Method and device for testing reliability of photovoltaic cable

Abstract

The invention discloses a photovoltaic cable reliability test method and device, and belongs to the field of photovoltaic technology. The photovoltaic cable reliability test method comprises the following steps: performing an electrical characteristic test on a test sample of a photovoltaic cable to obtain a first test result; immersing the test sample in a test liquid in a test environment, and carrying out an aging test on the test sample; performing an electrical characteristic test on the test sample after the aging test to obtain a second test result; and determining the reliability of the photovoltaic cable according to the first test result and the second test result. According to the invention, the long-term reliability of the photovoltaic cable working in the water immersion environment can be evaluated, and the test accuracy is improved.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and in particular, relates to a photovoltaic cable reliability testing method and device. Background Art

[0002] In recent years, the photovoltaic industry has developed rapidly. As the main body of solar power generation, the safety and reliability of photovoltaic modules are becoming increasingly important. The photovoltaic junction box is a key part of the photovoltaic module, responsible for transmitting the current generated by the photovoltaic module battery. The positive and negative terminal junction boxes are connected by photovoltaic cables to the positive and negative terminals. Therefore, photovoltaic cables need to be tested for reliability to ensure their long-term normal operation.

[0003] Currently, most photovoltaic cables are designed for ground-based power stations and rooftop distributed photovoltaics, and the reliability test of photovoltaic cables only conducts aging tests for conventional working environments. For working environments such as offshore photovoltaics, photovoltaic cables are at risk of being immersed in water for a long time, and there is no corresponding reliability test method. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a photovoltaic cable reliability test method and device, which can evaluate the long-term reliability of photovoltaic cables working in a water-immersed environment and improve the test accuracy.

[0005] In a first aspect, the present application provides a photovoltaic cable reliability testing method, comprising:

[0006] Performing an electrical characteristic test on a test sample of the photovoltaic cable to obtain a first test result;

[0007] Immersing the test sample in a test liquid in a test environment, and performing an aging test on the test sample;

[0008] Performing an electrical characteristic test on the test sample after the aging test to obtain a second test result;

[0009] The reliability of the photovoltaic cable is determined according to the first test result and the second test result.

[0010] According to the photovoltaic cable reliability test method of the present application, a test sample of the photovoltaic cable is provided, and the test sample is immersed in a test liquid in a test environment to simulate the actual working environment of the photovoltaic cable. An aging test is performed on the test sample to evaluate the long-term reliability of the photovoltaic cable working in a water immersion environment. The electrical characteristics test is performed on the test sample before and after the aging test, and the reliability of the photovoltaic cable is determined based on the results of the two electrical characteristics tests, thereby effectively improving the test accuracy.

[0011] According to one embodiment of the present application, the temperature in the test environment is greater than or equal to the temperature in the actual working environment of the photovoltaic cable, the boiling point of the test liquid under the pressure in the test environment is greater than the temperature in the test environment, the humidity in the test environment is greater than or equal to the humidity in the actual working environment of the photovoltaic cable, and the test liquid is seawater or salt water of target concentration.

[0012] According to one embodiment of the present application, the pressure in the test environment is 303.975 kPa, the temperature in the test environment is 121° C., the humidity in the test environment is 100% RH, and the target concentration is 10-50 g / L.

[0013] According to one embodiment of the present application, performing an aging test on the test sample includes:

[0014] Applying a voltage of a target duration to the test sample through a DC constant voltage power supply, wherein the positive electrode of the DC constant voltage power supply is connected to the electrode in the test liquid, and the negative electrode of the DC constant voltage power supply is respectively connected to two test ends of the test sample, and the two test ends of the test sample are located outside the test liquid;

[0015] A current of a target duration is applied to the test sample through a DC constant current power supply, the positive pole of the DC constant current power supply is connected to one test end of the test sample, and the negative pole of the DC constant current power supply is connected to the other test end of the test sample.

[0016] According to one embodiment of the present application, the voltage applied by the DC constant voltage power supply is 4KV, the current applied by the DC constant current power supply is 40A, and the target duration is 1000 hours.

[0017] According to one embodiment of the present application, the electrical characteristic test includes a contact resistance test, the first test result includes a first contact resistance, and the second test result includes a second contact resistance;

[0018] The determining the reliability of the photovoltaic cable according to the first test result and the second test result includes:

[0019] calculating a resistance ratio of the second contact resistance to the first contact resistance;

[0020] Comparing the resistance ratio with a target resistance ratio to obtain a resistance comparison result;

[0021] The reliability of the photovoltaic cable is determined according to the resistance comparison result.

[0022] According to an embodiment of the present application, the electrical characteristic test includes a capacitance test, the first test result includes a first capacitance, and the second test result includes a second capacitance;

[0023] The determining the reliability of the photovoltaic cable according to the first test result and the second test result includes:

[0024] Calculating a capacitance ratio of the second capacitance minus the first capacitance to the first capacitance;

[0025] Comparing the capacitance ratio with a target capacitance ratio to obtain a capacitance comparison result;

[0026] The reliability of the photovoltaic cable is determined according to the capacitance comparison result.

[0027] According to one embodiment of the present application, the electrical characteristics test of the test sample of the photovoltaic cable includes:

[0028] Performing a visual inspection on the test sample and performing a wet leakage test on the test sample;

[0029] When it is determined that the test sample has passed the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample of the photovoltaic cable.

[0030] According to one embodiment of the present application, the electrical characteristics test of the test sample after the aging test includes:

[0031] Performing a visual inspection on the test sample after the aging test, and performing a wet leakage test on the test sample after the aging test;

[0032] When it is determined that the test sample after the aging test passes the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample after the aging test.

