Testing device and testing method for photovoltaic cell acetic acid corrosion experiment

Abstract

The invention discloses a testing device and a testing method for an acetic acid corrosion experiment of a photovoltaic battery piece, and the device comprises a testing box body which is used for placing the battery piece and adding an acetic acid solution, and is also provided with a gas circulation unit; a steam cavity is formed in the receiving box body, a steam concentration detection unit and a steam temperature sensor are arranged in the steam cavity, and acetic acid steam in the testing box body is conveyed to the steam cavity through a gas conveying pipeline and then returns to the testing box body through a gas loop pipeline; the test host receives the actually measured concentration and temperature of the acetic acid steam, the target concentration of the acetic acid steam is preset in the test host, a temperature compensation algorithm is implanted in the test host, and the test host compares the obtained actually measured concentration with the target concentration after being calibrated by the temperature compensation algorithm; the liquid injection device is in communication connection with the test host and is also communicated with the test box body; if the comparison result exceeds the allowable fluctuation range of the preset target concentration, the liquid injection device is controlled to supplement liquid into the test box body, the concentration of the acetic acid solution is adjusted, and meanwhile alarm is triggered in a grading mode.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cell reliability testing technology, specifically to a testing device and method for acetic acid corrosion testing of photovoltaic cells. Background Technology

[0002] A crucial step in the production of solar photovoltaic cells is the reliability testing of acetic acid corrosion experiments. Currently, most existing acetic acid corrosion tests for solar cells use the static saturated steam method. This method has the drawback of not being able to monitor and actively control the concentration of acetic acid vapor in real time during the experiment. This leads to the following problems: ① Poor consistency of experimental conditions: Because the real-time concentration of acetic acid vapor cannot be known and controlled, it is greatly affected by temperature and sealing, resulting in poor comparability of test results between different batches and different laboratories. The attenuation rate test results have huge deviations (>15%), making it difficult to form industry standards; ② Low experimental efficiency and high cost: Frequent experimental failures and retests due to uncontrollable conditions (retest rate 30-45%) waste manpower and materials, increasing R&D and quality inspection costs; ③ Uncontrollable concentration and large data fluctuations: The existing experimental method uses the static saturated steam method, which cannot obtain the vapor concentration in real time, and cannot avoid the problem of large fluctuations in attenuation rate test data caused by factors such as vapor concentration fluctuations and failure of the test device seal. The test results of different batches can be seen in Table 1.

[0003] In summary, the existing reliability testing methods for acetic acid corrosion tests on solar cells show large discrepancies in the degradation rate results obtained by different photovoltaic cell manufacturers, resulting in low reliability of the test results. Summary of the Invention

[0004] The purpose of this invention is to provide a testing device and method for acetic acid corrosion experiments on photovoltaic cells, aiming to solve the problem that existing experimental methods (static saturated steam method) cannot avoid large deviations in attenuation rate test results caused by factors such as steam concentration fluctuations and sealing failure of the testing device.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention designs a testing device for acetic acid corrosion experiments on photovoltaic cells, the testing device comprising the following structural configuration: The test chamber is used to place the battery cells to be tested and to add acetic acid solution. The test chamber is also equipped with a gas circulation unit. The receiving chamber has a steam chamber inside, which is also equipped with a steam concentration detection unit and a steam temperature sensor. Acetic acid vapor in the test chamber is transported to the steam chamber through the gas circulation unit and the gas delivery pipeline, and then returned to the test chamber through the gas loop pipeline, realizing the circulation in this closed-loop gas path. The test host is used to receive real-time concentration data and real-time temperature data of acetic acid vapor detected by the steam concentration detection unit and the steam temperature sensor. The test host is also preset with a target concentration value of acetic acid vapor and has a temperature compensation algorithm. The test host is also used to compare the acquired measured concentration data of acetic acid vapor with the preset target concentration value after dynamic calibration by the temperature compensation algorithm. The test unit includes a liquid injection device, which is communicatively connected to the test host and also connected to the test chamber. If the comparison result exceeds the allowable fluctuation range of the preset target concentration, the test host controls the liquid injection device to replenish the liquid in the test chamber to adjust the concentration of the acetic acid solution, so that the acetic acid vapor concentration after state calibration meets the allowable fluctuation range of the target concentration, and also triggers alarms in stages. If the comparison result does not exceed the allowable fluctuation range of the preset target concentration, no liquid replenishment or alarm is triggered.

