Adaptable contact connection device for the electrical testing of a solar cell and associated testing method

Abstract

Device for establishing electrical contact between a photovoltaic cell and a voltage and / or current measuring device, comprising: - a ribbon (10) of separate, movable conducting wires (12; 12I, 12U; 128) which, in a measuring position, are in contact with a first face (FAV, FAR) of a photovoltaic cell (C, C1, C2) and, in a disconnected position, are held at a distance from the first face (FAV, FAR) and parallel to it; - an improved actuation device (25) having a set of wire actuators (25A, 25B), each actuator (25) being associated with a given conducting wire (12I, 12U, 128) of the ribbon and configured to allow movement of the given conducting wire between a first position and a second position among the disconnected position and the measuring position. Figure for the abstract: 4.

Description

Title of the invention: Adaptable contact connection device for the electrical testing of a solar cell and associated testing method. Technical field and prior art.

[0001] The present application relates generally to the testing of photovoltaic devices, and more particularly to that of devices enabling electrical contact to be established with a photovoltaic cell, and more particularly a crystalline silicon-based photovoltaic cell, of which one or more electrical parameters are to be measured.

[0002] Usually, at the end of the manufacturing process of solar cells, also called photovoltaic cells, and typically before they are assembled into a solar module, the cells are tested to determine their quality. Various measurement techniques exist to evaluate the properties of a cell, including electroluminescence imaging, thermal imaging, and current and voltage measurement to establish a current-voltage relationship and deduce a corresponding curve commonly called the "IV curve".

[0003] This latter technique consists of performing an electrical measurement under insolation while the insolated cell is electrically connected to a measuring device equipped with current and voltage measurement means. The cell is connected to the measuring device, and electrical measurements are taken when the cell is illuminated.The measuring device allows for a reading of the cell's voltages and currents and establishes a current-voltage relationship from which other parameters can be deduced, such as its open-circuit voltage: Vco representing the voltage generated by an illuminated, unconnected cell, its short-circuit current: Isc representing the current generated by an illuminated cell connected to itself, its maximum power point: MPP (in English: maximal power point) obtained for an optimal voltage and current: Vopt, lopt (sometimes noted Vmpp, Impp), the fill factor FF (from the English "fill factor") corresponding to the ratio between the maximum power MPP and the product of the open-circuit voltage Vco and the short-circuit current intensity Isc.

[0004] In addition to a light source typically emitting with a spectrum similar to that of the sun to perform such a type of measurement, a connection device with conductive elements is used to establish electrical contacts between the cell and the measuring device.

[0005] The document “GridTOUCH: Innovative Solution for Accurate IV Measurement of Busbarless Cells in Production and Laboratory Environments”, Bassi et al. Conference: 29th European Photovoltaic Solar Energy Conference and Exhibition January 2014, presents an example of a connection device in the form of a set of conductive wires arranged in a parallel wire array placed against a cell to be tested.

[0006] Such a device enabling electrical contact between the cell and one or more electronic boards can be formed, for example, on the front of the cell, by 30 conductive wires dedicated to current measurement and 5 wires dedicated to voltage measurement. To test the cell on the rear side, for example, 24 wires dedicated to current measurement and 5 wires dedicated to voltage measurement can be used. Such a high contact density can eliminate the need to consider the cell's line resistance and thus improve the measurement.

[0007] Such a device can be adapted to different arrangements of metallization of the cells in interconnecting bars (“bus-bars” according to Anglo-Saxon terminology) and conductive fingers (“fingers”), or even to cells without metallization.

[0008] However, this adaptation may require a lengthy dismantling of the connection device because, in the measurement position, the wires are held under pressure on the cell by a system formed for example of screws.

[0009] There is therefore a need to be able to test solar cells whose respective metallization arrangements differ significantly from one another without losing too much time between the different test steps carried out on these cells.

[0010] Similarly, there is a need to be able to carry out tests on cells of different formats, and again preferably while limiting the adaptation time of the measurement system. Description of the invention

[0011] It is therefore an object of the present invention to provide a device comprising:

[0012] - a set of separate and movable conductive wires which, in a position said to be "measuring" devices, are suitable for being placed in contact with a first face of a photovoltaic cell and, in a so-called "disconnection" position, are suitable for being kept at a distance from the first face of a photovoltaic cell and advantageously parallel to this first face,

[0013] - an actuation device having a set of actuators for the conductor wires of the ribbon cable, each actuator being associated with a given conductive wire of the ribbon cable and configured to allow movement of the given conductive wire, between a first position between the measurement position and the disconnection position and a second position between the disconnection position and the measurement position; the second position being distinct from the first position, and to move the given conducting wire between the second position and the first position.

[0014] The actuation device can further be configured to maintain a first conducting wire of the ribbon associated with at least a first actuator in the first position while a second conducting wire of the ribbon associated with at least a second actuator is maintained in the second position.

[0015] With such a device, the number of contacts on a cell can be easily adjusted, and a series of electrical tests can be quickly performed on one or more photovoltaic cells. Measurements can advantageously be carried out on cells of different sizes and / or with different metallizations using the same array of conductive elements, the positioning of the wires of which is modified according to the size or metallization.

