blades or fastening tabs 121a also allow attaching the electrical energy storage module 120 to the photovoltaic panel 110 without drilling in order to preserve the integrity of the aluminum frame 116. The parts in contact with the aluminum frame 116 may, for example, be either in aluminum or plastic to avoid any electrolytic torque.

[0096] In the example of FIG. 4b, the photovoltaic panel 110 does not comprise any frame. In this case, the securing means are in the form of one or more strips 121c fixed directly on the surface of the photovoltaic panel 110, for example by clamping.

[0097] The electrical energy storage module 120 further comprises means of adjustment, anti-theft means 123, insulation means 124, heat dissipation means 125 and first electrical connecting means 126 and second electrical connecting means 127.

[0098] Adjustment means may be provided to adjust the fastening of the electrical energy storage module 120 on devices 10 of different dimensions.

[0099] The adjustment means may, for example, be in the form of sliding parts (not represented) whose adjustment is achieved with the screws and nuts system 121b so as to adapt the length of the storage module 120 to the frame width 116 of the photovoltaic panel 110. The width may, for example, be adjustable over a length of 100 mm for a width of the photovoltaic module 110 comprised between 950 to 1,050 mm in order to accommodate a large number of photovoltaic modules of different types.

[0100] The adjustment of the length of the storage module 120 can also be achieved by using fastening means, for example, by adapting the length of the blades or tabs 121a or by using flexible blades or tabs 121a.

[0101] The anti-theft means 123 are, for example, in the form of self-breaking anti-theft screws or equipped with a tamper-proof head.

[0102] As shown in FIG. 3a, the insulation means 124 are configured to protect the electrical energy storage module 120 from high temperatures likely to be reached by the photovoltaic panel 110, particularly at its photovoltaic cells 112, for example above 40 C. as well as low temperature, such as below zero.

[0103] These insulation means 124 may advantageously be in the form of an insulating sheet having, for example, a white or reflective surface, mounted on the inner face FI of the storage module 120.

[0104] The heat dissipation means 125 are configured to improve heat convection, produced especially by the photovoltaic panel 110, and allow cooling the electrical energy storage module 120.

[0105] In this example, the dissipation means 125 are arranged on the outer face FE of the electrical energy storage module 120.

[0106] The first electrical connection means 126 are configured to electrically connect the electrical energy storage module 120, on the one hand, to the photovoltaic module 114 so as to store the electrical energy produced by the photovoltaic panel 110 and, on the other hand, to an internal inverter 130 or to an external inverter charger (reference FIG. 10) to provide it with the stored electrical energy. These first connection means 126 may be in the form of one or more connectors, for example, MC4 type known to those skilled in the art, as illustrated in the example of FIG. 3b, or power cables, as illustrated in the example of FIG. 3a.

[0107] The second electrical connection means 127 allow connecting the storage module 120 to at least another electrical energy storage module, preferably of the same type 120. In the example illustrated in FIG. 2, two electrical energy storage modules 120 are mounted in parallel on the rear face 12 of the photovoltaic panel 110 for converting photovoltaic energy into electrical energy in order to increase its electrical energy storage capacity.

[0108] These second connection means 127 can be in the form of one or more connectors, for example, MC4 type known to those skilled in the art, as illustrated in the example of FIG. 3b, electrical cables as illustrated in the example of FIG. 3a, or alternatively, for example, terminal blocks.

[0109] In order to store the energy produced by the photovoltaic panel 110, the storage module 120 comprises a plurality of electrical energy storage cells 128, lithium battery type, the storage capacity of each of its cells 128 being, for example, between 30 and 150 Wh. These storage cells 128 are interconnected in series in the storage module 120.

[0110] Advantageously, as partially shown transparently in FIG. 3a, the electrical energy storage module comprises ten LiFeP04 type storage cells 128 connected in series for a nominal voltage of 32 Vdc in the storage module 120. The photovoltaic panel in this case may comprise, for example, sixty photovoltaic cells. The nominal voltage of the set formed by the ten storage cells 128 is thus of the order of the nominal voltage of the set formed by the sixty photovoltaic cells, thereby avoiding the use of a tracking unit of the maximum power point (known to those skilled in the art) configured to continuously deliver maximum power to the electric energy storage module.

[0111] A storage module 120 may, for example, have a capacity equivalent to a production day. A 250 Wc photovoltaic panel produces from 0 to 1750 Wh in one day depending on the amount of sunshine in the site. The LiFeP04 cells are 3.2 V nominal. Ten 3.2 V-30 Ah-storage cells 128 would thus produce 960 Wh nominal voltage of stored electrical energy.

[0112] Such electrical energy storage module 120 is light, e.g. less than 10 kg, to make it easy to handle.

[0113] The management unit 140 may be cast in resin to improve its temperature resistance, its shock resistance and prevent copying.

[0114] Finally, it can be envisaged to mount several electrical energy storage modules 120 in parallel in order to increase the total storage capacity of the device 10.