[0006] Specifically, the acetic acid solution is composed of acetic acid, potassium chloride, and water. The connection between the steam chamber and the gas circuit pipeline is configured as an inverted funnel-shaped structure.

[0007] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells includes a drying chamber, which is located inside the drying chamber.

[0008] Specifically, the drying chamber can be used to heat the test chamber to accelerate the formation of acetic acid vapor, thereby speeding up the acetic acid corrosion process of the battery cells.

[0009] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells includes a cell support frame inside the testing chamber for placing the cells. This design prevents the cells from coming into contact with the acetic acid solution.

[0010] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells: the inner wall of the steam chamber is coated with a hydrophobic coating, and a heating module is provided on the outside.

[0011] Specifically, the hydrophobic coating on the inner wall of the steam chamber can be a hydrophobic fluorocarbon coating (contact angle > 120°), which can prevent acetic acid droplets from adhering and prevent steam condensation through the heating module.

[0012] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells includes a vapor concentration detection unit comprising an infrared light source and a detector, the surface of which is coated with a hydrophobic coating; the infrared light emitted by the infrared light source penetrates the acetic acid vapor in the vapor chamber and is received by the detector to detect the concentration of the acetic acid vapor.

[0013] Specifically, the hydrophobic coating on the detector surface can be a hydrophobic fluorocarbon coating (contact angle > 120°) to prevent acetic acid droplets from adhering.

[0014] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells includes a warning light and a buzzer, which are respectively connected in communication with the testing host.

[0015] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells: the liquid injection device includes a liquid injection valve, a liquid injection pipe, and several liquid carrier pipes respectively filled with acetic acid and water; During replenishment: Acetic acid or water is injected into the test chamber through the injection valve and injection tube to adjust the concentration of the acetic acid solution.

[0016] Furthermore, a testing device for acetic acid corrosion experiments on photovoltaic cells includes a collection tray disposed in the receiving box for collecting condensate generated in the receiving box.

[0017] This invention also provides a test method for acetic acid corrosion experiments on photovoltaic cells, the method comprising the following steps: S1. Start-up and circulation: Place the battery cell to be tested and the prepared acetic acid solution in the test chamber and seal it. Then place the whole thing in the drying chamber and start the gas circulation unit so that the acetic acid vapor in the test chamber continuously circulates in the closed-loop gas space consisting of the test chamber, gas delivery pipeline, vapor chamber and gas circuit pipeline. S2. Real-time detection: The concentration and temperature data of acetic acid vapor are acquired in real time through the steam concentration detection unit and the steam temperature sensor; S3. Data Comparison: The test host receives the measured acetic acid vapor concentration data and temperature data, and dynamically calculates the calibrated concentration value based on the built-in temperature compensation algorithm, and then compares the concentration value with the preset target concentration. Wherein, the concentration value calibrated by the temperature compensation algorithm = measured concentration × K; K is calculated with reference to the Arrhenius equation, i.e., k = a·e^(-Ea / RT); In the formula, K is the temperature compensation factor (dimensionless), used to correct the concentration reading; the value of a ranges from 0.11 to 0.13; and T is the measured temperature data. S4. Dynamic Control: Based on the comparison results of step S3, if the calibrated concentration value is lower than the lower limit of the preset target concentration's allowable fluctuation range, the test host calculates the required amount of acetic acid replenishment based on the deviation value using an algorithm and controls the injection device to inject a fixed amount of acetic acid into the test chamber to increase the acetic acid solution concentration until the concentration returns to the preset target concentration's allowable fluctuation range; if the calibrated concentration value is higher than the upper limit of the preset target concentration's allowable fluctuation range, the test host calculates the required amount of water replenishment based on the deviation value using an algorithm and controls the injection device to inject a fixed amount of water into the test chamber to dilute the acetic acid solution until the concentration returns to the preset target concentration's allowable fluctuation range. The preset target concentration of acetic acid vapor is 3.0% (volume concentration), with an allowable fluctuation range of ±5% (i.e., the allowable fluctuation range of the target concentration is 2.85% to 3.15%). The replenishment volume is calculated as follows: replenishment volume (ml) = |calibrated concentration value - 3.0%| × closed-loop gas path volume (L) × adjustment coefficient, with the adjustment coefficient being 0.08 to 0.12. Among them, the closed-loop gas path volume refers to the gas phase space volume participating in the gas path circulation, which is the total volume of the test chamber + steam chamber + gas delivery pipeline + gas loop pipeline. S5. Alarm and Recording: Based on the comparison results, if the calibrated concentration value exceeds the preset target concentration fluctuation range by 5-10%, a level one alarm will be triggered and recorded in the test host. If the calibrated concentration value exceeds the preset target concentration fluctuation range by more than 10%, a level 2 alarm will be triggered and recorded in the test host. If the measured concentration detected by the steam concentration detection unit continues to decrease at a rate > 0.1% / min, a seal failure alarm will be triggered to check for leaks in the closed-loop gas path. The alarm types are as follows: Level 1 alarm: flashing yellow warning light + test host prompt; Level 2 alarm: flashing red warning light + buzzer prompt + test host prompt.

