Potential induced degradation detection method, device and computer equipment for photovoltaic modules

Abstract

The present application relates to a method, device, computer equipment, computer-readable storage medium and computer program product for detecting potential-induced attenuation of photovoltaic modules. The method comprises: obtaining the degree of attenuation of electrical parameters after PID test of the photovoltaic module to be tested relative to that before PID test; wherein the degree of attenuation of electrical parameters includes the degree of attenuation of fill factor and the degree of volt-ampere attenuation, and the degree of volt-ampere attenuation includes the degree of attenuation of open circuit voltage or the degree of attenuation of short circuit current; determining the failure type of potential-induced attenuation according to the degree of attenuation of fill factor and the degree of volt-ampere attenuation; wherein the failure types include shunt type and polarization type, and the failure type of PID can be accurately determined.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic module detection, and in particular to a method, device, computer equipment, computer-readable storage medium and computer program product for detecting potential-induced degradation of a photovoltaic module. Background Art

[0002] Potential Induced Degradation (PID) refers to the power attenuation phenomenon caused by external factors in photovoltaic modules. In the actual operation of traditional P-type and N-type photovoltaic modules, potential induced degradation will affect the power generation efficiency of the modules. Therefore, PID testing is generally carried out in the reliability laboratory before the photovoltaic modules leave the factory.

[0003] However, for P-type or N-type photovoltaic modules that have already experienced PID failure, a detection method that can accurately determine the failure type of PID is urgently needed. Summary of the invention

[0004] Based on this, it is necessary to provide a potential induced degradation detection method, device, computer equipment, computer readable storage medium and computer program product for photovoltaic components that can accurately determine the failure type of PID in order to address the above technical problems.

[0005] In a first aspect, the present application provides a method for detecting potential induced degradation of a photovoltaic module, the method comprising:

[0006] Obtaining the degree of attenuation of electrical parameters of the photovoltaic module to be tested after the PID test relative to that before the PID test; wherein the degree of attenuation of electrical parameters includes the degree of attenuation of fill factor and the degree of volt-ampere attenuation, and the degree of volt-ampere attenuation includes the degree of attenuation of open circuit voltage or the degree of attenuation of short circuit current;

[0007] The failure type of the potential-induced decay is determined according to the fill factor decay degree and the volt-ampere decay degree; wherein the failure type includes a shunt type and a polarization type.

[0008] In one embodiment, determining the failure type of potential induced degradation according to the fill factor attenuation degree and the voltage or current attenuation degree includes:

[0009] In a case where the fill factor attenuation degree is greater than the volt-ampere attenuation degree, determining that the failure type of the potential induced decay is a shunt type;

[0010] In the case where the fill factor decay degree is less than the volt-ampere decay degree, it is determined that the failure type of the potential-induced decay is a polarization type.

[0011] In one embodiment, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test includes:

[0012] Respectively obtaining a first electrical parameter of the photovoltaic assembly to be tested before the PID test and a second electrical parameter of the photovoltaic assembly to be tested after the PID test; wherein the first electrical parameter and the second electrical parameter both include an open circuit voltage, a short circuit current, a maximum power voltage, and a maximum power current, and the fill factor is related to the open circuit voltage, the short circuit current, the maximum power voltage, and the maximum power current;

[0013] The fill factor attenuation degree and the volt-ampere attenuation degree are determined according to the first electrical parameter and the second electrical parameter, respectively.

[0014] In one of the embodiments, when the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is greater than or equal to a first threshold, the fill factor attenuation degree is greater than the volt-ampere attenuation degree;

[0015] When the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than or equal to the second threshold, the fill factor attenuation degree is less than the volt-ampere attenuation degree;

[0016] Among them, the filling factor decay rate is the ratio of the filling factor difference to the first filling factor, and the filling factor difference is the difference between the second filling factor after the PID test and the first filling factor before the PID test; the volt-ampere decay rate is the ratio of the volt-ampere parameter difference to the first volt-ampere parameter, and the volt-ampere parameter difference is the difference between the second volt-ampere parameter after the PID test and the first volt-ampere parameter before the PID test, and the first threshold is greater than the second threshold.

[0017] In one embodiment, the method further comprises:

[0018] Acquire verification parameters of the photovoltaic group to be tested after the PID test; wherein the verification parameters include the first maximum power after the photovoltaic group to be tested is subjected to a lighting test;

[0019] The accuracy of the failure type is reviewed based on the first maximum power and the second maximum power; wherein the second maximum power is the maximum power of the photovoltaic component to be tested after the PID test and before the illumination test.

[0020] In one embodiment, the method further comprises:

[0021] When the fill factor attenuation degree is equal to the volt-ampere attenuation degree, obtaining the verification parameters of the photovoltaic group to be tested after the PID test; wherein the verification parameters include the first maximum power after the illumination test of the photovoltaic group to be tested;

[0022] The failure type is determined according to the first maximum power and the second maximum power.

[0023] In one of the embodiments, when the difference between the first maximum power and the second maximum power parameters is greater than or equal to a third threshold, the failure type is determined to be a polarization type; or,

[0024] When the difference between the first maximum power and the second maximum power is less than or equal to a fourth threshold, the failure type is determined to be a shunt type; wherein the third threshold is greater than the fourth threshold.

[0025] In one embodiment, the method further comprises:

[0026] Acquire a first electroluminescent imaging image of the photovoltaic assembly to be tested after a PID test and an illumination test;

[0027] In the case where the failure type is polarization type and the first electroluminescent imaging image does not have defect features, determining that the polarization type failure type is accurate; or,

[0028] In the case that the failure type is a shunt type and the first electroluminescent imaging image has defect features corresponding to the shunt type, it is determined that the failure type of the shunt type is accurate.

[0029] In one embodiment, the method further comprises:

[0030] Acquire a second electroluminescent imaging image of the photovoltaic module to be tested after the PID test;

[0031] In the case where the failure type is a polarization type and the defect degree of the defect feature in the second electroluminescent imaging image is higher than the defect degree of the defect feature in the first electroluminescent imaging image, determining that the failure type is a polarization type is accurate.

[0032] In one embodiment, the method further comprises:

[0033] In the case where the failure type is a polarization type, a third maximum power and a fourth maximum power of the photovoltaic assembly to be tested are respectively obtained, wherein the third maximum power is the maximum power of the photovoltaic assembly to be tested after the first PID test, and the fourth maximum power is the maximum power of the photovoltaic assembly to be tested after the second PID test, and the loading voltages of the first PID test and the second PID test are opposite;

[0034] When the difference between the fourth maximum power and the third maximum power is greater than a preset power threshold, it is determined that the failure type is polarization-type accurate.

[0035] In one embodiment, the method further comprises:

[0036] Acquire a second electroluminescent imaging image after the photovoltaic assembly to be tested PID test;

[0037] Identify whether the second electroluminescent imaging image has a defect feature corresponding to the failure type;

[0038] In the case where the defect feature corresponding to the failure type exists, verifying that the failure type is accurate.

[0039] In one embodiment, in the presence of the defect feature corresponding to the failure type, determining that the detection of the failure type is accurate includes:

[0040] In the case where the failure type is a shunt type and the electroluminescent imaging image has a first defect feature, determining that the failure type is a shunt type is accurate;

[0041] In the case where the failure type is a polarization type and the electroluminescent imaging image has a second defect feature, it is accurate to determine that the failure type is a polarization type; wherein the first defect feature is different from the second defect feature.