[0016] According to a particularly advantageous aspect, the device may further comprise:

[0017] - a switching device coupled to the conductive wires of the ribbon cable and comprising a set of switching elements, each switching element being configured to, alternatively, adopt a first configuration connecting an input suitable for being coupled to a conductor wire of the ribbon cable to a first output suitable for being connected to a current measuring device while disconnecting the input from a second output suitable for being connected to a voltage measuring device, and a second configuration connecting the input to the second output while disconnecting the input from the first output.

[0018] With such a device, the association of a contact with a voltage or current measuring means can be adapted quickly and without disassembly. This also contributes to the possibility of rapidly performing a series of electrical tests on one or more photovoltaic cells. The implementation of such a device also makes it easy to perform measurements on cells of different sizes with the same ribbon of conductive elements, the association of each wire with a voltage or current measuring means being quickly modified.

[0019] According to one possible implementation, the device may further include: a second set of separate conducting wires which, in the so-called "measuring" position, are arranged in contact with a second face between the rear face and the front face and which is separate from the first face.

[0020] Preferably, the actuation device is also coupled to this second ribbon and further equipped with a second set of actuators to individually move the wires of the second ribbon.

[0021] Preferably also, the second ribbon is coupled to the switching device so that it is possible to select, for each conductor wire of the second ribbon, which measuring means, voltage or current, to associate it with.

[0022] A control device equipped with a computer and / or electronic processing unit, coupled to an interface circuit, the processing unit coupled to the interface circuit being configured to control the actuation device and / or the switching device, may also be provided.

[0023] Such a control device can thus be configured to emit an actuator control signal from the actuation device to at least one given actuator to trigger a movement of at least one given conductor wire by the given actuator.

[0024] Such a control device may be alternatively or in combination configured to emit a control signal from the switching device so as to trigger a change in configuration of at least one given switching element and to switch the given switching element from the first configuration to the second configuration or from the second configuration to the first configuration.

[0025] According to one possibility, the actuator control device and switching elements may further include a human-machine interface.

[0026] Such an interface can be capable of receiving a wire movement instruction from a user indicating that at least one given conductor wire in the ribbon cable is to be moved to or from a measurement position. The processing unit coupled to the interface circuit can then be configured to, upon receiving the wire movement instruction, send an actuator control signal to the actuation device so as to trigger a movement of the given conductor wire by at least one actuator associated with that conductor wire.

[0027] Such an interface may also be capable of receiving a wire association instruction for a given type of measuring device between a voltage measuring device and a current measuring device. In this case, the processing unit coupled to the interface circuit may be configured to, upon receiving the wire association instruction for a given type of measuring device, emit an electrical or electronic control signal to the switching device, so as to trigger a configuration change of at least one given switching element associated with the given conductor wire.

[0028] A wire movement instruction and a wire association instruction to a given type of measuring device can be grouped in the same command.

[0029] The control device can be configured to trigger a displacement of a set of conductive wires of the ribbon cable out of the measurement position so as to disconnect the entire photovoltaic cell while maintaining a group of conductive wires from the ribbon cable in the measurement position, or move the group of conductive wires into the measurement position so as to connect the group with the photovoltaic cell while maintaining a group of conductive wires from the ribbon cable in the measurement position, the control device being further configured to trigger a connection of one or more first conductive wires from the group to a current measuring device by placing one or more first switching elements of the switching device in a first configuration, while one or more second conductive wires from the group are connected to a voltage measuring device via one or more second switching elements of the switching device placed in a second configuration.the control device being further configured to trigger a change in the configuration of one or more given switching elements among the first switching elements and / or the second switching elements of the switching device.

[0030] According to one possible implementation, the device can also be equipped with pressure sensors, to measure the force exerted by the wires on the cell that these wires allow to be contacted.

[0031] Thus in a measurement position, a first end region of a given conducting wire is held against a first pressure sensor and a second end region of the conducting wire is held against a second pressure sensor.

[0032] The actuators can be linear actuators. One actuator per conductor wire can be provided.

[0033] According to one possibility, the actuators of a wire may comprise:

[0034] - a first electromagnet intended to be placed opposite a first region end of a conducting wire and a second electromagnet intended to be placed opposite a second end region of this conducting wire;

[0035] According to one possibility, the actuators of a wire may include:

[0036] - a first jack intended to be placed opposite a first end region of a conductor wire and a second jack intended to be placed opposite a second end region of this conductor wire.

[0037] According to another aspect, an embodiment of the present invention relates to a method for electrically testing at least one photovoltaic cell using a device as defined above.

