FR2959619A1 - SAFETY DEVICE FOR PHOTOVOLTAIC PANELS FOR ERP - Google Patents

Abstract

The present invention relates to a security device for a photovoltaic panel for short-circuiting the electrical power outputs of the panel, provided with a connector for connecting said electrical outputs of the panel in which the connector is provided with a switch with a first "passive" position to maintain the connection between the electrical outputs of the panel and a second "active" position to interrupt the connection between the electrical outputs of the panel, wherein the device is provided with a control element allowing the switch to move from its "passive" position to its "active" position.

Description

Security device for photovoltaic panels for ERP Current status of equipment: Photovoltaic solar panels are generators transforming solar light energy into DC voltage.

They generally consist of cells or photosensitive films constituting one or more semiconducting junctions. At the level of each cell, the excitation of these junctions by the photons releases electrons which are then collected through conductors (strings).

A set of cells is thus placed in series-parallel, said cells being encapsulated in a glass-glass or glass-support structure, in order to obtain a solar generator a few tens of volts, representing a peak power of a few tens to hundreds of volts. watts.

These panels are delivered in dimensions of the order of m2, and associated with a connection system generally consists of a junction box comprising by-pass diodes and 2 cables for the 2 polarities, provided with standardized connectors.

These panels are then connected in series, in order to obtain the greatest possible voltage compatible with the low voltage dielectric strength of these devices (1000V) as well as with the input ranges of DC / AC converters available on the market.

Such photovoltaic panels are subject to international standards, such as 0E161215, for example, which allows them to be qualified and approved, particularly for their resistance to climatic and environmental constraints.

Photovoltaic installations generally consist of panels placed in series, as described above, and installed on roofing, shade or other supports. The electrical collection circuits are then supplemented by surge arresters and disconnecting, or even fuse or magnetothermic protection for isolating the generator.

The installation thus constituted, with a power of a few tens to a few hundred kW, is connected to one or more converters transforming the collected energy in the form of direct current, into alternating current suitable for use, thus allowing its reinjection into the electrical distribution network or its storage by means of batteries, or its immediate use.

Such installations, with their disconnection, protection and connection to the network, are subject to the standards and installation guides such as the C15-400 or C15-712 guides.

In buildings known as ERP, that is to say likely to receive public, electrical installation must be able to be cut and disconnected from the network, safely and easily, by the security services. Thus, an intervention of firefighters on a fire outbreak will begin by de-energizing the general electrical installation (cut-off at the circuit-breaker of the installation) .30 However, the presence of a photovoltaic installation does not allow this operation: in fact, the installation can be disconnected at its connection to the network and firefighters can cut the panels at the protective boxes located upstream of the converters. However, these isolations do not power off the system.

In all cases, the panels remain electricity generators still operational during the day, and all the panels connected in series will always present a dangerous high voltage for the intervention services, even if the installation downstream has been turned off.

Therefore, when the response services arrive at the scene of a disaster and begin, first and foremost, by shutting down the electrical installation, they will still be able to find in this place cables and devices with dangerous voltages. goes against habits, procedures and safety rules.

The object of the invention is to eliminate the above drawback, being sure that the fact of cutting the electrical installation of the building, and therefore any connection to the network, will safely and instantaneously remove dangerous voltages, even if the photovoltaic system remains lit.

For this reason, the object of the invention is a security device for a photovoltaic panel enabling the electrical power outputs of the panel to be short-circuited, provided with a connector making it possible to connect the said electrical outputs of the panel in which the connector is provided with a switch with a first "passive" position to short-circuit the electrical outputs of the panel and a second "active" position to interrupt the short circuit of the electrical outputs of the panel, in which the device is provided with a control element allowing the switch to move from its "passive" position to its "active" position.

Thanks to this measurement, it is ensured that the device according to the invention is normally in natural short-circuit position. This means that the device is capable of producing power only if the switch is actively manipulated from its "passive" position, to ensure this short circuit, to an "active" position to enable said device to generate power. energy.

In case of power failure of the installation, the centralized power supply is also cut off and the device according to the invention no longer receives electricity. In other words, it returns to its "passive" position, bypassing the panel to which it is integrated.

In a preferred embodiment, the device comprises an electrical safety loop connected to the control element for actuating said control element with said electrical safety loop.

In a preferred embodiment, the device comprises a control element operated by means of a coded command.

In a preferred embodiment, the device comprises a power-operated control element.

In a preferred embodiment, the device comprises an electromagnetic relay. In a preferred embodiment, the device comprises a static relay.

In a preferred embodiment, the connector bypasses the electrical outputs of the panel.

In a preferred embodiment, the connector bypasses each electrical output of the panel to ground.