[0042] In one embodiment, the method further comprises:

[0043] Acquire a second electroluminescent imaging image after the photovoltaic assembly to be tested PID test;

[0044] In the case where corrosion features exist in the second electroluminescent imaging image, the failure type is determined to be corrosion type.

[0045] In one embodiment, the method further comprises:

[0046] Acquiring a second electroluminescent imaging image of the photovoltaic assembly to be tested after the illumination test;

[0047] In the case where corrosion features exist in the second electroluminescent imaging image, it is determined that the corrosion-type failure type is accurate.

[0048] In a second aspect, the present application further provides a potential induced degradation detection device for a photovoltaic module, the device comprising:

[0049] An acquisition module is used to obtain the degree of attenuation of electrical parameters of the photovoltaic module to be tested after the PID test relative to the degree of attenuation before the PID test; wherein the degree of attenuation of the electrical parameters includes the degree of attenuation of the fill factor and the degree of attenuation of the volt-ampere, and the degree of attenuation of the volt-ampere includes one of the degree of attenuation of the open circuit voltage, the degree of attenuation of the short circuit current and the degree of attenuation of the maximum power voltage;

[0050] A determination module is used to determine the failure type of the potential-induced decay according to the fill factor decay degree and the volt-ampere decay degree; wherein the failure type includes a shunt type and a polarization type.

[0051] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0052] Obtaining the degree of electrical parameter attenuation after the PID test of the photovoltaic module to be tested relative to that before the PID test; wherein the degree of electrical parameter attenuation includes a fill factor attenuation degree and a volt-ampere attenuation degree, and the volt-ampere attenuation degree includes one of an open circuit voltage attenuation degree, a short circuit current attenuation degree and a maximum power voltage attenuation degree;

[0053] The failure type of the potential-induced decay is determined according to the fill factor decay degree and the volt-ampere decay degree; wherein the failure type includes a shunt type and a polarization type.

[0054] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0055] Obtaining the degree of electrical parameter attenuation after the PID test of the photovoltaic module to be tested relative to that before the PID test; wherein the degree of electrical parameter attenuation includes a fill factor attenuation degree and a volt-ampere attenuation degree, and the volt-ampere attenuation degree includes one of an open circuit voltage attenuation degree, a short circuit current attenuation degree and a maximum power voltage attenuation degree;

[0056] The failure type of the potential-induced decay is determined according to the fill factor decay degree and the volt-ampere decay degree; wherein the failure type includes a shunt type and a polarization type.

[0057] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0058] Obtaining the degree of electrical parameter attenuation after the PID test of the photovoltaic module to be tested relative to that before the PID test; wherein the degree of electrical parameter attenuation includes a fill factor attenuation degree and a volt-ampere attenuation degree, and the volt-ampere attenuation degree includes one of an open circuit voltage attenuation degree, a short circuit current attenuation degree and a maximum power voltage attenuation degree;

[0059] The failure type of the potential-induced decay is determined according to the fill factor decay degree and the volt-ampere decay degree; wherein the failure type includes a shunt type and a polarization type.

[0060] The above-mentioned potential induced decay detection method, device, computer equipment, computer readable storage medium and computer program product of photovoltaic modules can obtain the degree of attenuation of electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test, and then determine the failure type of the potential induced decay according to the fill factor attenuation degree and the volt-ampere attenuation degree, such as shunt-type potential induced decay and polarization-type potential induced decay. In this way, in the PID reliability test, the failure type of photovoltaic module PID failure can be accurately determined by the test results, and the detection method is simple and efficient. In addition, based on the failure type, technicians can more accurately grasp the direction of improvement of photovoltaic modules, avoid or reduce the reliability risk of PID in the modules during the actual operation of the power station from the source, and reduce and minimize the risks and losses caused by PID failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0062] Figure 1 One of the flow diagrams of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0063] Figure 2 A structural block diagram of a PID test device in one embodiment;

[0064] Figure 3 It is a structural block diagram of a PID test device in another embodiment;

[0065] Figure 4 is a flow chart of step 102 in one embodiment;

[0066] Figure 5 The second schematic diagram is a flow chart of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0067] Figure 6a EL imaging image of sample 1 before PID test;

[0068] Figure 6b EL imaging image of sample 1 after PID test;

[0069] Figure 7a This is the EL imaging image of sample 2 before PID test;

[0070] Figure 7b This is the EL imaging image of sample 2 after PID test;

[0071] Figure 8a This is the EL imaging image of sample 3 before PID test;

[0072] Figure 8b This is the EL imaging image of sample 3 after PID test;

[0073] Figure 9a This is the EL imaging image of sample 4 before PID test;

[0074] Figure 9b This is the EL imaging image of sample 4 after the PID test;

[0075] Fig.10a This is the EL imaging image of sample 5 before the PID test;

[0076] Fig.10b This is the EL imaging image of sample 5 after the PID test;

[0077] Fig.11a This is the EL imaging image of sample 6 before PID test;

[0078] Fig.11b This is the EL imaging image of sample 6 after the PID test;

[0079] Fig.12 The third flow chart of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0080] Fig.13 FIG4 is a flow chart of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0081] Fig.14a This is the EL imaging image of sample 7 before the PID test;

[0082] Fig.14b This is the EL imaging image of sample 7 after the PID test;

[0083] Fig.14c This is the EL imaging image of sample 7 after the illumination test;

[0084] Fig.15a EL imaging image of sample 10 before PID test;

[0085] Fig.15b EL imaging image of sample 10 after PID test;

[0086] Fig.15c EL imaging image of sample 10 after illumination test;

[0087] Fig.16a EL imaging image of sample 11 before PID test;

[0088] Fig.16b EL imaging image of sample 11 after PID test;

[0089] Fig.16c This is the EL imaging image of sample 11 after the illumination test;

[0090] Fig.17 FIG5 is a fifth flow chart of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0091] Fig.18 FIG6 is a sixth flow chart of a method for detecting potential induced degradation of a photovoltaic module in one embodiment;

[0092] Fig.19 is a structural block diagram of a potential induced degradation detection device for a photovoltaic module in one embodiment;

[0093] Fig. 20 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0094] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0095] In an exemplary embodiment, Figure 1 As shown, a method for detecting potential induced degradation of a photovoltaic module is provided, including the following steps 102 to 104.

[0096] Step 102, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test.

[0097] In the embodiment of the present application, a PID test device can be used to perform a PID test on a photovoltaic module to be tested. The photovoltaic module to be tested is a photovoltaic module that may fail to function after the PID test. For example, the PID test device can provide a bias voltage for the photovoltaic module to be tested, wherein the bias voltage can be a negative voltage such as Figure 2 As shown in Figure 1, under negative bias conditions, the electric field is directed from the component frame and the glass surface to the inside of the battery. Optionally, the bias voltage can also be a positive voltage such as Figure 3 As shown in Figure 1, under positive bias conditions, the electric field is opposite, pointing from the battery to the outside. Figure 2 and Figure 3 As shown, the PID test device may include a cell 110, a film 120, a front glass 130, a back glass / backboard 140, a frame 150, and a terminal 160. Under the double 85 test conditions (for example, the test conditions are that the temperature is set to 85°C and the humidity is 85%), a thin layer of water vapor 170 will condense on the surface of the photovoltaic module. After the water vapor condenses on the glass surface, it is easier to form a leakage current channel. Under the action of the electric field, the external charge / Na + It will be enriched on the surface of the battery cell along the leakage current channel.

[0098] Before and after the PID test, the electrical parameters of the photovoltaic module to be tested can be obtained respectively, and then the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test can be obtained. The higher the attenuation degree of the electrical parameters, the higher the attenuation amount or attenuation rate or attenuation multiple of the corresponding electrical parameters.