[0033] In a second aspect, the present application provides a photovoltaic cable reliability testing device, comprising:

[0034] A first test module is used to perform an electrical characteristic test on a test sample of a photovoltaic cable to obtain a first test result;

[0035] An aging test module, used for immersing the test sample in a test liquid in a test environment and performing an aging test on the test sample;

[0036] A second testing module, used for performing an electrical characteristic test on the test sample after the aging test to obtain a second test result;

[0037] A determination module is used to determine the reliability of the photovoltaic cable according to the first test result and the second test result.

[0038] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0039] By providing test samples of photovoltaic cables, the test samples are immersed in test liquid in a test environment to simulate the real working environment of the photovoltaic cables, and aging tests are performed on the test samples to evaluate the long-term reliability of the photovoltaic cables working in a water immersion environment. The electrical characteristics of the test samples are tested before and after the aging test. The reliability of the photovoltaic cables is determined based on the results of the two electrical characteristics tests, which effectively improves the test accuracy.

[0040] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0042] Figure 1 This is one of the flow charts of the photovoltaic cable reliability testing method provided in the embodiment of the present application;

[0043] Figure 2 It is a schematic diagram of the connection relationship of the photovoltaic cables provided in the embodiment of the present application in the photovoltaic system;

[0044] Figure 3 This is the second flow chart of the photovoltaic cable reliability testing method provided in the embodiment of the present application;

[0045] Figure 4 It is a structural schematic diagram of a photovoltaic cable reliability testing device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0047] The following describes the photovoltaic cable reliability testing method and device provided in the embodiments of the present application with reference to the accompanying drawings.

[0048] Among them, the photovoltaic cable reliability test method can be applied to the terminal, and can be specifically executed by the hardware or software in the terminal. The photovoltaic cable reliability test in this embodiment includes at least one of the electrical characteristic test (such as contact resistance test, capacitance test, etc.) before and after the photovoltaic cable aging test, the appearance inspection and the wet leakage test. According to the test results before and after the photovoltaic cable aging test, the reliability of the photovoltaic cable is determined. If the test results before and after the photovoltaic cable aging test meet the test requirements, it is determined that the reliability of the photovoltaic cable is high; if any test result before and after the photovoltaic cable aging test does not meet the test requirements, it is determined that the reliability of the photovoltaic cable is low.

[0049] Figure 1 A schematic flow chart of a photovoltaic cable reliability testing method provided in an embodiment of the present application.

[0050] like Figure 1 As shown, the photovoltaic cable reliability testing method provided in the embodiment of the present application includes step 110, step 120, step 130 and step 140.

[0051] Step 110: Perform an electrical characteristic test on a test sample of the photovoltaic cable to obtain a first test result.

[0052] Photovoltaic cables are cables that connect various components in a photovoltaic system. Figure 2 As shown, the photovoltaic system includes a photovoltaic module 1, a plurality of junction boxes 2, a positive connector 3, a negative connector 4 and a photovoltaic cable 5. The junction box 2 can be arranged on the photovoltaic module 1, and the plurality of junction boxes 2 are connected in sequence to form a junction box circuit, one end of the junction box circuit is connected to the positive connector 3 through the photovoltaic cable 5, and the other end of the junction box circuit is connected to the negative connector 4 through the photovoltaic cable 5. For example, the plurality of junction boxes 2 include a positive junction box, an intermediate junction box and a negative junction box, and the two ends of the intermediate junction box are respectively connected to one end of the positive junction box and one end of the negative junction box to form a junction box circuit. One end of the junction box circuit (i.e., the other end of the positive junction box) is connected to the positive connector 3 through the photovoltaic cable 5, and the other end of the junction box circuit (i.e., the other end of the negative junction box) is connected to the negative connector 4 through the photovoltaic cable 5.

[0053] A photovoltaic cable of a certain length is selected as a test sample. The selection of the test sample must be representative and able to reflect the overall quality level of the production batch. The photovoltaic cable may include a conductive layer (such as a conductor material such as copper or aluminum) and an insulating sheath located around the conductive layer. After selecting the test sample of the photovoltaic cable, a portion of the insulating sheath may be peeled off at both ends of the test sample to expose the conductive layer at both ends of the test sample as two test ends. The electrical properties test may include basic electrical tests such as contact resistance test and capacitance test to ensure the electrical performance and safety of the photovoltaic cable. Before the test sample is subjected to an aging test, an electrical properties test is performed on the test sample, and the results of the electrical properties test (i.e., the first test result) are recorded and saved as the basis for subsequent comparative analysis.

[0054] In some embodiments, the electrical characteristics test includes a contact resistance test, and the first test result includes a first contact resistance. Performing an electrical characteristics test on the test sample of the photovoltaic cable to obtain a first test result in step 110 includes: performing a contact resistance test on the test sample to obtain a first contact resistance.

[0055] Before the aging test, the two test ends of the test sample are connected to a contact resistance tester (such as a multimeter) to test the test sample with a contact resistance tester to obtain the contact resistance value of the test sample, i.e., the first contact resistance, and record and save the first contact resistance R1. By testing the contact resistance of the test sample, the electrical connection quality of the photovoltaic cable can be detected.

[0056] In some embodiments, the electrical characteristics test includes a capacitance test, and the first test result includes a first capacitance. Performing an electrical characteristics test on the test sample of the photovoltaic cable to obtain a first test result in step 110 includes: performing a capacitance test on the test sample to obtain a first capacitance.

