CN217607778U

CN217607778U - Photovoltaic cell EL tester

Info

Publication number: CN217607778U
Application number: CN202123196880.9U
Authority: CN
Inventors: 谈仕祥; 施佳伟; 王亚楠; 谬杰; 李拴平
Original assignee: Tongwei Solar Meishan Co Ltd
Current assignee: Tongwei Solar Meishan Co Ltd
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-10-18
Anticipated expiration: 2031-12-17

Abstract

The utility model discloses a photovoltaic cell EL tester, including a plurality of detecting element, every detecting element centre gripping alone makes this electrode electroluminescence on an electrode on battery piece two sides, its characterized in that, an independent constant current source is connected in every detecting element wiring, this detecting element's of constant current source independent control detection voltage with the luminous luminance of electrode. The detection voltage on each electrode is independently controlled, so that the brightness of the whole battery piece is kept uniform before the test, the accuracy of the EL test of the battery can be improved, and the misjudgment of the detection result is avoided.

Description

Photovoltaic cell EL tester

Technical Field

The utility model belongs to the technical field of photovoltaic product check out test set, specifically speaking relates to a photovoltaic cell EL tester.

Background

The EL tester is generally called an electroluminescence tester, and is a device for detecting internal defects of a photovoltaic cell or a cell module. And (3) utilizing the electroluminescence principle of the crystalline silicon and a high-resolution CCD camera to shoot near-infrared images of the assembly, and acquiring and judging the defects of the photovoltaic cell assembly.

When the EL tester is used for testing, the probes are pressed on the electrodes on the front side and the back side of the battery piece, and then the constant current source is used for introducing forward biased voltage and current, so that the battery emits infrared rays and various defects in the battery are displayed.

The EL tester of the prior art controls the voltage and current of all the probes as a whole, and cannot control the voltage and current of a certain row of probes individually. Therefore, if a certain position of the cell is tested, one row of probes in the cell is in poor contact with the electrode, the light emitting brightness of the position is low, and dark spots like the defect of the cell are displayed on a camera picture. However, when the inspector judges the dark spots, the inspector cannot distinguish whether the dark spots are caused by the defects of the battery piece, so that the judgment error is easy to occur, the rework is caused, and the production progress is delayed.

SUMMERY OF THE UTILITY MODEL

1. Problems to be solved

When testing at EL among the prior art, the battery piece leads to the problem of darkening because of the probe contact failure, the utility model provides a photovoltaic cell EL tester arranges voltage single control to every probe, before making EL detect at every turn, and the battery piece keeps luminance unanimous, avoids measurement personnel erroneous judgement.

2. Technical scheme

In order to solve the problem, the utility model adopts the following technical scheme:

a photovoltaic cell EL tester comprises a plurality of detection units, wherein each detection unit is independently clamped on one electrode of a cell slice to enable the electrode to generate electroluminescence, each detection unit is connected with an independent constant current source, and the constant current source independently controls the detection voltage of the detection unit and adjusts the luminance of the cell slice.

Preferably, the detection unit comprises a first row of probes contacting with the front electrode of the battery piece, the first row of probes comprises a probe frame and a plurality of probes fixed on the probe frame at equal intervals, and one end of the probe frame is connected to the constant current source through a wiring.

Preferably, the detection unit includes a back conductive device, and the back conductive device is in contact with an electrode on the back of the battery piece to be detected.

Preferably, the back conductive means comprises a second row of probes, the second row of probes having the same structure as the first row of probes.

Preferably, the back conductive device comprises transparent conductive glass, a conductive layer of the transparent conductive glass is in contact with the back electrode of the cell, and the conductive layer is connected to the constant current source through a connection wire.

Preferably, the surface of the conductive layer of the transparent conductive glass is a plane.

Preferably, the conductive layer of the transparent conductive glass is fixedly connected with a plurality of conductive strips, and the conductive strips are supported on the electrodes on the back surface of the cell piece, so that the isolated conductive layer is connected with the electrodes through the conductive strips.

Preferably, the width of the conductive strip is greater than the electrode width.

3. Advantageous effects

Compared with the prior art, the beneficial effects of the utility model are that:

(1) The utility model discloses a photovoltaic cell EL tester, including a plurality of detecting element, every detecting element centre gripping alone makes this electrode electroluminescence on an electrode on battery piece two sides, and an independent constant current source is connected to every detecting element, constant current source independent control this detecting element's detection voltage, adjustment the luminous luminance of electrode. Therefore, the voltage of each detection unit can be controlled individually. The higher the voltage, the higher the brightness of the electroluminescence of the cell. Before testing, the voltage of each row of detection units is adjusted, so that the brightness of all positions of the whole battery piece before testing is kept consistent, dark spots caused by poor contact of a certain position are avoided, the EL testing accuracy of the battery can be improved, and misjudgment on the quality of the battery is prevented.

