A dynamic mechanical load synergic test method for photovoltaic modules in a temperature and humidity environment

Abstract

The application discloses a kind of photovoltaic module dynamic mechanical load synergic test methods under temperature and humidity environment, it is related to photovoltaic module reliability test technical field, including obtaining photovoltaic module structure parameter and service environment parameter, division test area and generation temperature and humidity cycle sequence, control temperature and humidity environment box and construct dynamic temperature and humidity test environment;According to temperature and humidity cycle stage generation dynamic mechanical load sequence, and according to the structure position of test area adjustment load amplitude, form regional dynamic mechanical load;Collect load response data, deformation response data and electrical performance response data, construct temperature and humidity-load synergic response data, extract different area fatigue response characteristics, calculate dynamic damage evaluation parameter, determine the test result of photovoltaic module under the joint action of temperature and humidity environment and dynamic mechanical load.The application can improve the accuracy of photovoltaic module reliability evaluation under complex service environment.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module reliability testing technology, and in particular to a method for dynamic mechanical load co-testing of photovoltaic modules under temperature and humidity conditions. Background Technology

[0002] With the rapid development of the new energy industry and the continuous advancement of large-scale photovoltaic power generation applications, photovoltaic modules, as the core energy conversion components in photovoltaic power generation systems, are receiving increasing attention for their long-term service reliability and environmental adaptability. In actual operation, photovoltaic modules are typically affected by multiple factors, including temperature changes, humidity corrosion, wind load, snow load, and stress on the installation structure. Temperature and humidity changes can cause aging of encapsulation materials, degradation of interface performance, and redistribution of internal stress within the module, while cyclic mechanical loads can further exacerbate failure processes such as solder strip fatigue, encapsulation layer cracking, and microcracks in the cells. Therefore, to accurately evaluate the reliability of photovoltaic modules under complex outdoor service conditions, existing technologies are gradually evolving from single mechanical load testing and static environment testing to comprehensive reliability testing under multi-factor coupled environments. Currently, photovoltaic module testing technology mainly focuses on mechanical load bearing capacity, electrical performance change monitoring, and environmental aging evaluation, analyzing the performance degradation patterns of modules by setting test conditions such as pressure, temperature, and humidity. However, existing testing methods typically employ single-factor or fixed-parameter loading conditions, lacking a dynamic correlation between temperature and humidity environments and mechanical loads. This makes it difficult to reflect the dynamic mechanical stress changes caused by diurnal temperature and humidity variations, seasonal cycles, and extreme weather during actual service. Furthermore, current testing methods often treat photovoltaic modules as a whole under uniform loading, failing to adequately consider localized stress concentrations in different regions of the module due to differences in structural location, boundary constraints, and material distribution. This results in inaccurate characterization of local fatigue damage evolution within the module. Therefore, constructing temperature and humidity conditions that match actual service environments and combining them with regionalized dynamic mechanical loads for coordinated testing to improve the accuracy of photovoltaic module reliability evaluation has become a pressing issue in the field of photovoltaic module testing.

[0003] CN102305741B discloses a dynamic / static load testing device and method for solar photovoltaic modules. The device includes a pressure chamber forming a sealed enclosure with the photovoltaic module. A pressure sensor is installed inside the pressure chamber. The pressure chamber is also connected via connection holes to a differential pressure sensor, and to a first and second air amplifier connected back-to-back in series. The first and second air amplifiers are connected to an air compressor via pipelines equipped with solenoid valves. The switching of the solenoid valves is controlled by a PLC controller, which also collects signals from the pressure sensor and the differential pressure sensor. This invention ingeniously utilizes the pressure load and load changes within the sealed enclosure formed by the solar photovoltaic module to detect the mechanical strength of the solar photovoltaic module, overcoming the current shortcomings of vague and unquantifiable mechanical strength testing. However, this method mainly tests the dynamic / static load capacity of the photovoltaic module's mechanical strength, simulating the mechanical load process through pressure changes. Its testing environment is primarily constructed around pressure load changes, without considering the impact of temperature and humidity changes on the module's material properties and structural stress during actual service, thus failing to establish a synergistic relationship between the temperature and humidity environment and the mechanical load. Meanwhile, this method uses an overall pressure loading approach, which makes it difficult to adjust the load distribution according to the structural characteristics of different regions of the component, and cannot effectively analyze the fatigue response characteristics and damage evolution process of local areas.

[0004] CN111327272B discloses a solar photovoltaic power supply monitoring system, including a monitoring host, a programmable logic controller (PLC), sensor components, and a monitoring power module. The monitoring host has a touch screen; the PLC is connected to an expansion module via a parallel bus; the sensor components include a photovoltaic voltage sensor, a battery pack voltage sensor, a load voltage sensor, a temperature sensor, and a current sensor; the sensor components transmit the signals they detect to the PLC or its expansion module; the monitoring host receives all signals through the PLC, processes them, and displays them on the touch screen. This application monitors parameters such as voltage, current, and temperature in a solar photovoltaic power generation system using a monitoring host and a PLC, and displays them on the touch screen. It can automatically and selectively activate the generator power supply based on the power generation of the photovoltaic panels, thereby ensuring the normal operation of the battery pack and the normal operation of the solar photovoltaic power generation system. However, this system is mainly used for monitoring the operating status of the photovoltaic power supply, judging the operating status of the photovoltaic system by collecting operating parameters such as voltage, current, and temperature. Its focus is on parameter monitoring and control during operation, and it does not involve the reliability testing process of photovoltaic modules under the combined action of temperature and humidity cycling environment and dynamic mechanical load. Meanwhile, this method lacks a comprehensive analysis mechanism for deformation response, fatigue response, and regional damage characteristics during the loading process, and cannot meet the requirements for evaluating the durability performance of photovoltaic modules under complex service environments. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section, as well as in the specification abstract and the title of the invention, to avoid obscuring the purpose of this section, the specification abstract, and the title of the invention. Such simplifications or omissions shall not be used to limit the scope of the invention.

[0006] In view of the problems that existing photovoltaic module reliability testing technologies have, such as the independent interaction between temperature and humidity environment and mechanical load process, insufficient dynamic coupling relationship, and difficulty in accurately characterizing local fatigue damage of modules, this invention is proposed.

[0007] Therefore, the problem to be solved by this invention is how to construct a test method that can simulate the combined effect of temperature and humidity cycling and dynamic mechanical load during the actual outdoor service of photovoltaic modules, and accurately evaluate the fatigue damage of the modules based on the structural response characteristics of different regions.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a method for dynamic mechanical load co-testing of photovoltaic modules under temperature and humidity conditions. The method includes: acquiring the module structure parameters and service environment parameters of the photovoltaic module to be tested; dividing the module test area according to the module structure parameters; generating a temperature and humidity cycle sequence according to the service environment parameters; and controlling the temperature and humidity environment chamber according to the temperature and humidity cycle sequence to place the photovoltaic module to be tested in a dynamically changing temperature and humidity environment. When the photovoltaic module under test is in a temperature and humidity environment, a dynamic mechanical load sequence is generated according to the environmental stage corresponding to the temperature and humidity cycle sequence, and the mechanical loading device is controlled to apply load to each test area according to the dynamic mechanical load sequence; wherein, the load amplitude of the corresponding area is adjusted according to the structural position of the test area to form a regionalized dynamic mechanical load that matches the temperature and humidity changes. During the application of regional dynamic mechanical loads, load response data, deformation response data, and electrical performance response data of the photovoltaic modules under test are collected to construct temperature and humidity-load co-response data, and fatigue response characteristics of different test areas of the modules are extracted based on the temperature and humidity-load co-response data. The dynamic damage evaluation parameters of the photovoltaic module under test are calculated based on the fatigue response characteristics, and the test results of the photovoltaic module under test under the combined action of temperature and humidity environment and dynamic mechanical load are determined based on the dynamic damage evaluation parameters.