[0099] Among them, the degree of electrical parameter attenuation includes the degree of fill factor attenuation and the degree of volt-ampere attenuation. Fill factor (FF) is an important parameter for measuring the performance of solar cells. The greater the degree of fill factor attenuation, the greater the efficiency attenuation of the solar cell. The degree of fill factor attenuation can be determined based on the fill factor before and after the PID test of the photovoltaic module to be tested.

[0100] The volt-ampere attenuation degree may include the open circuit voltage attenuation degree or the short circuit current attenuation degree. The open circuit voltage refers to the voltage of the photovoltaic module in the open circuit state (for example, the load is infinite), and the open circuit voltage attenuation degree can be determined based on the open circuit voltage before and after the PID test of the photovoltaic module to be tested. The short circuit current refers to the current of the photovoltaic module in the short circuit state (for example, the load is 0). The short circuit current attenuation degree can be determined based on the short circuit current before and after the PID test of the photovoltaic module to be tested.

[0101] Step 104: determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree.

[0102] Among them, the failure types include at least shunting-type PID (PID-s) and polarization-type PID (PID-p). Among them, shunting-type potential induced decay, also known as PID-s, is related to the sodium ions (Na + ) drift. The accumulation of sodium ions passes through the PN junction and causes the battery to short-circuit. The leakage path formed by the sodium ions will cause the parallel resistance of the battery to decrease, which will further cause the battery to decay. The main manifestation of PID-s is a significant decrease in the parallel resistance of the battery, and its fill factor decays significantly. Polarization potential induced decay, also known as PID-p, is mainly manifested by the destruction of the passivation on the battery surface. A large amount of charge accumulates on the battery cell to form an electric field opposite to the passivation field, which deteriorates the passivation effect on the surface of the battery cell. The failure of the passivation layer causes an increase in carrier recombination, which in turn affects the power failure of the component.

[0103] Since when a photovoltaic module has PID-s, its fill factor attenuation degree is greater than that of the fill factor under the PID-p failure type, and when a photovoltaic module has PID-s, its volt-ampere attenuation degree is smaller than that of the fill factor under the PID-p failure type, therefore, in the embodiment of the present application, by comparing the relative sizes of the fill factor attenuation degree and the volt-ampere attenuation degree, the failure type of the photovoltaic module PID can be determined.

[0104] The potential induced decay detection method for photovoltaic modules provided in the embodiment of the present application can obtain the degree of attenuation of electrical parameters of the photovoltaic module after the PID test relative to that before the PID test, and then determine the failure type of potential induced decay according to the fill factor attenuation degree and the volt-ampere attenuation degree, such as shunt-type potential induced decay and polarization-type potential induced decay. In this way, in the PID reliability test, the failure type of photovoltaic module PID failure can be accurately determined by the test results, and the detection method is simple and efficient. In addition, based on the failure type, technicians can more accurately grasp the direction of improvement of photovoltaic modules, avoid or reduce the reliability risk of PID in the modules during the actual operation of the power station from the source, and reduce and minimize the risks and losses caused by PID failure.

[0105] In an exemplary embodiment, Figure 4 As shown, step 102 includes steps 402 to 404. Among them:

[0106] Step 402 , respectively obtaining a first electrical parameter of the photovoltaic assembly to be tested before the PID test and a second electrical parameter of the photovoltaic assembly to be tested after the PID test.

[0107] Among them, the first electrical parameter and the second electrical parameter both include an open circuit voltage Voc, a short circuit current Isc, a maximum power voltage Vmp, and a maximum power current Imp. For the open circuit voltage Voc and the short circuit current Isc, please refer to the above description and will not be repeated here. The maximum power voltage Vmp is the peak voltage corresponding to the maximum power point of the photovoltaic module to be tested. The maximum power current Imp is the peak current corresponding to the maximum power point of the photovoltaic module to be tested.

[0108] Among them, the first electrical parameter before the photovoltaic module PID test and the second electrical parameter after the PID test can be obtained by the detection equipment used for photovoltaic module PID failure detection. Exemplarily, the detection equipment may include a variable resistor, an ammeter and a voltmeter. Among them, the voltmeter is connected in parallel with the variable resistor, and the variable resistor, the ammeter and the photovoltaic module are connected in series in sequence. Exemplarily, the first end of the variable resistor is connected to the positive lead end of the photovoltaic module, and the second end of the variable resistor is connected to the negative end of the photovoltaic module through the ammeter as an example for explanation. During the detection process, the resistance of the variable resistor can be adjusted to infinity, and the open circuit voltage of the current photovoltaic module can be read through the voltmeter. The resistance of the variable resistor can be adjusted to zero, and the short-circuit current of the current photovoltaic module can be read through the ammeter. The resistance of the variable resistor can be adjusted to be consistent with the internal resistance of the photovoltaic module, and the maximum power voltage Vmp and the maximum power current Imp when the photovoltaic module has the maximum output power can be obtained through the voltmeter and the ammeter.

[0109] The fill factor is related to the open circuit voltage, short circuit current, maximum power voltage and maximum power current. Specifically, fill factor (FF) = (maximum power point voltage*maximum power point current) / (open circuit voltage*short circuit current) = (Vmp*Imp) / (Voc*Isc).

[0110] Step 404 : Determine the fill factor attenuation degree and the volt-ampere attenuation degree according to the first electrical parameter and the second electrical parameter, respectively.

[0111] The degree of electrical parameter attenuation includes but is not limited to being expressed by attenuation rate, attenuation multiple, etc. Among them, the attenuation rate can be understood as the ratio of the electrical parameter reduction before and after the PID test of the photovoltaic module to be tested, for example, the difference between the second electrical parameter after the PID test of the photovoltaic module to be tested and the first electrical parameter after the PID test of the photovoltaic module to be tested, and the ratio of the first electrical parameter, such as attenuation rate = 100% * (second electrical parameter - first electrical parameter) / first electrical parameter, optionally, the attenuation rate can be a percentage. The attenuation multiple can be understood as the ratio of the corresponding second electrical parameter to the first electrical parameter, such as attenuation multiple = second electrical parameter / first electrical parameter.

[0112] In the embodiments of the present application, for the sake of convenience, the attenuation degree of the electrical parameter is represented by the attenuation rate as an example.

[0113] Based on the first filling factor of the photovoltaic module to be tested before the PID test and the second filling factor of the photovoltaic module to be tested after the PID test, the filling factor attenuation rate can be determined, and then the filling factor attenuation degree can be determined.

[0114] Correspondingly, based on the first volt-ampere parameter of the photovoltaic assembly to be tested before the PID test, and the second volt-ampere parameter of the photovoltaic assembly to be tested after the PID test, the volt-ampere parameter attenuation rate can be determined, and then the degree of attenuation of the volt-ampere parameter can be determined. Among them, the volt-ampere parameter may include the degree of attenuation of the open circuit voltage or the short circuit current. For example, based on the first open circuit voltage before the PID test of the photovoltaic assembly to be tested, and the second open circuit voltage after the PID test of the photovoltaic assembly to be tested, the open circuit voltage attenuation rate can be determined, and then the degree of attenuation of the open circuit voltage can be determined. Based on the first short-circuit current before the PID test of the photovoltaic assembly to be tested, and the second short-circuit current after the PID test of the photovoltaic assembly to be tested, the short-circuit current attenuation rate can be determined, and then the degree of attenuation of the short-circuit current can be determined.