(2) The back conductive device comprises transparent conductive glass, a conductive layer of the transparent conductive glass is contacted with the back electrode of the cell piece, and the conductive layer is connected to the constant current source through a wiring. The whole surface of the transparent conductive glass is in contact with the back electrode of the cell, so that the contact area of the transparent conductive glass and the back electrode is increased, the probability of poor contact between detection equipment and the electrode is reduced, and the detection accuracy is improved.

On the other hand, the transparent conductive glass can not block the camera from shooting, so that the shooting area of the camera is enlarged, and the detection efficiency is improved.

(3) And the conductive strips are arranged on the transparent conductive glass and supported on the electrodes on the back of the cell piece. The conducting bar and the first row of probes clamp the electrodes of the battery piece from the upper surface and the lower surface, and the problem that part of the battery pieces cannot be attached to the conductive glass due to local slight bending can be solved. And because the shielding area of the conductive strips is much smaller than that of the probe rows, the EL test image can still be kept complete.

The width of conducting strip is greater than the electrode width, guarantees that the conducting strip can fully contact with the electrode in the testing process, avoids appearing both contact failure problem.

Drawings

Fig. 1 is a schematic connection diagram of an EL tester in side view in embodiment 1 of the present invention;

fig. 2 is a schematic front view of a detection unit in embodiment 1 of the present invention;

FIG. 3 is a schematic view of the installation of the transparent conductive glass structure of the present invention;

fig. 4 is a schematic view of the installation of the conductive strip structure in a side view of the present invention;

in the figure:

1. a detection unit; 11. a first row of probes; 111. a probe holder; 112. a probe;

12. a back side conductive device; 121. a second row of probes; 122. transparent conductive glass; 1221. a conductive layer;

123. a support table-board; 124. a conductive strip;

2. a battery piece; 21. an electrode;

3. and a constant current source.

Detailed Description

The following detailed description of exemplary embodiments of the invention refers to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. The following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to provide the best mode contemplated for carrying out the invention and to enable any person skilled in the art to practice the invention. Accordingly, the scope of the invention is to be limited only by the following claims.

In order to solve the above problems, the following description is made with reference to the accompanying drawings:

a photovoltaic cell EL tester (also called an electroluminescence tester) is a device for detecting internal defects of a photovoltaic cell or a cell assembly. When the photovoltaic cell EL tester is used for testing, the probes 112 are pressed on the electrodes 21 on the front surface and the back surface of the cell 2, and then the constant current source 3 is used for introducing forward biased voltage and current, so that the cell emits infrared rays, and various defects in the cell are displayed.

Example 1:

the EL tester mainly comprises a detection unit 1, wherein the detection unit 1 is connected to a constant current source 3 and is used for electrifying an electrode 21 on a cell 2 so that the cell 2 can emit light. The detection unit 1 comprises a first row of probes 11 and a back conductive device 12, wherein the first row of probes 11 is pressed on the electrode 21 on the front side of the battery piece 2 during testing. The back conductive device 12 is located on the back of the cell 2 and contacts with the back electrode 21 of the cell 2 during testing, and a closed circuit is formed among the first row of probes 11, the back conductive device 12 and the constant current source 3. Because each battery piece 2 is provided with a plurality of electrodes 21, each electrode 21 needs to be powered by one detection unit 1 during detection, so that the area can emit light for detection.

The number of the detection units 1 is the same as that of the electrodes 21 of the battery piece 2 to be detected. Each detection unit 1 is connected with an independent constant current source 3, and the constant current source 3 can adjust the voltage of the detection unit 1. When the detection power supply voltage is increased, the brightness of the battery slice 2 in the corresponding area of the detection unit 1 is increased, otherwise, the brightness is decreased. Therefore, when the brightness of one detection unit 1 is obviously different from the brightness of other units, the voltage of the detection unit 1 is adjusted to keep the brightness consistent with other areas. The occurrence of dark spots due to poor contact at a certain position is avoided, so that the accuracy of the EL test of the battery can be improved, and the misjudgment of the quality of the battery is prevented.

The first row of probes 11 comprises a probe holder 111, and a plurality of probes 112 are fixed on the probe holder 111 at equal intervals. The probes 112 and the probe holder 111 are made of conductive material. During testing, the probe 112 is driven by the probe holder 111 to move towards the cell 2, and the back conductive device 12 is matched to clamp the electrodes 21 on the front and back of the cell 2. One end of the probe holder 111 is connected to the negative electrode of the constant current source 3 to which it belongs through a wiring, and the back conductive device 12 is connected to the positive electrode of the constant current source 3 through a wiring.

The back conductive device 12 includes a second row of probes 121, the second row of probes 121 has the same structure as the first row of probes 11, and the second row of probes 121 are clamped on the electrode 21 on the back of the battery piece 2.

Example 2:

since the probes 112 of the second row of probes 121 are in point contact with the electrodes 21 of the battery piece 2, they easily slide under the pressure of the first row of probes 11, and a problem of poor contact occurs.

