Test system for rapidly detecting PID (Proportion Integration Differentiation) reliability of solar cell

Abstract

The utility model provides a test system for rapidly detecting the PID reliability of a solar cell, which comprises a constant temperature environment box body, a sealed container and a power supply, the sealed container and the power supply are respectively arranged inside and outside the constant temperature environment box body, a cell bearing platform is arranged in the sealed container, the solar cell to be detected is externally connected with the power supply, and a fan is also arranged in the sealed container. An acetic acid solution is injected into the bottom of the sealed container, and the front and back surfaces of the solar cell to be detected are infiltrated with a NaCl solution. A certain temperature is simulated through the constant-temperature environment box body, a certain humidity is simulated through the cooperation of the sealed container, the acetic acid solution, the NaCl solution and the fan, a bias voltage is simulated through an external reverse direct-current power supply, so that the solar cell is in a certain negative voltage condition, and finally, the output power of the solar cell is tested. And calculating the attenuation degree of the output power of the solar cell before and after the PID test so as to judge whether the solar cell has the anti-PID effect capability or not.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar cell production technical field, specifically, it shows a kind of test system for the quick detection solar cell piece PID reliability. BACKGROUND

[0002] Solar cell is a kind of photovoltaic semiconductor wafer using sunlight to generate electricity, as long as certain illumination is met, voltage can be output and current can be generated in the case of loop, simply speaking, solar cell is the device for converting light energy into electric energy by photoelectric effect.

[0003] Solar cell has excellent photoelectric performance, and it is also a kind of renewable and environment-friendly power generation method, and greenhouse gases such as carbon dioxide are not generated in the process of power generation, and the environment is not polluted, so solar cell is widely used in the world at present.

[0004] PID (Potential Induced Degradation) refers to the phenomenon that solar cell power attenuation occurs under certain external voltage for a long time.

[0005] During the operation of outdoor power station, lightning protection measures are considered, so the frame of module is grounded, which can cause negative bias between module and frame. The frame is positively charged during negative bias, so Na in the front glass will migrate. Na + will migrate. Na + Under the action of electric field, it passes through glass and adhesive film, gathers in the surface film layer of cell piece, and then diffuses into the defects (dislocation) of silicon crystal, passes through PN junction, and forms leakage current channel at both ends of PN junction.

[0006] PID is one of important factors of power attenuation of solar module during long-term operation, and solar cell piece needs to be detected by PID before use. Traditional cell end PID reliability test equipment, such as Freiberg Instrument PIDcon tester, often needs to use the stacking structure of glass, EVA film (Ethylene-vinyl Acetate Copolymer, EVA, ethylene-vinyl acetate copolymer) and cell piece. High temperature in preparation process can make EVA melt, and glass and cell piece are bonded together and cannot be easily separated without damage, which causes that only single test can be carried out after PID test, which is not conducive to the characterization analysis of solar cell, and the solar cell module used for test is scrapped after test, which increases cost.

[0007] Therefore, it is an urgent problem to find a kind of test system for quickly detecting the PID reliability of solar cell. UTILITY MODEL CONTENTS

[0008] The utility model discloses a kind of test systems of fast detection solar cell piece PID reliability, the test system includes: constant-temperature environment box, sealed container, power supply, the sealed container is set in constant-temperature environment box, the power supply is set in constant-temperature environment box, the middle position in the sealed container is provided with the cell piece bearing platform for placing the solar cell piece to be measured, the solar cell piece to be measured is connected power supply, the side position in the sealed container is provided with fan, the bottom of the sealed container is injected with acetic acid solution, the front and back of the solar cell piece to be measured are infiltrated with NaCl solution.

[0009] The utility model discloses a kind of test systems of fast detection solar cell piece PID reliability, the test system includes: constant-temperature environment box, sealed container, power supply, the sealed container is set in constant-temperature environment box, the power supply is set in constant-temperature environment box, the middle position in the sealed container is provided with the cell piece bearing platform for placing the solar cell piece to be measured, the solar cell piece to be measured is connected power supply, the side position in the sealed container is provided with fan, the bottom of the sealed container is injected with acetic acid solution, the front and back of the solar cell piece to be measured are infiltrated with NaCl solution.