In a preferred embodiment, the device is integrated in the photovoltaic panel.

Next, the present invention also relates to a photovoltaic system comprising at least one photovoltaic panel and a connector in which the photovoltaic system comprises the security device according to the invention and wherein said security system has characteristics enabling it to be positioned between the panel power electrical outlets and the connector.

In addition, the present invention relates to a photovoltaic panel comprising the security system according to the invention.

The invention will be better appreciated on reading the description which refers to the drawings in which: FIG. 1 shows a first embodiment of the device according to the invention, FIG. 2 shows a second embodiment of the device according to the invention. FIG. 3 shows a panel of the device provided with the device according to the invention, FIG. 4 shows a second embodiment of a panel provided with the device according to the invention, and FIG. a photovoltaic panel integrating the device according to the invention.

In Fig. 1, a short circuit device 10 of a photovoltaic panel 40 is shown. This device 10 is electromechanical or static and can be placed in the individual connection box of each panel 40. It can also be made in a separate housing and connected to said panel 40, in the case where it is already existing. The device 10 is normally and naturally in the short-circuit position. It requires the contribution of external energy very low voltage to de-short circuit board 40.

In the case where different photovoltaic panels 40 are used together to construct a photovoltaic system, a safety loop consisting of a conductive cable of small section, for example a telephone pair, connects all the devices 10 of short circuit in parallel.

The centralized supply device of the device according to the invention can be integrated in the photovoltaic converter, but can, alternatively, be a simple power supply TBT (12 or 24V).

In normal operation, the centralized power supply excites each device 10 through the security loop 11 which connects them. Each device 10 is thus kept in an "active" position and allows each panel to deliver its electrical energy.

In the event of an electrical power failure, the centralized power supply is also cut off and the safety loop no longer excites each DSPP. It returns to its "closed" position, bypassing the panel to which it is integrated.

In a similar manner, the disconnection of a panel 40 or the tearing off of its connections immediately causes the safety loop 11 to be de-energized, causing the panel 40 to short circuit and the cancellation of any dangerous voltage at its terminals. (the photovoltaic current is looped back on itself).

In Fig. 1, the short circuit device 10 of a panel 40 is shown in a first embodiment. The device 10 may be produced using an electromechanical or static relay whose single contact bypasses the two polarities 12, 13 of the panel 40. In its "passive" position, the security device 10 according to FIG. provides the connection of the two polarities 12, 13 of the panel 40. With the safety loop 11, the switch 14 can be moved from a "passive" position to short-circuit the two polarities 12 13 to an "active" position to allow the panel 40 to deliver its electrical energy.

A second embodiment is shown in FIG. 2, in which the device 20 for short-circuiting a panel 40 is made by means of an electromechanical and static relay whose contacts short-circuit each polarity 12, 13 of the panel 40 to the Earth.

The advantage of this latter embodiment is that the panel 40 is in short circuit and ground potential.

The device 20 according to Figure 2 may be fed in series or in parallel by the safety loop 11, according to the diagram or the component used.

The fact that the device 10, 20 requires an external supply of energy to be excited and remain in the "active" position, ensures full and safe short-circuiting of the generators if the installation is de-energized, that is, ie disconnected from the power grid.

The fact that the device 10, 20 is integrated in the panel 40, or in its connection box, ensures that the panel 40 is always off, when it is handled, torn off or when it is laid. Any panel 40 thus becomes non-hazardous because de-energized from the moment it is not connected to a live electrical installation.

It will always be advantageous to place the device 10, 20 closer to the cell assembly constituting the photovoltaic panel 40 so that it is inseparable.

The device 10, 20 according to the invention can be added to the photovoltaic panel 40 in several ways. A first possibility is shown in FIG. 3, according to which the device 10, 20 according to the invention is directly integrated into the connection box 41 of the panel 40. The entire photovoltaic panel 40 and the connection box 41 then have two cables. 12, 13 and two cables forming an integral part of the safety loop 11.

A second possibility for integrating the device 10, 20 according to the invention into the panel is shown in FIG. 4. According to this FIG. 4, the entire photovoltaic panel 40 and the connection box 41 have an output comprising two power cables. 12, 13. Each power cable 12, 13 is connected, via a connection 15, 16, to two input cables, an independent housing which forms the device 10, 12. The housing 50 has an output comprising two power 51, 52 that can be connected to an installation, for example an electrical network, and to the two cables forming part of the loop 11.

The solution according to Figure 4 is suitable for any photovoltaic panel 40 commercially available.