[0009] Compared with existing technologies, the advantages of this invention are as follows: By acquiring the structural parameters and service environment parameters of the photovoltaic module under test, and dividing the module test area according to the structural parameters and generating a temperature and humidity cycle sequence according to the service environment parameters, a correspondence is established between the temperature and humidity changes during the test and the structural characteristics and climate change patterns in the actual installation environment of the module, providing an environmental basis for subsequent regional dynamic mechanical load application; by generating a dynamic mechanical load sequence according to the environmental stage corresponding to the temperature and humidity cycle sequence, and adjusting the load amplitude in combination with the structural position of different test areas, the frame area, junction box area, and cell area are subjected to dynamic mechanical loads that match their own structural characteristics, changing the traditional fixed load and overall loading that cannot reflect the differences in local fatigue damage. The current problem is to improve the matching degree between the mechanical load process and the actual service state; by collecting load response data, deformation response data, and electrical performance response data, temperature and humidity-load coordinated response data is constructed, and fatigue response characteristics are extracted from different test areas to characterize the response differences of different structural regions inside the module under the combined action of temperature and humidity changes and mechanical loads, which is used to analyze the correlation between microcrack propagation, structural deformation, and electrical performance degradation; furthermore, dynamic damage evaluation parameters are calculated based on fatigue response characteristics, and test results are determined based on dynamic damage evaluation parameters, so that the reliability evaluation of photovoltaic modules is transformed from a single mechanical strength judgment to a damage degree evaluation under the coupled action of temperature and humidity environment and dynamic mechanical load, thereby improving the ability of test results to characterize the long-term service reliability of modules. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of a method for coordinating dynamic mechanical load testing of photovoltaic modules under temperature and humidity conditions. Detailed Implementation

[0011] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0012] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort should fall within the scope of protection of this invention.

[0013] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0014] As mentioned in the background section, existing photovoltaic module testing methods typically test for single environmental factors or overall mechanical loads, making it difficult to reflect the coupling effect between material performance degradation caused by temperature and humidity changes and the accumulation of mechanical stress. Furthermore, they cannot effectively analyze the differentiated damage responses of different structural regions of the module under complex environments. To address these issues, this invention provides a method for the coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions.

[0015] Reference Figure 1 , Figure 1 This is a flowchart illustrating a method for coordinating dynamic mechanical load testing of photovoltaic modules under temperature and humidity conditions according to an embodiment of the present invention. Figure 1 As shown, a method for coordinating dynamic mechanical load testing of photovoltaic modules under temperature and humidity conditions includes: S1: Obtain the component structure parameters and service environment parameters of the photovoltaic module to be tested, divide the component test area according to the component structure parameters, and generate a temperature and humidity cycle sequence according to the service environment parameters; control the temperature and humidity environment chamber according to the temperature and humidity cycle sequence to keep the photovoltaic module to be tested in a dynamically changing temperature and humidity environment.

[0016] S1.1: Obtain the structural parameters of the photovoltaic module to be tested. The structural parameters include frame position parameters, cell arrangement parameters, junction box position parameters, and backsheet thickness parameters. The frame position parameters, cell arrangement parameters, junction box position parameters, and backsheet thickness parameters are obtained by manually measuring the physical dimensions of the photovoltaic module to be tested or by consulting the specification sheet of the photovoltaic module to be tested.

[0017] S1.2: Based on the preset installation area information of the photovoltaic module to be tested, retrieve the historical temperature data, historical humidity data, daily temperature difference data and seasonal humidity fluctuation data corresponding to the preset installation area through the preset climate database, use the historical temperature data, historical humidity data, daily temperature difference data and seasonal humidity fluctuation data as the service environment parameters of the photovoltaic module to be tested, and store the module structure parameters and service environment parameters in the test database.

[0018] Specifically, historical observation data from meteorological stations in multiple geographical locations around the world are acquired. The historical observation data includes daily maximum temperature, daily minimum temperature, daily average relative humidity, daily maximum relative humidity, and daily minimum relative humidity. The historical observation data is cleaned, and data from years with more than 5% missing values ​​are removed. The remaining missing values ​​are filled using linear interpolation. The cleaned data is archived and stored according to geographical location and year to construct the original climate database.

[0019] Furthermore, on an annual basis, the latest annual meteorological observation data is obtained from the National Meteorological Data Center or international climate monitoring organizations to incrementally update the original climate database.

[0020] Furthermore, the method for retrieving data from the preset climate database is as follows: Based on the longitude and latitude coordinates in the preset installation area information of the photovoltaic module to be tested, search the preset climate database for geographical location records that match the longitude and latitude coordinates; if an exact matching geographical location record exists, directly extract the historical temperature data and historical humidity data corresponding to that geographical location; if no exact matching geographical location record exists, search all geographical location records within a range of ±0.5° of the longitude and latitude coordinates of the preset installation area, calculate the spherical distance between each searched geographical location and the preset installation area, select the geographical location record with the smallest spherical distance, and extract its corresponding historical temperature data and historical humidity data as substitute data.

[0021] S1.3: Based on the frame position parameters and junction box position parameters in the component structure parameters, the area within a preset width along the inner side of the frame of the photovoltaic module to be tested, and the area within a preset radius centered on the junction box position parameters, are determined as stress concentration areas; based on the cell arrangement parameters in the component structure parameters, the area on the surface of the photovoltaic module to be tested, excluding the stress concentration areas, is divided into multiple stress non-concentration areas according to a preset grid size; the stress concentration areas and stress non-concentration areas are jointly determined as the component test area, and each component test area is assigned an area number.

[0022] In this embodiment, the method for determining the stress concentration region is as follows: The inner boundary line of the frame on the surface of the photovoltaic module under test is determined according to the frame position parameters in the component structural parameters; the annular region formed by offsetting a preset first distance from the inner boundary line of the frame towards the center of the module is determined as the frame adjacent region; the vertical projection center point of the junction box on the back of the photovoltaic module under test is determined according to the junction box position parameters in the component structural parameters; the circular region with the vertical projection center point as the center and a preset second distance as the radius is determined as the junction box back region; the union region of the frame adjacent region and the junction box back region is determined as the stress concentration region.

[0023] It should be noted that the preset first distance is: the border width value is extracted based on the border position parameter in the component structure parameters, and 1.5 to 2.5 times the border width value is used as the preset first distance; the preset second distance is: the maximum external dimension of the junction box is extracted based on the junction box position parameter in the component structure parameters, and 1.2 to 1.8 times the maximum external dimension of the junction box is used as the preset second distance; the preset first distance is 80mm to 120mm, and the preset second distance is 50mm to 100mm.

[0024] The method for dividing multiple stress-non-concentration regions is as follows: Based on the cell arrangement parameters in the module structure parameters, extract the gap positions between each cell unit and the corner positions of each cell unit. Using the gap positions as the dividing boundaries and the corner positions as grid nodes, divide the continuous area on the surface of the photovoltaic module under test, excluding the stress-concentration region, into multiple equal-area rectangular grid units according to the preset number of grid rows and preset number of grid columns; each rectangular grid unit is determined as a stress-non-concentration region.