In order to solve the problem of poor contact between the second probe 112 and the electrode 21, the back conductive device 12 is made of transparent conductive glass 122 (transparent as a whole, having a conductive function). The conductive layer 1221 of the transparent conductive glass 122 is brought into contact with the back electrode 21 of the cell 2, and then the conductive layer 1221 is wired to the constant current source 3. The entire surface of the transparent conductive glass 122 is in contact with the rear surface electrode 21 of the cell 2, and the contact area between the two is increased. Even if the battery piece 2 slightly slides in the detection process, the poor contact problem can not occur. In addition, the transparent conductive glass 122 does not block the camera from taking a picture, so that the picture taking area of the camera is enlarged, and the detection efficiency is improved.

The transparent conductive glass 122 is arranged on the support table-board 123, the positive slide blocks are arranged on the edge of the support table-board 123, and when a battery to be detected is placed on the transparent conductive glass 122, the positive slide blocks on the periphery slide towards the center, so that the battery can slide to the center to be detected. The upper probe 11 in the first row is moved downward to a position corresponding to the electrode 21 of the battery to be tested, and is pressed against the electrode 21.

And debugging the power supply current of each detection unit 1 to keep the brightness of the whole photovoltaic cell consistent, and taking a picture by using a camera to generate an EL image of the cell.

Example 3:

during the detection process using the transparent conductive glass 122, it is found that the electrode 21 in the region cannot be completely attached to the transparent conductive glass 122 due to slight bending deformation of a local part of the cell 2 itself, and the contact between the two is poor.

Therefore, the transparent conductive glass 122 is further improved to include a conductive strip 124 disposed on the transparent conductive glass 122. The conductive strip 124 is a metal strip for connecting the back of the battery piece 2 for conducting electricity. In use, the conductive strips 124 are supported on the electrodes 21 on the back side of the cell 2 in a corresponding clamping relationship with the first row of probes 11, and clamped together on the electrodes 21 on both sides of the cell 2. The arranged conducting bars 124 are supported on the electrodes 21 of the cell 2 to jack up the cell 2, and the local abutting mode can avoid the deformation area of the cell 2 and solve the problem of poor contact of the area.

The conductive strips 124 are in a long and thin strip-shaped structure, and the number and the spacing of the conductive strips are consistent with the electrodes 21 of the cell 2. The width of the conductive strip 124 is greater than the width of the electrode 21, preferably 2-3 times the width of the electrode 21 of the cell 2, so that the conductive strip 124 can be sufficiently attached to the electrode 21 of the cell 2. Because the conductive strip 124 is a slender structure, the area of the conductive strip that shields the camera is much smaller than the area of the probe 112, so that the EL test image can still be kept complete, and the current conduction effect in the test process is ensured.

The present invention and its embodiments have been described above schematically, and the description is not limited thereto, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art should understand that without departing from the spirit of the present invention, the person skilled in the art should not inventively design the similar structural modes and embodiments to the technical solution, and all shall fall within the protection scope of the present invention.

Claims

1. A photovoltaic cell EL tester comprises a plurality of detection units (1), wherein each detection unit (1) is independently clamped on one electrode (21) of a cell to enable the electrode (21) to emit light in an electroluminescence mode, and the photovoltaic cell EL tester is characterized in that each detection unit (1) is connected with an independent constant current source (3), and the constant current sources (3) independently control the detection voltage of the detection units (1) to adjust the light emitting brightness of the cell (2).

2. The photovoltaic EL tester as claimed in claim 1, wherein the test unit (1) comprises a first row of probes (11) contacting the front electrode (21) of the cell, the first row of probes (11) comprising a probe holder (111) and a plurality of probes (112) fixed on the probe holder (111) at equal intervals, one end of the probe holder (111) being connected to the constant current source (3) through a wire.

3. The photovoltaic EL tester as claimed in claim 2, characterized in that the detection unit (1) comprises back conductive means (12), the back conductive means (12) being in contact with the electrodes (21) of the back of the cell piece to be tested.

4. The photovoltaic EL tester as claimed in claim 3, characterized in that the back conductive means (12) comprise a second row of probes (121), the second row of probes (121) being structurally identical to the first row of probes (11).

5. The photovoltaic EL tester as claimed in claim 3, characterized in that the back conductive means (12) comprise a transparent conductive glass (122), a conductive layer (1221) of the transparent conductive glass (122) being in contact with the cell sheet back electrode (21), the conductive layer (1221) being connected to the constant current source (3) by a wire.

6. The photovoltaic EL tester as recited in claim 5, characterized in that the surface of the conductive layer (1221) of the transparent conductive glass (122) is planar.

7. The photovoltaic EL tester as claimed in claim 5, wherein the conductive layer (1221) of the transparent conductive glass (122) has a plurality of conductive strips (124) affixed thereto, the conductive strips (124) being supported on the electrodes (21) on the back side of the cell sheet, such that the isolated conductive layer (1221) is connected to the electrodes (21) via the conductive strips (124).

8. The photovoltaic EL tester as recited in claim 7, wherein the width of the conductive strip (124) is greater than the width of the electrode (21).