[0038] According to another particular aspect, the present invention relates to a method for electrically testing a photovoltaic cell comprising:

[0039] - A step consisting of

[0040] - move a set of conductive wires of the ribbon cable out of the measuring position so as to disconnect a first photovoltaic cell from the assembly of conductive wires while maintaining a group of conductive wires of said ribbon in the measurement position on the first photovoltaic cell, or

[0041] - move said assembly of conducting wires into the measuring position so to connect said assembly with said first photovoltaic cell while maintaining a group of conductive wires of said ribbon in the measuring position, one or more first conductive wires of said group being connected to a current measuring device via switching elements of the switching device placed in the first configuration, while one or more second conductive wires of said group are connected to a voltage measuring device via switching elements of said switching device placed in the second configuration, then,

[0042] -a step consisting of

[0043] - modify the configuration of one or more given switching elements of said switching device, so as to modify the number of conductors of said group that are connected to a voltage measuring device and to modify the number of conductors of said group connected to a current measuring device, then,

[0044] - a step consisting of:

[0045] - measure the current flowing through at least one given conducting wire of said group or the voltage between the ends of at least one given conducting wire of said group in contact with the first photovoltaic cell, while the first photovoltaic cell is kept under illumination.

[0046] The movement of the set of conducting wires is carried out, preferably in translation and along a direction orthogonal to a principal plane of the cell.

[0047] When the movement of the assembly of conducting wires is a movement out of the measurement position, it is carried out so as to result in a second position, the assembly of conducting wires then being held in the second position during the measurement of current or voltage carried out on at least one given conducting wire of the group of wires in the measurement position.

[0048] Advantageously, prior to moving the entire set of conductive wires of the ribbon cable, the method may further comprise one or more steps consisting of:

[0049] - place the ribbon of conductive wires in contact with another cell photovoltaic, the set of conductive wires being in contact with the other cell and measuring at least one current or voltage using the ribbon cable, while the other photovoltaic cell is kept under illumination.

[0050] According to one possible implementation, the other cell may have a different format from that of the first photovoltaic cell. Brief description of the drawings

[0051] The present invention will be better understood on the basis of the following description and the accompanying drawings in which:

[0052] [Fig-1] illustrates a mat of conductive wires for the electrical testing of a photovoltaic cell.

[0053] [Fig.2] illustrates a so-called "measurement" position of a conducting wire of the ribbon on a photovoltaic cell to make electrical contact and to be able to perform current and / or voltage measurements on this photovoltaic cell.

[0054] [Fig.3] illustrates a test device under insolation of a photovoltaic cell using an example of a connection device including the ribbon of conductive wires arranged in the measurement position.

[0055] [Fig.4] illustrates an actuation device for individually moving the wires of the conductive wire bundle and the ability to hold certain wires in a measurement position while other wires are held in another position outside the measurement position, as well as a control system for this actuation device.

[0056] [Fig.5] illustrates a particular arrangement of actuators at the ends of the conductive wires of the wire harness.

[0057] [Fig.6] illustrates a particular configuration of the sheet, obtained by displacement of certain wires in order to adapt the number of contacts on the cell.

[0058] [Fig.7] illustrates a particular configuration of the tablecloth, where some wires are kept at a distance in order to adapt the number of contacts to the cell format.

[0059] [Fig.8] illustrates a pressure measuring device in which the conducting wires The connection device may exert forces on the face of a photovoltaic cell being tested.

[0060] [Fig.9A]

[0061] [Fig.9B] illustrate different possibilities of controlling the displacement of each conductor wire and of associating each conductor wire of the ribbon with a measuring means selected from a voltage measuring means or a current measuring means.

[0062] [Fig. 10] illustrates an example of a switching element structure of a switching device capable of being integrated into a connection device according to the invention in order to be able to perform electrical measurements on a solar cell and alternatively connect to a contact either to a voltage measurement means or to a current measurement.

[0063] [Fig. 11] illustrates a method for setting up an electrical test of a cell for which a change in the positioning of the wires and the configuration of the switching device are implemented to allow testing of this cell.

[0064] In addition, in the description below, terms which depend on the orientation of a structure such as "front", "upper", "rear", "lower", "lateral", apply considering that the structure is oriented in the manner illustrated in the figures.

[0065] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0066] Reference is now made to [Fig.1] used to illustrate, by way of a top view, a connection device to enable at least one current measuring device and at least one measuring device to make contact with a photovoltaic cell such as a crystalline silicon-based photovoltaic cell (not shown), in order to measure one or more parameters, such as the voltage Vco, the current Isc, the MPP point, the fill factor FF, and / or to determine a current-voltage relationship to establish an IV curve of the cell.

[0067] The connection device has a plurality of oblong conductive elements, in particular conductive wires 12, arranged in a bundle 10 of separate wires, typically spaced apart and parallel to each other, according to a given spacing pr which can be fixed, for example between 2 and 15 mm, advantageously between 4 and 6 mm, for example 5 mm. These conductive wires 12 are intended to contact a face, front or rear, of the photovoltaic cell.

[0068] The conductive wires 12 used can be designed with a width (dimension taken parallel to the x-axis of the coordinate system [O;x;y;z] in [Fig. 1]) sufficiently small to avoid excessive shading on the cell under test, but large enough to maintain a contact surface that ensures both accurate measurement and good mechanical strength. For example, the conductive wires 12 can have a diameter between 100 and 300 µm. Preferably, the conductive wires 12 are made of a material with good electrical conductivity, typically metallic, and low susceptibility to oxidation. Thus, the conductive wires 11, 12 can, for example, be made of copper.