[0025] It should be noted that the cell arrangement parameters in the component structure parameters are read to extract the number of cell cell rows and columns on the surface of the photovoltaic module under test; the preset number of grid rows is set to twice the number of cell cell rows, and the preset number of grid columns is set to twice the number of cell cell columns; when twice the number of cell cell rows is less than 4, the preset number of grid rows is set to 4; when twice the number of cell cell rows is less than 4, the preset number of grid columns is set to 4.

[0026] The method for determining the component test area is as follows: stress concentration areas and all stress non-concentration areas are merged into a set of areas covering the entire surface of the photovoltaic module to be tested according to their spatial position. Each stress concentration area and each stress non-concentration area in the set of areas is regarded as an independent component test area. Each component test area has a unique and non-overlapping spatial coverage on the surface of the photovoltaic module to be tested, and the sum of the spatial coverage of all component test areas is equal to the total area of ​​the surface of the photovoltaic module to be tested.

[0027] In an optional embodiment, a region number is assigned to each component test area: following the order of scanning line by line from the upper left corner to the lower right corner of the photovoltaic module under test, a first-class region number is assigned to each stress-non-concentration region, and the first-class region number is... to ,in, In the diagram, N is a prefix indicating that the region is a stress-free area; 01 is the number, representing the first grid cell assigned to this region among all stress-free areas, scanned row by row from the top left to the bottom right; M is the total number of stress-free areas; after all stress-free areas are assigned, a second type of area number is assigned to each stress-free area according to the order of the border-adjacent areas first, followed by the areas behind the junction box. The second type of area number is... to ,in, In the diagram, S is a prefix indicating that the area is a stress concentration area; 01 is a number indicating that the area is the first one assigned to among all stress concentration areas, following the order of the adjacent areas on the border first and the areas on the back of the junction box last; K is the total number of stress concentration areas; the first type of area number and the second type of area number are used together as the area number of each component test area.

[0028] S1.4: Statistically analyze historical temperature data in the service environment parameters, extract the maximum and minimum temperature values ​​to obtain the temperature extreme value range; statistically analyze historical humidity data, extract the maximum and minimum humidity values ​​to obtain the humidity extreme value range; calculate the temperature change per unit time based on daily temperature difference data to obtain the temperature change rate range; extract the repetition period of humidity change based on seasonal humidity fluctuation data to obtain the humidity fluctuation period.

[0029] S1.5: According to the seasonal order corresponding to the preset installation area of ​​the photovoltaic module to be tested, the extreme temperature range and extreme humidity range are divided into multiple temperature ranges and humidity ranges corresponding to multiple time nodes. The transition time between two adjacent time nodes is determined based on the temperature change rate range and humidity fluctuation cycle. The multiple temperature ranges, humidity ranges and corresponding transition times arranged in time sequence are combined into a temperature and humidity cycle sequence, which includes multiple temperature and humidity cycle stages.

[0030] It should be noted that the preset installation area refers to the geographical location information of the photovoltaic module to be tested in the actual photovoltaic power station. The preset installation area includes the longitude coordinates, latitude coordinates and altitude corresponding to the geographical location information.

[0031] The example illustrates the division of temperature and humidity ranges for multiple time points as follows: Following the seasonal order corresponding to the preset installation region, the twelve natural months of the year are divided into four seasonal periods: spring, summer, autumn, and winter. For each seasonal period, the average of the daily maximum temperatures within that period is extracted from the extreme temperature range as the seasonal maximum temperature, and the average of the daily minimum temperatures within that period is extracted as the seasonal minimum temperature. The seasonal maximum and minimum temperatures are then combined to form the corresponding temperature range. Similarly, for each seasonal period, the average of the daily maximum humidity within that period is extracted from the extreme humidity range as the seasonal maximum humidity, and the average of the daily minimum humidity within that period is extracted as the seasonal minimum humidity. The seasonal maximum and minimum humidity values ​​are then combined to form the corresponding humidity range. The temperature and humidity ranges for each seasonal period are arranged in the chronological order of spring, summer, autumn, and winter to obtain multiple temperature and humidity ranges corresponding to each time point, with each seasonal period serving as a separate time point.

[0032] S1.6: Read the temperature and humidity cycle stages in the temperature and humidity cycle sequence sequentially according to time. Generate temperature and humidity control commands for the temperature and humidity ranges corresponding to the current temperature and humidity cycle stage. Send the temperature and humidity control commands to the control unit of the temperature and humidity environment chamber. The control unit adjusts the output power of the heating device or cooling device according to the difference between the actual temperature value and the temperature range in the temperature and humidity environment chamber, and adjusts the output power of the humidification device or dehumidification device according to the difference between the actual humidity value and the humidity range in the temperature and humidity environment chamber, so as to adjust the actual temperature value and actual humidity value of the photovoltaic module under test to the temperature and humidity ranges corresponding to the current temperature and humidity cycle stage.

[0033] In this embodiment, the method for generating a temperature and humidity control command is as follows: The temperature range corresponding to the current temperature and humidity cycle stage is read, and the midpoint of the temperature range is used as the target temperature value; the humidity range corresponding to the current temperature and humidity cycle stage is read, and the midpoint of the humidity range is used as the target humidity value; the actual temperature value at each location within the temperature and humidity chamber is compared with the target temperature value, and the temperature deviation value at each location is calculated; the temperature deviation value at each location is input to a PID controller, and the PID controller outputs a first control signal for the heating or cooling device at each location; the actual humidity value at each location within the temperature and humidity chamber is compared with the target humidity value, and the humidity deviation value at each location is calculated; the humidity deviation value at each location is input to a PID controller, and the PID controller outputs a second control signal for the humidifying or dehumidifying device at each location; the first control signal and the second control signal are combined to form a temperature and humidity control command.

[0034] S1.7: By using temperature and humidity sensors installed in the temperature and humidity chamber and corresponding to multiple component test areas, the local temperature and humidity values ​​of each component test area are collected. The local temperature and humidity values ​​are compared with the temperature and humidity ranges corresponding to the current temperature and humidity cycle stage. If the local temperature or humidity value exceeds the corresponding range, the deviation data corresponding to the deviation range is fed back to the control unit. The output power of the heating device, cooling device, humidification device or dehumidification device at the location corresponding to the deviation data in the temperature and humidity chamber is adjusted until the local temperature and humidity values ​​converge to the temperature and humidity ranges respectively. After the transition time corresponding to the current temperature and humidity cycle stage ends, the next temperature and humidity cycle stage is read, so that the photovoltaic module under test is in a dynamically changing temperature and humidity environment corresponding to the temperature and humidity cycle sequence.

[0035] In this embodiment, the adjustment method is as follows: the difference between the local temperature value and the target temperature value in the deviation data is used as the temperature adjustment deviation amount. The temperature adjustment deviation amount is input to the PID controller, and the PID controller outputs a temperature compensation control signal. The output power of the heating device or cooling device at the location corresponding to the deviation data is adjusted according to the temperature compensation control signal. The difference between the local humidity value and the target humidity value in the deviation data is used as the humidity adjustment deviation amount. The humidity adjustment deviation amount is input to the PID controller, and the PID controller outputs a humidity compensation control signal. The output power of the humidifying device or dehumidifying device at the location corresponding to the deviation data is adjusted according to the humidity compensation control signal.