[0057] Before the aging test, connect the two test ends of the test sample to a capacitance tester (such as a bridge meter) to test the capacitance of the test sample using the capacitance tester to obtain the capacitance value of the test sample, i.e., the first capacitance, and record and save the first capacitance C1. The insulation and electrical properties of the photovoltaic cable can be detected by performing a capacitance test on the test sample.

[0058] In some embodiments, the electrical characteristics test includes a contact resistance test and a capacitance test, and the first test result includes a first contact resistance and a first capacitance. Performing an electrical characteristics test on the test sample of the photovoltaic cable in step 110 to obtain a first test result includes: performing a contact resistance test on the test sample to obtain a first contact resistance; performing a capacitance test on the test sample to obtain a first capacitance.

[0059] The order of the contact resistance test and the capacitance test is not specifically limited. After obtaining the first contact resistance and the first capacitance, the first contact resistance R1 and the first capacitance C1 are recorded and saved.

[0060] In some embodiments, the electrical characteristics test of the test sample of the photovoltaic cable in step 110 includes:

[0061] Conduct visual inspection on the test samples and conduct wet leakage test on the test samples;

[0062] When it is determined that the test sample has passed the appearance inspection and the wet leakage test, the electrical characteristics test is performed on the test sample of the photovoltaic cable.

[0063] Before the aging test, the test sample may be subjected to an appearance inspection and a wet leakage test, etc. The order of the appearance inspection and the wet leakage test is not specifically limited.

[0064] Appearance inspection refers to visual inspection of the appearance of the test sample to check whether the appearance is abnormal, such as checking whether the surface of the test sample has defects such as damage, cracks, stains, rust, etc. that may affect the electrical performance and durability of the photovoltaic cable. If the appearance of the test sample is found to be abnormal, it is determined that the appearance inspection of the test sample is unqualified, and the subsequent testing of the test sample can be stopped, and the photovoltaic cable reliability test can be repeated after the test sample is replaced; if the appearance of the test sample is normal, it is determined that the appearance inspection of the test sample is qualified, and the subsequent testing of the test sample can continue.

[0065] The wet leakage test is to test the electrical performance and safety of photovoltaic cables in a humid environment. The wet leakage test is performed on the test samples in accordance with IEC61215. Among them, IEC 61215 is an international test standard developed by the International Electrotechnical Commission (IEC) and is specifically used to evaluate the quality and performance of photovoltaic modules.

[0066] Immerse the test part of the test sample (i.e. the part covered by the insulating sheath) in a solution with a resistivity that meets the requirements, with the two test ends of the test sample exposed to the solution. Apply a certain voltage to the test sample, which can be 1000V, 1500V or 2000V, etc. according to the product model. Use an insulation resistance tester to measure the resistance between the test sample and the solution, i.e. the first insulation resistance.

[0067] Compare the measured first insulation resistance with the target insulation resistance (such as 2000MΩ). The target insulation resistance can be the minimum resistance value specified in the test standard. If the measured first insulation resistance is greater than the target insulation resistance, it is determined that the wet leakage test of the test sample is qualified, and the subsequent test of the test sample can be continued; if the measured first insulation resistance is less than or equal to the target insulation resistance, it is determined that the wet leakage test of the test sample is unqualified, and the subsequent test of the test sample can be stopped, and the photovoltaic cable reliability test can be repeated after the test sample is replaced.

[0068] When it is determined that the appearance inspection and wet leakage test of the test sample are qualified, continue to perform electrical characteristics test on the test sample.

[0069] Step 120: Immerse the test sample in a test liquid in a test environment, and perform an aging test on the test sample.

[0070] According to the actual working environment of the photovoltaic cable, such as temperature, humidity, light intensity and ultraviolet radiation, the test environment can be simulated to ensure that the test environment can accurately reflect the various conditions that the photovoltaic cable may encounter in long-term use. This embodiment can simulate the test environment based on humid, rainy, water, offshore and other working environments.

[0071] In the test environment, immerse the test sample in a test liquid of a certain depth. It should be noted that the two test ends of the test sample are located outside the test liquid, that is, the two test ends of the test sample extend a certain distance out of the test liquid, and the test part of the test sample (the part covered by the insulating sheath) is immersed in the test liquid. The test liquid matches the liquid in which the photovoltaic cable is immersed in the actual working environment. For example, for offshore photovoltaic working environments, the test liquid can be seawater, or salt water with a target concentration can be used to simulate seawater. Among them, the target concentration of salt water means that the NaCl concentration in the salt water is the target concentration. For example, the target concentration is 10 to 50 g / L.

[0072] In some embodiments, the temperature in the test environment is greater than or equal to the temperature in the actual working environment of the photovoltaic cable, the boiling point of the test liquid under the pressure in the test environment is greater than the temperature in the test environment, and the humidity in the test environment is greater than or equal to the humidity in the actual working environment of the photovoltaic cable.

[0073] The temperature in the test environment may be the temperature in the real working environment of the photovoltaic cable, and the humidity in the test environment may be the humidity in the real working environment of the photovoltaic cable, so as to simulate the real working environment of the photovoltaic cable in outdoor immersion, high temperature and high humidity. In order to obtain reliable test results in a short time, the temperature and humidity in the test environment may be increased, that is, the temperature in the test environment may be greater than the temperature in the real working environment of the photovoltaic cable, and the humidity in the test environment may be greater than the humidity in the real working environment of the photovoltaic cable, so as to achieve the test effect of accelerated aging.

