A solar cell outdoor stability test system and test method based on LabVIEW measurement and control

Abstract

The invention discloses a solar cell outdoor stability test system and test method based on LabVIEW measurement and control, including an adjustable angle test fixing bracket, a solar cell to be tested, a digital source meter, a relay control unit, a plurality of sensors and a host computer. The I-V characteristic curve of the solar cell and the outdoor environment temperature, humidity, solar radiation intensity and other data are collected by each measurement module built into the LabVIEW software in the host computer. The data is processed and graphically displayed through the monitoring interface. At the same time, according to the set test time, the automatic switching between the daytime I-V data measurement and the nighttime outdoor temperature and humidity data collection can be realized, and the data collected each time is stored in the host computer document. The present invention can automatically and efficiently complete the evaluation of the working state of the solar cell in the outdoor environment, and truly reflect the stability performance of the solar cell in the outdoor environment. The system is simple and easy to use and does not require manual intervention.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell outdoor stability testing system and method based on LabVIEW measurement and control. Background Art

[0002] Among the numerous energy sources developed and utilized by human society, renewable clean energy is gradually becoming the most important source of future energy demand. Among them (solar energy, wind energy, tidal energy, hydropower, etc.), solar energy has always been a research hotspot in the field of renewable energy due to its inexhaustible reserves and relatively clean and pollution-free advantages. The third-generation solution-processable solar cells have the characteristics of good flexibility, low price, and light weight, and have become one of the research hotspots in the field of photovoltaic technology. In order to realize the practical application of related solar cells, on the one hand, the energy conversion efficiency of the battery should be improved, and on the other hand, the service life of the device should be extended. The key to improving the energy conversion efficiency lies in the design and synthesis of new high-efficiency donor materials and acceptor materials, as well as the development of new device structures; to extend the service life of the device, the light and thermal stability of the device must be considered. Although the photoelectric conversion efficiency of organic solar cells has reached the requirements of commercial and market promotion, the sensitivity of organic materials to the environment limits the long-term stability of organic solar cells. At present, the current solar cell stability test is mainly based on a xenon lamp solar simulator or other light source simulator with constant light intensity. Most of the environmental conditions are tested under constant temperature and nitrogen protection conditions. However, complex outdoor working conditions such as spectral distribution, light intensity, temperature and humidity changes are quite different from the current indoor tests. Therefore, accurate evaluation of the stability of solar cells under different conditions has become an indispensable step for new photovoltaic cells to enter the market. Further outdoor performance and stability tests are conducted to evaluate the performance evolution under external environmental factors, study the attenuation mechanism and propose strategies to improve stability. These have far-reaching significance for accelerating the organic solar cells from the laboratory to large-scale industrialization. Therefore, the present invention has developed a set of solar cell outdoor stability test system and method based on LabVIEW measurement and control. The system uses LabVIEW's intuitive and concise graphical programming method, encapsulated compilation modules and rich and diverse controls. The software has strong scalability and a visual monitoring interface, which greatly improves the efficiency of solar cell performance testing and stability evaluation. Summary of the invention

[0003] In view of the shortcomings of existing stability testing technology and the lack of knowledge about outdoor stability, one of the main purposes of the present invention is to provide a solar cell outdoor stability testing system and method based on LabVIEW measurement and control, aiming to conveniently and quickly evaluate the working performance of solar cells under outdoor conditions, and record the changing trends of solar cell performance on different time scales, so as to truly reflect the stability performance of the battery in outdoor atmospheric environment.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A solar cell outdoor stability test system based on LabVIEW measurement and control is characterized in that it comprises an adjustable angle test fixing bracket, a solar cell to be tested, a digital source meter, a relay control unit, a solar irradiance sensor, an ambient temperature and humidity sensor, a temperature sensor, an RS485 to USB bus communication interface and a host computer; the solar cell to be tested, the solar irradiance sensor, and the ambient temperature and humidity sensor are coplanarly installed on the adjustable angle test fixing bracket to ensure the consistency of test conditions; the temperature sensor is attached to the back of the solar cell to be tested and is used to evaluate the battery temperature and heating degree under outdoor working conditions; the relay control unit is respectively connected to the battery to be tested and the digital source meter, the digital source meter, the relay control unit, the solar irradiance sensor, the ambient temperature and humidity sensor, and the temperature sensor are respectively connected to the host computer through the RS485 to USB bus communication interface, and the built-in measurement unit of the LabVIEW software sends commands to each sensor for control.