[0018] Furthermore, a testing method for acetic acid corrosion experiments on photovoltaic cells is provided: the testing host is also equipped with a pressure compensation algorithm. The testing host dynamically calibrates the acquired measured concentration data of acetic acid vapor using both temperature compensation and pressure compensation algorithms, and then compares it with a preset target concentration value. If the concentration value after dynamic calibration by either compensation algorithm exceeds the allowable fluctuation range of the target concentration, liquid replenishment and a corresponding alarm level are triggered. If the concentration values ​​after dynamic calibration by both compensation algorithms exceed the allowable fluctuation range of the preset target concentration, the required liquid replenishment amount is calculated separately, and the average value is taken for liquid replenishment. Wherein, the concentration value after calibration by the pressure compensation algorithm = measured concentration × (P standard / P measured), where P standard refers to the pressure of acetic acid vapor calculated according to the ideal gas law at 85℃, and P measured is the pressure data measured by the pressure sensor set in the vapor chamber.

[0019] The beneficial effects of this invention are: The testing device designed in this invention for acetic acid corrosion experiments on photovoltaic cells can not only monitor the concentration of acetic acid vapor in real time during the acetic acid corrosion resistance test of the cells, but also dynamically control the concentration of acetic acid vapor, ensuring the reliability of the degradation rate test results. This solves the problem of large deviations in degradation rate test results of different batches and different experiments caused by the inability to know and control the real-time concentration of acetic acid vapor in existing testing methods.

[0020] The testing device and method for acetic acid corrosion experiments on photovoltaic cells provided by this invention have the following advantages: ① Reduced retry rate: It solves the problem of large deviations in degradation rate testing caused by factors such as concentration fluctuations and sealing failures, reducing the retry rate from 30-45% to <3%; ② Achieved precise, stable, and visual control of concentration: Due to the adoption of the "closed-loop gas circulation + real-time detection" technical solution, the traditional static and blind testing mode is completely changed, thereby improving the steam concentration control accuracy from ±20% of the traditional method to within ±0.5% of this invention (a 40-fold improvement), and realizing visual monitoring of the concentration throughout the experiment, effectively improving the reliability and efficiency of cell testing. ③ Significantly improves the reliability and repeatability of test results: Thanks to the precise control of steam concentration and dynamic compensation algorithm of this invention, the main factors causing large test deviations are fundamentally eliminated. Experimental results show that this invention can reduce the retry rate from 30-45% of the traditional method to below 3%, making the data between different test batches and laboratories highly comparable (small deviation); ④ Improves the level of automation and intelligence of the experiment: Due to the introduction of an automatic control system based on dynamic compensation algorithm, the testing device can automatically maintain the concentration stability and issue an early warning when abnormal, reducing manual intervention and opening the lid operation, which not only improves efficiency, but also reduces the experimental failure caused by human operation error. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1This is a schematic diagram of the test device for acetic acid corrosion experiments on photovoltaic cells designed in Embodiment 1 of the present invention; Figure 2 The external structural diagram (excluding the drying chamber) of the test device for acetic acid corrosion test of photovoltaic cells designed for Embodiment 1 of the present invention is shown. Figure 3 The stability curves of acetic acid vapor concentration in Examples 3 and 4 are recorded. Figure 4 A process flow diagram of the test method provided in Example 4; Figure 5 The flowchart shows the dynamic control process of acetic acid vapor concentration in Examples 3 and 4.