[0036] As illustrated in the example, let the temperature range corresponding to the current temperature and humidity cycle stage be... The corresponding humidity range is When the local temperature value corresponding to the test area of ​​a certain component Less than When the local temperature value is determined to be below the temperature range, [the following will be implemented]. and The difference is fed back to the control unit as the temperature regulation deviation. The control unit increases the output power of the heating device at the location corresponding to the deviation data based on the temperature regulation deviation. Greater than When the local temperature value is determined to be higher than the temperature range, [the following will be implemented]. and The difference is fed back to the control unit as a temperature regulation deviation. The control unit increases the output power of the refrigeration device at the location corresponding to the deviation data based on the temperature regulation deviation. When the local humidity value corresponding to the test area of ​​a certain component... Less than When the local humidity value is determined to be below the humidity range, [the following will be implemented]. and The difference is fed back to the control unit as the humidity adjustment deviation. The control unit increases the output power of the humidifier at the position corresponding to the deviation data based on the humidity adjustment deviation. Greater than When the local humidity value is determined to be higher than the humidity range, and The difference is fed back to the control unit as a humidity regulation deviation. The control unit increases the output power of the dehumidifier at the position corresponding to the deviation data based on the humidity regulation deviation. This is the lower limit of the temperature range corresponding to the current temperature and humidity cycle phase, that is, the average of the minimum daily temperatures within the seasonal period in which this temperature and humidity cycle phase occurs. This is the upper limit of the temperature range corresponding to the current temperature and humidity cycle phase, that is, the average of the daily maximum temperatures within the seasonal period in which this temperature and humidity cycle phase occurs. This is the lower limit of the humidity range corresponding to the current temperature and humidity cycle phase, that is, the average of the minimum daily humidity values ​​within the seasonal period in which this temperature and humidity cycle phase occurs. This represents the upper limit of the humidity range corresponding to the current temperature and humidity cycle phase, which is the average of the daily maximum humidity values ​​within the seasonal period of this temperature and humidity cycle phase.

[0037] S2: When the photovoltaic module under test is in a temperature and humidity environment, a dynamic mechanical load sequence is generated according to the environmental stage corresponding to the temperature and humidity cycle sequence, and the mechanical loading device is controlled to apply load to each test area according to the dynamic mechanical load sequence; wherein, the load amplitude of the corresponding area is adjusted according to the structural position of the test area to form a regionalized dynamic mechanical load that matches the temperature and humidity changes.

[0038] S2.1: Read the temperature range, humidity range and transition time corresponding to the current temperature and humidity cycle stage from the temperature and humidity cycle sequence, and use the midpoint of the temperature range as the current ambient temperature value and the midpoint of the humidity range as the current ambient humidity value.

[0039] S2.2: Determine the type of test area for each component based on the area number, where the type includes stress concentration area and stress non-concentration area.

[0040] In this embodiment of the application, when the area number belongs to the first type of area number to If the test area is a stress-concentration region, then the test area is determined to be a stress-free region; if the test area is a stress-concentration region, then a first load reference amplitude is assigned to the test area; if the region number belongs to the second type of region number... to If the test area is a stress concentration area, then the test area of ​​the component is determined to be a stress concentration area; if the test area of ​​the component is a stress non-concentration area, then a second load reference amplitude is assigned to the test area of ​​the component.

[0041] Where M is the total number of stress-nonconcentrated areas and K is the total number of stress-concentrated areas; the first type of area number corresponds to each stress-nonconcentrated area according to the allocation rules in S1.3, and the second type of area number corresponds to the area adjacent to the frame and the area behind the junction box according to the allocation rules in S1.3.

[0042] As illustrated in the example, suppose the stress concentration region includes the frame adjacent region and the junction box back region. The frame adjacent region is close to the rigid frame structure of the photovoltaic module under test, and the junction box back region is located in the orthographic projection area of ​​the junction box mounting position on the back of the photovoltaic module under test. Since the frame adjacent region and the junction box back region experience higher stress levels than other regions during service, a first load reference amplitude is assigned to both the frame adjacent region and the junction box back region. Suppose the stress non-concentration region is the cell-covered area, and a second load reference amplitude is assigned to all stress non-concentration regions.

[0043] It should be noted that the first load reference amplitude is greater than the second load reference amplitude; the first load reference amplitude is determined based on the moment of inertia of the frame section extracted from the frame position parameters and the mass of the junction box extracted from the junction box position parameters; the second load reference amplitude is determined based on the battery cell spacing and backsheet thickness parameters extracted from the battery cell arrangement parameters.

[0044] S2.3: Calculate the temperature correction factor based on the current ambient temperature value, calculate the humidity correction factor based on the current ambient humidity value, and use the product of the temperature correction factor and the humidity correction factor as the environmental load correction factor.

[0045] In this embodiment, the temperature correction coefficient is calculated as follows: using 25°C as the reference temperature value, the difference between the current ambient temperature value and the reference temperature value is divided by the reference temperature value to obtain the temperature deviation ratio; the temperature deviation ratio is multiplied by a preset temperature sensitivity coefficient to obtain the temperature deviation impact value; the difference between 1 and the temperature deviation impact value is used as the temperature correction coefficient. The humidity correction coefficient is calculated as follows: using 50%RH as the reference humidity value, the difference between the current ambient humidity value and the reference humidity value is divided by the reference humidity value to obtain the humidity deviation ratio; the humidity deviation ratio is multiplied by a preset humidity sensitivity coefficient to obtain the humidity deviation impact value; the difference between 1 and the humidity deviation impact value is used as the humidity correction coefficient.

[0046] S2.4: Multiply the first load reference amplitude or the second load reference amplitude of each component test area by the environmental load correction factor to obtain the load amplitude of each component test area.

[0047] S2.5: Based on the load amplitude and transition duration, generate a dynamic mechanical load sequence corresponding to the test area of ​​each component.

[0048] It should be noted that the dynamic mechanical load sequence includes the loading rate, peak load holding time, and unloading rate; the loading rate is determined by the ratio of the transition time to the load amplitude, the peak load holding time is determined by the type of temperature and humidity cycle stage, and the unloading rate is the same as the loading rate.

[0049] In this embodiment, the method for generating a dynamic mechanical load sequence is as follows: the ratio of load amplitude to transition duration is used as the loading rate; the type of the current temperature and humidity cycle stage is read; if the current temperature and humidity cycle stage is the temperature and humidity cycle stage corresponding to a summer month, a first preset duration is used as the peak load holding time; if the current temperature and humidity cycle stage is the temperature and humidity cycle stage corresponding to a winter month, a second preset duration is used as the peak load holding time; if the current temperature and humidity cycle stage is the temperature and humidity cycle stage corresponding to a spring month or an autumn month, a third preset duration is used as the peak load holding time, wherein the first preset duration is longer than the third preset duration, and the third preset duration is longer than the second preset duration; the unloading rate is set to the same value as the loading rate; and the loading rate, peak load holding time, and unloading rate are combined into a dynamic mechanical load sequence according to the time sequence.

[0050] S2.6: Convert the dynamic mechanical load sequence corresponding to the test area of ​​each component into the control signal of each mechanical loading device.

[0051] It should be noted that the control signals include the output pressure values ​​and action timing of each mechanical loading device, and each mechanical loading device is set to correspond one-to-one with the test area of ​​each component.