[0006] In the above-mentioned LabVIEW-based solar cell outdoor stability test system, the host computer is a computer with LabVIEW test software installed, and the LabVIEW test software has built-in IV test module, battery test selection module, battery temperature measurement module, ambient temperature and humidity measurement module, solar irradiance measurement module and data processing and storage module.

[0007] In the above-mentioned LabVIEW-based solar cell outdoor stability test system,

[0008] The IV test module is used to configure and control the test parameters of the digital source meter, and can adjust the starting and ending voltages, clamping current size, acquisition rate and accuracy, test points, etc. of the battery IV measurement.

[0009] The battery test selection module is used for program control of the relay control unit to realize sequential selection of batteries to be tested by the relay control unit. The digital source meter connects the selected batteries to be tested through the relay control unit and forms a current loop to realize IV curve testing of the batteries one by one.

[0010] The battery temperature measurement module, the ambient temperature and humidity measurement module, and the solar irradiance measurement module are respectively connected to read the measurement data of the temperature sensor, the ambient temperature and humidity sensor, and the solar irradiance sensor, and collect the battery temperature, ambient temperature, humidity, and solar irradiance intensity of the single battery currently being tested in the environment.

[0011] The data processing and storage module is used for data processing of the response information in the MODBUS communication protocol format returned by each sensor and the IV curve data processing measured by the digital source meter, including interception of data in the data area of ​​the data frame, hexadecimal to decimal conversion, and numerical to character conversion; calculation of short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, photoelectric conversion efficiency, etc. in the IV curve, and finally storing it in a designated location document in text format.

[0012] A test method for a solar cell outdoor stability test system based on LabVIEW measurement and control, the steps are as follows:

[0013] Step 1: Building a solar cell outdoor stability test system based on LabVIEW control as described in claim 1;

[0014] Step 2: Set up the LabVIEW front panel in the host computer. The front panel includes the test parameter setting area, data storage setting area, battery selection area to be tested, IV curve display area and battery result display area. In the test parameter setting area, configure the communication ports of each test instrument, the digital source meter to measure the start and end voltage, clamp current size, acquisition rate and accuracy, number of test points, daytime IV test start and end time, test cycle, solar cell area and other test parameters.

[0015] Step 3: Set the data storage target path in the LabVIEW front panel data storage setting area on the host computer, and select the battery number to be tested in the battery selection area.

[0016] Step 4: The solar cell stability test starts. The host computer configures the instrument drive and measurement parameters. The software reads the current system time and determines whether it is between the start test time and the end time.

[0017] Step 5: If the set test time range is not met, the night environment temperature and humidity acquisition mode is performed, and the LabVIEW software environment temperature and humidity measurement module in the host computer sends a read command to the environment temperature and humidity sensor, reads the data, processes and stores it in the specified location document. If the set test time range is met, the daytime IV test mode is performed, and the built-in modules of the host computer LabVIEW software send the test command to each sensor and control measurement unit through the RS485 to USB bus communication interface.

[0018] Step 6: The relay control unit selects the first battery to be tested, and then the digital source meter performs an IV test on the selected battery. Synchronously, the ambient temperature and humidity sensor returns the ambient temperature and humidity, the solar irradiance sensor returns the solar irradiance, and the temperature sensor returns the battery temperature. The IV curve data is processed to obtain short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, photoelectric conversion efficiency, etc., and then the collected data is stored in the specified location document and displayed in the battery test result display area on the front panel. The IV test curve is drawn and displayed in the IV curve display area.

[0019] Step 7: The relay control unit connects the next battery to be tested with the digital source meter according to the battery test number selected in the battery selection area to be tested, and repeats step 6 until all batteries are tested.

[0020] Step 8: According to the test cycle set in the test parameter setting area, wait for the corresponding time and make a time judgment, then enter the step 5 test process, thereby completing the process of automatic and efficient data collection and processing.

[0021] In the above test method, the LabVIEW software has built-in time judgment, which realizes the separation of the two modes of daytime IV data measurement and nighttime temperature and humidity data collection. Under dark conditions at night, the battery is in an open circuit state, and the digital source meter suspends scanning, avoiding the battery performance degradation caused by the digital source meter current and voltage scanning excitation under dark conditions at night.