[0023] The markings in the image are as follows: 1-Test chamber, 2-Receiving chamber, 3-Test host, 4-Liquid injection device, 5-Steam concentration detection unit, 6-Steam temperature sensor, 7-Gas delivery pipeline, 8-Gas circuit pipeline, 9-Drying chamber, 10-Collection tray, 11-Battery cell, 12-Gas circulation unit, 21-Steam chamber, 41-Liquid injection valve, 42-Liquid injection pipe, 43-Liquid carrier pipe, 51-Infrared light source, 52-Detector. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "top," and "bottom," etc., indicating orientation or positional relationships, are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein.

[0026] Example 1

[0027] like Figures 1-2 As shown in Example 1, this invention designs a testing device for acetic acid corrosion experiments on photovoltaic cells, which includes the following structural configuration: The test chamber 1 is equipped with a battery cell support for placing several battery cells 11 to be tested. The test chamber 1 is also used to store acetic acid solution. The test chamber 1 is also equipped with a gas circulation unit 12 (fan, specifically a ceramic bearing fan with a wind speed of 0.45 to 0.55 m / s). The test chamber 1 is also set inside the drying chamber 9. The receiving housing 2 contains a steam chamber 21. The inner wall of the steam chamber 21 is coated with a hydrophobic coating (hydrophobic fluorocarbon coating), and a heating module is installed on the outside to achieve condensation. The steam chamber 21 also contains a steam concentration detection unit 5 and a steam temperature sensor 6 (PT100 platinum resistance thermometer, in direct contact with the steam environment). The steam concentration detection unit 5 includes an infrared light source 51 (narrowband IR). An LED (center wavelength 9.7±0.05μm, pulsed emission to reduce thermal interference) and a detector 52 (western quadrant thermopile sensor, used with a lock-in amplifier circuit to detect absorbed signals) are used. The surface of the detector 52 is coated with a hydrophobic coating (hydrophobic fluorocarbon coating) to prevent acetic acid droplets from adhering. The infrared light emitted by the infrared light source 51 penetrates the acetic acid vapor in the steam chamber 21 and is received by the detector 52 to detect the concentration of acetic acid vapor. The acetic acid vapor in the test chamber 1 is transported to the steam chamber 21 through the gas circulation unit 12 and the gas delivery pipeline 7, and then returned to the test chamber 1 through the gas loop pipeline 8 (the connection between the steam chamber 21 and the gas loop pipeline 8 is designed as an inverted funnel, which facilitates the return of condensate to the test chamber 1 under the blowing of steam), realizing a closed-loop circulation of steam. The receiving chamber 2 is also equipped with a collection tray 10, which can be used to collect the condensate generated in the receiving chamber 2. The test host 3 is communicatively connected to the steam concentration detection unit 5 and the steam temperature sensor 6. It is used to receive real-time concentration data and real-time temperature data of acetic acid vapor detected by the steam concentration detection unit 5 and the steam temperature sensor 6. The test host 3 is also preset with a target concentration value of acetic acid vapor and has an embedded temperature compensation algorithm. The test host 3 compares the acquired measured concentration data of acetic acid vapor with the preset target concentration value after dynamic calibration by the temperature compensation algorithm. The test host 3 is communicatively connected to an alarm light and a buzzer for triggering alarm signals. And the liquid injection device 4, which includes a liquid injection valve 41 (electromagnetically controlled micro valve), a liquid injection tube 42 and several liquid carrier tubes 43 respectively filled with acetic acid and water. The liquid injection valve 41 is communicatively connected to the test host 3, and the two ends of the liquid injection tube 42 are respectively connected to the test chamber 1 and the liquid injection valve 41. If the comparison between the concentration value after dynamic calibration by the temperature compensation algorithm and the preset target concentration value exceeds the allowable fluctuation range of the preset target concentration, the test host 3 controls the injection valve 41 to replenish the test chamber 1 through the injection pipe 42 (the replenishment includes water or acetic acid, which is injected into the test chamber 1 through the injection valve 41 and the injection pipe 42 during replenishment) to adjust the concentration of the acetic acid solution and ensure that the acetic acid vapor concentration after dynamic calibration meets the allowable fluctuation range of the target concentration. At the same time, the corresponding alarm signal is also triggered. If the comparison result does not exceed the allowable fluctuation range of the preset target concentration, replenishment and alarm are not triggered.

