Abstract:
This short-circuiting device establishes and maintains a short-circuit across the terminals of a photovoltaic array having at least one photovoltaic panel. It comprises a member designed, on a given signal, to establish and maintain a short-circuit between two electrically conductive tracks each connected to a terminal of the photovoltaic panels of the photovoltaic array. The short-circuiting device furthermore comprises an indicator that the short circuit has been established and is being maintained, the means being mechanically activated by the member designed to establish and maintain the short-circuit. The indicator includes a warning light independent of the member and establishing and maintaining the short-circuit, and that can move, under the action of an elastic member, between a retracted position, in which it indicates that electrical power is being produced by the array, and a visible position, indicating that a short-circuit has been established and is maintained between the tracks.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a National Stage of International Application No. PCT/FR2011/052005 filed Sep. 1, 2011, which published as WO 2012/089947 on Jul. 5, 2012. PCT &#39;005 claims priority to French Application No. 10 56926 filed Sep. 1, 2010. All the above applications are herein incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to a short-circuiting device for a photovoltaic array designed to establish and maintain a short-circuit across the terminals of photovoltaic panels installed in the building. 
       BACKGROUND 
       [0003]    In the field of energy production by recovering solar radiation, it is common to install photovoltaic panels on the roofs of buildings, whether they are individual homes or professional buildings. The energy produced is either provided to the public grid, or used in the buildings themselves for various purposes. 
         [0004]    During emergency or maintenance operations, it is necessary to stop energy production by the photovoltaic arrays so as to guarantee the physical integrity of the people performing those operations. Firefighters in particular must deactivate energy production before any intervention on fires. 
         [0005]    From that perspective, it is known, for example from EP-A-1 720 241 to use means for interrupting the production of electrical current in particular using circuit breakers or short-circuiting devices, so as to guarantee that the building is secured. These means are generally activated from a predefined part of the building at the time of the operation. 
         [0006]    Once this manipulation has been done, it is necessary for the operating personnel to be notified that the building has been secured. To that end, FR-A-2 940 548 provides indicators in particular implementing visual signals. However, these indicator means do not make it possible to be sure that the array is actually secured, since these means in particular operate using electronic detection and indicator members that may be subject to malfunctions, in particular in case of fire. 
         [0007]    It is known from DE-A-20 2006 020 737 to equip a short-circuiting device with indicator means mechanically connected to the member performing the short-circuit, so as to show or hide a signal as a function of the movement of that member. However, the solution does not provide enough precision and reliability, in particular visual. 
         [0008]    The invention aims to resolve these drawbacks by proposing a short-circuiting device for a photovoltaic array making it possible to indicate the actual performance of the short-circuit across the terminals of photovoltaic panels reliably and to prevent the indicator means from being activated in an untimely manner. 
       SUMMARY 
       [0009]    To that end, the invention relates to a short-circuiting device designed to establish and maintain a short-circuit across the terminals of a photovoltaic array comprising at least one photovoltaic panel, said short-circuiting device having a member designed, on a given signal, to establish and maintain a short-circuit between two electrically conductive tracks each connected to a terminal of the photovoltaic panels of the photovoltaic array, the short-circuiting device comprising a means for visually indicating that the short-circuit has been established and is being maintained. This short-circuiting device is characterized in that the indicator means is activated mechanically by the member designed to establish and maintain the short-circuit, and in that the visual indicating means comprises a warning light that is independent of the member designed to establish and maintain the short-circuit, and that can move, under the action of the elastic member, between a retracted position, in which it indicates that electrical power is being produced by the array, and a visible position, in which it indicates that a short-circuit has been established and is being maintained between the tracks. 
         [0010]    Owing to the invention, the member that physically produces the short-circuit across the terminals of the photovoltaic panels itself activates the visual indicator indicating that the building has been secured. This activation is done mechanically, it does not depend on the operation of electronic components, and it does not risk being activated in an untimely manner, or being activated when the short-circuit has not actually been done. 