A third possibility of integrating the device 10, 20 according to the invention to the photovoltaic panel 40 consists in integrating said device 10, 20 directly inside the panel between the two glass panels 42, 43 ("glass-glass" technology ) or between the glass panel 42 and the rear support 43. In any case, the circuit can then be inserted into a housing formed in the rear support 43.

The device 10, 20 can be produced by a normally closed electromechanical relay or 'vacuum bulb' type, if the device 10, 20 is outside the panel, or in its connection box 41. In the case where the device 10, 20 is integrated in the panel 40, as shown in Figure 5, it will preferably be made statically (MOS transistor very low RdsON, or thyristor).

In FIG. 5, the device 10, 20 is integrated inside a housing present in the rear support 43 of the photovoltaic panel 40. In the case where the "glass-glass" technology is used, this rear support 43 The device 10, 20 comprises a plurality of electronic components embedded in a coating 44. The cables forming the safety loop 11 exit the device 10, 20 in order to be connected to a power supply. centralized to which will be connected all the security loops 11 of all panels 40 of the system.

In order to inform the security services, the presence of a device according to the invention can be signaled near the cut-off and disconnection devices, by indication panels "photovoltaic installation ERP: switching off the panels by cutting connection to the network ".

The device 10, 20 according to the invention can be controlled in several ways. According to a first option, the device 10, 20 can be controlled directly. In this case, it is the direct supply of the safety loop 11 by a very low voltage that excites the switch 14 short circuit, allowing its opening.

According to a second option, the device 10, 20 according to the invention can be controlled by means of a coded command. In this case, the short circuit device 10, 20 is associated with a specialized microcontroller which will continuously analyze the safety loop 11 which also serves as a power supply.

This security loop 11, connected to the converter, is permanently traversed by an encrypted control code. When the device 10, 20 is integrated in the panel 40 sees this code and decrypts it with its private key, it bypasses the panel 40 (transition to "open" mode), which can then supply its energy to the converter. The code associated with the converter can be inserted at the installation of the converter and corresponding panels 40.

According to a third option, the device 10, 20 according to the invention can be controlled by carrier current. In this case, the safety loop 11 consists of the two power cables 12, 13 of the panel 40: the coded signal, injected at the converter, is extracted from the two power cables 12, 13 of the panel 40 and processed by the microprocessor to decide the short circuit of the panel 40.

The different control strategies are available to control the operation of the device 10, 20 according to the invention. When connecting the converters to the distribution network, for feedback: - the presence of the mains voltage on the output of the converter causes the supply of the safety loop 11, or the sending of the control code (on the loop or in the input power network of the converter), - when the code is correctly decoded, or the safety loop 11 fed, the device 10, 20 goes into open mode, which allows the energy of the panels 40 of reach the converters.

When disconnecting the inverters from the distribution network: - the absence of mains voltage on the output of the converter causes the safety loop 11 to go out, or the control code to stop sending (on the loop 11 or in the input power network of the converter), - the absence of the code, or the de-energization of the safety loop 11, puts the device 10, 20 in closed mode, which bypasses the panel 40 and no longer allows the energy of the panels 40 to reach the converters: all the circuits located downstream of the device 10, 20 are found off, and possibly grounded according to the embodiment of the device 10, 20.

Claims (1)

REVENDICATIONS1. Safety device for a photovoltaic panel CLAIMS1. Security device for a photovoltaic panel for short-circuiting the electrical power outputs of the panel, provided with a connector for connecting said electrical outputs of the panel in which the connector is provided with a switch with a first "passive" position To bypass the electrical outputs of the panel and a second "active" position to interrupt the short circuit of the electrical outputs of the panel, wherein the device is provided with a control element allowing the switch to move from his "passive" position towards his "active" position. An apparatus according to claim 1, wherein the device comprises an electrical safety loop connected to the control element for actuating said control element with said electrical safety loop. Device according to claims 1 or 2, wherein the control element is actuated by means of a coded command. Device according to claims 1 or 2, wherein the control element is actuated by carrier current. Device according to one of claims 1 to 4, wherein the device comprises an electromagnetic relay. Device according to one of claims 1 or 4, wherein the device comprises a static relay. Apparatus according to claim 5 or 6, wherein the connector bypasses the electrical outputs of the panel. Apparatus according to claim 5 or 6, wherein the connector bypasses each electrical outlet of the panel to ground. Device according to one of the preceding claims wherein the device is integrated in the photovoltaic panel. Photovoltaic system comprising at least one photovoltaic panel and a connector, in which the photovoltaic system comprises a safety device according to one of claims 1 to 8, wherein said security system has characteristics enabling it to be positioned between the electrical outputs power of the panel and the connector. Photovoltaic panel comprising the safety device according to one of claims 1 to 6.