[0115] In this embodiment, by obtaining the first electrical parameters of the photovoltaic component to be tested before the PID test (for example, the first filling factor, the first open circuit voltage, the first short circuit current), and the second electrical parameters of the photovoltaic component to be tested before the PID test (for example, the second filling factor, the second open circuit voltage, the second short circuit current), the attenuation rate or attenuation multiple of the corresponding electrical parameters can be obtained, and then the filling factor attenuation degree and the volt-ampere attenuation degree can be obtained, and then the PID failure type can be determined according to the filling factor attenuation degree and the volt-ampere attenuation degree.

[0116] In an exemplary embodiment, determining the failure type of potential induced decay according to the fill factor decay degree and the volt-ampere decay degree includes: when the fill factor decay degree is greater than the volt-ampere decay degree, determining the failure type of potential induced decay as PID-s. For example, when the fill factor decay degree is greater than the open circuit voltage decay degree, the short circuit decay degree, or the maximum power voltage decay degree, determining the failure type of potential induced decay as PID-s.

[0117] Optionally, the size of the filling factor attenuation degree and the volt-ampere attenuation degree can be determined by comparing the size of the filling factor attenuation rate and the volt-ampere attenuation rate. Exemplarily, when the difference between the absolute value of the filling factor attenuation rate and the absolute value of the volt-ampere attenuation rate is greater than or equal to the first threshold, it is determined that the filling factor attenuation degree is less than the volt-ampere attenuation degree. The filling factor attenuation rate is the ratio of the filling factor difference to the first filling factor, and the filling factor difference is the difference between the second filling factor after the PID test and the first filling factor before the PID test, such as the filling factor difference = the second filling factor-the first filling factor. The volt-ampere attenuation rate is the ratio of the volt-ampere parameter difference to the first volt-ampere parameter, and the volt-ampere parameter difference is the difference between the second volt-ampere parameter after the PID test and the first volt-ampere parameter before the PID test. Take the volt-ampere parameter as the open circuit voltage as an example for explanation. The open circuit voltage attenuation rate is the difference between the second open circuit voltage and the first open circuit voltage, and the ratio to the first open circuit voltage. Among them, the first threshold can be set according to the actual situation, for example, it can be 1%. It should be noted that when the volt-ampere parameters are different, the corresponding first thresholds may also be different.

[0118] The open circuit voltage, short circuit current, maximum power voltage, maximum power current and fill factor of the PV module will decrease before the PID failure relative to after the failure.

[0119] Table 1 is a comparison table of test results of open circuit voltage, short circuit current, maximum power voltage, maximum power current and fill factor of multiple photovoltaic modules before and after PID failure.

[0120]

[0121] Based on the test data recorded in Table 1, it can be seen that after the PID test, the attenuation rate of the fill factor FF of Sample 1 and Sample 2 is significantly greater than the open circuit voltage Voc and the short circuit voltage Isc. Therefore, it can be determined that the PID failure type of the two samples is PID-s failure.

[0122] In an exemplary embodiment, when the fill factor attenuation is less than the volt-ampere attenuation, the step of determining the failure type of potential induced degradation as PID-p. Exemplarily, when the fill factor attenuation is less than the open circuit voltage attenuation, the short circuit attenuation or the maximum power voltage attenuation, the failure type of potential induced degradation is determined to be PID-p.

[0123] Optionally, when the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than or equal to the second threshold, it is determined that the fill factor attenuation degree is less than the volt-ampere attenuation degree. Exemplarily, when the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than or equal to the second threshold, it is determined that the fill factor attenuation degree is less than the volt-ampere attenuation degree. The second threshold can be set according to actual conditions, for example, the second threshold can be -0.5%. It should be noted that when the volt-ampere parameters are different, the corresponding second thresholds may also be different.

[0124] Table 2 is a comparison table of the test results of open circuit voltage, short circuit current, maximum power voltage, maximum power current and fill factor of multiple photovoltaic modules before and after PID failure.

[0125]

[0126] Based on the test data recorded in Table 2, it can be known that after the PID test, the attenuation rate of the fill factor FF of Sample 3 and Sample 4 is significantly smaller than the open circuit voltage Voc and the short circuit voltage Isc. Therefore, it can be determined that the PID failure type of the two samples is PID-p failure.

[0127] Based on any of the above embodiments, in an exemplary embodiment, the method for detecting potential induced degradation of a photovoltaic module may further include a step of verifying (or rechecking) the failure type determined in step 104. The method for verifying or rechecking the failure type may include at least one of the following:

[0128] First, an image method for identifying the electroluminescence (EL) imaging image of the photovoltaic module after the PID test;

[0129] Second, the illumination method of conducting illumination test on the photovoltaic modules after PID test;

[0130] Third, for PV modules with failure type PID-p, a multiple PID test method is used in which the PV modules after PID test are subjected to PID test again.

[0131] The following describes the above three methods for verifying or reviewing failure types in combination with relevant drawings and test data.

[0132] In an exemplary embodiment, the method for verifying or rechecking the failure type may be an image method. The image method in this embodiment may be applied to the photovoltaic module to be tested after the PID test. Figure 5 As shown, the potential induced degradation detection method of a photovoltaic module includes steps 502 to 510.

[0133] Step 502, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test.

[0134] Step 504: determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree.

[0135] Step 506, obtaining a second electroluminescent imaging image after the PID test of the photovoltaic module to be tested.

[0136] The second electroluminescent imaging image is an electroluminescent imaging image after the photovoltaic module to be tested completes the PID test.

[0137] Step 508: Identify whether the second electroluminescent imaging image has defect features corresponding to the failure type.

[0138] A first defect feature corresponding to the PID-s failure type and a second defect feature corresponding to the PID-p failure type are preset and stored, wherein the first defect feature is different from the second defect feature.

[0139] Exemplarily, the first defect feature may be a rounded rectangular pattern located at the edge of the cell, such as a "runway type". Optionally, the first defect feature may also be a black area on the peripheral edge of the photovoltaic module, such as the blackening of the peripheral edge area of ​​the photovoltaic module. It should be noted that the photovoltaic module includes a plurality of cells arranged in an array. The second defect feature may be that the first electroluminescent imaging image includes a plurality of cells with different grayscale values, such as the first electroluminescent imaging image includes obvious light and dark cells. Optionally, the second defect feature may also be that the average grayscale value of the first electroluminescent imaging image is less than the preset average grayscale value, such as the first electroluminescent imaging image is overall darker than the electroluminescent imaging image before the PID test. The preset average grayscale value is the average grayscale value of the electroluminescent imaging image of the photovoltaic module before the PID test. The average grayscale value can be obtained by calculating the average grayscale value of all pixels in the electroluminescent imaging image, wherein the average grayscale value ranges from 0 to 255, where 0 represents black and 255 represents white.

[0140] It can be identified by image recognition whether the second electroluminescent imaging image has the first defect feature or the second defect feature.

[0141] Step 510 , in the case where there are defect features corresponding to the failure type, verify that the failure type is accurate.

[0142] When the second electroluminescent imaging image has a failure type corresponding to the failure type in step 504 , it is also verified that the failure type determined in step 504 is accurate.

[0143] Further, when the failure type is PID-s and the electroluminescent imaging image has the first defect feature, it is determined that the failure type is PID-s accurately.

[0144] Exemplary, among which Figure 6a This is the EL imaging image of sample 1 before PID test. Figure 6b This is the EL imaging image of sample 1 after the PID test. After the PID test, on the one hand, as shown in the test data of sample 1 in Table 1, the decay rate of the fill factor FF after the PID test is significantly greater than the decay rates of the open circuit voltage Voc, the short circuit current Isc, and the maximum power voltage Vmp. Therefore, it can be determined that the failure type of PID is PID-s failure. On the other hand, the EL imaging image of the photovoltaic module has the first defect, such as the "runway-type" pattern on the cell of sample 1, so it can be verified that its failure type is also PID-s failure.