[0052] In this embodiment, the conversion method is as follows: read the load amplitude in the dynamic mechanical load sequence of each component test area, and convert the load amplitude into the output pressure value of each mechanical loading device according to the pressure-force conversion coefficient of each mechanical loading device; read the loading rate, peak load holding time and unloading rate in the dynamic mechanical load sequence of each component test area, take the duration corresponding to the loading rate as the loading action duration, take the peak load holding time as the pressure holding action duration, take the duration corresponding to the unloading rate as the unloading action duration, and combine the loading action duration, pressure holding action duration and unloading action duration in sequence into an action sequence; encapsulate the output pressure value and action sequence corresponding to each mechanical loading device into the control signal of each mechanical loading device.

[0053] S2.7: Each mechanical loading device applies the load in the dynamic mechanical load sequence to the corresponding component test area according to the control signal; during the application of load, each mechanical loading device alternately executes loading and unloading actions according to the action sequence in the control signal, forming a regionalized dynamic mechanical load that matches the temperature and humidity changes.

[0054] In this embodiment, each mechanical loading device increases the output pressure from zero to the output pressure value according to the loading action duration in the action sequence; after reaching the output pressure value, each mechanical loading device maintains the output pressure value unchanged during the pressure holding action duration; after the pressure holding action duration ends, each mechanical loading device reduces the output pressure from the output pressure value to zero according to the unloading action duration in the unloading action duration; after the output pressure decreases to zero, each mechanical loading device waits for the preset interval time in the action sequence before repeating the next round of loading action duration, pressure holding action duration, and unloading action duration until the transition time of the current temperature and humidity cycle stage ends; each mechanical loading device corresponding to each component test area independently executes the loading and unloading actions according to its own control signal, so that each component test area bears the dynamic mechanical load corresponding to its own load amplitude.

[0055] S3: During the application of regional dynamic mechanical loads, load response data, deformation response data, and electrical performance response data of the photovoltaic module under test are collected to construct temperature and humidity-load co-response data, and fatigue response characteristics of different test areas of the module are extracted based on the temperature and humidity-load co-response data.

[0056] S3.1: During the process of each mechanical loading device applying load to the test area of ​​each component according to the dynamic mechanical load sequence, load response data, deformation response data and electrical performance response data of each component test area are collected synchronously at a preset sampling frequency.

[0057] In this embodiment of the application, the method for acquiring load response data is as follows: by using force sensors set between each mechanical loading device and each component test area, the real-time load force value applied by each mechanical loading device to the corresponding component test area is acquired according to a preset sampling frequency, and each real-time load force value is associated with and stored with the area number of each component test area to obtain the load response data of each component test area.

[0058] The method for collecting deformation response data is as follows: A single infrared rangefinder is set at a preset deformation monitoring point on the surface of the photovoltaic module under test, and the real-time displacement of the photovoltaic module under test under dynamic mechanical load is collected according to a preset sampling frequency. This displacement is used as the overall deformation response value of the module. The overall deformation response value is associated with the area number of each module's test area and stored to obtain the deformation response data of each module's test area.

[0059] The method for acquiring electrical performance response data is as follows: by connecting current sensors and voltage sensors to the output terminal of the photovoltaic module under test, the real-time output current value and real-time output voltage value of the photovoltaic module under test are acquired according to a preset sampling frequency, and the real-time output current value and real-time output voltage value are associated and stored to obtain electrical performance response data.

[0060] It should be noted that the preset sampling frequency is 100Hz to 1000Hz; the sampling frequency of the force sensor, the sampling frequency of the displacement sensor, and the sampling frequency of the current sensor and voltage sensor are the same, all of which are preset sampling frequencies.

[0061] S3.2: Time alignment is performed on the load response data and deformation response data. The real-time load force value and real-time displacement at the same sampling time are associated according to the region number to generate load-deformation response data pairs.

[0062] In this embodiment, the method for generating load-deformation response data pairs is as follows: First timestamps carried in the load response data of each component test area are read; second timestamps carried in the deformation response data of each component test area are read; real-time load force values ​​and real-time displacement values ​​whose difference between the first and second timestamps is less than a preset time synchronization threshold are determined to be data from the same sampling time, where the preset time synchronization threshold is set to half the reciprocal of the preset sampling frequency; real-time load force values ​​and real-time displacement values ​​determined to be from the same sampling time are paired according to the area number, and load-deformation response data pairs corresponding to each component test area at each sampling time are generated with the real-time load force value as the vertical axis and the real-time displacement value as the horizontal axis.

[0063] S3.3: Based on the load-deformation response data pair, extract the current elastic modulus of each component's test area at each sampling time; generate stiffness degradation data for each component's test area based on the ratio of the current elastic modulus to the reference elastic modulus.

[0064] In this embodiment of the application, the current elastic modulus extraction method is as follows: for the load-deformation response data pairs corresponding to each sampling time of each component test area, select the linear segment data from the load-deformation response data pairs during the process of the real-time load force value increasing from zero to the load amplitude; perform linear fitting on each data point in the linear segment data to obtain the slope value of the fitted line, and use the slope value of the fitted line as the current elastic modulus of the component test area at that sampling time.

[0065] It should be noted that, for the load-deformation response data pairs corresponding to each sampling time in the test area of ​​each component, a load-deformation curve is constructed with the real-time load force value as the abscissa and the real-time displacement value as the ordinate. Starting from the origin of the load-deformation curve, the slope value between adjacent data points is calculated sequentially along the direction of load increase. When the relative deviation between the continuously calculated slope values ​​does not exceed 5%, the continuous data segment is determined to be a linear segment. When the relative deviation of the slope value exceeds 5% for the first time, the data point is taken as the end point of the linear segment. All data points from the origin to the end point of the linear segment are selected as linear segment data. If the relative deviation of the slope value between the first three data points starting from the origin exceeds 5%, the two data points with the smallest load force value among the first three data points are taken as linear segment data.

[0066] The method for generating stiffness degradation data is as follows: read the reference elastic modulus of the photovoltaic module under test, which is the initial elastic modulus of the photovoltaic module under test when no dynamic mechanical load is applied and it is not in a temperature and humidity environment; divide the current elastic modulus corresponding to each sampling time by the reference elastic modulus to obtain the modulus retention rate corresponding to each sampling time; take the difference between 1 and the modulus retention rate as the stiffness degradation value corresponding to each sampling time; arrange the stiffness degradation values ​​of each sampling time in the order of sampling time to generate stiffness degradation data for each module test area.

[0067] It should be noted that the reference elastic modulus is the initial elastic modulus of the photovoltaic module under test when no dynamic mechanical load is applied and it is not in a temperature and humidity environment; the stiffness degradation data is used to characterize the degree of stiffness decay of each module's test area under the combined action of temperature and humidity environment and dynamic mechanical load.

[0068] S3.4: Based on the load-deformation response data pair, extract the residual displacement of each component test area in each loading-unloading cycle; use the ratio of each residual displacement to the corresponding load amplitude as the plastic deformation cumulative coefficient of each component test area, and arrange the plastic deformation cumulative coefficients in the order of sampling time to generate the plastic cumulative data of each component test area.

[0069] In this embodiment of the application, for each complete loading-unloading cycle of each component test area, the loading-unloading cycle includes the duration of a loading action, the duration of a pressure holding action, the duration of an unloading action, and a preset interval duration, which are executed sequentially; from the data segment after the unloading action duration of the loading-unloading cycle ends and before the next loading action duration begins, the real-time displacement collected by the displacement sensor is extracted as the residual displacement corresponding to that loading-unloading cycle.