         [0011]    According to other examples, such a short-circuiting device may incorporate one or more of the following features, considered in any technically allowable combination: 
         [0012]    In the retracted position, the visual indicating means is completely housed inside an opaque box and, in the visible position, the visual indicating means extends at least partially outside the box. 
         [0013]    The member designed to establish and maintain the short-circuit is a closing lever that is hinged relative to one of the conductive tracks and subjected to a force exerted by an elastic member, said force tending to move the closing lever toward a position, corresponding to the establishment of the short-circuit, in which the closing lever is in electrical contact with the two conductive tracks. 
         [0014]    The warning light can be moved along an axis parallel to an axis of rotation of the closing lever toward its position corresponding to the establishment of the short-circuit. 
         [0015]    The closing lever is kept in an open position, in which the array draws current normally, by a maintaining hook that is articulated relative to a bottom of the short-circuiting device. 
         [0016]    The short-circuiting device includes an actuator designed to drive the maintaining hook into a position releasing the closing lever. 
         [0017]    The actuator comprises a rod striking the maintaining hook, designed to move in translation toward the maintaining hook under the effect of a second actuator. 
         [0018]    The second actuator is a pneumatic member. 
         [0019]    The pneumatic member is a compressed gas cartridge. 
         [0020]    Alternatively, the second actuator is a mechanical member that can be actuated by a person. 
         [0021]    The warning light is kept in a position indicating the production of electricity by the photovoltaic array by a retaining lever designed to bearingly receive a stop of the indicating means. 
         [0022]    The retaining lever can be moved toward a position in which the indicating means is released toward its position indicating the establishment and maintenance of the short-circuit through a mechanical action exerted by the member designed to establish and maintain the short-circuit. 
         [0023]    The closing lever can strike the retaining lever when it is moved toward its position corresponding to the establishment of the short-circuit. 
         [0024]    The retaining lever comprises a notch for receiving a portion of the indicating means and defines a bearing surface for the stop, around the notch. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention can be better understood, and other advantages thereof appear more clearly, in light of the following description of one embodiment of a short-circuiting device for a photovoltaic array according to its principle, provided solely as an example and done in reference to the appended drawings, in which: 
           [0026]      FIG. 1  is a perspective view of a short-circuiting device according to an example of the invention; 
           [0027]      FIG. 2  is a cross-section in plane II of the short-circuiting device of  FIG. 1 ; 
           [0028]      FIG. 3  is a cross-section similar to  FIG. 2 , in a short-circuit configuration done by the short-circuiting device; 
           [0029]      FIG. 4  is a cross-section in plane IV of the short-circuiting device of  FIG. 1 , in the retracted configuration of a means for indicating the short-circuit belonging to the short-circuiting device according to the invention identical to that of  FIG. 2 ; 
           [0030]      FIG. 5  is a cross-section similar to  FIG. 4 , in the configuration of  FIG. 3  where the indicating means is visible. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]      FIG. 1  shows a short-circuiting device  1  including a box  10  made from an opaque plastic material with a strong resistance to deterioration, in particular to fire, including a bottom  28  and an indicating dome  12  mounted on the box  10 . The short-circuiting device  1  is designed to be inserted, in a building, between photovoltaic panels belonging to a photovoltaic array producing electricity from solar energy (not shown), and energy conversion and storage devices that make it possible to connect the photovoltaic array to the AC electrical grid. This photovoltaic array may include one or more photovoltaic panels connected to each other in a known manner. 
         [0032]    The conversion device may be an inverter (not shown) making it possible to convert the DC current generated by the array into AC current that can be used in particular by household electrical devices. This inverter may incorporate an energy storage device of the capacitance type. 
         [0033]    The short-circuiting device is inserted into the electrical circuit of the photovoltaic array by means of two terminals  14  connected to the positive polarities, and two terminals  16  connected to the negative polarities. 
         [0034]    As shown in  FIGS. 2 and 3 , each of the terminals  14  is connected to a track  20  and  22  by an electrical line L 20  or L 22 . 