[0022] In the above-mentioned test method, a novel outdoor stability evaluation method is adopted, with the cumulative solar radiation received by the solar cell as the horizontal coordinate, the solar cell output energy under the corresponding radiation as the vertical coordinate, or the overall average photoelectric conversion efficiency of the ratio of the two as the vertical coordinate as the judgment standard for outdoor stability. This method eliminates the influence of fluctuations in environmental factors such as daytime light intensity and temperature on the commonly used stability evaluation standard with time as the horizontal coordinate and photoelectric conversion efficiency as the vertical coordinate.

[0023] The present invention has the following technical effects or advantages:

[0024] (1) Through the RS485 to USB bus communication interface, the host computer and each sensor are directly connected to build a convenient outdoor stability test system controlled by LabVIEW, which greatly saves development time. At the same time, combined with the advantages of computer USB multi-port, multi-channel synchronous measurement can be easily realized;

[0025] (2) Using LabVIEW programming software, data can be collected, processed and saved automatically in real time, and test results can be displayed in real time, which is efficient and intuitive;

[0026] (3) Data collection time judgment, realizing automatic switching between the two working modes of daytime IV measurement and nighttime temperature and humidity data collection, without the need for manual operation and reducing the impact of the digital source meter voltage excitation on the stability of battery performance.

[0027] (4) Real-time acquisition of performance parameters under different solar radiation intensities, ambient temperatures, humidity, and different battery temperatures. This truly reflects the working conditions of solar cells in outdoor environments, and obtains battery-related output characteristic parameters (including: short-circuit current, open-circuit voltage, fill factor, maximum output power, series resistance, parallel resistance), effectively realizing the stability evaluation of solar cell performance in outdoor environments.

[0028] (5) The host computer uses LabVIEW programming software and has built-in different measurement modules. Flexible module matching and parameter settings can be used according to actual needs to achieve different functional test purposes. For example, by shielding the ambient temperature and humidity measurement module and time judgment, indoor solar cell performance and stability testing and characterization can be quickly realized with diversified functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution in this embodiment, the following briefly introduces the drawings required for use in the description of the embodiment. The drawings in the following description are only used for the purpose of preferred implementation and are not considered to be limitations of the present invention.

[0030] Figure 1 It is a schematic diagram of the structure of the test system of the present invention.

[0031] Figure 2 It is a schematic diagram of the testing method flow of the present invention.

[0032] Figure 3 It is a schematic diagram of the rear panel of the LabVIEW software of the test system of the present invention.

[0033] Figure 4 It is a schematic diagram of the LabVIEW software front panel of the test system of the present invention.

[0034] Figure 5 This is a schematic diagram of the solar cell daytime test data results.

[0035] Figure 6 This is a schematic diagram of a novel outdoor stability evaluation method of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings, and the technical solution of the present invention is clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] like Figure 1 As shown, the present invention discloses a solar cell outdoor stability test system based on LabVIEW control, which includes an adjustable angle test fixture, a solar cell to be tested, a digital source meter, a relay control unit, a solar irradiance sensor, an ambient temperature and humidity sensor, a temperature sensor, an RS485 to USB bus communication interface and a host computer. The solar cell to be tested, the solar irradiance sensor, and the ambient temperature and humidity sensor are coplanarly mounted on the adjustable angle test fixture to ensure the consistency of the test conditions, and the fixture is adjusted to the optimal angle to meet the local optimal inclination angle to obtain the maximum solar power generation.

[0038] The relay control unit connects the battery to be tested and the digital source meter respectively, and the test battery is selected through the relay control unit, so that a current loop is formed between the digital source meter and the selected battery. The temperature sensor is attached to the back of the solar cell to be tested using CPU thermal conductive silicone and fixed with thermoplastic resin, which is used to evaluate the battery temperature and heat level under outdoor working conditions.

[0039] In this embodiment, the digital source meter, relay control unit, solar irradiance sensor, ambient temperature and humidity sensor, and temperature sensor are connected to the host computer through the RS485 to USB bus communication interface, and the built-in measurement unit of LabVIEW software sends commands to each sensor to control it. The test command and return data meet the Modbus communication protocol.

