Testing method and system for rapidly evaluating PID of photovoltaic module

Abstract

The invention relates to the field of photovoltaic technology, in particular to a test method and system for rapidly evaluating PID of a photovoltaic module, and the method comprises the steps: obtaining a PID test sample; performing aging treatment on the PID test sample in the target environment to obtain an aged PID test sample; respectively performing power test on the PID test samples before and after the aging treatment to obtain corresponding power data, and evaluating the PID test of the photovoltaic module by using the corresponding power data; wherein the target environment is characterized in that the environment temperature is 100-150 DEG C, the environment humidity is 80-100 RH%, and the environment pressure is 0-1.5 MPa. According to the method, a high-temperature, high-humidity, high-voltage, weak-acid and weak-base environment is provided, the influence of the system voltage on the photovoltaic module in a working state when the photovoltaic module is connected to the power station can be evaluated, and the reliability of a product used by the photovoltaic module in the power station can be quickly determined.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic technology, and particularly relates to a method and system for quickly evaluating the PID test of photovoltaic modules. Background Art

[0002] In the photovoltaic industry, potential induced degradation (PID) has become a key problem significantly affecting the performance and reliability of photovoltaic modules. The gradual attenuation of the power output of photovoltaic modules caused by the PID phenomenon is mainly attributed to the semiconductor materials inside the modules. When they are subjected to external voltage for a long time and simultaneously eroded by a humid and hot environment, saline-alkali land, ammonia environment, and acidic environment, their performance degrades. Such attenuation will undoubtedly cause serious damage to the overall efficiency and service life of the photovoltaic system. Therefore, effective monitoring and accurate testing of PID are essential for ensuring the quality and long-term stability of photovoltaic modules.

[0003] In the past, the traditional PID test method was generally to encapsulate the cells into large modules and then conduct the test. However, this test method has many drawbacks. On the one hand, the test cost is high, consuming a large amount of encapsulation materials, and with the continuous change of the module format, additional investment and maintenance costs for the test equipment are required; on the other hand, at least two personnel are usually required to cooperate in the operation, and the test cycle is long. These problems make it difficult for enterprises to reduce costs and quickly judge the reliability of photovoltaic modules. In addition, the test environment of the traditional method is relatively single and fails to fully simulate the complex environment faced by photovoltaic modules during actual use. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for quickly evaluating the PID test of photovoltaic modules to solve the above technical problems.

[0005] To achieve the above purpose, the present invention provides a method for quickly evaluating the PID test of photovoltaic modules, and the method includes:

[0006] Obtain a PID test sample;

[0007] Age the PID test sample under a target environment to obtain an aged PID test sample;

[0008] Conduct power tests on the PID test samples before and after the aging treatment respectively to obtain corresponding power data, and evaluate the PID test of the photovoltaic module using the corresponding power data;

[0009] Among them, the target environment includes: the environmental temperature is 100 - 150 °C, the environmental humidity is 80 - 100 RH%, and the environmental pressure is 0 - 1.5 MPa.

[0010] Optionally, use a single or multiple battery laminates as the PID test sample.

[0011] Optionally, the target environment further includes: an alkaline environment with a pH of 7.5 - 12.0.

[0012] Optionally, the target environment further includes: an acidic environment with a pH of 2.0 - 5.6.

[0013] Optionally, the target environment further includes: an ammonia environment with a concentration of 0 - 17000 ppm.

[0014] The present invention also provides a rapid evaluation photovoltaic module PID test system, and the system includes:

[0015] An acquisition unit, configured to acquire a PID test sample;

[0016] An aging unit, configured to age the PID test sample in a target environment to obtain the PID test sample after aging treatment;

[0017] A test unit, configured to respectively perform power tests on the PID test samples before and after aging treatment to obtain corresponding power data, and evaluate the photovoltaic module PID test by using the corresponding power data;

[0018] Wherein, the target environment includes: an environmental temperature of 100 - 150 °C, an environmental humidity of 80 - 100 RH%, and an environmental pressure of 0 - 1.5 MPa.

[0019] Optionally, the aging unit includes:

[0020] A fixture sub-unit, configured to fix and position the PID test sample;

[0021] An environment simulation sub-unit, configured to provide different target environments required for aging treatment of the PID test sample;

[0022] An intelligent control sub-unit, configured to control the fixture sub-unit and the environment simulation sub-unit.

[0023] Optionally, the environment simulation sub-unit includes:

[0024] A temperature control module, configured to provide the temperature required for aging treatment of the PID test sample;

[0025] A humidity control module, configured to provide the humidity required for aging treatment of the PID test sample;

[0026] A corrosion environment module, configured to provide the corrosion conditions required for aging treatment of the PID test sample.