[0074] For example, the temperature in the test environment can be 121°C, and the humidity in the test environment can be 100% RH (RH is relative humidity). Under normal circumstances, the temperature in the test environment is 121°C, and the water in the test liquid will boil. At this time, the operability and safety of the experiment cannot be met, so the pressure in the test environment can be increased to avoid boiling water at 121°C. For example, the test environment provides 3 standard atmospheric pressures, that is, the pressure in the test environment can be 303.975 kPa. The boiling point of water at 3 standard atmospheric pressures is 132.9°C, so water will not boil under this test environment.

[0075] In the test environment, with the test sample immersed in the test liquid, an aging test is performed on the test sample.

[0076] In some embodiments, performing an aging test on the test sample in step 120 includes:

[0077] A voltage of a target duration is applied to the test sample by a DC constant voltage power supply, the positive electrode of the DC constant voltage power supply is connected to the electrode in the test liquid, the negative electrode of the DC constant voltage power supply is connected to two test ends of the test sample, and the two test ends of the test sample are located outside the test liquid;

[0078] A current of a target duration is applied to the test sample through a DC constant current power supply, the positive electrode of the DC constant current power supply is connected to one test end of the test sample, and the negative electrode of the DC constant current power supply is connected to the other test end of the test sample.

[0079] During the aging test, the test sample is subjected to a DC constant voltage aging test and a DC constant current aging test in sequence. In the DC constant voltage aging test, an electrode (such as a copper electrode) can be fixed in the test liquid, the positive electrode of the DC constant voltage power supply is connected to the electrode in the test liquid, and the negative electrode of the DC constant voltage power supply is connected to the two test ends of the test sample. A constant voltage is applied to the conductor and the outer surface of the test sample by a DC constant voltage power supply for a target duration to detect the waterproof performance and water-blocking performance of the photovoltaic cable. If the waterproofing of the test sample fails during the test, a breakdown will occur, resulting in a significant change in the electrical characteristics of the test sample. Among them, the voltage applied by the DC constant voltage power supply can be determined according to the test standard and the rated voltage of the photovoltaic cable, for example, the voltage applied by the DC constant voltage power supply is 4KV.

[0080] In the DC constant current aging test, the positive pole of the DC constant current power supply is connected to one test end of the test sample, and the negative pole of the DC constant current power supply is connected to the other test end of the test sample. A constant current is applied to the test sample through the DC constant current power supply for a target duration to simulate the DC power supply during the normal operation of the photovoltaic cable under water immersion. Among them, the current applied by the DC constant current power supply can be determined according to the test standard and the rated current of the photovoltaic cable, for example, the current applied by the DC constant current power supply is 40A.

[0081] The target duration is the duration of one cycle of the DC constant voltage aging test and the duration of one cycle of the DC constant current aging test. The target duration can be determined based on the expected service life of the photovoltaic cable and the setting of the accelerated aging factor. For example, the target duration is 1000 hours.

[0082] The test environment uses the target duration as a single test, and the single test can also be tightened according to the test situation. Through the Arrhenius equation (Accelerated Factor) simulation calculation, a single test in the test environment in this embodiment can be equivalent to the actual outdoor working years:

[0083] AF=(RHs / RHu) 3 ×e (E / K)(1 / Tu-1 / Ts) .

[0084] Among them, RHs is the humidity in the test environment, Rhu is the humidity in the actual working environment of the photovoltaic cable, Ts is the temperature in the test environment, Tu is the temperature in the actual working environment of the photovoltaic cable, and AF is the acceleration factor. When RHs is 100% RH, Rhu is 80% RH, Ts is 121°C, and Tu is 45°C, it can be calculated that AF is 269.5. It can be seen that 1000 hours of aging test is equivalent to 30.76 years of long-term operation of photovoltaic cables at 45°C, 80% RH, and a water immersion depth (salt water, seawater, etc.) of 0.5-4m.

[0085] Step 130 : Perform an electrical characteristic test on the test sample after the aging test to obtain a second test result.

[0086] After the aging test is performed on the test sample, an electrical characteristic test is performed on the test sample, and the result of the electrical characteristic test, i.e., the second test result, is recorded and saved. The electrical characteristic test of the test sample after the aging test is the same as the electrical characteristic test of the test sample before the aging test, so that the electrical characteristic test results before and after the aging test can be compared and analyzed.

[0087] In some embodiments, the electrical characteristics test includes a contact resistance test, and the second test result includes a second contact resistance. Performing an electrical characteristics test on the test sample after the aging test to obtain a second test result in step 130 includes: performing a contact resistance test on the test sample after the aging test to obtain a second contact resistance.

[0088] After the aging test, the two test ends of the test sample are connected to a contact resistance tester (such as a multimeter) to perform a contact resistance test on the test sample using the contact resistance tester to obtain the contact resistance value of the test sample, that is, the second contact resistance, and record and save the second contact resistance R2.

[0089] During the aging test, the test samples are affected by the test environment such as temperature and humidity, which leads to an increase in contact resistance. However, excessive contact resistance may cause problems such as poor contact, heating, and even short circuit of the photovoltaic cable. Therefore, it is necessary to compare and analyze the contact resistance of the test samples before and after the aging test.

[0090] In some embodiments, the electrical characteristics test includes a capacitance test, and the second test result includes a second capacitance. Performing an electrical characteristics test on the test sample after the aging test to obtain a second test result in step 130 includes: performing a capacitance test on the test sample after the aging test to obtain a second capacitance.

[0091] After the aging test, the two test ends of the test sample are connected to a capacitance tester (such as a bridge meter) to perform a capacitance test on the test sample using the capacitance tester to obtain the capacitance value of the test sample, that is, the second capacitance, and record and save the second capacitance C2.