[0145] Exemplary, where Figure 7a This is the EL imaging image of sample 2 before PID test. Figure 7b This is the EL imaging image of sample 2 after the PID test. After the PID test, on the one hand, as shown in the test data of sample 2 in Table 1, the decay rate of the fill factor FF after the PID test is significantly greater than the decay rate of the open circuit voltage Voc, the short circuit current Isc, and the maximum power voltage Vmp. Therefore, it can be judged that the failure type of PID is PID-s failure. On the other hand, the EL imaging image of the photovoltaic module has the first defect feature, such as the presence of a black area near the peripheral edge of the photovoltaic module in sample 2, that is, the peripheral edge of the photovoltaic module is black, so it can be verified that its failure type is also PID-s failure.

[0146] Optionally, when the failure type is PID-p and the electroluminescent imaging image has a second defect feature, it is determined that the failure type is PID-p accurately.

[0147] in Figure 8a This is the EL imaging image of sample 3 before PID test. Figure 8b This is the EL imaging image of sample 3 after the PID test. After the PID test, on the one hand, as shown in the test data of sample 3 in Table 2, the decay rate of the fill factor FF after the PID test is significantly smaller than the decay rate of the open circuit voltage Voc, the short circuit current Isc, and the maximum power voltage Vmp. Therefore, it can be judged that the failure type of PID is PID-p failure. On the other hand, the EL imaging image of the photovoltaic module has a second defect feature, such as Figure 8b The average gray value is less than Figure 8a That is, the EL imaging image of sample three becomes darker as a whole after the PID test, so it can be verified that its failure type is also PID-p failure.

[0148] in Figure 9a This is the EL imaging image of sample 4 before the PID test. Figure 9b This is the EL imaging image of sample 4 after the PID test. After the PID test, on the one hand, as shown in the test data of sample 4 in Table 2, the decay rate of the fill factor FF after the PID test is significantly smaller than the decay rate of the open circuit voltage Voc, the short circuit current Isc, and the maximum power voltage Vmp. Therefore, it can be judged that the failure type of PID is PID-p failure. On the other hand, the EL imaging image of the photovoltaic module has a second defect feature, such as Figure 9b It includes multiple battery cells with different grayscale values, that is, sample 4 shows relatively obvious light and dark cells after the PID test, so it can be verified that its failure type is also PID-p failure.

[0149] The potential induced degradation detection method for photovoltaic modules provided in this embodiment can also determine or verify the failure type of PID based on the EL imaging image after the PID test, which can further improve the accuracy of the failure type.

[0150] In an exemplary embodiment, the imaging method can not only be used to verify whether the failure type of its PID-p and PID-s is accurate, but also can be used to determine the failure type of its PID-c. Among them, the potential induced degradation detection method of photovoltaic modules can also include: obtaining a second electroluminescent imaging image after the PID test of the photovoltaic module to be tested, and in the case that there are corrosion features in the second electroluminescent imaging image, determining that the failure type is corrosion-type PID (PID-c for short). Among them, PID-c is mainly caused by the entry of water vapor and the electrochemical reaction of the metal contact part in the water vapor. At the same time, after the water vapor enters the photovoltaic module, EVA hydrolysis will generate acetic acid, which will corrode the grid line on the surface of the battery cell, causing the series resistance to increase and the performance to decay.

[0151] The corrosion features in the second electroluminescent imaging image include but are not limited to at least one of the following: the gate lines on the cell have burr features, the thickness of the same gate line is uneven, the grayscale values ​​of the same gate line are different, the thickness of different gate lines is uneven, and the average grayscale values ​​of different gate lines are different.

[0152] in Fig.10a This is the EL imaging image of sample 5 before the PID test. Fig.10b This is the EL imaging image of sample 5 after the PID test; Fig.11a This is the EL imaging image of sample 6 before the PID test. Fig.11b This is the EL imaging image of sample 6 after the PID test. Figure 10a-11bIt can be seen that after the PID test, obvious corrosion can be seen on the surface of the battery cells of Samples 5 and 6, and it can be confirmed that the failure type of PID is PID-c failure.

[0153] In this embodiment, by acquiring the second electroluminescent imaging image of the photovoltaic component to be tested after the PID test and analyzing whether there are corrosion features in the second electroluminescent imaging image, it is possible to determine whether the PID failure is a PID-c failure, thereby improving the accuracy of the judgment of PID-c failure.

[0154] In an exemplary embodiment, the method for verifying or checking the failure type may be a light test method. Fig.12 As shown, the potential induced degradation detection method of a photovoltaic module includes steps 1202 to 1208.

[0155] Step 1202, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test.

[0156] Step 1204: determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree.

[0157] Step 1206, obtaining verification parameters of the photovoltaic group to be tested after the PID test.

[0158] After determining the failure type of potential induced decay in the above steps, the verification parameters of the photovoltaic group to be tested after the PID test can be obtained accordingly. The verification parameters include the first maximum power of the photovoltaic group to be tested after the illumination test. Exemplarily, the test conditions of the illumination test include but are not limited to outdoor illumination or indoor environmental chamber illumination, and the cumulative irradiance is not less than 5kwh / m 2 For example, the irradiation can be 5kwh / m 2 、10kwh / m 2 or 15kwh / m 2 . In the embodiments of the present application, it should be noted that the irradiance of the illumination test can be set according to the failure type of potential induced decay. In the process of performing illumination tests on photovoltaic modules, the direction in which the light is incident on the photovoltaic module can be determined according to the type of photovoltaic module. Among them, the incident direction can be the light-receiving surface or the backlight surface of the photovoltaic module, and the types of photovoltaic modules may include N-type, P-type, single-glass type and double-glass type. For example, for a double-glass photovoltaic module, the light can be incident on the back of the photovoltaic module, for example, the backlight surface.

[0159] Step 1208: Check whether the failure type is accurate based on the first maximum power and the second maximum power.

[0160] The second maximum power is the maximum power of the photovoltaic module to be tested after the PID test and before the illumination test. For example, for a photovoltaic module with a failure type of PID-s, its maximum power can recover slightly after the illumination test, while for a photovoltaic module with a failure type of PID-p, its maximum power can recover significantly after the illumination test. In this way, by comparing the first maximum power and the second maximum power, the failure type obtained in the above steps can be verified or reviewed.

[0161] In an embodiment of the present application, after determining the PID failure type, the accuracy of the PID failure type can be verified or reviewed based on the first maximum power after the lighting test and the second maximum power before the lighting test, thereby further improving the accuracy of the failure type.

[0162] Optionally, in an exemplary embodiment, when the fill factor attenuation degree is equal to the volt-ampere attenuation degree, the aforementioned steps 1206 to 1208 may be performed.

[0163] Among them, the fill factor attenuation degree is equal to the volt-ampere attenuation degree, which can be understood as there is no obvious relative difference between the fill factor attenuation degree and the volt-ampere attenuation degree, for example, the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than the first threshold and greater than the second threshold. In this case, it can be explained that there is no obvious relative difference between the attenuation rate of the open circuit voltage Voc, the short circuit current Isc and the fill factor FF of the photovoltaic module after the PID test. In this way, its failure type may be PID-p or PID-s, and then steps 1206-1208 can be executed, and the PID failure type can be determined according to the first maximum power after the illumination test and the second maximum power before the illumination test.