[0069] When in a measuring position, a conductive wire 11, 12 of the ribbon cable 10 is brought into contact with the cell and / or a conductive track formed on it. Thus, in the example illustrated in the cross-sectional view of [Fig. 2], a conductive wire 12 in the measuring position is placed on an interconnecting bar 103 located on the front face of a photovoltaic cell CL

[0070] On [Fig.3], the conductive ribbon 10 is shown in the measurement position of all its conductive wires on the front face of the photovoltaic cell Cl under insolation, a light source 200, for example of type Xe-flash combined with a pulsed LED source can be provided above the cell CL The source 200 is typically provided to comply with an illumination of class A+A+A+ and according to the standard IEC 60904-9.

[0071] For the sake of simplicity, in the illustrated example, only one conductor 121, also called "contact I," is connected to a current measuring device 301, and another conductor 12U, also called "contacts U," is connected to a voltage measuring device 302. However, the ribbon cable 10 typically includes several "contacts I" 121, each of which is to be connected to a current measuring device, and several "contacts U" 12U, which can be connected to a voltage measuring device. The voltage measuring device and the current measuring device may be integrated into a single measuring apparatus 300. Such a measuring apparatus 300 may typically include several voltage measuring channels or devices and several current measuring channels or devices.

[0072] Typically, a higher proportion of I contacts than U contacts is provided to allow electrical measurements to be made on the cell Cl without having to take into account the line resistance of the metallization of the cell Cl in the measurements. For example, a ribbon cable 10 can be provided comprising between 16 and 50, for example 30 conductive wires 121, serving as I contacts, and 5 conductive wires 12U serving as U contacts, or for example 42 conductive wires 121, serving as I contacts, and 9 conductive wires 12U. A sufficient number of U contacts is preferably maintained, in particular to allow for a good measurement of the voltage Voc of the cell Cl.

[0073] However, a measurement performed with a large number of contacts is not necessarily representative of the performance of cell Cl once it has been integrated into a photovoltaic module with other cells, since the module assembly is typically achieved with more widely spaced contacts. Therefore, it may be necessary to modify the number of contacts to perform other measurements.

[0074] Thus, according to a particular aspect illustrated in [Fig.4], a wire connection device is provided, itself equipped with an actuation device 25 having a plurality of actuators 25A, 25B, configured to move, and in particular move in translation, individually each conductor wire 121, 12U of the ribbon 10.

[0075] In the illustrated example, each wire is associated with a pair of linear actuators 25A, 25B schematically represented by a double arrow, signifying that a conducting wire 11, 12 can be moved vertically, that is, in a direction orthogonal or substantially orthogonal to a principal plane of the cell Cl or of a cell support (not shown), between a first position and at least a second position, and conversely between at least the second position and the first position. The "principal plane" of the cell is understood here and throughout the description to be a plane passing through the cell and parallel to a given plane [O; x; y] on the [Fig.4]

[0076] Thus, each actuator or pair of actuators 25A, 25B of displacement can be configured to allow the conductor wire to which it is associated to be moved, here vertically, from the measurement position to another position distinct from the measurement position and to move, here vertically, this same conductor wire from a position outside the measurement position to the measurement position.

[0077] The conductive wires 11,12 are preferably kept parallel to the cell during their movements by the actuators 25A, 25B.

[0078] The actuators 25A, 25B are typically linear actuators configured to move the conducting wires along a straight line. For example, actuators using an electric motor, which can be coupled to an element, such as a screw, to convert the rotation of an electric motor into linear motion and against which the conducting wire rests, can be provided.

[0079] When another bundle of conductive wires (not shown in this figure) is provided on a face opposite to that on which bundle 10 is located, this other bundle can also be coupled to the actuation device, this device then being provided with additional actuators to also be able to move each conductive wire of this other bundle individually, relative to the other wires.

[0080] Different types of conductor wire displacement actuators are possible.

[0081] According to one embodiment, the actuator can be equipped with hydraulic or pneumatic cylinders: a cylinder can thus be placed at each end of a conductive wire to be moved. Thus, for a ribbon having, for example, 20 conductive wires, 40 cylinders can be provided, distributed at the ends of the conductive wires 11, 12.

[0082] According to another embodiment, an electrical actuation can be provided with, for example, at least one electromagnet arranged at each end of the conductive wire to be moved. Thus, for example, for a ribbon 10 as illustrated in [Fig. 5] having, for example, 20 conductive wires, 40 electromagnets 251, ..., 2512, ..., 25220 are provided with 20 electromagnets 251..., 2512 arranged on one side of the ribbon 10 to move a first end of the conductive wires 121, 12U and 20 other electromagnets 252b..., 25220 arranged on a second side of the ribbon 10 to simultaneously move a second end of the conductive wires.

[0083] The contact or contacts to be removed, in other words the conductive wire or wires that one wishes to move out of the measuring position, can be selected by means of a control system 50 coupled to the actuation device 25.