[0027] Optionally, the corrosion environment module includes:

[0028] An acidic environment sub-module for providing the acid solution required for the aging treatment of PID test samples;

[0029] An alkaline environment sub-module for providing the alkali solution required for the aging treatment of PID test samples;

[0030] An ammonia supply sub-module for providing the ammonia required for the aging treatment of PID test samples;

[0031] A pure water supply unit for providing water vapor.

[0032] Optionally, an anti-corrosion material is coated on the inner walls of the acidic environment sub-module and the alkaline environment sub-module.

[0033] The technical effects and advantages of the present invention:

[0034] This method uses single or multiple battery modules for testing, which is convenient for operation while reducing the packaging cost and test resources, and provides environments of high temperature, high humidity, high pressure, weak acid and weak base. It can not only evaluate the influence of the system voltage on the photovoltaic module when it is connected to the power station and in the working state, but also quickly determine the reliability of the products of the photovoltaic module used in the power station.

[0035] Other features and advantages of the present invention will be described in the subsequent specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Figure 1 It is a flowchart for quickly evaluating the PID test method of photovoltaic modules. Detailed Embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope in which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0039] To solve the deficiencies of the prior art, the present invention discloses a method for quickly evaluating the PID test of photovoltaic modules, as Figure 1 shown, the method includes:

[0040] Obtain a PID test sample;

[0041] Age the PID test sample under the target environment to obtain the PID test sample after aging treatment;

[0042] Perform power tests on the PID test samples before and after aging treatment respectively to obtain the corresponding power data, and use the corresponding power data to evaluate the PID test of the photovoltaic module;

[0043] Among them, the target environment includes: the environmental temperature is 100 - 150 °C, the environmental humidity is 80 - 100 RH%, and the environmental pressure is 0 - 1.5 MPa.

[0044] Among them, the target environment also includes: an alkaline environment with a pH of 7.5 - 12.0, an acidic environment with a pH of 2.0 - 5.6, and an ammonia environment with a concentration of 0 - 17000 ppm. Specifically: The present invention respectively introduces three typical chemical media to simulate different application scenarios, such as a weakly alkaline environment - adding a 0.02% sodium carbonate solution (pH ≈ 11.6) to simulate the high pH environment of saline-alkali land; a weakly acidic environment - adding a 3% acetic acid - potassium chloride mixed solution (pH ≈ 4.0) corresponding to the corrosion conditions of acid rain weather; an ammonia environment - injecting 6667 ppm ammonia (weakly alkaline when dissolved in water) to restore the environment containing ammonia volatiles. It has more scene authenticity than the traditional single-environment test and significantly improves the time compression ratio of the PID effect.

[0045] Among them, single-piece or multi-piece battery laminates are used as PID test samples. The specific operation steps are as follows: (1) First, cut the encapsulation material (the cut size can cover the battery cells). Secondly, weld the main grid lines on the battery cells according to the welding process and use solder tapes to lead out. Then, stack and lay the front plate / EVA film / solar cell / EVA film / back sheet in the order from bottom to top, and laminate under certain process conditions to form small laminates of single or multiple battery cells (hereinafter collectively referred to as test samples). (2) Seal the periphery of the test samples with a frame sealant and let it stand for 24 - 48 hours to fully cure.

[0046] By using single-piece or multi-piece battery laminates as PID test samples, the junction box and metal frame simulation structures required for traditional large modules are discarded. Based on the metal foil electrode wrapping and direct voltage loading technologies, an equivalent electric field environment is effectively constructed, enabling the experimental module to be independent of the photovoltaic module size. Compared with traditional test methods, the material cost is significantly reduced, and the problem of increased equipment adaptation costs caused by new formats such as double-sided modules and extra-large-sized modules is avoided.

[0047] Among them, the PID test samples are aged in the target environment to obtain the aged PID test samples. Specifically, it includes:

[0048] (1) Test equipment: The internal size of the equipment is preferably 2.0m * 1.5m, equipped with a fixture sub-unit, an environment simulation sub-unit, an intelligent control sub-unit, and a corrosion-resistant protection system. The equipment can provide test conditions with a temperature range of 100 - 150 °C (accuracy ±3 °C), a humidity control range of 80 - 100 RH% (accuracy ±2 RH%), and a pressure regulation range of 0 - 1.5 MPa. The equipment integrates compressed air and ammonia pipelines, a water tank, and a cabin for placing acid and alkaline solution containers inside. The boiler is divided into three parts, respectively for containing pure water, acid, and alkaline solution. The water, acid, and alkaline solution are boiled into steam by heating means, and then the steam enters the test chamber. To prevent the equipment from being corroded, which may affect the test results and shorten the service life, the inner walls of the boiler for containing acid and alkaline solutions and the inner walls of the equipment are coated with acid-resistant, alkali-resistant, and high-temperature-resistant ceramic coatings.