[0028] Specifically, the vapor concentration detection unit 5 in the above embodiment 1 uses infrared spectroscopy (wavelength 9.7μm) to measure the absorption rate of acetic acid vapor with an accuracy of ±0.1% to measure the concentration of acetic acid vapor; sampling frequency: real-time data update once per second.

[0029] Example 2

[0030] The difference between Example 2 and Example 1 is that Example 2 also incorporates a pressure compensation algorithm in the test host 3 and sets up a pressure sensor in the steam chamber 21. The other conditions of Example 2 are the same as those of Example 1.

[0031] Example 3

[0032] This embodiment 3 provides a test method for acetic acid corrosion experiments on photovoltaic cells. The method uses the test device of embodiment 1 and includes the following steps: S1. Start-up and circulation: Place the battery cell 11 to be tested on the battery cell support and put it into the test chamber 1. Pass the prepared acetic acid solution into the test chamber 1 and seal it. Then place the entire test chamber 1 into the drying chamber 9 to promote the evaporation of the acetic acid solution to form acetic acid vapor. Start the gas circulation unit 12 so that the acetic acid vapor in the test chamber 1 continuously circulates in the closed-loop gas path space composed of the test chamber 1, the gas delivery pipeline 7, the vapor chamber 21 and the gas circuit pipeline 8. S2. Real-time detection: The concentration and temperature data of acetic acid vapor are acquired in real time through the steam concentration detection unit 5 and the steam temperature sensor 6. S3. Data comparison: The test host 3 receives the measured acetic acid vapor concentration and temperature data and performs dynamic calibration calculation on the measured acetic acid vapor concentration data based on the temperature compensation algorithm built into the test host 3. The calculated calibrated concentration value is compared with the preset target concentration value in the test host 3. Wherein, the concentration value calibrated by the temperature compensation algorithm = measured concentration × K; K is calculated using the Arrhenius equation, i.e., k = a·e^(-Ea / RT); where: the value of a ranges from 0.11 to 0.13, and T is the measured temperature data; S4. Dynamic Control: Based on the comparison results in step S3, if the dynamically calibrated concentration value is lower than the lower limit of the preset target concentration's allowable fluctuation range, the test host 3 calculates the required acetic acid replenishment amount according to the deviation value using an algorithm and controls the injection device 4 (injection valve 41) to inject a fixed amount of acetic acid into the test chamber 1 through the injection pipe 42 until the concentration returns to the preset target concentration's allowable fluctuation range; if the calibrated concentration value is higher than the upper limit of the preset target concentration's allowable fluctuation range, the test host 3 calculates the required water replenishment amount according to the deviation value using an algorithm and controls the injection valve 41 to inject a fixed amount of water into the test chamber 1 through the injection pipe 42 until the concentration returns to the preset target concentration's allowable fluctuation range; the dynamic control process for acetic acid vapor concentration is as follows. Figure 5 As shown; The preset target concentration of acetic acid vapor is 3.0% (volume concentration), and the allowable fluctuation range is ±5% (that is, the allowable fluctuation range of the target concentration is 2.85 to 3.15%). The replenishment volume is calculated as follows: Replenishment volume (ml) = |calibrated concentration value - 3.0%| × closed-loop gas path volume (L) × adjustment coefficient, where the adjustment coefficient is 0.08 to 0.12; S5. Alarm and Recording: Based on the comparison results, if the fluctuation range of the preset target concentration is not exceeded, no liquid replenishment or alarm will be triggered. The corrosion resistance test will continue for 8 hours until the end, and the acetic acid vapor concentration curve will be recorded (e.g., Figure 3 (As shown), generate a test report; If the calibrated concentration value exceeds the preset target concentration allowable fluctuation range and the excess is between 5% and 10%, a level one alarm will be triggered and recorded in the test host 3. If the calibrated concentration value exceeds the preset target concentration allowable fluctuation range and exceeds the range by more than 10%, a level 2 alarm will be triggered and recorded in the test host 3; If the measured concentration detected by the steam concentration detection unit 5 continues to decrease at a rate > 0.1% / min, a seal failure alarm will be triggered. The test host 3 will automatically save the data for the first 10 minutes before the fault for tracing, and the leak point in the closed-loop gas path space will be manually checked. The alarm is divided into two levels: Level 1 alarm: yellow warning light flashing + test host prompts observation; Level 2 alarm: red warning light flashing + buzzer prompting + test host prompts that immediate manual intervention is required.