[0092] During the aging test, the test sample is affected by the test environment such as temperature and humidity, which causes the capacitance to increase. However, if the capacitance is too large, the insulation performance of the photovoltaic cable may be degraded, and there are risks such as short circuit and breakdown. Therefore, it is necessary to compare and analyze the capacitance of the test sample before and after the aging test.

[0093] In some embodiments, the electrical characteristics test includes a contact resistance test and a capacitance test, and the second test result includes a second contact resistance and a second capacitance. Performing an electrical characteristics test on the test sample after the aging test to obtain a second test result in step 130 includes: performing a contact resistance test on the test sample after the aging test to obtain a second contact resistance; performing a capacitance test on the test sample after the aging test to obtain a second capacitance.

[0094] The order of the contact resistance test and the capacitance test is not specifically limited. After obtaining the second contact resistance and the second capacitance, the second contact resistance R2 and the second capacitance C2 are recorded and saved.

[0095] In some embodiments, performing an electrical characteristic test on the test sample after the aging test includes:

[0096] Conduct visual inspection on the test samples after the aging test, and conduct wet leakage test on the test samples after the aging test;

[0097] When it is determined that the appearance inspection of the test sample after the aging test is qualified and the wet leakage test is qualified, an electrical characteristic test is performed on the test sample after the aging test.

[0098] After the aging test, the test sample may be subjected to an appearance inspection and a wet leakage test, etc. The order of the appearance inspection and the wet leakage test is not specifically limited.

[0099] The appearance inspection method after the aging test can be the same as the appearance inspection method before the aging test, and will not be described in detail here. Perform an appearance inspection on the test sample after the aging test. If it is detected that the appearance of the test sample after the aging test is abnormal, it is determined that the appearance inspection of the test sample after the aging test is unqualified, that is, the appearance inspection does not meet the test requirements, and the subsequent testing of the test sample can be stopped. After replacing the test sample, the photovoltaic cable reliability test can be repeated; if the appearance of the test sample after the aging test is normal, it is determined that the appearance inspection of the test sample after the aging test is qualified, that is, the appearance inspection meets the test requirements, and the test sample can continue to be subjected to subsequent testing.

[0100] The wet leakage test method after the aging test can be the same as the wet leakage test method before the aging test, and will not be described in detail here. Perform a wet leakage test on the test sample after the aging test to obtain a second insulation resistance. Compare the second insulation resistance with the target insulation resistance (such as 2000MΩ). If the second insulation resistance is greater than the target insulation resistance, it is determined that the wet leakage test of the test sample after the aging test is qualified, that is, the wet leakage test meets the test requirements, and the test sample can continue to be tested subsequently; if the second insulation resistance is less than or equal to the target insulation resistance, it is determined that the wet leakage test of the test sample after the aging test is unqualified, that is, the wet leakage test does not meet the test requirements, and the subsequent testing of the test sample can be stopped, and the photovoltaic cable reliability test can be re-performed after the test sample is replaced.

[0101] When it is determined that the appearance inspection and wet leakage test of the test sample after the aging test are qualified, continue to perform electrical characteristics test on the test sample after the aging test.

[0102] Step 140: Determine the reliability of the photovoltaic cable according to the first test result and the second test result.

[0103] The second test result is compared and analyzed with the first test result to evaluate the performance change of the photovoltaic cable during the aging process. According to the performance change of the photovoltaic cable during the aging process, the reliability of the photovoltaic cable is evaluated.

[0104] In some embodiments, the electrical characteristic test includes a contact resistance test, the first test result includes a first contact resistance, and the second test result includes a second contact resistance. Determining the reliability of the photovoltaic cable according to the first test result and the second test result in step 140 includes:

[0105] calculating a resistance ratio of the second contact resistance to the first contact resistance;

[0106] Comparing the resistance ratio with the target resistance ratio to obtain a resistance comparison result;

[0107] The reliability of the photovoltaic cable is determined based on the resistance comparison results.

[0108] The contact resistance of the test sample after the aging test increases, but the change cannot be too large. Obtain the first contact resistance R1 before the aging test and the second contact resistance R2 after the aging test, and calculate the resistance ratio R2 / R1 of the second contact resistance R2 and the first contact resistance R1. Compare the resistance ratio R2 / R1 with the target resistance ratio (such as 1.5). If the resistance ratio R2 / R1 is less than or equal to the target resistance ratio, such as R2 / R1≤1.5, then the resistance comparison result is determined to be that the contact resistance test of the test sample is qualified, that is, the contact resistance test meets the test requirements; if the resistance ratio R2 / R1 is greater than the target resistance ratio, such as R2 / R1>1.5, then the resistance comparison result is determined to be that the contact resistance test of the test sample is unqualified, that is, the contact resistance test does not meet the test requirements.

[0109] In the case where the electrical characteristic test includes a contact resistance test, if the contact resistance test meets the test requirements, the photovoltaic cable can be evaluated as having good reliability; if the contact resistance test does not meet the test requirements, the photovoltaic cable can be evaluated as having poor reliability.

[0110] In some embodiments, the electrical characteristic test includes a capacitance test, the first test result includes a first capacitance, and the second test result includes a second capacitance. Determining the reliability of the photovoltaic cable according to the first test result and the second test result in step 140 includes:

[0111] Calculating a capacitance ratio of the second capacitance minus the first capacitance to the first capacitance;

[0112] Comparing the capacitance ratio with the target capacitance ratio to obtain a capacitance comparison result;

[0113] Based on the capacitance comparison results, the reliability of the PV cable is determined.