[0049] The equipment is also equipped with a pressure system, a temperature control module, an automatic water supply system, and a corrosion environment module. The opening and closing of the chamber door are precisely controlled by the pressure system. Before the test starts, the equipment will automatically complete water filling; according to different application scenarios, different test environments are selected through the control system. During the test process, the acid and alkali are automatically replenished according to the usage requirements; ammonia gas enters the test chamber at a speed of 0.1 - 10 L / min through the pressure system. After the test ends, the equipment can automatically stop running and perform pressure relief, drainage, and liquid discharge operations. At the same time, the acid (alkali) solution will automatically flow back into the upper liquid container.

[0050] (2) Preparation before testing: Check the appearance of the test sample, conduct power, wet leakage current tests on the components and perform EL imaging, and record the test results. Then connect the positive and negative terminals to the corresponding lead wires respectively, and wrap the test sample with aluminum foil.

[0051] (3) Testing process:

[0052] a. Turn on the compressed air switch, turn on the power supply of the environmental test chamber, place the device under test in the test chamber, connect its positive and negative poles to the positive and negative terminals of the power supply respectively, and fix the ground wire on the aluminum foil wrapping the laminate at the same time.

[0053] b. Open the test program of the environmental test chamber, set the test parameters, such as temperature 121 °C, humidity 100RH%, test time 2.5h, 5h, 7h, and select the test environment and turn on the corresponding switch.

[0054] c. Click the run button. The environmental test chamber automatically fills with water until the system prompts and then shuts off the water source. At the same time, it automatically fills with acidic and alkaline solutions until a certain amount is reached and then stops automatically. When using an ammonia test environment, the entire test process is in progress.

[0055] d. After the test temperature, humidity, and pressure reach the specified conditions, turn on the stress condition of the system voltage, and the rated system voltage is -1500V.

[0056] (5) End of testing: After aging, conduct power, wet leakage current tests again and perform EL imaging.

[0057] (6) Judgment: Conduct power tests on the PID test samples before and after aging treatment respectively to obtain the corresponding power data, and judge whether the attenuation between the two exceeds 0.5%.

[0058] To better understand this solution, examples and comparative examples are also given below.

[0059] Comparative example

[0060] In this experiment, 1 large component encapsulated by 22 pieces of 166 cells was selected as Sample 1; 1 small laminate encapsulated by 2 pieces of 166 cells was selected as Sample 2; 1 small laminate encapsulated by 4 pieces of 166 cells was selected as Sample 3. At the same time, PID tests were carried out for different durations under the environmental conditions of temperature 85 °C, humidity 85RH%, and applied voltage -1500V. See Table 1 for details.

[0061] Table 1 Power change of components before and after PID test

[0062]

[0063] Among them, P0 is the initial power of the sample, and P1 is the power after aging for n hours.

[0064] Embodiment

[0065] In this experiment, 1 large module encapsulated by 22 pieces of 166 cells was selected as Sample 4; 1 small laminate encapsulated by 2 pieces of 166 cells was selected as Sample 5; 1 small laminate encapsulated by 4 pieces of 166 cells was selected as Sample 6. At the same time, PID tests with different durations were carried out under the environmental conditions of temperature 121°C, humidity 100RH%, pressure 1.09MPa, and applied voltage -1500V. See Table 2 for details.

[0066] Table 2 Power change of the module before and after PID test

[0067]

[0068]

[0069] According to the above data, the aging test conditions of the embodiment (temperature 121°C, humidity 100RH%, pressure 1.09MPa) shorten the test time, from the original 96h to 2.5h, 192h to 5h, and 288h to 7h. Compared with the traditional high temperature and high humidity (85°C / 85RH%) test, the accelerated aging greatly shortens the test cycle of reliability evaluation and saves time cost.

[0070] In addition, from the above data, it can also be seen that the difference in power attenuation between the embodiment and the comparative example is less than 0.5% (for example, the power attenuation of Sample 4 in the embodiment after aging for 7h is 4.39%, and the power attenuation of its corresponding Comparative Example Sample 1 after aging for 288h is 4.0%. The difference between the two is 0.39%, which is less than 0.5%). The power attenuation trends of the two are the same, proving that the test method adopted in this patent is reasonable in the design of the accelerated aging model and meets the determination requirements of IEC 61730-1:2016 for the equivalence of damp heat aging.