         [0035]    A closing lever  24  is articulated on the track  20  around an axis A 24 . The tracks  20  and  22  are parallel to each other and extend over a plate  26  fixed to the box  10  and parallel to the flat bottom  28  of that box. The bottom  28  defines a plane P 28 . The axis A 24  is perpendicular to the plane P 28  and the closing lever  24  is designed to pivot parallel to the plane P 28 . 
         [0036]    The closing lever  24  is designed to create and maintain the short-circuit of the terminals of the photovoltaic array by establishing an electrical contact between the tracks  20  and  22 , as emerges from  FIG. 3 . To that end, the closing lever  24  is made from an electrically conductive material. 
         [0037]    A spring  30  exerts a force F 1  on the closing lever  24  that tends to drive the closing lever  24  into a closed position, in which said lever  24  puts the tracks  20  and  22  in electrical contact, and establishes and maintains the short-circuit. 
         [0038]    When the short-circuit is not required, the closing lever  24  is kept in an open position, shown in  FIG. 2 , in which to end  241  opposite the axis A 24  is retained by a maintaining hook  40 . In this configuration, the photovoltaic array draws current normally in the grid by means of the terminals  14  and  16 , which are electrically connected to each other, by means of electrical lines L 16 . 
         [0039]    The maintaining hook  40  is articulated on the plate  26  around an axis A 40  perpendicular to the plane P 28 . The hook  40  includes a tongue  42  making it possible to withstand the force F 1 , by opposing a bearing surface  421  to the end  241  of the lever  24 . 
         [0040]    As shown in  FIGS. 4 and 5 , short-circuiting device  1  includes a means for indicating the establishment and maintenance of the short-circuit across the terminals of the photovoltaic array, which has a warning light  60 , which is generally cylindrical, designed to be translated between a retracted position, shown in  FIG. 4 , in which the warning light  60  is completely housed in the box  10 , and a visible position, shown in  FIG. 5 , in which the warning light  60  is located at the dome  12 . In that configuration, the warning light  60  is visible to operating teams intending to enter the building, through the dome  12 , which is transparent. The dome  12  may be made from glass or a material with strong resistance to deterioration. 
         [0041]    The warning light  60  is kept in the retracted position in the housing  10  by a retaining lever  62 , which is articulated on the plate  26  around an axis A 62  perpendicular to the plane P 28 . The warning light  60  includes a rod  64  connected to a shell  65  of the warning lights  60  by an end  641 . At its other end  643 , the rod  64  includes a stop  645 , formed by a nut and designed to bear against a surface  621  of the retaining lever  62  turned toward the bottom  28 , while the end  643  is engaged in a notch  622  of that lever. The bearing between the stop  645  and the surface  621  around the notch  622  makes it possible to withstand a force F 2  exerted by a spring  66  and which tends to drive the warning light  60  perpendicularly relative to the plane P 28  toward the inside of the dome  12 , in its visible position. The spring  66  is, in the retracted position of the warning light  60 , compressed between a bottom surface  651  of the shell  65  and a plate  27  secured to the box  10 , parallel to the plate  26  and arranged above the plate  26 . The retaining lever  62  makes it possible to retain the warning light  60  in its retracted configuration when the short-circuiting of the array is not necessary. 
         [0042]    In case of fire or another accident affecting the building supporting the photovoltaic array, the short-circuiting device is remotely controlled by means of a lever or emergency button striking a compressed gas cartridge  80 . The gas cartridge  80  is connected to the short-circuiting device  1  by a metal tube  82  inserted into a port  101  of the box  10 , which communicates with the chamber  103 . A piston  105 , translatable in the chamber  103  along an axis A 105 , is secured to a rod  107  that protrudes from the body  108  in which the chamber  103  is defined, toward the maintaining hook  40 . 
         [0043]    The short-circuiting device  1  may be triggered automatically in case of fire by the temperature destruction of the maintaining hook  40  or by a command sent to the cartridge  80  from a fire detector. 
         [0044]    For clarity of the drawing, the cartridge  80  is not shown in  FIG. 1 . 