[0010] Preferably, a plurality of arrayed solder strips are welded on the front and back of the solar cell piece to be measured, the side of the plurality of solder strips is aligned, and the plurality of solder strips on the same surface are welded on a bus bar, and one end of the bus bar extends outward.

[0011] Preferably, the acetic acid solution is prepared with 10L and the concentration is 0.3% to 0.5%, and the NaCl solution is prepared with saturated solution at normal temperature and pressure.

[0012] Preferably, the fan blows from top to bottom along the vertical direction.

[0013] Preferably, the bottom end of the cell piece bearing platform is spaced apart from the liquid level of the solution a in the sealed container.

[0014] Further preferably, two cell piece bearing platforms are vertically arranged in the sealed container in parallel and spaced apart, and a rest platform is horizontally protruded inward in the middle of the inner wall of the cell piece bearing platform.

[0015] Further preferably, the cell piece bearing platform is integrally formed by using corrosion-resistant material.

[0016] Based on the above test system, the solar cell piece PID reliability is tested, specifically, including the following steps:

[0017] Step one, sample preparation:

[0018] Take a solar cell piece to be measured, weld solder strips on the front and back thereof respectively, connect the solder strips welded on the front and back of the solar cell piece to be measured on a bus bar respectively, prepare the solar cell piece to be measured, test the initial power of the sample by using IV tester, and record as P0;

[0019] Step two, solution preparation:

[0020] Solution a, i.e. acetic acid solution; solution b, i.e. NaCl solution;

[0021] Step three, test environment preparation:

[0022] Prepare a constant temperature environment box, and embed a sealed container in the constant temperature environment box, set a battery piece bearing table in the middle of the inside of the sealed container, set a fan on one side of the inside of the sealed container, and set a power supply outside the constant temperature environment box;

[0023] Step four, test work:

[0024] First, pour solution a into the sealed container; then immerse the front and back surfaces of the to-be-tested solar cell piece in solution b completely, and place the to-be-tested solar cell piece on the battery piece bearing table, and expose the front and back surfaces of the to-be-tested solar cell piece, and connect the two bus bars on the to-be-tested solar cell piece to the positive and negative poles of the power supply respectively; then, set the temperature of the constant temperature environment box to 85±5 DEG C, turn on the fan and start the power supply;

[0025] The test time is 8h, after the test time, turn off the power supply and the fan, and stand still for 15-30min, then take out the to-be-tested solar cell piece, and test the decay power of the sample by using an IV tester, and record it as P 衰 ;

[0026] The decay data η calculation formula is:

[0027]

[0028] Test work is completed.

[0029] Compared with the prior art, the beneficial effects of the utility model lie in that: the test conditions under a certain temperature are simulated through the constant temperature environment box, the test conditions under a certain humidity are simulated through the cooperation of the sealed container, the acetic acid solution, the NaCl solution and the fan, that is, the Na + Corrosion is simulated by using the NaCl solution, the acid produced by the hydrolysis of the adhesive film on the solar cell piece is simulated by using the acetic acid solution, the air circulation in the sealed container is improved by the fan, so that the air flow concentration in a certain local space in the sealed container is avoided to be too high, the bias voltage is simulated by using the external reverse direct current power supply, so that the solar cell piece is under a certain negative voltage condition, finally, the output power of the solar cell piece is tested, the decay degree of the output power of the solar cell piece before and after the PID test is calculated, so that whether the solar cell piece has the ability of resisting the PID effect is judged, if the decay ratio of the output power of the solar cell piece before and after the PID effect test is less than 25%, it is considered that the related process of manufacturing the solar cell piece reaches the standard of resisting the PID ability, and vice versa.

[0030] The test system can save a large amount of time, has small volume, is convenient to transport, greatly reduces the cost of PID detection, and is convenient to disassemble the test system after test, is favorable for subsequent characterization analysis of the solar cell piece used for test, and improves timeliness and accuracy of PID performance judgment of the solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic view of a test system for rapidly detecting PID reliability of a solar cell piece according to the utility model;

[0032] Figure 2 is a schematic view of how to prepare a sample according to an embodiment of the utility model;

[0033] Corresponding marks in the drawings: 1-constant temperature environment box, 2-sealed container, 3-power supply, 4-cell piece bearing table, 41-resting part, 5-fan, 6-solar cell piece to be tested, 61-welding strip, 62-bus bar. DETAILED DESCRIPTION

[0034] The preferred embodiments of the utility model are described in detail below in combination with the drawings, so that the advantages and features of the utility model can be more easily understood by those skilled in the art, and the protection scope of the utility model can be more clearly and explicitly defined.