[0070] Read the load amplitude of each component's test area, divide the residual displacement corresponding to each loading-unloading cycle by the corresponding load amplitude to obtain the cumulative plastic deformation coefficient corresponding to each loading-unloading cycle; arrange the cumulative plastic deformation coefficients of each loading-unloading cycle according to the execution order of the loading-unloading cycle to generate the cumulative plastic data of each component's test area.

[0071] S3.5: Perform fatigue damage analysis on the load-deformation response data pair, extract the phase difference between the peak load and peak deformation in the test area of ​​each component during the duration of each loading action; generate dynamic response hysteresis data for the test area of ​​each component based on the phase difference.

[0072] In this embodiment of the application, the fatigue damage analysis of the load-deformation response data pair is as follows: for the duration of each loading action in the test area of ​​each component, the first time point corresponding to when the real-time load force value reaches its maximum value within the duration of the loading action, and the second time point corresponding to when the real-time displacement reaches its maximum value within the duration of the loading action, are extracted from the load-deformation response data pair; the absolute value of the time difference between the first time point and the second time point is taken as the phase difference corresponding to the duration of the loading action; the phase differences of the duration of each loading action are arranged according to the execution order of the loading action duration to generate dynamic response hysteresis data for the test area of ​​each component.

[0073] S3.6: Correlate the stiffness degradation data, plasticity accumulation data and dynamic response hysteresis data of each component test area with the local temperature and local humidity values ​​of each component test area according to the area number, and construct the temperature-humidity-load co-response data of each component test area.

[0074] S3.7: Based on the temperature-humidity-load co-response data, extract the stiffness degradation rate, plastic accumulation rate, and dynamic response hysteresis rate of change of each component test area in each temperature-humidity cycle stage of the temperature-humidity cycle sequence; use the stiffness degradation rate, plastic accumulation rate, and dynamic response hysteresis rate of change as the fatigue response characteristics of each component test area.

[0075] As illustrated in the example, the stiffness degradation rate is the rate of change of stiffness degradation data over time in the test area of ​​each component within a temperature and humidity cycle; the plasticity accumulation rate is the rate of change of plasticity accumulation data with the number of cycles of dynamic mechanical load in the test area of ​​each component within a temperature and humidity cycle; and the dynamic response hysteresis rate is the rate of change of dynamic response hysteresis data with the number of alternations between the duration of loading and the duration of unloading in the test area of ​​each component within a temperature and humidity cycle.

[0076] S4: Calculate the dynamic damage evaluation parameters of the photovoltaic module under test based on the fatigue response characteristics, and determine the test results of the photovoltaic module under test under the combined action of temperature and humidity environment and dynamic mechanical load based on the dynamic damage evaluation parameters.

[0077] S4.1: From the fatigue response characteristics of each component test area, read the stiffness degradation rate, plastic accumulation rate and dynamic response hysteresis change rate of each component test area in each temperature and humidity cycle stage; at the same time, read the area number of each component test area.

[0078] S4.2: Assign corresponding damage weight coefficients to the test areas of each component; the first damage weight coefficient for stress concentration areas is greater than the second damage weight coefficient for stress non-concentration areas.

[0079] In this embodiment, the area number of each component test area is read, and the component test areas belonging to the second type of area numbers S-01 to SK are determined as stress concentration areas; the second type of area numbers correspond to the adjacent area of ​​the frame and the back area of ​​the junction box according to the allocation rule in S1.3; the component test areas belonging to the first type of area numbers N-01 to NM are determined as stress non-concentration areas; the first type of area numbers correspond to each stress non-concentration area according to the allocation rule in S1.3.

[0080] It should be noted that the allocation of the first damage weighting coefficient and the second damage weighting coefficient is based on the following: the stress concentration area experiences a higher stress level during service than the stress non-stress concentration area. Under the same fatigue response characteristic value, the damage in the stress concentration area has a greater impact on the overall safety of the photovoltaic module under test. Therefore, the first damage weighting coefficient corresponding to the stress concentration area is greater than the second damage weighting coefficient corresponding to the stress non-stress concentration area.

[0081] Preferably, the first damage weighting coefficient is determined based on the area ratio of stress concentration areas in the photovoltaic module under test; the second damage weighting coefficient is determined based on the area ratio of stress non-concentration areas in the photovoltaic module under test, and the weighting coefficients of all module test areas satisfy the normalization condition, that is, the sum of the weighting coefficients of each module test area is equal to the number of each module test area.

[0082] S4.3: Compare the stiffness degradation rate, plastic accumulation rate, and dynamic response hysteresis rate of each component's test area with the preset stiffness degradation rate threshold, preset plastic accumulation rate threshold, and preset dynamic response hysteresis rate threshold, respectively, to generate stiffness degradation damage sub-items, plastic accumulation damage sub-items, and dynamic response hysteresis damage sub-items for each component's test area.

[0083] In this embodiment, when the stiffness degradation rate is greater than a preset stiffness degradation rate threshold, the ratio of the stiffness degradation rate to the preset stiffness degradation rate threshold is used as a stiffness degradation damage sub-item; otherwise, the stiffness degradation damage sub-item is 0. When the plasticity accumulation rate is greater than a preset plasticity accumulation rate threshold, the ratio of the plasticity accumulation rate to the preset plasticity accumulation rate threshold is used as a plasticity accumulation damage sub-item; otherwise, the plasticity accumulation damage sub-item is 0. When the dynamic response hysteresis rate is greater than a preset dynamic response hysteresis rate threshold, the ratio of the dynamic response hysteresis rate to the preset dynamic response hysteresis rate threshold is used as a dynamic response hysteresis damage sub-item; otherwise, the dynamic response hysteresis damage sub-item is 0.

[0084] S4.4: The stiffness degradation damage sub-item, plastic cumulative damage sub-item, and dynamic response hysteresis damage sub-item are calculated according to the regional damage fusion formula to obtain the regional dynamic damage evaluation parameters of the test area of ​​each component.

[0085] In this embodiment, the regional damage fusion formula is: ; in, Let be the region dynamic damage evaluation parameter for the test area of ​​the i-th component. For the stiffness degradation damage sub-item of the i-th component test area, For the cumulative plastic damage sub-item of the i-th component test area, For the dynamic response hysteresis impairment sub-item of the i-th component test area, To preset the stiffness degradation weighting factor, To preset the cumulative plasticity weighting factor, To preset the dynamic response lag weighting factor, .

[0086] It should be noted that the values ​​of the preset stiffness degradation weight factor, preset plasticity accumulation weight factor, and preset dynamic response hysteresis weight factor are determined based on the laminated structure information of the photovoltaic module under test.

[0087] S4.5: Calculate the regional dynamic damage evaluation parameters according to the component overall damage fusion formula to obtain the component overall dynamic damage evaluation parameters.

[0088] In this embodiment of the application, the overall damage fusion formula for the component is: ; in, Here, K represents the total number of test areas for the component, and K is the overall dynamic damage evaluation parameter for the component. For the i-th component test area, the first damage weighting coefficient or the second damage weighting coefficient is... The parameters for evaluating the dynamic damage of the i-th component's test area are as follows:

[0089] S4.6: Read the preset damage threshold and compare the overall dynamic damage evaluation parameters of the module with the preset damage threshold; when the overall dynamic damage evaluation parameters of the module are greater than or equal to the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a failure state; when the overall dynamic damage evaluation parameters of the module are less than the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a pass state.

[0090] It should be noted that both the overall dynamic damage evaluation parameters of the module and the preset damage threshold are dimensionless numerical evaluation indicators. Both are constructed based on the same damage evaluation dimension system. The preset damage threshold is used to characterize the maximum permissible damage that the photovoltaic module under test can withstand under the combined action of temperature and humidity environment and dynamic mechanical load.