[0164] The potential induced degradation detection method for photovoltaic modules provided in this embodiment can determine the PID failure type according to the first maximum power after the illumination test and the second maximum power before the illumination test after the PID test. This method can be used to determine or verify the failure type of the PID, and can improve the accuracy of the failure type.

[0165] In an exemplary embodiment, determining the PID failure type according to the first maximum power after the illumination test and the second maximum power before the illumination test may specifically include: when the difference between the first maximum power and the second maximum power parameters is greater than or equal to the third threshold, determining or verifying that the failure type is PID-p. Optionally, when the difference between the first maximum power and the second maximum power is less than or equal to the fourth threshold, determining or verifying that the failure type is PID-p. The third threshold is greater than the fourth threshold. The third threshold and the second threshold can be set based on actual needs, for example, the third threshold can be 50, the fourth threshold can be 5, etc.

[0166] Table 3 is a comparison table of the test results of open circuit voltage, short circuit current, maximum power voltage, maximum power current, fill factor and maximum power of multiple photovoltaic modules before and after PID failure and before and after illumination test.

[0167]

[0168] As shown in Table 3, after the PID test, there is no obvious relative difference between the open circuit voltage Voc, short circuit current Isc and the attenuation rate of the fill factor FF of the PV module. However, after the illumination test, its first maximum power significantly increases relative to the second maximum power. Therefore, it can be judged that the failure type of PID is PID-p failure.

[0169] Table 4 is a comparison table of the test results of open circuit voltage, short circuit current, maximum power voltage, maximum power current, fill factor and maximum power of multiple photovoltaic modules before and after PID failure and before and after illumination test.

[0170]

[0171] As shown in Table 4, the attenuation rate of the fill factor FF of the photovoltaic module after the PID test is larger than that of the open circuit voltage Voc and the short circuit current Isc. It can be determined that the failure type of PID is PID-s failure. Moreover, after the illumination test, the recovery ratio of the first maximum power relative to the second maximum power is small. Therefore, it can be further determined that the failure type of PID is PID-s failure.

[0172] In an exemplary embodiment, when the failure type is PID-p, the illumination intensity of the illumination test may be at least 15 kwh / m 2 For example, if the cumulative irradiance of a single lighting test is 5 kwh / m 2 , when the failure type is PID-p, the number of illumination tests can be at least 3 times. For example, after the PID test, the maximum power attenuation rate of the front side of the photovoltaic module is -3.40%, and the maximum power attenuation rate of the back side is -11.59%. After the first illumination test, the maximum power continues to decay (front attenuation rate -5.70%, back attenuation rate -47.60%), and the maximum power rises after the second illumination test (front attenuation rate -3.2%, back attenuation rate -17.32%). After the third illumination test, the maximum power continues to rise (front attenuation rate -2.45%, back attenuation rate -6.77%). This special failure is also a manifestation of PID-p failure.

[0173] In an exemplary embodiment, the method for verifying or rechecking the failure type may be an image method, wherein the image method in this embodiment may be applied to the photovoltaic module to be tested after the illumination test. Fig.13 As shown, the potential induced degradation detection method of a photovoltaic module includes steps 1302 to 1310.

[0174] Step 1302, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test.

[0175] Step 1304: determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree.

[0176] Step 1306, obtaining a first electroluminescent imaging image after the PID test of the photovoltaic module to be tested.

[0177] The first electroluminescent imaging image is an electroluminescent imaging image after the photovoltaic module completes a PID test and an illumination test.

[0178] Step 1308 : When the failure type is PID-p and the first electroluminescent imaging image does not have defect features, determine that the failure type of PID-p is accurate.

[0179] Step 1310: When the failure type is PID-s and the second electroluminescent imaging image has defect features corresponding to PID-s, determine that the failure type of PID-s is accurate.

[0180] Any of the following methods may be used to determine whether the first electroluminescent imaging image has defect features corresponding to the PID-p failure type or the corresponding PID-s failure type.

[0181] Method 1: Performing pattern recognition processing on the first electroluminescent imaging image to identify whether the first defect feature or the second defect feature exists. The identification method can be referred to the above description and will not be described in detail here.

[0182] Method 2: Compare the first electroluminescent imaging image and the third electroluminescent imaging image to determine whether the first defect feature or the second defect feature exists. The third electroluminescent imaging image is an electroluminescent imaging image of the photovoltaic module to be tested before the PID test.

[0183] If the first electroluminescent imaging image and the third electroluminescent imaging image are similar, it is determined that the first electroluminescent imaging image does not have the first defect feature or the second defect feature. Wherein, similarity can be understood as the grayscale distribution of the first electroluminescent imaging image and the third electroluminescent imaging image being the same or substantially the same.

[0184] If the grayscale distributions of the first electroluminescent imaging image and the third electroluminescent imaging image are different, it is determined that the first electroluminescent imaging image has the first defect feature or the second defect feature.

[0185] The potential induced degradation detection method of the photovoltaic module provided in this embodiment can also verify the PID failure type according to the EL image after the PID test and the illumination test, which can further improve the accuracy of the failure type.

[0186] In an exemplary embodiment, the image method and the illumination method can be used simultaneously to verify the failure type. While verifying whether the failure type is accurate based on the first maximum power and the second maximum power, the first electroluminescent imaging image of the photovoltaic module to be tested after the PID test can also be synchronously obtained to verify whether the failure type is accurate. For example, while determining that its failure type is PID-p based on the illumination method, the electroluminescent images of the photovoltaic module to be tested at different test stages can also be obtained.

[0187] Fig.14a This is the EL imaging image of sample 7 before the PID test. Fig.14b This is the EL imaging image of sample 7 after the PID test. Fig.14c This is the EL imaging image of sample 7 after the illumination test. After the illumination test, as shown in Table 3, the first maximum power has significantly increased relative to the second maximum power, so it can be judged that the failure type of PID is PID-p failure. On the other hand, the EL imaging image of the photovoltaic module can also be seen to have obvious recovery, so it can also be judged that its failure type is also PID-p failure.

[0188] in Fig.15a This is the EL imaging image of sample 10 before the PID test. Fig.15b This is the EL imaging image of sample 10 after the PID test. Fig.15c The EL imaging image of sample 10 after the illumination test. After the illumination test is restored, on the one hand, as shown in Table 4, the ratio of the first maximum power to the second maximum power is small, so it can be further judged that the failure type of PID is PID-s failure. On the other hand, the EL imaging image of the photovoltaic module has not been restored, so it can also be judged that its failure type is also PID-s failure.

[0189] In an exemplary embodiment, an image method may also be used to verify whether the failure type is PID-c accurately. Specifically, the potential induced degradation detection method of a photovoltaic module may also include the steps of obtaining a second electroluminescent imaging image of the photovoltaic module to be tested after the illumination test; and determining whether the failure type of the corrosion type is accurate when there are corrosion features in the second electroluminescent imaging image.

[0190] in Fig.16a This is the EL imaging image of sample 11 before the PID test. Fig.16b This is the EL imaging image of sample 11 after the PID test. Fig.16c EL imaging image of sample 11 after the illumination test. Fig.16b As shown in Figure 1, the photovoltaic module has obvious corrosion characteristics from the EL imaging image after the PID test, which can be judged as the PID failure type of PID-c, and as Fig.16c As shown in the figure, this corrosion feature cannot be restored after restoration after illumination, so it can also be verified that its failure type is also PID-c failure.