[0084] A control system 50, combining electronics and computer science, as schematically represented in figures 4 and 5, can be provided to control the actuators individually.

[0085] In [Fig. 4], the control system 50 has a human-machine interface 51, for example in the form of a keyboard and / or a touchscreen, associated with a processing unit 52, for example a computerized device such as a computer, the processing unit being composed of at least one processor or microprocessor or microcontroller. The processing unit 52 can be coupled to one or more memories 53, including a main memory equipped, for example, with volatile memory or non-volatile memory. One or more other storage elements, for example, such as a hard drive, a multipurpose digital disc (DVD), a memory card, or a USB flash drive, may also be provided. The processing unit 52 is also coupled to an interface circuit 54 equipped with components for producing electrical and / or electronic control signals for the actuators.Such a circuit 54 can take different forms and include, for example, among its stages or components at least one of: one or more transistors, a digital-to-analog converter, an H-bridge, a power control circuit, an electronic voltage switch, an electronic current switch, leakage current control ... .

[0086] Such a control system 50 allows a user Ut to control the actuation device and to be able to trigger the movement of one or more selected wires of the ribbon 10.

[0087] The user Ut of the control system 50 can for example choose which area(s) of a cell he / she wishes to contact via the user interface 51 and consequently which conductive wire(s) of the ribbon cable 10 to move out of the measurement position and which conductive wire(s) to move or keep in the measurement position among all the conductive wires of the ribbon cable 10.

[0088] Such a selection of contact(s) can also be made, for example, according to the type of photovoltaic cell to be tested, in particular its format. For example, for an M2 format cell (i.e., with dimensions 156.75 x 156.75 mm), the control system 50 can trigger, via the actuators, a measurement positioning of a greater number of conductive wires than for an ML format cell. According to another example, for an M2 format cell, the control system 50 can maintain a greater number of conductive wires in the measurement position than for a half-cell of the same format ("1 / 2M2"), the number of conductive wires brought out of the measurement position being greater for the half-cell than for the entire M2 cell.

[0089] By individually controlling each conductive wire and putting more or fewer conductive wires, in particular contacts I, in the measurement position, one takes into account more or less the line resistance of the metallization design printed on a precursor, in other words a solar cell without metallization allowing electrical contact.

[0090] With such a control system, it is also possible to adapt the number of conductive wires in the measurement position in order to establish different measurements of the same parameter, in particular of the filling factor FF on the same cell.

[0091] It may be necessary to modulate the number of contacts I, but maintain the number of contacts U, for example, to perform a series of measurements on the same cell where the number of contacts I differs from one measurement to another, while maintaining a constant number of contacts U from one measurement to the next. In this case, the control system 50 only drives the wires dedicated to current measurement, while the wires dedicated to voltage measurement remain fixed and, in particular, in the measurement position.

[0092] Thus, in a particular test example illustrated in [Fig. 6], to establish a relationship between I and V, a set of current-measuring wires 12211241126I are moved out of the measurement position (arrow pointing upwards), while a group 12L 12I3 12I5 of current-measuring wires are kept in contact with cell Cl (arrow pointing downwards). The voltage-measuring wires 12i U, ..., 125U are all kept in the measurement position. From one end to the other, the ribbon cable 10 comprises an alternation of wires in contact with cell Cl, 103, 105, ..., Cl9, located in the foreground, and wires distant from cell Cl and located in a second plane distinct from the first plane.

[0093] As previously stated, another advantage related to the possibility of individual actuation of the wires lies in the possibility of adapting to different cell formats for example: M2, / 2 M2,, M12, / 2 M12...), without complex and lengthy modification of the measurement system.

[0094] Thus, in the particular embodiment illustrated in [Fig. 7], to perform a measurement on a photovoltaic cell C2 smaller than the previously tested cell Cl, the contact of wires arranged at the outer edges 10e1, 10e2 of the ribbon 10 is eliminated in order to reduce the measurement area. Here, all the edge wires 10e1, 10e2 of the ribbon dedicated to current and voltage measurement are moved away from cell C2 by translation, while the wires of a central portion 10C of the ribbon 10 are maintained in the measurement position.

[0095] Specific examples of possible configurations for different formats, maintaining a spacing of 5 mm between adjacent or neighboring wires of the ribbon cable 10, for example, between two wires dedicated to current measurement and inserting a wire dedicated to voltage measurement between wires dedicated to voltage measurement every 25 mm, include:

[0096] -42 conductive wires dedicated to current measurement and 9 conductive wires dedicated to the voltage measurement for a G12 cell format (i.e., dimensions 210 x 210 mm),

[0097] -35 wires dedicated to current measurement and 7 wires dedicated to voltage measurement for a M6 format

[0098] -30 wires dedicated to current measurement and 5 wires dedicated to voltage measurement for a M2 format

[0099] -16 wires for current measurement and 3 wires dedicated to voltage measurement for a format

[0100] ½ M2.