[0114] The capacitance of the test sample after the aging test increases, but the change cannot be too large. Obtain the first capacitance C1 before the aging test and the second capacitance C2 after the aging test, calculate the difference C2-C1 between the second capacitance C2 and the first capacitance C1, and then calculate the capacitance ratio (C2-C1) / C1 of the difference C2-C1 and the first capacitance C1, that is, calculate the capacitance change rate. Compare the capacitance ratio (C2-C1) / C1 with the target capacitance ratio (such as 8%). If the capacitance ratio (C2-C1) / C1 is less than or equal to the target capacitance ratio, such as (C2-C1) / C1≤8%, then determine that the capacitance comparison result is that the capacitance test of the test sample is qualified, that is, the capacitance test meets the test requirements; if the capacitance ratio (C2-C1) / C1 is greater than the target capacitance ratio, such as (C2-C1) / C1>8%, then determine that the capacitance comparison result is that the capacitance test of the test sample is unqualified, that is, the capacitance test does not meet the test requirements.

[0115] In the case where the electrical characteristic test includes a capacitance and resistance test, if the capacitance test meets the test requirements, the photovoltaic cable can be evaluated to have good reliability; if the capacitance test does not meet the test requirements, the photovoltaic cable can be evaluated to have poor reliability.

[0116] In some embodiments, the electrical characteristic test includes a contact resistance test and a capacitance test, the first test result includes a first contact resistance and a first capacitance, and the second test result includes a second contact resistance and a second capacitance. Determining the reliability of the photovoltaic cable according to the first test result and the second test result in step 140 includes:

[0117] calculating a resistance ratio of the second contact resistance to the first contact resistance;

[0118] Comparing the resistance ratio with the target resistance ratio to obtain a resistance comparison result;

[0119] Calculating a capacitance ratio of the second capacitance minus the first capacitance to the first capacitance;

[0120] Comparing the capacitance ratio with the target capacitance ratio to obtain a capacitance comparison result;

[0121] The reliability of the photovoltaic cable is determined based on the resistance comparison results and the capacitance comparison results.

[0122] When it is determined that the resistance comparison result is that the contact resistance test of the test sample is qualified, and the capacitance comparison result is that the capacitance test of the test sample is qualified, both the contact resistance test and the capacitance test meet the test requirements, and the photovoltaic cable can be evaluated as having good reliability; when it is determined that the resistance comparison result is that the contact resistance test of the test sample is unqualified, or the capacitance comparison result is that the capacitance test of the test sample is unqualified, both the contact resistance test or the capacitance test meet the test requirements, and the photovoltaic cable can be evaluated as having poor reliability.

[0123] It should be noted that based on the reliability assessment of photovoltaic cables, improvement measures can be proposed for the design, production, and use of photovoltaic cables to optimize the reliability and performance of photovoltaic cables.

[0124] like Figure 3 As shown, the embodiment of the present application also provides a photovoltaic cable reliability testing method, including steps 210 to 290.

[0125] Step 210: Provide a test sample of a photovoltaic cable.

[0126] For example, prepare a 5-meter photovoltaic cable, and peel off 0.6 cm of the insulation sheath at both ends of the photovoltaic cable as a test sample.

[0127] Step 220: Perform a visual inspection on the test sample and determine whether the appearance inspection is qualified.

[0128] For example, a visual inspection is performed on the appearance of the test sample, and if there is no abnormality in the appearance, it is determined that the appearance inspection is qualified.

[0129] Step 230: Perform a wet leakage test on the test sample and determine whether the wet leakage test is qualified.

[0130] For example, a voltage of 1500V is applied to the test sample, and the insulation resistance is detected to be greater than 8000MΩ, which determines that the wet leakage test is qualified.

[0131] Step 240: Perform a contact resistance test on the test sample to obtain a first contact resistance.

[0132] For example, a contact resistance test is performed on the test sample, and a first contact resistance R1 = 1Ω is recorded.

[0133] Step 250: Perform a capacitance test on the test sample to obtain a first capacitance.

[0134] For example, a capacitance test is performed on the test sample, and a first capacitance C1 = 439.65 pF is recorded.

[0135] Step 260: Immerse the test sample in the test liquid under the test environment, and perform an aging test on the test sample.

[0136] For example, the pressure in the test environment is 303.975 kPa, the temperature is 121°C, and the humidity is 100% RH (100% humidity). The test sample is placed in salt water to a depth of 4m. Both ends of the test sample extend 20-40cm above the water surface as two test ends.

[0137] Connect the positive electrode of the DC constant voltage power supply to the electrode in the salt water, and connect the negative electrode of the DC constant voltage power supply to the two test ends of the test sample. The DC constant voltage power supply stably outputs 4KV voltage for 1000 hours in a cycle. Connect the positive electrode of the DC constant current power supply to one test end of the test sample, and connect the negative electrode of the DC constant current power supply to the other test end of the test sample. The DC constant current power supply stably outputs 40A current for 1000 hours in a cycle.

[0138] Step 270: Perform an appearance inspection on the test sample after the aging test, and determine whether the appearance inspection is qualified.

[0139] For example, a visual inspection is performed on the appearance of the test sample after the aging test, and if there is no abnormality in the appearance, it is determined that the appearance inspection is qualified.

[0140] Step 280: Perform a wet leakage test on the test sample after the aging test, and determine whether the wet leakage test is qualified.