[0191] In an exemplary embodiment, the method for verifying or rechecking the failure type may be a multiple PID test method. The image method in this embodiment may be applied to the photovoltaic module to be tested after two PID tests. Fig.17 As shown, the potential induced degradation detection method of a photovoltaic module includes steps 1702 to 1708.

[0192] Step 1702, obtaining the attenuation degree of the electrical parameters of the photovoltaic module to be tested after the PID test relative to before the PID test.

[0193] Step 1704: determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree.

[0194] Step 1706, when the failure type is polarization type (PID-p), respectively obtain the third maximum power and the fourth maximum power of the photovoltaic component to be tested, wherein the third maximum power is the maximum power of the photovoltaic component to be tested after the first PID test, and the fourth maximum power is the maximum power of the photovoltaic component to be tested after the second PID test, and the loading voltages of the first PID test and the second PID test are opposite.

[0195] In the embodiment of the present application, the bias voltages loaded in the first PID test and the second PID test are different and opposite. Exemplarily, the bias voltage loaded in the first PID test may be -1500V, and the bias voltage loaded in the second PID test may be +1500V, and the other test conditions of the two PID tests are the same. It should be noted that the first PID test is used to determine the PID failure type, and the second PID test is used to verify whether its PID failure type (for example, PID-p) is accurate.

[0196] Step 1708: When the difference between the fourth maximum power and the third maximum power is greater than a preset power threshold, determine that the failure type is PID-p accurate.

[0197] The preset power threshold can be set according to the PID test conditions, for example, it can be 10. In the present application test, the preset power threshold is not specifically limited. After the forward PID test is performed on the photovoltaic module with PID-p failure, its maximum power will rise significantly. Therefore, by comparing the third maximum power and the fourth maximum power, it can be determined whether the failure type is PID-p.

[0198] Table 5 is a comparison table of the test results of open circuit voltage, short circuit current, maximum power voltage, maximum power current, fill factor and maximum power of multiple photovoltaic modules before and after two PID tests.

[0199]

[0200] As shown in Table 5, after the first PID test, the attenuation rate of the open-circuit voltage Voc and the short-circuit current Isc of the PV module is larger than that of the fill factor FF. It can be judged that the failure type of PID is PID-p failure. After the forward PID test (the second PID test), the maximum power also rebounds significantly. Therefore, it can be verified that the PID failure type is still PID-p failure.

[0201] The potential induced degradation detection method for photovoltaic modules provided in this embodiment can determine that the failure type of PID is PID-p failure after the first PID test. In addition, a second PID test can be performed on the photovoltaic module after the first PID test to verify the accuracy of the PID-p failure based on the maximum power recovery amount, which can further improve the accuracy of the failure type.

[0202] In an exemplary embodiment, Fig.18 As shown, the potential induced degradation detection method of a photovoltaic module may include the following steps:

[0203] Step 1, providing a photovoltaic module to be tested with a PID failure, for example, a P-type or N-type photovoltaic module;

[0204] Step 2, obtaining an EL imaging image of the photovoltaic module to be tested after the PID test, and if there is no corrosion feature in the EL imaging image, executing step 3; if there is a corrosion feature in the EL imaging image, determining that the PID failure type is PID-c;

[0205] Step 3, obtaining the attenuation rate of the electrical performance parameters before and after the PID test;

[0206] Step 4: If the FF attenuation rate is larger than the Voc or Isc attenuation rate, the PID failure type is determined to be PID-s; or, if the Voc or Isc attenuation rate is larger than the FF attenuation rate, the PID failure type is determined to be PID-p; or, if there is no significant difference in the FF, Voc and Isc attenuation rates, proceed to step 5;

[0207] Step 5, observe the EL imaging image of step 2 again (or, the step of verifying the failure type by imaging method);

[0208] Step six, if the EL imaging image has a "runway-type" image or the edge of the photovoltaic module is black, the PID failure type is determined to be PID-s; or, if the EL imaging image becomes dark as a whole or there are serious light and dark patches, the PID failure type is determined to be PID-p.

[0209] Step 7, performing an illumination test or a forward PID test (for PID-p) on the component after the PID test, and obtaining an EL imaging image of the illumination test;

[0210] Step 8: The maximum power recovery ratio after the illumination test is small and the EL imaging image is not restored, and the PID failure type is verified to be PID-s; or,

[0211] If the maximum power after the illumination test is restored (or the maximum power attenuation ratio is obvious) and the EL imaging image after the illumination test is obviously restored (or the light and dark patches in the EL imaging image after the illumination test are more serious), the PID failure type is verified to be PID-p; or,

[0212] The corrosion features in the EL imaging image after the illumination test could not be restored, and the PID failure type was verified to be PID-c.

[0213] The potential induced degradation detection method for photovoltaic modules provided in this embodiment can accurately determine the type of module PID failure through test results in the PID reliability test, and can verify the failure type in a variety of ways, thereby improving the accuracy of failure type detection, and thus enabling technical personnel to make improvement methods in advance from the source according to the specific type of PID failure, grasp the direction of improvement, and thereby reduce or avoid reliability risks at the downstream end of the power station, and reduce and minimize losses.

[0214] Based on the same inventive concept, the embodiment of the present application also provides a potential-induced decay detection device for photovoltaic modules for implementing the potential-induced decay detection method for photovoltaic modules involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the potential-induced decay detection device for one or more photovoltaic modules provided below can refer to the limitations of the potential-induced decay detection method for photovoltaic modules above, and will not be repeated here.

[0215] In an exemplary embodiment, Fig.19 As shown, a potential induced degradation detection device for a photovoltaic module is provided, comprising: an acquisition module 1910 and a determination module 1920, wherein:

[0216] The acquisition module 1910 is used to obtain the attenuation degree of the electrical parameters after the PID test of the photovoltaic module to be tested relative to that before the PID test; wherein the attenuation degree of the electrical parameters includes the attenuation degree of the fill factor and the attenuation degree of the volt-ampere, and the attenuation degree of the volt-ampere includes one of the attenuation degree of the open circuit voltage, the attenuation degree of the short circuit current and the attenuation degree of the maximum power voltage;

[0217] The determination module 1920 is used to determine the failure type of potential induced degradation according to the fill factor degradation degree and the volt-ampere degradation degree; wherein the failure types include shunt type and polarization type.

[0218] The potential induced decay detection device for photovoltaic modules provided in the embodiment of the present application can obtain the degree of attenuation of electrical parameters of the photovoltaic module after the PID test relative to that before the PID test, and then determine the failure type of potential induced decay according to the fill factor attenuation degree and the volt-ampere attenuation degree, such as shunt-type potential induced decay and polarization-type potential induced decay. In this way, in the PID reliability test, the failure type of photovoltaic module PID failure can be accurately determined through the test results, and the detection method is simple and efficient. In addition, based on the failure type, technicians can more accurately grasp the direction of improvement of photovoltaic modules, avoid or reduce the reliability risk of PID in the modules during the actual operation of the power station from the source, and reduce and minimize the risks and losses caused by PID failure.

[0219] Each module in the above-mentioned photovoltaic module potential induced degradation detection device can be implemented in whole or in part by software, hardware and their combination. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0220] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Fig. 20As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store PID test and illumination test data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a potential induced degradation detection method for a photovoltaic component is implemented.

[0221] Those skilled in the art will understand that Fig. 20 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0222] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the method for detecting potential induced degradation of a photovoltaic module in any of the aforementioned embodiments is implemented.

[0223] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method for detecting potential induced degradation of a photovoltaic module in any of the aforementioned embodiments is implemented.

[0224] In one embodiment, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the method for detecting potential induced degradation of a photovoltaic module in any of the aforementioned embodiments is implemented.