[0101] In either of the examples described above, a conductive ribbon 10 is provided in contact with a first face of the photovoltaic cell C, for example its front face FAV. It is also possible to have, simultaneously, on a second face of the cell C opposite to the first face, for example its rear face FAR, another ribbon 10' also formed of a plurality of parallel and distinct conductive wires, each individually movable, to actuate one or more actuators of an actuation device as described above. The number of contacts maintained on the second face, in other words the number of conductive elements of the other ribbon 10', is controllable by the control system described above.

[0102] In a particular embodiment illustrated in [Fig. 8], the pressure exerted by the conductive wires of a ribbon 10 arranged on the front face FAV of a photovoltaic cell C, and / or by the conductive wires of another ribbon 10' arranged on the rear face FAR of the photovoltaic cell C, can be measured by means of force or pressure sensors 81, 83. Such sensors can be in the form of thin-film ribbons and can prevent possible breakage of the cell C due to excessive pressure exerted by the ribbon(s) 10 and / or 10'.

[0103] In the case where two conductive ribbons 10, 10' are arranged, one on the front face FAV and the other on the rear face FAR of a cell, the wires of ribbon 10 can also be offset from the wires of the other ribbon 10'. Thus, in order to limit the risk of short circuits, the ribbons are preferably arranged so that a conductive wire of ribbon 10 is not in the same plane orthogonal to the main plane of the cell as a conductive wire of the other ribbon 10'.

[0104] In a particular embodiment illustrated in Figures 9A and 9B, the control device 50 as described above in connection with [Fig.4] is further configured to drive a switching device 90 connected to the ribbon 10 of conductor wires 11, 12 and arranged between this ribbon 10 and a measuring device 300 to which the switching device 90 is also connected.

[0105] This switching device 90 is formed of a plurality of switching elements 91, each switching element 91 being associated with a given conductor 128 and allowing this given conductor 128 of the ribbon cable 10 to be connected when in the measuring position to one of a current measuring device and a measuring device of the device 300 while disconnecting this given conductor wire 128 from the other of the current measuring device and the measuring device.

[0106] Thus, when the control device 50 receives an instruction from, for example, its human-machine interface, to associate a given conductor 128 of the ribbon 10 with a first type of measuring device, for example a voltage measuring device, with a given conductor 2, its processing unit coupled to its interface circuit produces an electrical or electronic control signal for the switching device 50, so as to trigger a change in the configuration of the switching element associated with the given conductor 128.

[0107] On [Fig.9A], a Scoml control signal to the switching device 90 triggers a change in configuration of a switching element 91 to which the given conductor 128 is connected, this switching element 91 then consecutively adopting a first configuration allowing the given conductor 128 to be connected to a voltage measuring device 301 (or channel).

[0108] On [Fig.9B], a control signal Scom2 to the switching device 90 triggers a change in configuration of the switching element 91 to which the given conductor 128 is connected, this switching element 91 then adopting a second configuration allowing the given conductor 128 to be connected this time to a current measuring device 302 (or channel).

[0109] Such control can be carried out individually wire by wire, the control device 50 being configured to allow one or more conductors of the ribbon 10 to be associated with a voltage measuring device, while one or more other conductors are associated with a current measuring device. The configuration of the measuring device can thus be quickly changed without having to disconnect or disassemble it, making it possible to rapidly chain different measurements. When another ribbon of conductors (not shown in this figure) is provided on a face opposite to that on which ribbon 10 is located, this other ribbon is also connected to the switching device 90 so that, for each conductor of this other ribbon, the current or voltage measuring means to which it is associated can also be selected.

[0110] Thus, one or more switching elements 91 are controlled, for example, to adopt a first configuration while one or more switching elements 91 are adopted to adopt a second configuration.

[0111] A particular example of a switching device 90 has a matrix arrangement such as in [Fig. 10].

[0112] Each conducting wire, when in contact with the photovoltaic cell, i.e. in the measurement position, can be connected to a column Ci (or row) vertical) of the matrix arrangement, while the lines (or horizontal rows) are directly connected to the channels or measuring devices, either for voltage or current.

[0113] In this figure, only 16 columns are shown, but the switching device can be provided with a larger number of channels, for example 60.

[0114] It is also possible to group several conductor wires dedicated to current measurement I in the same column in order to simplify the measurement.

[0115] The switching elements 91 of the switching device 90 are each located at the intersection of a row and a column to a measuring line (I or U) and are typically formed of one or more switches.

[0116] Each switching element 91 is here configured to, alternatively, adopt a first configuration connecting an input 92e; 94e suitable for being coupled to a conductor wire of the ribbon cable to a first output 93s; 95s suitable for being connected to a current measuring device while disconnecting said input from a second output 97s; 99s suitable for being connected to a voltage measuring device, and a second configuration connecting said input 92e; 94e to said second output 97s; 99s while disconnecting said input from said first output 93s; 95s.