[0040] like Figure 2 The following is a flow chart of the outdoor stability test method for solar cells based on LabVIEW control. The test steps are as follows:

[0041] Step 1: Build a solar cell outdoor stability test system based on LabVIEW measurement and control;

[0042] Step 2: Set up the LabVIEW front panel in the host computer, configure the communication ports of each test instrument in the test parameter setting area, and use the digital source meter to measure the start and end voltages, clamp current size, acquisition rate and accuracy, number of test points, daytime IV test start and end time, test cycle, solar cell area and other test parameters.

[0043] Step 3: Set the data storage target path in the LabVIEW front panel data storage setting area on the host computer, and select the battery number to be tested in the battery selection area.

[0044] Step 4: The solar cell stability test begins. The host computer configures the instrument drive and measurement parameters. The software reads the current system time and determines whether it is between the start test time and the end test time.

[0045] Step 5: If the set test time range is not met, the night environment temperature and humidity acquisition mode is carried out, and the LabVIEW software environment temperature and humidity measurement module in the host computer works, sends a read command to the environment temperature and humidity sensor, reads the data, processes and stores it in the specified location document. If the set test time range is met, the daytime IV test mode is carried out, and the built-in module of the host computer LabVIEW software sends the test command to each sensor and control measurement unit through the RS485 to USB bus communication interface.

[0046] Step 6: The relay control unit selects the first battery to be tested, and then the digital source meter performs an IV test on the selected battery. The ambient temperature and humidity sensor synchronously returns the ambient temperature and humidity, the solar irradiance sensor returns the solar irradiance, and the temperature sensor returns the battery temperature. The IV curve data is processed to obtain short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, photoelectric conversion efficiency, etc., and then the collected data is stored in the specified location document and displayed in the battery test result display area on the front panel. The IV test curve is drawn and displayed in the IV curve display area.

[0047] Step 7: The relay control unit connects the next battery to be tested with the digital source meter according to the battery test number selected in the battery selection area to be tested, and repeats step 6 until all batteries are tested.

[0048] Step 8: According to the test cycle set in the test parameter setting area, wait for the corresponding time and then make a time judgment, and enter the test process of step 5, thereby completing the process of automatic and efficient data collection and processing.

[0049] The built-in time judgment of LabVIEW software realizes the separation of the two modes of daytime IV measurement and nighttime temperature and humidity data collection. At night, the battery is in an open circuit state under dark conditions, and the digital source meter suspends scanning, avoiding the battery performance degradation caused by the current and voltage scanning excitation of the digital source meter under dark conditions at night.

[0050] Figure 3The figure shows the rear panel diagram of the LabVIEW test software installed on the host computer of the solar cell outdoor stability test system based on LabVIEW measurement and control. The LabVIEW test software has built-in IV test module, battery test selection module, battery temperature measurement module, ambient temperature and humidity measurement module, solar irradiance measurement module and data processing and storage module.

[0051] The IV test module is used to configure and control the test parameters of the digital source meter, and can adjust the starting and ending voltages, clamping current size, acquisition rate and accuracy, test points, etc. of the battery IV measurement.

[0052] The battery test selection module is used for program control of the relay control unit to realize sequential selection of batteries to be tested by the relay control unit. The digital source meter connects the selected batteries to be tested through the relay control unit and forms a current loop to realize IV curve testing of the batteries one by one.

[0053] The battery temperature measurement module, the ambient temperature and humidity measurement module, and the solar irradiance measurement module are respectively connected to read the measurement data of the temperature sensor, the ambient temperature and humidity sensor, and the solar irradiance sensor, and collect the battery temperature, ambient temperature, humidity, and solar irradiance intensity of the single battery currently being tested in the environment.

[0054] The data processing and storage module processes the data of the response information in the MODBUS communication protocol format and the IV curve data measured by the digital source meter, including the interception of the data in the data area of ​​the data frame, the conversion from hexadecimal to decimal, and the conversion from numerical value to character; the calculation of the short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, photoelectric conversion efficiency, etc. in the IV curve, and finally stores it in a designated location document in a text format.