[0225] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0226] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0227] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for detecting potential induced degradation of a photovoltaic module, characterized in that: The method comprises: Respectively obtaining a first electrical parameter of the photovoltaic assembly to be tested before the PID test and a second electrical parameter of the photovoltaic assembly to be tested after the PID test; Determine the fill factor attenuation degree and the volt-ampere attenuation degree according to the first electrical parameter and the second electrical parameter, respectively; wherein the first electrical parameter and the second electrical parameter both include an open circuit voltage, a short circuit current, a maximum power voltage, and a maximum power current, and the fill factor is related to the open circuit voltage, the short circuit current, the maximum power voltage, and the maximum power current; the volt-ampere attenuation degree includes an open circuit voltage attenuation degree or a short circuit current attenuation degree; In a case where the fill factor attenuation degree is greater than the volt-ampere attenuation degree, determining that the failure type of the potential induced decay is a shunt type; In the case where the fill factor attenuation degree is less than the volt-ampere attenuation degree, the failure type of the potential-induced attenuation is determined to be a polarization type; wherein, When the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is greater than or equal to a first threshold, the fill factor attenuation degree is greater than the volt-ampere attenuation degree; When the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than or equal to the second threshold, the fill factor attenuation degree is less than the volt-ampere attenuation degree; Among them, the filling factor decay rate is the ratio of the filling factor difference to the first filling factor, and the filling factor difference is the difference between the second filling factor after the PID test and the first filling factor before the PID test; the volt-ampere decay rate is the ratio of the volt-ampere parameter difference to the first volt-ampere parameter, and the volt-ampere parameter difference is the difference between the second volt-ampere parameter after the PID test and the first volt-ampere parameter before the PID test, and the first threshold is greater than the second threshold.

2. The method according to claim 1, characterized in that The method further comprises: Acquire verification parameters of the photovoltaic group to be tested after the PID test; wherein the verification parameters include the first maximum power after the photovoltaic group to be tested is subjected to a lighting test; Check whether the failure type is accurate based on the first maximum power and the second maximum power; wherein the second maximum power is the maximum power of the photovoltaic component to be tested after the PID test and before the illumination test.

3. The method according to claim 1, characterized in that: The method further comprises: When the fill factor attenuation degree is equal to the volt-ampere attenuation degree, obtaining the verification parameters of the photovoltaic group to be tested after the PID test; wherein the verification parameters include the first maximum power after the illumination test of the photovoltaic group to be tested; The failure type is determined according to the first maximum power and the second maximum power; wherein the second maximum power is the maximum power of the photovoltaic component to be tested after the PID test and before the illumination test.

4. The method according to claim 2 or 3, characterized in that: In a case where the difference between the first maximum power and the second maximum power parameters is greater than or equal to a third threshold, determining that the failure type is a polarization type; or, When the difference between the first maximum power and the second maximum power is less than or equal to a fourth threshold, the failure type is determined to be a shunt type; wherein the third threshold is greater than the fourth threshold.

5. The method according to claim 1 or 2, characterized in that: The method further comprises: Acquire a first electroluminescent imaging image of the photovoltaic assembly to be tested after a PID test and an illumination test; In the case where the failure type is polarization type and the first electroluminescent imaging image does not have defect features, determining that the polarization type failure type is accurate; or, In the case that the failure type is a shunt type and the first electroluminescent imaging image has defect features corresponding to the shunt type, it is determined that the failure type of the shunt type is accurate.

6. The method according to claim 1 or 2, characterized in that: The method further comprises: Acquire a second electroluminescent imaging image of the photovoltaic module to be tested after the PID test; In the case where the failure type is a polarization type and the defect degree of the defect feature in the second electroluminescent imaging image is higher than the defect degree of the defect feature in the first electroluminescent imaging image, determining that the failure type is a polarization type is accurate.

7. The method according to claim 1, characterized in that The method further comprises: In the case where the failure type is a polarization type, a third maximum power and a fourth maximum power of the photovoltaic assembly to be tested are respectively obtained, wherein the third maximum power is the maximum power of the photovoltaic assembly to be tested after the first PID test, and the fourth maximum power is the maximum power of the photovoltaic assembly to be tested after the second PID test, and the loading voltages of the first PID test and the second PID test are opposite; When the difference between the fourth maximum power and the third maximum power is greater than a preset power threshold, it is determined that the failure type is polarization-type accurate.

8. The method according to claim 1, characterized in that The method further comprises: Acquire a second electroluminescent imaging image after the photovoltaic assembly to be tested PID test; Identify whether the second electroluminescent imaging image has a defect feature corresponding to the failure type; In the case where the defect feature corresponding to the failure type exists, verifying that the failure type is accurate.

9. The method according to claim 8, characterized in that In the case where the defect feature corresponding to the failure type exists, determining that the detection of the failure type is accurate includes: In the case where the failure type is a shunt type and the electroluminescent imaging image has a first defect feature, determining that the failure type is a shunt type is accurate; In the case where the failure type is a polarization type and the electroluminescent imaging image has a second defect feature, it is accurate to determine that the failure type is a polarization type; wherein the first defect feature is different from the second defect feature.

10. The method according to claim 1, characterized in that The method further comprises: Acquire a second electroluminescent imaging image after the photovoltaic assembly to be tested PID test; In the case where corrosion features exist in the second electroluminescent imaging image, the failure type is determined to be corrosion type.

11. The method according to claim 10, characterized in that The method further comprises: Acquiring a second electroluminescent imaging image of the photovoltaic assembly to be tested after the illumination test; In the case where corrosion features exist in the second electroluminescent imaging image, it is determined that the corrosion-type failure type is accurate.

12. A potential induced degradation detection device for a photovoltaic module, characterized in that: The device comprises: An acquisition module, used to respectively acquire a first electrical parameter of a photovoltaic assembly to be tested before a PID test, and a second electrical parameter of the photovoltaic assembly to be tested after the PID test; determine a fill factor attenuation degree and a volt-ampere attenuation degree according to the first electrical parameter and the second electrical parameter; wherein the first electrical parameter and the second electrical parameter both include an open circuit voltage, a short circuit current, a maximum power voltage, and a maximum power current, the fill factor is related to the open circuit voltage, the short circuit current, the maximum power voltage, and the maximum power current, and the volt-ampere attenuation degree includes one of an open circuit voltage attenuation degree, a short circuit current attenuation degree, and a maximum power voltage attenuation degree; A determination module is used to determine that the failure type of the potential-induced decay is a shunt type when the fill factor decay degree is greater than the volt-ampere decay degree; and to determine that the failure type of the potential-induced decay is a polarization type when the fill factor decay degree is less than the volt-ampere decay degree; wherein, When the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is greater than or equal to a first threshold, the fill factor attenuation degree is greater than the volt-ampere attenuation degree; When the difference between the absolute value of the fill factor attenuation rate and the absolute value of the volt-ampere attenuation rate is less than or equal to the second threshold, the fill factor attenuation degree is less than the volt-ampere attenuation degree; Among them, the filling factor decay rate is the ratio of the filling factor difference to the first filling factor, and the filling factor difference is the difference between the second filling factor after the PID test and the first filling factor before the PID test; the volt-ampere decay rate is the ratio of the volt-ampere parameter difference to the first volt-ampere parameter, and the volt-ampere parameter difference is the difference between the second volt-ampere parameter after the PID test and the first volt-ampere parameter before the PID test, and the first threshold is greater than the second threshold.

13. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 11 are implemented.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 11 are implemented.

15. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 11 are implemented.

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