         [0045]    When the short-circuit order is given, the compressed gas contained in the cartridge  80  is released in the chamber  103  and drives a translational movement T 3  of the piston  105 . This movement drives the striking of a surface  44  of the hook  40  by the end  109  of the rod  107  opposite the piston  105 . This impact results in driving the hook  40  in a rotational movement R 4  around the axis A 40 . This movement R 4  makes it possible to release the closing lever  24  and the pivoting thereof under the effect of the force F 1 , making it possible to establish the short-circuit between the tracks  20  and  22 , and therefore between the terminals  14 . 
         [0046]    When the closing lever  24  pivots, its end  241  strikes an extension  623  of the retaining lever  62 , driving a rotational movement R 5  of the lever  62  around the axis A 62 . This movement R 5  results in extracting the end  643  of the rod  64  from the notch  622  and releasing the stop  645 . Nothing then opposes the translation of the shell  65  under the effect of the force F 2 , and the warning light  60  is therefore driven toward the inside of the dome  12  in its visible position, making it possible to indicate the establishment and maintenance of the short-circuit across the terminals of the photovoltaic array and the securing of the building, before the operation by the emergency services. 
         [0047]    The release of the warning light  60  is activated mechanically by the closing lever  24 , which establishes the short-circuit between the tracks  20  and  22 . In fact, the lever  24  acts on the lever  62 , which releases the warning light  60  during its rotation R 5 . One can therefore be sure that the short-circuit is established when the warning light  60  comes to its visible position within the dome  12 , inasmuch as the retaining lever  62  can only be set in motion by the closing lever  24 . 
         [0048]    The warning light  60  is movable along an axis A 60  parallel to the axis of rotation A 24  of the closing lever  24 . 
         [0049]    The system is reliable because it is the last moving part, i.e., the lever  24 , that controls the activation of the warning light  60 . The system therefore does not depend on the status of an intermediate part, such as the members  105  and  40 , the malfunction of which would be able to activate the appearance of the warning lights  60  whereas the short-circuit is not actually established, and conversely, not signaling the short-circuit when it has been established. Furthermore, the fact that the closing lever  24 , which performs the short-circuit, and the warning light  60  are independent parts improves the reliability of the short-circuiting device. 
         [0050]    The gas cartridge  80  contains a gas such as carbon dioxide. This cartridge  80  is intended for a single use and must be replaced each time the short-circuit is activated and the short-circuiting device  1  is rearmed. It may be considered for the short-circuiting device  1  to include mechanical rearming means. Using a gas cartridge makes it possible to have a safe energy source for activating the short-circuit and makes it possible to avoid using electricity, which improves the reliability of the short-circuiting device  1 . 
         [0051]    Alternatively, it is possible to consider the translational movement of the rod  107  being initiated by other means such as pneumatic, hydraulic, mechanical or pyrotechnic actuators. In particular, the movement of the rod  107  can be obtained by a mechanical member, controlled by a maneuvering member such as a pole, which can be actuated directly by a person. It may also be considered for the transmission of forces and the activation of certain movements of the component parts of the system to be done by a cam system. 
         [0052]    The warning light  60  is advantageously painted a color, for example red, yellow or orange, allowing it to be viewed clearly from an area remote from the building, such as a road down below. The warning light  60  can advantageously be covered with a reflective or fluorescent material so as to be able to be distinguished at night. 
         [0053]    The box  10  of the short-circuiting device  1  includes fasteners  100  making it possible to fix it in a high-up outer area of the building, such as a façade or a roof, using any suitable means. 
         [0054]    The short-circuiting device  1  is placed as close as possible to the photovoltaic panels, so that the electrical connections between the short-circuiting device  1  and the photovoltaic panels are as short as possible, which reduces the risk of opening of the electrical circuit following the destruction of cables due to the accident, for example in the event of collapse of the structures. 
         [0055]    Depending on the electrical powers and the number of photovoltaic panels used in the array, the short-circuiting device  1  can comprise a larger number of terminals  14  and  16  and closing levers  24 , and several short-circuiting devices  1  according to the invention may be provided.