[0141] For example, a voltage of 1500V is applied to the test sample after the aging test, and the insulation resistance is detected to be greater than 8000MΩ, which determines that the wet leakage test is qualified.

[0142] Step 290: Perform a contact resistance test on the test sample after the aging test to obtain a second contact resistance.

[0143] For example, a contact resistance test is performed on the test sample after the aging test, and a second contact resistance R2=1.1Ω is recorded.

[0144] Step 310: Determine whether the contact resistance test is qualified according to the first contact resistance and the second contact resistance.

[0145] For example, the ratio of the second contact resistance to the first contact resistance is calculated to be R2 / R1≤1.1, and it is determined that the contact resistance test is qualified.

[0146] Step 320: Perform a capacitance test on the test sample after the aging test to obtain a second capacitance.

[0147] For example, a capacitance test is performed on the test sample after the aging test, and the second capacitance C2=461.63 pF is recorded.

[0148] Step 330: Determine whether the capacitance test is qualified based on the first capacitance and the second capacitance.

[0149] For example, the difference between the second capacitance and the first capacitance is calculated, and then the ratio of the difference to the first capacitance is calculated (C2-C1) / C1=4.999%, and it is determined that the capacitance test is qualified.

[0150] Step 340: If the appearance inspection, wet leakage test, contact resistance test and capacitance test are all qualified, it is determined that the photovoltaic cable has high reliability; otherwise, it is determined that the photovoltaic cable has low reliability.

[0151] It should be noted that the order of the appearance inspection, wet leakage test, contact resistance test and capacitance test before the aging test is not specifically limited. The order of the appearance inspection, wet leakage test, contact resistance test and capacitance test after the aging test is not specifically limited.

[0152] Through the reliability test of photovoltaic cables, it can be ensured that photovoltaic cables maintain stable performance and a long service life in complex and changeable working environments, providing strong protection for the safe and stable operation of photovoltaic power generation systems.

[0153] According to the photovoltaic cable reliability testing method provided in the embodiment of the present application, a test sample of the photovoltaic cable is provided, and the test sample is immersed in a test liquid in a test environment to simulate the actual working environment of the photovoltaic cable. An aging test is performed on the test sample to evaluate the long-term reliability of the photovoltaic cable working in a water immersion environment. The electrical characteristics test is performed on the test sample before and after the aging test, and the reliability of the photovoltaic cable is determined based on the results of the two electrical characteristics tests, thereby effectively improving the test accuracy.

[0154] The photovoltaic cable reliability test method provided in the embodiment of the present application can be executed by a photovoltaic cable reliability test device. In the embodiment of the present application, the photovoltaic cable reliability test method is executed by a photovoltaic cable reliability test device as an example to illustrate the photovoltaic cable reliability test device provided in the embodiment of the present application.

[0155] like Figure 4 As shown, the photovoltaic cable reliability testing device provided in the embodiment of the present application includes a first testing module 410 , an aging testing module 420 , a second testing module 430 and a determination module 440 .

[0156] A first test module 410 is used to perform an electrical characteristic test on a test sample of a photovoltaic cable to obtain a first test result;

[0157] An aging test module 420, used to immerse the test sample in a test liquid in a test environment and perform an aging test on the test sample;

[0158] A second test module 430 is used to perform an electrical characteristic test on the test sample after the aging test to obtain a second test result;

[0159] The determination module 440 is used to determine the reliability of the photovoltaic cable according to the first test result and the second test result.

[0160] According to the photovoltaic cable reliability testing device provided in the embodiment of the present application, a test sample of the photovoltaic cable is provided, and the test sample is immersed in a test liquid in a test environment to simulate the actual working environment of the photovoltaic cable. An aging test is performed on the test sample to evaluate the long-term reliability of the photovoltaic cable working in a water immersion environment. The electrical characteristics test is performed on the test sample before and after the aging test, and the reliability of the photovoltaic cable is determined based on the results of the two electrical characteristics tests, thereby effectively improving the test accuracy.

[0161] In some embodiments, the temperature in the test environment is greater than or equal to the temperature in the actual working environment of the photovoltaic cable, the boiling point of the test liquid under the pressure in the test environment is greater than the temperature in the test environment, the humidity in the test environment is greater than or equal to the humidity in the actual working environment of the photovoltaic cable, and the test liquid is seawater or salt water of target concentration.

[0162] In some embodiments, the pressure in the test environment is 303.975 kPa, the temperature in the test environment is 121° C., the humidity in the test environment is 100% RH, and the target concentration is 10-50 g / L.

[0163] In some embodiments, the aging test module 420 is further configured to:

[0164] Applying a voltage of a target duration to the test sample through a DC constant voltage power supply, wherein the positive electrode of the DC constant voltage power supply is connected to the electrode in the test liquid, and the negative electrode of the DC constant voltage power supply is respectively connected to two test ends of the test sample, and the two test ends of the test sample are located outside the test liquid;

[0165] A current of a target duration is applied to the test sample through a DC constant current power supply, the positive pole of the DC constant current power supply is connected to one test end of the test sample, and the negative pole of the DC constant current power supply is connected to the other test end of the test sample.

[0166] In some embodiments, the voltage applied by the DC constant voltage power supply is 4KV, the current applied by the DC constant current power supply is 40A, and the target duration is 1000 hours.

[0167] In some embodiments, the electrical characteristic test includes a contact resistance test, the first test result includes a first contact resistance, and the second test result includes a second contact resistance; the determination module 440 is further configured to:

[0168] calculating a resistance ratio of the second contact resistance to the first contact resistance;

[0169] Comparing the resistance ratio with a target resistance ratio to obtain a resistance comparison result;

[0170] The reliability of the photovoltaic cable is determined according to the resistance comparison result.