[0055] For the program block diagram of the back panel of the LabVIEW test software, the simplest combination of structural block diagrams is used to achieve different logical outputs. The sequential structure realizes the sequential response of the relay control unit and the digital source meter, first selecting the battery to be tested, and then performing IV test scanning on the selected battery; the For loop structure specifies the number of program loops of each internal module, controls the selected battery to be input and tested in sequence, which is the logical embodiment of test step seven; the Case structure responds to the time judgment, and realizes the judgment and execution of the two modes of daytime IV measurement and nighttime temperature and humidity data collection, which corresponds to test step five; the outermost While loop structure and the Event structure together constitute the event structure, which is used to respond to the start and stop button pressing events, corresponding to the start test and stop test, and at the same time, in the Event structure, initialize the communication ports of each instrument and wait for the test command to be issued. The host computer uses LabVIEW programming software and a modular design concept. It can use flexible module matching and parameter settings according to actual needs to achieve the test purpose of different functions, shield the environmental temperature and humidity measurement module and time judgment, and quickly realize the indoor solar cell performance and stability test and characterization.

[0056] See also Figure 4 The front panel diagram of the LabVIEW test software installed on the host computer of the solar cell outdoor stability test system based on LabVIEW measurement and control is shown, including the test parameter setting area, data storage setting area, test battery selection area, IV curve display area and battery result display area. In the test parameter setting area, the communication ports of each test instrument are configured, and the digital source meter measures the start and end voltage, clamp current size, acquisition rate and accuracy, number of test points, daytime start test time and end time, test cycle, solar cell area and other test parameters; the data storage setting area sets the data storage target path; in the test battery selection area, select the battery number to be tested, and the For loop structure retrieves the selected battery index number in turn, and performs the internal test of the For loop structure one by one; the IV curve display area draws the current battery IV curve measured by the digital source meter; the battery result display area displays the test results of all batteries within the For loop structure cycle, that is, test step seven, including the test battery number, test time, ambient temperature, humidity, solar radiation intensity, short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, photoelectric conversion efficiency, battery temperature and other data.

[0057] Furthermore, the embodiment of the present invention adopts a novel outdoor stability evaluation method, according to Figure 5 The figure shows the results of solar cell daytime test data. The fluctuation of daytime light intensity, temperature and other environmental factors has a great impact on the commonly used stability evaluation standard with time as the horizontal axis and photoelectric conversion efficiency as the vertical axis. It is difficult to conduct a direct stability evaluation. Figure 6The criterion for judging outdoor stability is the cumulative solar radiation received by the solar cell as the horizontal axis and the solar cell output energy (i.e. maximum power) under the corresponding radiation as the vertical axis, or the overall average photoelectric conversion efficiency of the ratio of the two as the vertical axis. This method not only truly reflects the working performance of solar cells under outdoor conditions, but also facilitates subsequent data processing and rapid research and comparison of outdoor stability of different types of solar cells.

[0058] The above embodiments are only illustrative of the principles and effects of the present invention, as well as some embodiments of its application. For those skilled in the art, several modifications and improvements may be made without departing from the creative concept of the present invention, and all of these belong to the protection scope of the present invention.