[0035] Referring to Figure 1 and Figure 2 , a test system for rapidly detecting PID reliability of a solar cell piece according to the embodiment includes a constant temperature environment box 1, a sealed container 2 and a power supply 3. The sealed container 2 is arranged in the constant temperature environment box 1. The sealed container is not a completely closed container, which means that the sealed container has good sealing performance and can be opened. The constant temperature environment box is a conventional constant temperature box, which can be set to a temperature. The power supply 3 is arranged outside the constant temperature environment box 1 and is a direct current power supply. An intermediate position in the sealed container 2 is provided with a cell piece bearing table 4 for placing a solar cell piece 6 to be tested. The solar cell piece 6 to be tested is connected with the power supply 3. A side position in the sealed container 2 is provided with a fan 5. The bottom of the sealed container 2 is filled with acetic acid solution a. The front and back surfaces of the solar cell piece 6 to be tested are soaked with NaCl solution b.

[0036] The test conditions of PID in the prior art are: relative temperature of 85 DEG C, relative humidity of 85%, and negative loading voltage. In the embodiment, the constant temperature environment box is used to simulate test conditions under a certain temperature, and NaCl solution is used to simulate Na in PID. +The erosion solar cell is simulated by using acetic acid solution to simulate the acid generated by the hydrolysis of the adhesive film on the solar cell, the fan can improve the air circulation in the sealed container to avoid the air concentration in a local space in the sealed container being too high, and the reverse direct current power supply is connected to simulate the bias voltage so that the solar cell is in a certain negative voltage condition.

[0037] In the embodiment, a plurality of solder strips 61 are welded on the front and back surfaces of the solar cell 6 to be tested, the side edges of the solder strips 61 are aligned, and the solder strips 61 on the same surface are welded on a bus bar 62, one end of the bus bar 62 extends outward, and the bus bar is used to concentrate and transmit the electric energy generated by the solar cell, which is convenient for connecting the power supply.

[0038] In the embodiment, the acetic acid solution a is prepared in 10L and the concentration is 0.3% to 0.5%, and the NaCl solution b is prepared in the saturated solution at normal temperature and pressure.

[0039] In the embodiment, the fan 5 blows air along the vertical direction from top to bottom to form internal circulation in the sealed container 2.

[0040] In the embodiment, the means for immersing the front and back surfaces of the solar cell 6 to be tested in the NaCl solution b is to completely immerse the front and back surfaces of the solar cell 6 to be tested in the NaCl solution b.

[0041] In the embodiment, a certain distance is left between the bottom end of the solar cell carrying table 4 and the liquid surface of the solution a in the sealed container 2 to avoid corrosion of the bottom end of the solar cell carrying table 4 caused by long-term immersion in the acetic acid solution.

[0042] In the embodiment, two solar cell carrying tables 4 are vertically arranged in the sealed container 2 in parallel and at intervals, the solar cell carrying tables 4 can be hung on the side wall of the sealed container 2, in general, as long as the bottom end of the solar cell carrying table is not in contact with the liquid surface of the acetic acid solution, and a rest table part 41 is horizontally and inwardly protruded in the middle of the inner wall of the solar cell carrying table 4, and the two ends of the solar cell 6 to be tested are placed on the rest table parts 41 of the two solar cell carrying tables 4, which can fully expose the front and back surfaces of the solar cell 6 to be tested to the environment in the sealed container 2.

[0043] In the embodiment, the solar cell carrying table 4 is made of a corrosion-resistant material, such as PTFE and PVDF.

[0044] The test method in the prior art is as follows: first, cut the solar cell into half, then weld into a string, lay the cell string on the back adhesive film (the lower side is back glass / back plate), and then cover the front adhesive film and front glass in sequence, and then perform high-temperature lamination; the laminated assembly has been formed, then encapsulate the frame and junction box with silicone, and after encapsulation, a period of time is allowed to stand before PID test.

[0045] First test component I-V, get the initial power P0, while retaining EL image; then the component is connected to 1500V power supply, the component frame is connected to the positive of power supply, the positive of component is connected to the negative of power supply, the component is placed in the environment of temperature 85℃, humidity 85%, test time 96h / time, test twice, test component I-V, EL each time, get P96, P192 respectively.