[0033] Example 4

[0034] This embodiment 4 provides a test method for acetic acid corrosion experiments on photovoltaic cells. The method uses the test device of embodiment 2 and includes the following steps: S1. Start-up and circulation: Place the battery cell 11 to be tested on the battery cell support and put it into the test chamber 1. Pass the prepared acetic acid solution into the test chamber 1 and seal it. Then place the entire test chamber 1 into the drying chamber 9 to promote the evaporation of the acetic acid solution to form acetic acid vapor. Start the gas circulation unit 12 so that the acetic acid vapor in the test chamber 1 continuously circulates in the closed-loop gas path space composed of the test chamber 1, the gas delivery pipeline 7, the vapor chamber 21 and the gas circuit pipeline 8. S2. Real-time detection: The concentration and temperature data of acetic acid vapor are acquired in real time through the steam concentration detection unit 5 and the steam temperature sensor 6. S3. Data Comparison: The test host 3 receives the measured acetic acid vapor concentration and temperature data and performs dynamic calibration calculation on the measured acetic acid vapor concentration data based on the temperature compensation algorithm built into the test host 3. The test host 3 also performs dynamic calibration calculations on the measured acetic acid vapor concentration data based on the pressure compensation algorithm built into the test host 3; the test host 3 compares the concentration value after dynamic calibration by any compensation algorithm (temperature compensation algorithm / pressure compensation algorithm) with the preset target concentration value; if any comparison result exceeds the allowable fluctuation range of the target concentration, liquid replenishment and the corresponding alarm level are triggered. Wherein, the concentration value calibrated by the temperature compensation algorithm = measured concentration × K; K is calculated using the Arrhenius equation, i.e., k = a·e^(-Ea / RT); where: the value of a ranges from 0.11 to 0.13, and T is the measured temperature data; Wherein, the concentration value after calibration by the pressure compensation algorithm = measured concentration × (P standard / P measured), where P standard refers to the pressure of acetic acid vapor calculated at 85℃ according to the ideal gas law (PV = nRT), and P measured is the pressure data measured by the pressure sensor set in the vapor chamber 21; S4. Dynamic Control: Based on the comparison results in step S3, if the concentration value after dynamic calibration by any compensation algorithm is lower than the lower limit of the preset target concentration's allowable fluctuation range, the test host 3 calculates the required acetic acid replenishment amount according to the deviation value using an algorithm and controls the injection device 4 (injection valve 41) to inject a fixed amount of acetic acid into the test chamber 1 through the injection pipe 42 until the concentration returns to the preset target concentration's allowable fluctuation range; if the calibrated concentration value is higher than the upper limit of the preset target concentration's allowable fluctuation range, the test host 3 calculates the required water replenishment amount according to the deviation value using an algorithm and controls the injection valve 41 to inject a fixed amount of water into the test chamber 1 through the injection pipe 42 until the concentration returns to the preset target concentration's allowable fluctuation range; wherein, the dynamic control process of acetic acid vapor concentration is as follows: Figure 5 As shown; If the concentration values ​​after dynamic calibration by the two compensation algorithms both exceed the allowable fluctuation range of the preset target concentration, then calculate the required replenishment volume for each and take the average value for replenishment. The preset target concentration of acetic acid vapor is 3.0% (volume concentration), and the allowable fluctuation range is ±5% (that is, the allowable fluctuation range of the target concentration is 2.85 to 3.15%). The replenishment volume is calculated as follows: Replenishment volume (ml) = |calibrated concentration value - 3.0%| × closed-loop gas path volume (L) × adjustment coefficient, where the adjustment coefficient is 0.08 to 0.12; S5. Alarm and Recording: Based on the comparison results, if the fluctuation range of the preset target concentration is not exceeded, no liquid replenishment or alarm will be triggered. The corrosion resistance test will continue for 8 hours until the end, and the acetic acid vapor concentration curve will be recorded (e.g., Figure 3 (As shown), generate a test report; If the calibrated concentration value exceeds the preset target concentration allowable fluctuation range and the excess is between 5% and 10%, a level one alarm will be triggered and recorded in the test host 3. If the calibrated concentration value exceeds the preset target concentration allowable fluctuation range and exceeds the range by more than 10%, a level 2 alarm will be triggered and recorded in the test host 3; If the measured concentration detected by the steam concentration detection unit 5 continues to decrease at a rate > 0.1% / min, a seal failure alarm will be triggered. The test host 3 will automatically save the data for the first 10 minutes before the fault for tracing, and the leak point in the closed-loop gas path space will be manually checked. The alarm is divided into two levels: Level 1 alarm: yellow warning light flashing + test host prompts observation; Level 2 alarm: red warning light flashing + buzzer prompting + test host prompts that immediate manual intervention is required.