[0091] In this embodiment of the application, if the test result is a failure state, the mechanical loading devices are stopped from applying loads to the photovoltaic module under test, the temperature and humidity chamber is stopped from running according to the temperature and humidity cycle sequence, the photovoltaic module under test is taken out of the temperature and humidity chamber, and failure analysis is performed on the photovoltaic module under test. The failure analysis includes acquiring electroluminescent images of the photovoltaic module under test, and determining the location of the cell cracks and the direction of crack propagation based on the electroluminescent images.

[0092] If the test result is determined to be pass, the remaining temperature and humidity cycle stages in the current temperature and humidity cycle sequence and the dynamic mechanical load sequence corresponding to each mechanical loading device will continue to be executed until all temperature and humidity cycle stages in the temperature and humidity cycle sequence have been completed. After all temperature and humidity cycle stages have been completed, the trend curve of the overall dynamic damage evaluation parameters of each photovoltaic module under test in each temperature and humidity cycle stage is output as a function of time.

[0093] It should be noted that the preset damage threshold is determined based on the daily temperature difference data and seasonal humidity fluctuation data in the service environment parameters of the photovoltaic module under test. The larger the daily temperature difference data and the larger the seasonal humidity fluctuation data, the smaller the value of the preset damage threshold.

[0094] For example, reading the daily temperature difference data from the service environment parameters. and seasonal humidity fluctuation data ;by , The reference baseline value corresponds to the reference damage threshold. ;when Calculate the temperature difference correction factor when the temperature is >15℃. ;when At ≤15℃, ;when Calculate the humidity fluctuation correction factor when RH is >30%. ;when When ≤30%RH, Divide the reference damage threshold by the product of the temperature difference correction factor and the humidity fluctuation correction factor to obtain the preset damage threshold, i.e. Furthermore, the preset damage threshold has a lower limit of 0.30 and an upper limit of 0.70.

[0095] S4.7: Output the overall dynamic damage evaluation parameters and test results of the module to the test database, and store them in association with the module structure parameters and service environment parameters of the photovoltaic module under test.

[0096] As illustrated in the example, the overall dynamic damage evaluation parameters and test results of the photovoltaic module are output to the test database: Assume the total number K of the test areas for the photovoltaic module under test is 20, of which 4 are stress concentration areas and 16 are stress non-concentration areas; the first damage weight coefficient for stress concentration areas is set to 1.5, and the second damage weight coefficient for stress non-concentration areas is set to 0.8; after calculating the regional dynamic damage evaluation parameters for each test area of ​​the module using S4.4, these parameters are substituted into the overall module damage fusion formula to obtain the overall dynamic damage evaluation parameters of the module; assuming a preset damage threshold of 0.55, when the overall dynamic damage evaluation parameter of the module is 0.62, it is determined that the overall dynamic damage evaluation parameter of the module is greater than the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a failure state, and the overall dynamic damage evaluation parameter of 0.62 and the failure state are output to the test database; when the overall dynamic damage evaluation parameter of the module is 0.43, it is determined that the overall dynamic damage evaluation parameter of the module is less than the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a pass state, and the overall dynamic damage evaluation parameter of 0.43 and the pass state are output to the test database.

[0097] In summary, this invention obtains the structural parameters and service environment parameters of the photovoltaic module under test, divides the module test area according to the structural parameters, and generates a temperature and humidity cycle sequence according to the service environment parameters. This establishes a correspondence between the temperature and humidity changes during the test and the structural characteristics and climate change patterns in the actual installation environment of the module, providing an environmental basis for subsequent regional dynamic mechanical load application. By generating a dynamic mechanical load sequence based on the environmental stage corresponding to the temperature and humidity cycle sequence, and adjusting the load amplitude according to the structural position of different test areas, the frame area, junction box area, and cell area are subjected to dynamic mechanical loads that match their own structural characteristics. This overcomes the problem in traditional testing where fixed loads and overall loading fail to reflect differences in local fatigue damage. Improve the matching degree between the mechanical load process and the actual service state; construct temperature and humidity-load coordinated response data by collecting load response data, deformation response data and electrical performance response data, and extract fatigue response characteristics from different test areas to characterize the response differences of different structural regions inside the module under the combined action of temperature and humidity changes and mechanical loads, which is used to analyze the correlation between microcrack propagation, structural deformation and electrical performance degradation; further calculate dynamic damage evaluation parameters based on fatigue response characteristics, and determine the test results based on dynamic damage evaluation parameters, so that the reliability evaluation of photovoltaic modules is transformed from a single mechanical strength judgment to a damage degree evaluation under the coupled action of temperature and humidity environment and dynamic mechanical load, thereby improving the ability of test results to characterize the long-term service reliability of modules.

[0098] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for coordinating dynamic mechanical load testing of photovoltaic modules under temperature and humidity conditions, characterized in that, include: Obtain the component structure parameters and service environment parameters of the photovoltaic module to be tested, divide the component test area according to the component structure parameters, and generate a temperature and humidity cycle sequence according to the service environment parameters; control the temperature and humidity environment chamber according to the temperature and humidity cycle sequence to keep the photovoltaic module under test in a dynamically changing temperature and humidity environment; When the photovoltaic module under test is in the temperature and humidity environment, a dynamic mechanical load sequence is generated according to the environmental stage corresponding to the temperature and humidity cycle sequence, and the mechanical loading device is controlled to apply load to each of the test areas according to the dynamic mechanical load sequence; wherein, the load amplitude of the corresponding area is adjusted according to the structural position of the test area to form a regionalized dynamic mechanical load that matches the temperature and humidity changes. During the application of the regionalized dynamic mechanical load, load response data, deformation response data, and electrical performance response data of the photovoltaic module under test are collected to construct temperature and humidity-load co-response data, and fatigue response characteristics of different test areas of the module are extracted based on the temperature and humidity-load co-response data. The dynamic damage evaluation parameters of the photovoltaic module under test are calculated based on the fatigue response characteristics, and the test results of the photovoltaic module under test under the combined action of the temperature and humidity environment and the dynamic mechanical load are determined based on the dynamic damage evaluation parameters.

2. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 1, characterized in that, The determination of the test results includes: A preset damage threshold is read, and the overall dynamic damage evaluation parameters of the component are compared with the preset damage threshold. When the overall dynamic damage evaluation parameters of the component are greater than or equal to the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a failure state. If the test result is in a failure state, the mechanical loading devices are stopped from applying load to the photovoltaic module under test, the temperature and humidity chamber is stopped from running according to the temperature and humidity cycle sequence, the photovoltaic module under test is taken out of the temperature and humidity chamber, and failure analysis is performed on the photovoltaic module under test. When the overall dynamic damage evaluation parameter of the component is less than the preset damage threshold, the test result of the photovoltaic module under test is determined to be in a pass state. If the test result is determined to be in a pass state, the remaining temperature and humidity cycle stages in the current temperature and humidity cycle sequence and the dynamic mechanical load sequence corresponding to each mechanical loading device are executed until all temperature and humidity cycle stages in the temperature and humidity cycle sequence are completed. After all temperature and humidity cycle stages are completed, the trend curve of the overall dynamic damage evaluation parameter of the photovoltaic module under test changing with time in each temperature and humidity cycle stage is output.

3. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 2, characterized in that, The acquisition of the overall dynamic damage evaluation parameters of the component includes: From the fatigue response characteristics of each component test area, the stiffness degradation rate, plasticity accumulation rate and dynamic response hysteresis rate of each component test area in each temperature and humidity cycle stage are read; at the same time, the area number of each component test area is read. Each component test area is assigned a corresponding damage weight coefficient, wherein the type includes stress concentration area and stress non-concentration area; the first damage weight coefficient corresponding to the stress concentration area is greater than the second damage weight coefficient corresponding to the stress non-concentration area. The stiffness degradation rate, plastic accumulation rate, and dynamic response hysteresis rate of each component's test area are compared with preset stiffness degradation rate thresholds, preset plastic accumulation rate thresholds, and preset dynamic response hysteresis rate thresholds, respectively, to generate stiffness degradation damage sub-items, plastic accumulation damage sub-items, and dynamic response hysteresis damage sub-items for each component's test area. The stiffness degradation damage sub-item, plastic cumulative damage sub-item, and dynamic response hysteresis damage sub-item are calculated according to the regional damage fusion formula to obtain the regional dynamic damage evaluation parameters of the test area of ​​each component. The dynamic damage evaluation parameters of the region are calculated according to the overall component damage fusion formula to obtain the overall component dynamic damage evaluation parameters.

4. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 3, characterized in that, The methods for determining the type of test area for each component include: The type of test area for each component is determined based on the area number; When the area code belongs to the first type of area code to If the test area of ​​the component is determined to be a stress-free region, then if the test area of ​​the component belongs to the stress-concentrated region, then a first load reference amplitude is assigned to the test area of ​​the component. When the area number belongs to the second type of area number to If the test area of ​​the component is determined to be a stress concentration area, then if the test area of ​​the component belongs to the stress non-concentration area, then a second load reference amplitude is assigned to the test area of ​​the component.

5. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 4, characterized in that, The area number includes: Following the scanning sequence from the top left corner to the bottom right corner of the photovoltaic module under test, each stress-non-concentration region is assigned a first-class region number, wherein the first-class region number is... to ,in, In the diagram, N is a prefix indicating that the region is a stress-free region; 01 is the number, representing the first mesh cell assigned to this region among all stress-free regions, in the order of scanning row by row from the top left to the bottom right; M is the total number of stress-free regions. After all non-stress concentration areas have been assigned, the second category of area numbers are assigned to each stress concentration area in the order of the area adjacent to the border first, followed by the area behind the junction box. In the text, S is a prefix indicating that the area is a stress concentration area; 01 is a number indicating that the area is the first one assigned to among all stress concentration areas, following the order of the areas adjacent to the border first and the areas behind the junction box last; K is the total number of stress concentration areas. The first type of region number and the second type of region number are used together as the region number of each component test area.

6. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 3, characterized in that, The generation of the stiffness degradation damage sub-item, the plastic cumulative damage sub-item, and the dynamic response hysteresis damage sub-item includes: When the stiffness degradation rate is greater than a preset stiffness degradation rate threshold, the ratio of the stiffness degradation rate to the preset stiffness degradation rate threshold is taken as a stiffness degradation damage sub-item; otherwise, the stiffness degradation damage sub-item is 0. When the plasticity accumulation rate is greater than a preset plasticity accumulation rate threshold, the ratio of the plasticity accumulation rate to the preset plasticity accumulation rate threshold is taken as a plasticity accumulation damage sub-item; otherwise, the plasticity accumulation damage sub-item is 0. When the dynamic response hysteresis rate is greater than a preset dynamic response hysteresis rate threshold, the ratio of the dynamic response hysteresis rate to the preset dynamic response hysteresis rate threshold is taken as a dynamic response hysteresis damage sub-item; otherwise, the dynamic response hysteresis damage sub-item is 0.

7. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 3, characterized in that, The acquisition of the fatigue response characteristics includes: Based on temperature and humidity-load co-response data, the stiffness degradation rate, plasticity accumulation rate and dynamic response hysteresis rate of change of each component test area in each temperature and humidity cycle stage of the temperature and humidity cycle sequence were extracted. The stiffness degradation rate, plasticity accumulation rate, and dynamic response hysteresis rate are used as fatigue response characteristics of the test areas of each component.

8. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 7, characterized in that, The construction of the temperature, humidity and load coordinated response data includes: During the process of each mechanical loading device applying load to the test area of ​​each component according to the dynamic mechanical load sequence, load response data, deformation response data and electrical performance response data of each component test area are collected synchronously at a preset sampling frequency. The load response data and the deformation response data are time-aligned, and the real-time load force value and real-time displacement at the same sampling time are associated according to the region number to generate load-deformation response data pairs; Based on the load-deformation response data pair, the current elastic modulus of each component's test area at each sampling time is extracted; and stiffness degradation data of each component's test area is generated according to the ratio of the current elastic modulus to the reference elastic modulus. Based on the load-deformation response data pair, the residual displacement of each component test area in each loading-unloading cycle is extracted; the ratio of each residual displacement to the corresponding load amplitude is used as the plastic deformation cumulative coefficient of each component test area, and the plastic deformation cumulative coefficient is arranged in the order of sampling time to generate the plastic cumulative data of each component test area. Fatigue damage analysis is performed on the load-deformation response data pairs to extract the phase difference between the peak load and peak deformation in the test area of ​​each component during the duration of each loading action; dynamic response hysteresis data of each component test area is generated based on the phase difference. The stiffness degradation data, plasticity accumulation data, and dynamic response hysteresis data of each component's test area are correlated with the local temperature and humidity values ​​of each component's test area according to the area number to construct temperature-humidity-load coordinated response data.

9. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 8, characterized in that, The acquisition of the dynamic mechanical load sequence includes: Read the temperature range, humidity range and transition time corresponding to the current temperature and humidity cycle stage from the temperature and humidity cycle sequence, and use the midpoint of the temperature range as the current ambient temperature value and the midpoint of the humidity range as the current ambient humidity value. Calculate a temperature correction factor based on the current ambient temperature value, calculate a humidity correction factor based on the current ambient humidity value, and use the product of the temperature correction factor and the humidity correction factor as the environmental load correction factor. Multiply the first load reference amplitude or the second load reference amplitude of each component test area by the environmental load correction factor to obtain the load amplitude of each component test area; Based on the load amplitude and the transition duration, a dynamic mechanical load sequence corresponding to the test area of ​​each component is generated.

10. The method for coordinated testing of dynamic mechanical loads on photovoltaic modules under temperature and humidity conditions as described in claim 1 or 9, characterized in that, The temperature and humidity cycle sequence includes: Statistical analysis was performed on historical temperature data in the service environment parameters to extract the maximum and minimum temperature values, thus obtaining the temperature extreme value range; statistical analysis was performed on historical humidity data to extract the maximum and minimum humidity values, thus obtaining the humidity extreme value range; the temperature change rate range was obtained by calculating the temperature change per unit time based on the daily temperature difference data; and the humidity fluctuation period was obtained by extracting the repetition period of humidity changes based on the seasonal humidity fluctuation data. According to the seasonal order corresponding to the preset installation area of ​​the photovoltaic module to be tested, the extreme temperature range and the extreme humidity range are divided into multiple temperature ranges and humidity ranges corresponding to multiple time nodes. The transition time between two adjacent time nodes is determined according to the temperature change rate range and humidity fluctuation cycle. The multiple temperature ranges, humidity ranges and corresponding transition times arranged in time sequence are combined into a temperature and humidity cycle sequence.

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