[0046]

[0047]

[0048] The PID96 and PID192 data are obtained, the test is ended, and the component is scrapped.

[0049] And the solar cell PID reliability test method based on the test system provided in the above embodiment of the utility model, specifically, comprises the following steps:

[0050] Step one, sample preparation:

[0051] Take a piece of solar cell to be tested, weld solder strips on the front and back surfaces respectively, connect the solder strips welded on the front and back surfaces of the solar cell to be tested to a busbar respectively, complete the preparation of the solar cell to be tested, test the initial power of the sample by using IV tester, and mark it as P0;

[0052] Step two, solution preparation:

[0053] Prepare solution a, i.e. acetic acid solution; prepare solution b, i.e. NaCl solution;

[0054] Step three, test environment preparation:

[0055] Prepare a constant temperature environment box, insert a sealed container into the constant temperature environment box, set a battery piece bearing table in the middle of the inside of the sealed container, set a fan on one side of the inside of the sealed container, and set a power supply outside the constant temperature environment box;

[0056] Step four, test work:

[0057] First, pour solution a into the sealed container; then immerse the front and back surfaces of the solar cell to be tested in solution b completely, place the solar cell to be tested on the battery piece bearing table, expose the front and back surfaces of the solar cell to be tested, and connect the two busbars on the solar cell to be tested to the positive and negative of the power supply respectively; then set the temperature of the constant temperature environment box to 85±5℃, open the fan and start the power supply;

[0058] The test time is 8h, after the test time, turn off the power supply and the fan, and stand still for 15-30min, then take out the solar cell to be tested, and test the decay power of the sample by using IV tester, mark it as P衰 ;

[0059] The attenuation data η is calculated according to the following formula:

[0060]

[0061] The test work is completed.

[0062] If the output power of the solar cell piece is less than 25% before and after the PID effect test, it is considered that the related process of manufacturing the solar cell piece meets the PID resistance requirement, and vice versa.

[0063] The above only describes some embodiments of the present application. For those skilled in the art, without departing from the inventive concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A test system for rapidly detecting the PID reliability of solar cells, characterized in that: The test system comprises: a constant temperature environment box (1), a sealed container (2), and a power supply (3); the sealed container (2) is arranged in the constant temperature environment box (1); the power supply (3) is arranged outside the constant temperature environment box (1); a cell support platform (4) for placing a solar cell (6) to be tested is arranged in the middle position of the sealed container (2); the solar cell (6) to be tested is externally connected to the power supply; a fan (5) is arranged at a side position of the sealed container (2); an acetic acid solution is injected into the bottom of the sealed container (2); and the front and back surfaces of the solar cell (6) to be tested are soaked with a NaCl solution.

2. A test system for rapidly detecting PID reliability of solar cells according to claim 1, characterized in that: A plurality of array-arranged welding strips (61) are welded to the front and back sides of the solar cell sheet (6) to be tested, one side of the plurality of welding strips (61) is aligned, and the plurality of welding strips (61) on the same side are welded together to a bus bar (62), one end of which extends outward.

3. A test system for rapidly detecting PID reliability of solar cells according to claim 1, characterized in that: The acetic acid solution is prepared in 10 L with a concentration of 0.3% to 0.5%, and the NaCl solution is prepared as a saturated solution at normal temperature and pressure.

4. A test system for rapidly detecting PID reliability of solar cells according to claim 1, characterized in that: The wind direction of the fan (5) is to blow air from top to bottom in a vertical direction.

5. A test system for rapidly detecting PID reliability of solar cells according to claim 1, characterized in that: A certain distance is left between the bottom end of the battery cell supporting platform (4) and the liquid surface of the solution a in the sealed container (2).

6. A test system for rapidly detecting PID reliability of solar cells according to claim 5, characterized in that: Two battery cell support platforms (4) are vertically arranged in a parallel and spaced manner in the sealed container (2), and a shelf portion (41) is provided in the middle of the inner wall of the battery cell support platform (4) protruding inward horizontally.

7. A test system for rapidly detecting PID reliability of solar cells according to claim 6, characterized in that: The cell support platform (4) is made of corrosion-resistant material and is integrally formed.

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