[0117] The control device 50 of such a switching device 90 is further configured to trigger a change in the configuration of each switching element 91, in other words, an opening or closing of its switches, in order to modify the association between at least one input-connected conductor and a voltage or current measuring means. The current measuring means can be associated with, and thus connected to, the conductor in a given configuration (for example, corresponding to an opening of its switches) of the switching element 91 while the voltage measuring means is disconnected from this conductor, and in another configuration of the switching element 91 (for example, corresponding to a closing of its switches), the voltage measuring means is associated with, and thus connected to, the conductor, while the voltage measuring means is disconnected from this conductor.

[0118] Such a switching device has the advantage of being able to allow rapid modification of the number of I contacts and U contacts and thus to quickly adapt the proportion of I contacts and U contacts.

[0119] Once one or more current and / or voltage measurements have been taken on a photovoltaic cell C1, one may then want to take one or more current and / or voltage measurements on another cell. In the embodiment illustrated in [Fig. 1 1], another cell C2, with a different format than the cell previously tested, is installed.

[0120] To accommodate the smaller format, in this example, a set El of conductive wires from the ribbon 10 is moved out of the measuring position so as to disconnect this set El from the photovoltaic cell C2 while maintaining a group G of conductive wires from the ribbon in the measuring position. One or more of the first conductive wires of group G are then connected to a current measuring device (or channel) of the measuring instrument 300, while one or more of the second conductive wires are connected to a voltage measuring device of the measuring instrument 300.

[0121] The configuration of one or more given switching elements of the switching device can then be modified so as to change the number of conductor wires of group G that are connected to a voltage measuring device (or channel) of the apparatus and to change the number of conductor wires of group G connected to a current measuring device (or channel).

[0122] We can then measure the current through at least one given conducting wire 128 of group G or the voltage between the ends of a given conducting wire 128 of group G in contact with the photovoltaic cell C2, the latter being at the same time kept under illumination by means of a light source (not shown in [Fig. 11]).

[0123] In order to carry out a viable IV measurement, it may be preferable to maintain a given ratio, for example of the order of 15%, between a number NI of conductive wires forming I contacts and a number NU of conductive wires forming U contacts. The control device and the associated switching device make it possible to maintain this ratio easily and quickly regardless of the cell format put in contact with the bundle(s) of conductive wires.

[0124] The control device also allows the distribution of contacts on the cell to be controlled. Thus, when measuring a G12 cell, for example, 7 U contacts are provided for 40 I contacts, and when measuring an M2 format cell, 5 U contacts for 30 I contacts.

[0125] To adapt to V2 cells, it is advantageous to be able to choose the nature of the contact between I and U associated with the same conducting wire in order to maintain the aforementioned ratio. Such a device thus makes it easy to adapt to a large number of cell measurement formats.

Claims

1.

2. Demands Device for establishing electrical contact between a photovoltaic cell and at least one voltage and / or current measuring device, comprising: - a bundle (10) of separate and movable conducting wires (12; 121, 12U; 128) which, in a so-called "measurement" position, are suitable for being placed in contact with a first face (FAV, FAR) of a photovoltaic cell (C, Cl, C2) and in a so-called "disconnection" position, are suitable for being kept at a distance from the first face (FAV, FAR) of a photovoltaic cell and advantageously parallel to this first face, - an actuation device (25) having a set of actuators (25A, 25B) for the conductor wires of the ribbon cable (10), each actuator (25) being associated with a given conductor wire (121, 12U, 128) of the ribbon cable and configured to allow movement of the given conductor wire between a first position (between the measurement position and the disconnection position) and a second position (between the disconnection position and the measurement position) distinct from the first position, and to move the given conductor wire between the second position and the first position, the actuation device (25) being configured to hold a first conductor wire of the ribbon cable associated with at least a first actuator in the first position while a second conductor wire of the ribbon cable associated with at least a second actuator is held in the second position. Device according to claim 1, further comprising: - a switching device (90) coupled to the conductor wires (12, 12U, 121, 128) of the ribbon cable (10) and comprising a set of switching elements (91), each switching element (91) being configured to alternately adopt a first configuration connecting an input (92e; 94e), suitable for being coupled to a conductor wire of the ribbon cable (10), to a first output (92s; 94s), suitable for being connected to a current measuring device (302), while disconnecting said input from a second output (92s; 94s), suitable for being connected to a voltage measuring device (301), and a second configuration connecting said input (92e; 94e) to said second output while disconnecting said input from said first output.

3. Device according to claim 2, wherein, in the measuring position, the conductive wires of said ribbon (10) are arranged in contact with a first face, between a front face (FAV) and a rear face (FAR) of the photovoltaic cell (C, Ci, C2), the device further comprising: - a second ribbon (10') of separate conductive wires which, in the so-called "measuring" position, are arranged in contact with a second face between the rear face and the front face separate from the first face, the actuation device (50) further being provided with a second set of actuators for individually moving the wires of the second ribbon (10'), the second ribbon being coupled to the switching device.