Claims

1. A test method for a solar cell outdoor stability test system based on LabVIEW measurement and control, characterized in that: Here are the steps: Step 1: Build a solar cell outdoor stability test system based on LabVIEW measurement and control. The solar cell outdoor stability test system based on LabVIEW measurement and control includes an adjustable angle test fixed bracket, a solar cell to be tested, a digital source meter, a relay control unit, a solar irradiance sensor, an ambient temperature and humidity sensor, a temperature sensor, an RS485 to USB bus communication interface and a host computer; the solar cell to be tested, the solar irradiance sensor, and the ambient temperature and humidity sensor are coplanarly installed on the adjustable angle test fixed bracket to ensure the consistency of test conditions; the temperature sensor is attached to the back of the solar cell to be tested, and is used to evaluate the battery temperature and heating degree of the battery under outdoor working conditions; the relay control unit is respectively connected to the battery to be tested and the digital source meter, and the digital source meter, the relay control unit, the solar irradiance sensor, the ambient temperature and humidity sensor, and the temperature sensor are respectively connected to the host computer through the RS485 to USB bus communication interface, and the built-in measurement unit of the LabVIEW software sends commands to each sensor for control; Step 2: Set up the LabVIEW front panel in the host computer. The front panel includes the test parameter setting area, data storage setting area, battery selection area to be tested, IV curve display area and battery result display area; configure the communication ports of each test instrument in the test parameter setting area, the digital source meter to measure the start and end voltage, clamp current size, acquisition rate and accuracy, number of test points, daytime IV test start and end time, test cycle, and solar cell area test parameters; Step 3: Set the data storage target path in the LabVIEW front panel data storage setting area on the host computer, and select the battery number to be tested in the battery selection area to be tested; Step 4: The solar cell stability test starts, the host computer configures the instrument drive and measurement parameters, and the software reads the current system time and determines whether it is between the start test time and the end time; Step 5: If the set test time range is not met, the night environment temperature and humidity acquisition mode is entered, and the environment temperature and humidity measurement module of the LabVIEW software in the host computer sends a read command to the environment temperature and humidity sensor, reads the data, processes and stores it in the specified location document; if the set test time range is met, the daytime IV test mode is performed, and each module built into the LabVIEW software of the host computer sends the test command to each sensor and control measurement unit through the RS485 to USB bus communication interface; Step 6: The relay control unit selects the first battery to be tested, and then the digital source meter performs an IV test on the selected battery. Synchronously, the ambient temperature and humidity sensor returns the ambient temperature and humidity, the solar irradiance sensor returns the solar irradiance, and the temperature sensor returns the battery temperature. The IV curve data is processed to obtain the short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, and photoelectric conversion efficiency. The collected data is then stored in a designated location document and displayed in the battery test result display area on the front panel. The IV test curve is drawn and displayed in the IV curve display area. Step 7: The relay control unit connects the next battery to be tested with the digital source meter according to the battery test number selected in the battery selection area to be tested, and repeats step 6 until all batteries are tested; Step 8: According to the test cycle set in the test parameter setting area, wait for the corresponding time and make a time judgment, then enter the test process of step 5, thereby completing the process of automatic and efficient data collection and processing.

2. The test method of the solar cell outdoor stability test system based on LabVIEW measurement and control according to claim 1, characterized in that: The host computer is a computer installed with LabVIEW test software, and the LabVIEW test software has built-in IV test module, battery test selection module, battery temperature measurement module, environmental temperature and humidity measurement module, solar irradiance measurement module and data processing and storage module.

3. The test method of the solar cell outdoor stability test system based on LabVIEW measurement and control according to claim 2, characterized in that: The IV test module is used to configure and control the test parameters of the digital source meter, and can adjust the starting and ending voltages, clamping current size, acquisition rate and accuracy, and test points of the battery IV measurement; The battery test selection module is used to program the relay control unit to realize the relay control unit to select the batteries to be tested in sequence, and the digital source meter is connected to the selected batteries to be tested through the relay control unit to form a current loop to realize IV curve testing of the batteries one by one; The battery temperature measurement module, the ambient temperature and humidity measurement module, and the solar irradiance measurement module are used to read the measurement data of the temperature sensor, the ambient temperature and humidity sensor, and the solar irradiance sensor, respectively, and collect the battery temperature, ambient temperature, humidity, and solar irradiance intensity of the single battery currently being tested in the environment; The data processing and storage module is used for data processing of the response information in the MODBUS communication protocol format returned by each sensor and data processing of the IV curve measured by the digital source meter, including interception of data in the data area of ​​the data frame, conversion from hexadecimal to decimal, and conversion from numerical value to character; calculation of short-circuit current, open-circuit voltage, fill factor, maximum power, series-parallel resistance, and photoelectric conversion efficiency in the IV curve, and finally storing it in a designated location document in text format.

4. The test method of the solar cell outdoor stability test system based on LabVIEW measurement and control according to claim 1, characterized in that: The LabVIEW software has built-in time judgment, which realizes the separation of the two modes of daytime IV data measurement and nighttime temperature and humidity data collection. Under dark conditions at night, the battery is in an open circuit state, and the digital source meter suspends scanning, thereby avoiding battery performance degradation caused by the current and voltage scanning excitation of the digital source meter under dark conditions at night.

5. The test method of the solar cell outdoor stability test system based on LabVIEW measurement and control according to claim 4 is characterized in that: An outdoor stability evaluation method is adopted, with the cumulative solar radiation received by the solar cell as the horizontal coordinate and the solar cell output energy under the corresponding radiation as the vertical coordinate, or the overall average photoelectric conversion efficiency of the ratio of the two as the vertical coordinate as the judgment standard for outdoor stability. This method eliminates the influence of fluctuations in daytime light intensity and temperature environmental factors on the commonly used stability evaluation standard with time as the horizontal coordinate and photoelectric conversion efficiency as the vertical coordinate.

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