[0035] The process flow of the test method for acetic acid corrosion testing of photovoltaic cells provided in Example 4 above is as follows: Figure 4As shown; the dynamic control process for acetic acid vapor concentration is as follows: Figure 5 As shown.

[0036] Table 1 shows the detection results of different experimental batches using the existing experimental methods.

[0037] The acetic acid corrosion test method for battery cells provided by this invention has the following advantages compared with the traditional test method (static saturated steam method) for acetic acid corrosion reliability testing:

[0038] This invention presents an innovative testing device structure that utilizes real-time monitoring and dynamic control of acetic acid vapor concentration. This fundamentally solves the problems of unknown vapor concentration and large deviations in test degradation rate results during the acetic acid corrosion process of photovoltaic cells, ensuring the reliability of the test. The solution of this invention is applicable to all types of photovoltaic cells, not limited to PERC, Topcon, and BC cells.

[0039] The above-described preferred embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of the invention. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A testing device for photovoltaic cell piece acetic acid corrosion experiment, characterized in that, The testing device comprises the following structural arrangement: A test box (1) is internally used for placing a battery piece (11) to be tested and adding acetic acid solution, and a gas circulation unit (12) is further arranged on the test box (1); A receiving box (2) is internally provided with a steam cavity (21), and the steam cavity (21) is further provided with a steam concentration detection unit (5) and a steam temperature sensor (6); acetic acid steam in the test box (1) is delivered to the steam cavity (21) through the gas circulation unit (12) and a gas delivery pipeline (7), and then returned to the test box (1) through a gas return pipeline (8); A test host (3) is used for receiving real-time concentration and temperature data of the acetic acid steam detected by the steam concentration detection unit (5) and the steam temperature sensor (6), and the test host (3) is further provided with a target concentration value of the acetic acid steam and implanted with a temperature compensation algorithm; the test host (3) is further used for comparing the dynamically calibrated acetic acid steam measured concentration data with the preset target concentration value through the temperature compensation algorithm; And a liquid injection device (4) is in communication connection with the test host (3) and is further arranged in communication with the test box (1); if the comparison result exceeds the allowable fluctuation range of the preset target concentration, the test host (3) controls the liquid injection device (4) to supplement liquid to the test box (1) to adjust the concentration of the acetic acid solution, so that the calibrated acetic acid steam concentration meets the allowable fluctuation range of the target concentration, and a hierarchical alarm is further triggered; if the comparison result does not exceed the allowable fluctuation range of the preset target concentration, the liquid supplementing and alarm are not triggered.

2. The testing device for the acetic acid corrosion experiment of a photovoltaic cell according to claim 1, characterized in that, The testing device further comprises a drying box (9), and the test box (1) is arranged in the drying box (9).

3. The testing device for the acetic acid corrosion experiment of photovoltaic cells according to claim 1 or 2, characterized in that, The inside of the test box (1) is further provided with a battery piece support for placing the battery piece (11).

4. The testing device for the acetic acid corrosion experiment of photovoltaic cells according to claim 1, characterized in that, The inner wall of the steam cavity (21) is plated with a hydrophobic coating, and the outside is provided with a heating module.

5. The testing device for the acetic acid corrosion experiment of photovoltaic cells according to claim 1, characterized in that, The steam concentration detection unit (5) comprises an infrared light source (51) and a detector (52), and the surface of the detector (52) is plated with a hydrophobic coating; the infrared light emitted by the infrared light source (51) is received by the detector (52) after penetrating the acetic acid steam in the steam cavity (21), so as to realize the detection of the concentration of the acetic acid steam.