[0071] The present invention also provides a rapid evaluation photovoltaic module PID test system, and the system includes:

[0072] An acquisition unit for acquiring a PID test sample;

[0073] An aging unit for aging the PID test sample under a target environment to obtain an aged PID test sample;

[0074] A test unit for respectively performing power tests on the PID test samples before and after aging treatment, obtaining corresponding power data, and evaluating the photovoltaic module PID test by using the corresponding power data;

[0075] Among them, the target environment includes: the environmental temperature is 100 - 150 °C, the environmental humidity is 80 - 100 RH%, and the environmental pressure is 0 - 1.5 MPa.

[0076] Among them, the aging unit includes:

[0077] A fixture sub - unit for fixing and positioning the PID test sample;

[0078] An environmental simulation sub - unit for providing different target environments required during the aging treatment of the PID test sample;

[0079] An intelligent control sub - unit for controlling the fixture sub - unit and the environmental simulation sub - unit.

[0080] Among them, the environmental simulation sub - unit includes:

[0081] A temperature control module for providing the temperature required during the aging treatment of the PID test sample;

[0082] A humidity control module for providing the humidity required during the aging treatment of the PID test sample;

[0083] A corrosion environment module for providing the corrosion conditions required during the aging treatment of the PID test sample.

[0084] Among them, the corrosion environment module includes:

[0085] An acidic environment sub - module for providing the acid solution required during the aging treatment of the PID test sample;

[0086] A basic environment sub - module for providing the alkaline solution required during the aging treatment of the PID test sample;

[0087] An ammonia supply sub - module for providing the ammonia required during the aging treatment of the PID test sample;

[0088] A pure water supply unit for providing water vapor.

[0089] Among them, an anti - corrosion substance is applied to the inner walls of the acidic environment sub - module and the basic environment sub - module. Specifically, a three - layer composite protection is adopted: ① Substrate: 316L stainless steel (thickness 2 - 3 mm) ② Transition layer: Plasma - sprayed NiCrAlY alloy (thickness 50 - 80 μm) ③ Surface layer: Alumina - titania ceramic coating (thickness 150 - 200 μm).

[0090] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rapid evaluation method for the PID test of photovoltaic modules, characterized in that, The method includes: Obtaining a PID test sample; Performing an aging treatment on the PID test sample in a target environment to obtain an aged PID test sample; Performing power tests on the PID test samples before and after the aging treatment respectively to obtain corresponding power data, and evaluating the PID test of the photovoltaic module by using the corresponding power data; Wherein, the target environment includes: the environmental temperature is 100 - 150 °C, the environmental humidity is 80 - 100 RH%, and the environmental pressure is 0 - 1.5 MPa.

2. The method according to claim 1, wherein Using a single or multiple cell laminates as the PID test sample.

3. The method according to claim 1, characterized in that The target environment further includes: an alkaline environment with a pH of 7.5 - 12.

0.

4. The method according to claim 3, characterized in that, The target environment further includes: an acidic environment with a pH of 2.0 - 5.

6.

5. The method according to claim 4, characterized in that The target environment further includes: an ammonia gas environment with a concentration of 0 - 17000 ppm.

6. A rapid evaluation photovoltaic module PID test system, characterized in that, The system includes: An obtaining unit for obtaining a PID test sample; An aging unit for performing an aging treatment on the PID test sample in a target environment to obtain an aged PID test sample; A testing unit for performing power tests on the PID test samples before and after the aging treatment respectively to obtain corresponding power data, and evaluating the PID test of the photovoltaic module by using the corresponding power data; Wherein, the target environment includes: the environmental temperature is 100 - 150 °C, the environmental humidity is 80 - 100 RH%, and the environmental pressure is 0 - 1.5 MPa.

7. The system according to claim 6, characterized in that, The aging unit includes: A fixture sub-unit for fixing and positioning the PID test sample; An environment simulation sub-unit for providing different target environments required for the aging treatment of the PID test sample; An intelligent control sub-unit for controlling the fixture sub-unit and the environment simulation sub-unit.

8. The system according to claim 7, wherein The environment simulation sub-unit includes: A temperature control module for providing the temperature required for the aging treatment of the PID test sample; A humidity control module for providing the humidity required for the aging treatment of the PID test sample; A corrosion environment module for providing the corrosion conditions required for the aging treatment of the PID test sample.

9. The system according to claim 8, wherein The corrosion environment module includes: An acidic environment sub-module for providing the acid solution required for the aging treatment of the PID test sample; An alkaline environment sub-module for providing the alkali solution required for the aging treatment of the PID test sample; An ammonia gas supply sub-module for providing the ammonia gas required for the aging treatment of the PID test sample; A pure water supply unit for providing water vapor.

10. The system according to claim 9, wherein Coating an anti-corrosion material on the inner walls of the acidic environment sub-module and the alkaline environment sub-module.

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