[0171] In some embodiments, the electrical characteristic test includes a capacitance test, the first test result includes a first capacitance, and the second test result includes a second capacitance; the determination module 440 is further configured to:

[0172] Calculating a capacitance ratio of the second capacitance minus the first capacitance to the first capacitance;

[0173] Comparing the capacitance ratio with a target capacitance ratio to obtain a capacitance comparison result;

[0174] The reliability of the photovoltaic cable is determined according to the capacitance comparison result.

[0175] In some embodiments, the first test module 410 is further configured to:

[0176] Performing a visual inspection on the test sample and performing a wet leakage test on the test sample;

[0177] When it is determined that the test sample has passed the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample of the photovoltaic cable.

[0178] In some embodiments, the second test module 430 is further configured to:

[0179] Performing a visual inspection on the test sample after the aging test, and performing a wet leakage test on the test sample after the aging test;

[0180] When it is determined that the test sample after the aging test passes the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample after the aging test.

[0181] An embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the above-mentioned photovoltaic cable reliability testing method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0182] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0183] An embodiment of the present application also provides a computer program product, including a computer program, which implements the above-mentioned photovoltaic cable reliability testing method when executed by a processor.

[0184] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0185] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned photovoltaic cable reliability testing method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0186] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0187] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0188] In the description of the present application, “plurality” means two or more.

[0189] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0190] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A photovoltaic cable reliability testing method, characterized in that: include: Performing an electrical characteristic test on a test sample of the photovoltaic cable to obtain a first test result; Immersing the test sample in a test liquid in a test environment, and performing an aging test on the test sample; Performing an electrical characteristic test on the test sample after the aging test to obtain a second test result; The reliability of the photovoltaic cable is determined according to the first test result and the second test result.

2. The photovoltaic cable reliability testing method according to claim 1, characterized in that: The temperature in the test environment is greater than or equal to the temperature in the actual working environment of the photovoltaic cable, the boiling point of the test liquid under the pressure in the test environment is greater than the temperature in the test environment, the humidity in the test environment is greater than or equal to the humidity in the actual working environment of the photovoltaic cable, and the test liquid is seawater or salt water of target concentration.

3. The photovoltaic cable reliability testing method according to claim 2, characterized in that: The pressure in the test environment is 303.975 kPa, the temperature in the test environment is 121° C., the humidity in the test environment is 100% RH, and the target concentration is 10 to 50 g / L.

4. The photovoltaic cable reliability testing method according to claim 1, characterized in that: The step of performing an aging test on the test sample comprises: Applying a voltage of a target duration to the test sample through a DC constant voltage power supply, wherein the positive electrode of the DC constant voltage power supply is connected to the electrode in the test liquid, and the negative electrode of the DC constant voltage power supply is respectively connected to two test ends of the test sample, and the two test ends of the test sample are located outside the test liquid; A current of a target duration is applied to the test sample through a DC constant current power supply, the positive pole of the DC constant current power supply is connected to one test end of the test sample, and the negative pole of the DC constant current power supply is connected to the other test end of the test sample.

5. The photovoltaic cable reliability testing method according to claim 4, characterized in that: The voltage applied by the DC constant voltage power supply is 4KV, the current applied by the DC constant current power supply is 40A, and the target duration is 1000 hours.

6. The photovoltaic cable reliability testing method according to claim 1, characterized in that: The electrical characteristic test includes a contact resistance test, the first test result includes a first contact resistance, and the second test result includes a second contact resistance; The determining the reliability of the photovoltaic cable according to the first test result and the second test result includes: calculating a resistance ratio of the second contact resistance to the first contact resistance; Comparing the resistance ratio with a target resistance ratio to obtain a resistance comparison result; The reliability of the photovoltaic cable is determined according to the resistance comparison result.

7. The photovoltaic cable reliability testing method according to claim 1, characterized in that: The electrical characteristic test includes a capacitance test, the first test result includes a first capacitance, and the second test result includes a second capacitance; The determining the reliability of the photovoltaic cable according to the first test result and the second test result includes: Calculating a capacitance ratio of the second capacitance minus the first capacitance to the first capacitance; Comparing the capacitance ratio with a target capacitance ratio to obtain a capacitance comparison result; The reliability of the photovoltaic cable is determined according to the capacitance comparison result.

8. The photovoltaic cable reliability testing method according to claim 1, characterized in that: The electrical characteristics test of the photovoltaic cable test sample includes: Performing a visual inspection on the test sample and performing a wet leakage test on the test sample; When it is determined that the test sample has passed the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample of the photovoltaic cable.

9. The photovoltaic cable reliability testing method according to any one of claims 1 to 8, characterized in that: The electrical characteristics test of the test sample after the aging test comprises: Performing a visual inspection on the test sample after the aging test, and performing a wet leakage test on the test sample after the aging test; When it is determined that the test sample after the aging test passes the appearance inspection and the wet leakage test, an electrical characteristic test is performed on the test sample after the aging test.

10. A photovoltaic cable reliability testing device, characterized in that: include: A first test module is used to perform an electrical characteristic test on a test sample of a photovoltaic cable to obtain a first test result; An aging test module, used for immersing the test sample in a test liquid in a test environment and performing an aging test on the test sample; A second testing module, used for performing an electrical characteristic test on the test sample after the aging test to obtain a second test result; A determination module is used to determine the reliability of the photovoltaic cable according to the first test result and the second test result.

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