6. The testing device for the acetic acid corrosion experiment of photovoltaic cells according to claim 1, characterized in that, The testing device further comprises a warning light and a buzzer, which are respectively in communication connection with the test host (3).

7. The testing device for the acetic acid corrosion experiment of photovoltaic cells according to claim 1, characterized in that, The liquid injection device (4) comprises a liquid injection valve (41), a liquid injection pipe (42) and a plurality of liquid carrying pipes (43) respectively provided with acetic acid and water; When supplementing liquid, acetic acid or water is injected into the test box (1) through the liquid injection valve (41) and the liquid injection pipe (42) to adjust the concentration of the acetic acid solution.

8. The testing device for the acetic acid corrosion experiment of a photovoltaic cell according to claim 1, characterized in that, The testing device further comprises a collection disc (10) arranged in the receiving box (2) for collecting condensate generated in the receiving box (2).

9. The test method for the acetic acid corrosion experiment of a photovoltaic cell according to any one of claims 1-8, characterized in that, The method comprises the following steps: S1, start and cycle: the battery to be tested (11) and the prepared acetic acid solution are placed in the test box (1) and sealed, and then the whole is placed in the dry box (9), the gas circulation unit (12) is started, and the acetic acid vapor in the test box (1) is circulated in the closed loop gas path space composed of the test box (1), the gas conveying pipeline (7), the vapor cavity (21) and the gas return pipeline (8); S2, real-time detection: the concentration and temperature data of acetic acid vapor are obtained in real time by the vapor concentration detection unit (5) and the vapor temperature sensor (6); S3, data comparison: the test host (3) receives the measured concentration and temperature data and dynamically calculates the calibrated concentration value based on the built-in temperature compensation algorithm, and compares the value with the preset target concentration; Wherein, the concentration value calibrated by the temperature compensation algorithm = measured concentration × K; K = a·e^(-Ea / RT); In the formula: the value range of a is 0.11-0.13, and T is the measured temperature data; S4, dynamic regulation: according to the comparison result, if the calibrated concentration value is lower than the lower limit of the allowable fluctuation range of the preset target concentration, the test host (3) calculates the required acetic acid supplement and controls the liquid injection device (4) to inject a certain amount of acetic acid into the test box (1) until the concentration returns to the allowable fluctuation range of the preset target concentration; if the calibrated concentration value is higher than the upper limit of the allowable fluctuation range of the preset target concentration, the test host (3) calculates the required water supplement and controls the liquid injection device (4) to inject a certain amount of water into the test box (1) until the concentration returns to the allowable fluctuation range of the preset target concentration; Wherein, the preset acetic acid vapor target concentration value is 3.0%, and the allowable fluctuation range is ±5%; the liquid supplement calculation method is: liquid supplement = |calibrated concentration value-3.0%|×closed loop gas path volume×adjustment coefficient, and the adjustment coefficient is 0.08-0.12; S5, alarm and record: according to the comparison result, if the calibrated concentration value exceeds the allowable fluctuation range of the preset target concentration and exceeds the range by 5-10%, a first level alarm is triggered and recorded in the test host (3); If the calibrated concentration value exceeds the allowable fluctuation range of the preset target concentration and exceeds the range by >10%, a second level alarm is triggered and recorded in the test host (3); If the measured concentration detected by the vapor concentration detection unit (5) continues to decrease at a rate of >0.1% / min, a sealing failure alarm is triggered; Wherein, the first level alarm: yellow warning light flickering + test host prompt; the second level alarm: red warning light flickering + buzzer prompt + test host prompt.

10. The test method for the acetic acid corrosion experiment of a photovoltaic cell according to claim 9, characterized in that, The test host (3) is also implanted with a pressure compensation algorithm, and the test host (3) compares the measured concentration data of acetic acid vapor obtained by the temperature compensation algorithm and the pressure compensation algorithm with the preset target concentration value; if the concentration value calibrated by any compensation algorithm exceeds the allowable fluctuation range of the target concentration, the liquid supplement and the corresponding level alarm are triggered. The concentration value calibrated by the pressure compensation algorithm = the measured concentration × (P standard / P measured), wherein P standard refers to the pressure of acetic acid vapor at 85°C calculated according to the ideal gas state equation, and P measured refers to the pressure data measured by the pressure sensor arranged in the vapor cavity.

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