[0115] C) Terminal 20

[0116] The terminal 20 is configured to communicate with the communication sub-unit 142 of the management unit 140 of the device 10 in order to control said management unit 140. For example, the terminal 20 can be configured to control the load state of the electrical energy storage module 120, in particular each of its storage cells 128, its voltage, its input current, its outgoing current and/or the commissioning or shutdown of said storage module 120. To this end, the terminal 20 comprises in this example a screen 22 for displaying these parameters and controlling the management unit 140. It should be noted that any other control means of the management unit 140 may be used, e.g. buttons or control keys.

[0117] II. Implementation examples according to the invention

[0118] FIGS. 5-7 illustrate three modes of implementation of the device 10 according to the invention when it is connected to an electrical network 30.

[0119] In a first implementation mode, shown in FIG. 5, the internal inverter 130 injects electrical energy, produced by photovoltaic module 114 from the photovoltaic energy collected by the plurality of photovoltaic cells 112, directly into the electrical network 30.

[0120] In a second implementation mode, shown in FIG. 6, when the network cannot or should not accept the production, the photovoltaic module 114 provides the electrical energy produced to the storage module 120 which stores it in the storage cells 128. This can be used in particular to limit the maximum power injected on a low electrical network 30, to keep the surplus production in a subsistence installation, or even to adapt the production of the internal inverter 130 to local consumption.

[0121] In a third implementation mode, shown in FIG. 7, the storage module 120 provides power to the internal inverter 130 which then injects electrical energy into the electrical network 30. This mode may be implemented when the photovoltaic module 114 does not produce any electricity, for example at night or during cloudy periods.

[0122] FIGS. 8-10 illustrate three implementation modes of the device 10 according to the invention operating in isolation, that is to say, when connected directly to an electrical energy consuming unit 40 such as, for example, an apartment building, a telecommunications relay, a lighting system or a factory. In these implementation modes, two conversion devices 10 are used for supplying electrical energy to the unit 40.

[0123] In a first implementation, shown in FIG. 8, each device 10 comprises a charger type internal inverter 130. These inverter chargers 130 operate in parallel in a configuration with one master and n slaves (here n=I) so that the master controls the one or more slaves, for example in frequency for monophasic synchronized operation or shifted to 120 for three-phase operation, to provide energy to the unit 40.

[0124] In a second implementation mode, shown in FIG. 9, each device 10 comprises an internal micro-inverter 130. An external inverter 150, for example a reversible inverter charger, allows frequency management and network operation with the internal micro-inverters 130 of the set formed by the devices 10 to provide energy to the unit 40. The external inverter 150 is further connected to a battery bank for storing part of the electrical energy supplied by the devices.

[0125] In a third implementation mode, shown in FIG. 10, the storage modules 120 of the devices 10 are connected in parallel with their respective second electrical connection means 127 and provide a voltage, for example between 20 and 36 Vdc, to an inverter charger or an external direct current converter 160 which in turn supplies the unit 40 and an external battery bank 170. It should be noted that, in the latter mode, the device 10 does not comprise an internal inverter 130.

[0126] During the implementation of the device 10 according to the invention, the terminal 20 may be used at any time to manage the one or more electrical energy storage module(s) 120, by communicating via the communication sub-unit 142 of the management unit 140 of the device 10. For example, the terminal 20 may be used to display the load state of the one or more electrical energy storage module(s) 120, in particular each of their storage cells 128, their voltage, their input current, their outgoing current and/or allow the commissioning or shutdown of said one or more storage module(s) 120.

[0127] The device according to the invention is advantageously not affected by the irregularity of photovoltaic production over time as it integrates electrical energy storage, and avoids the implementation difficulties of storage modes external to solar panels.

[0128] The supply of electricity can thus be easily managed, in particular by distributing it over the day, for example, by interrupting production of part of the internal inverters 130 at midday, then operating these internal inverters 130 at night.

[0129] In addition, several devices according to the invention can be connected together easily and quickly in order to increase the capacity of energy production, making such a set modular and evolutionary. In such case, if one of the devices is defective, the others continue producing.

[0130] If the device 10 does not comprise an internal inverter 130, the device 10 may be directly connected to an external inverter 160. In addition, maintenance and/or monitoring the device 10 may also advantageously be done remotely thanks to the terminal 20.

[0131] The electrical energy storage module 120 and the device 10 are thus both modular and evolutionary and it suffices to add one or more devices 10 to increase the capacity of the set. The electrical energy storage module 120 is also very easy to replace and can be replaced without accreditation or particular skills as part of the maintenance.

[0132] If the device 10 comprises several electrical energy storage modules 120 and one of them is defective, the others can continue to supply electricity. The installation and use of the electrical energy storage module 120 according to the invention are easy and do not require specific technical skills.

[0133] The electrical energy storage module 120 may also be mounted on most standard photovoltaic panels 110 without modification thereof. Finally, if the electrical energy storage module 120 fails, the photovoltaic panel 110 remains operational.

[0134] It should be noted, moreover, that the present invention is not limited to the examples described above and may be subject to numerous variants available to those skilled in the art.

[0135] In particular, the shapes of the photovoltaic panel 110 and the storage module 120, the number and type of storage cells 128, the nature of the fastening means, the adjustment means, the anti-theft means 123, the insulation means 124, the heat dissipation means 125, the first electrical connection means 126 and the second electrical connection means 127, as shown in the figures in order to illustrate an exemplary embodiment of the invention, cannot be interpreted as limiting.