4. A device according to any one of claims 1 to 3, when combined with claim 2, further comprising: - a control device (50) for the actuating device (25) and / or the switching device (90), the control device (50) being provided with a processing unit (52) coupled to an interface circuit (54), the processing unit (52) coupled to the interface circuit (54) being configured to: - emit an actuator control signal (SAc) for actuator(s) (25A, 25B) of said actuating device (25) to at least one given actuator to trigger a displacement of at least one given conductor wire by said given actuator, and / or - emit a control signal (SComi,SCom 2) of the switching device (90) so as to trigger a configuration change of at least one given switching element (91) and to switch the given switching element from the first configuration to the second configuration or from the second configuration to the first configuration.

5. A device according to claim 4, wherein the control device (50) further comprises a human-machine interface (51) for receiving a wire-movement instruction from a user (U) indicating that at least one given conductive wire (128) of said cable is to be moved to or from a measuring position, the processing unit (52) coupled to the interface circuit (54) being configured to, upon receiving the wire-movement instruction, emit a signal of actuator control to the actuation device (25) so as to trigger a displacement of said given conductor wire by at least one actuator (25) associated with the given conductor wire.

6. Device according to any one of claims 4 or 5, wherein the control device (50) further comprises a human-machine interface (51) for receiving a wire association instruction to a given type of measuring device between a voltage measuring device and a current measuring device, the processing unit (52) coupled to the circuit (54) being configured to, following receipt of the wire association instruction to a given type of measuring device, emit an electrical or electronic control signal to the switching device (90), so as to trigger a configuration change of at least one given switching element associated with the given conductor wire.

7. Device according to any one of claims 4 to 6, the control device (50) being configured to trigger a displacement of a set (El) of conductive wires of said ribbon (10) out of the measuring position so as to disconnect said set (El) from said photovoltaic cell while maintaining a group (G) of conductive wires of said ribbon in the measuring position or to move said set (El) of conductive wires into the measuring position so as to connect said set with said photovoltaic cell while maintaining a group (G) of conductive wires of said ribbon in the measuring position, the control device (50) being further configured to trigger a connection of one or more first conductive wires of said group (G) to a current measuring device by putting one or more first switching elements (91) of the switching device (90) into a first configuration,while one or more second conducting wires of said group (G) are connected to a voltage measuring device via one or more second switching elements of said switching device (90) placed in a second configuration, the control device being further configured to trigger a change in the configuration of one or more switching elements (91) given from said first elements of, switching and / or said second switching elements of said switching device.

8. Device according to any one of claims 1 to 7, wherein in the measuring position, a first end region of the given conducting wire is held against a first pressure sensor (81) and a second end region of the conducting wire is held against a second pressure sensor (83), to measure the pressure exerted by the given conducting wire on the photovoltaic cell (C, Cl, C2).

9. Device according to any one of claims 1 to 8, wherein the actuators (25A, 25B) comprise: - a first electromagnet intended to be placed opposite a first end region of a conducting wire and a second electromagnet intended to be placed opposite a second end region of this conducting wire; or - a first cylinder intended to be placed opposite a first end region of a conducting wire and a second cylinder intended to be placed opposite a second end region of this conducting wire.

10. A method for electrically testing at least one photovoltaic cell (C2) using a device according to any one of claims 2 to 7 or according to any one of claims 8 or 9 taken in relation to claim 2, the method comprising the following steps: - A first step consisting of: - moving a set of conductive wires of said ribbon out of the measurement position so as to disconnect a first photovoltaic cell (C2) from said set of conductive wires while maintaining a group of conductive wires of said ribbon in the measurement position on the first photovoltaic cell (C2), said movement of said set of conductive wires being carried out, preferably in translation and in a direction orthogonal to a principal plane of the cell, said movement of said set of conductive wires being a movement out of the measurement position carried out so as to result in a second position,or - move said set of conductive wires into the measuring position so as to connect said set with said first, photovoltaic cell (C2) while maintaining a group of conductive wires of said ribbon in the measuring position, one or more first conductive wires of said group being connected to a current measuring device via switching elements of the switching device placed in the first configuration, while one or more second conductive wires of said group are connected to a voltage measuring device via switching elements of said switching device placed in the second configuration, then, - a second step consisting of - modifying the configuration of one or more given switching elements (91) of said switching device (90), so as to modify the number of conductive wires of said group that are connected to a voltage measuring device and to modify the number of conductive wires of said group connected to a current measuring device, then,- a third step consisting of: - measuring the current flowing through at least one given conductive wire of said group or the voltage between the ends of at least one given conductive wire of said group in contact with the first photovoltaic cell, while the first photovoltaic cell is kept under illumination, said set of conductive wires being held in said second position during the current or voltage measurement carried out on said at least one given conductive wire in the case where said set of conductive wires of said array has been moved out of the measurement position in the first step.

11. A method according to claim 10, wherein prior to moving said set of conductive wires of said mat, the method comprises one or more steps consisting of: - placing the mat (10) of conductive wires in contact with another photovoltaic cell (Ci), said set of conductive wires being in contact with said other cell (Ci) and measuring at least one current or voltage using said mat, while the other photovoltaic cell is kept under illumination. 22

12. A method according to any one of claim 11, wherein the other cell (Ci) has a different format from that of said first photovoltaic cell (C2).

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