A method and device for testing solar cells and components based on short pulse width

Abstract

A method and device for testing solar cells and components based on short pulse width, belonging to the field of solar cell testing, characterized in that: Voc, Isc, and Pmax are obtained through the first IV curve test within a flash cycle, and the accurate Pmax value is further obtained through the second test after adjusting the test parameters. By presetting the equivalent magnification of the second sampling delay, it is ensured that the test data collection in the Pmax core area in the second test is in a stable period. After setting, the test process does not require manual intervention, and accurate test results can be obtained by clicking once; the test method of the present invention does not rely on long pulse width to eliminate the capacitance effect during the test process, and can achieve the purpose of accurate testing within a relatively short pulse width, with simple effects and suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the field of solar cell testing, and in particular relates to a method and a device for testing solar cells and components based on short pulse width. Background Art

[0002] With the progress of the industrialization layout of high-efficiency batteries, mass production of PERC, N-type TOP Con and HJT in the promotion stage, the battery efficiency is getting higher and higher. The higher the battery efficiency, the more difficult it is to accurately test. At present, the industrial end tests high-efficiency solar cells and modules based on the electronic load IV and VI modes with long pulse width to evaluate the relative difference in Pmax of the two tests to evaluate whether they meet the test requirements. Since the industrial end usually adopts an assembly line operation method, it has high requirements for test capacity and beat, and it is impossible to conduct instant evaluation of each test object at the industrial site and make real-time adjustments based on its characteristics. Laboratories and third-party institutions often use multiple 10ms segmented tests to fit the complete IV curve. N-type TOP Con and HJT have a larger capacitance effect. Using 10ms segments to obtain relatively accurate electrical performance, dozens or even hundreds of segmented tests need to be set up to meet the test requirements of this type of solar cells and modules.

[0003] At the same time, the industrial end uses long pulse width and matching electronic load modulation to solve the capacitance effect of the test object and obtain more accurate electrical performance parameters. However, the long pulse width requires the test equipment to have good performance. The total energy released by the light source during the long pulse width test is relatively large, and the partial loss of the light source and the power consumption of the equipment are bound to be more serious. Currently, solar simulators mostly use xenon lamps as light sources. Xenon lamps are consumables. For clients, the energy consumption and practical costs brought about by using long pulse width tests are relatively higher. Summary of the invention

[0004] The present invention aims to solve the above problems and provide a method and device for testing solar cells and components based on short pulse width, which does not need to strictly rely on long pulse width and can obtain test results through only two tests.

[0005] In a first aspect, the present invention provides a method for testing solar cells and components based on short pulse width, comprising the following steps:

[0006] Performing two IV curve tests within one flash cycle; the two IV curve tests are a first IV curve test and a second IV curve test;

[0007] Through the first IV curve test, Voc, Isc and maximum power Pmax are obtained under set test parameters; according to the maximum power Pmax of the first IV curve test, the voltage and current corresponding to the maximum power Pmax are marked as point P;

[0008] The test parameters include scanning area, sampling delay time and number of electronic load adjustment;

[0009] Adjust test parameters;

[0010] The scanning area of ​​the second IV curve test is adjusted backward from the aforementioned point P to 1%-15% of the scanning area of ​​the first IV curve test;

[0011] Adjust the electronic load adjustment times of the second IV curve test to 0.1%-10% of the electronic load adjustment times of the first IV curve test;

[0012] The sampling delay time of the second IV curve test is adjusted according to the preset equivalent magnification, so that the sampling time during the second IV curve test is in a stable period within the test cycle;

[0013] Perform a second IV curve test and output the test results.

[0014] Furthermore, in the method for testing solar cells and components based on short pulse width of the present invention, the sampling delay time of the second IV curve test is equal to the product of the preset equivalent magnification and the sampling delay time in the first IV curve test.

[0015] Furthermore, the method for testing solar cells and components based on short pulse width of the present invention is characterized in that: the range of the equivalent magnification is 1-10000 times; the selection of the equivalent magnification is related to the pulse width tested; the equivalent magnification adopted makes the corresponding electronic load adjust and the entire acquisition system enter a stable period after a delay during the process of measuring the maximum power. Entering the stable period means that the capacitance effect is eliminated, and the accuracy of the test can be met.

[0016] Furthermore, in the method for testing solar cells and components based on short pulse width described in the present invention, the number of electronic load adjustments in the first IV curve test is 10-2000; one adjustment of the electronic load causes the balance of the test to be broken, and the electronic load needs to be adjusted a corresponding number of times from short circuit to open circuit to draw the corresponding curve, otherwise it is easy to cause curve distortion.

[0017] In a second aspect, the present invention provides a device for testing solar cells and components based on short pulse width, comprising a test module, an adjustment module and an output module connected in sequence;

[0018] The test module is used to test solar cells and components according to set test parameters;

[0019] The adjustment module is used to adjust the second test parameters according to the first test parameters;

[0020] The output module is used to output the test results of the test module.

[0021] Furthermore, in the device for testing solar cells and modules based on short pulse width of the present invention, the adjustment of the second test parameters is specifically as follows: the scanning area of ​​the second IV curve test is adjusted backward from the aforementioned point P to 1%-15% of the scanning area in the first IV curve test;

[0022] Adjust the electronic load adjustment times of the second IV curve test to 0.1%-10% of the electronic load adjustment times of the first IV curve test;

[0023] The sampling delay time of the second IV curve test is adjusted according to the preset equivalent magnification so that the sampling time during the second IV curve test is in a stable period within the test cycle.

[0024] The method and device for testing solar cells and components based on short pulse width described in the present invention obtain Voc, Isc, and Pmax through the first IV curve test within a flash cycle, and further obtain accurate Pmax value through the second test after adjusting the test parameters. By presetting the equivalent magnification of the second sampling delay, it is ensured that the test data collection in the Pmax core area in the second test is in a stable period. After setting, the test process does not require manual intervention, and accurate test results can be obtained by clicking once; the test method described in the present invention does not rely on long pulse width to eliminate the capacitance effect during the test process, and can achieve the purpose of accurate testing within a relatively short pulse width. It is simple and effective, and suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of electrical parameters during the test of solar cells and components based on short pulse width according to the first embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of a solar cell and component testing device based on short pulse width testing according to Embodiment 3 of the present invention;

[0027] Among them, 1-irradiance line, 2-voltage loop signal, 3-current loop signal. DETAILED DESCRIPTION

[0028] The method and device for testing solar cells and components based on short pulse width according to the present invention are described in detail below through the accompanying drawings and embodiments.

[0029] Embodiment 1

[0030] In the example disclosed in the present invention, the light source is a xenon lamp. Taking IV mode as an example, the performance of electrical parameters such as irradiance, voltage, and current during the test is as follows: Figure 1As shown, line 1 is the irradiance line, representing the energy output state of the xenon lamp; line 2 is the voltage loop signal of the object under test; and line 3 is the current loop signal of the object under test. After the xenon lamp is triggered, the light energy output by the xenon lamp enters a stable output state after being modulated by the PID negative feedback circuit. After a preset delay, data is collected during the output stable time period. Since the electronic load is in an open circuit state at this time, the tested voltage is Voc, and the disconnected current of the test circuit is zero. When the electronic load is controlled and modulated from the open circuit state to the short circuit state, after a delay, as shown in lines 2 and 3, the voltage is zero, and the current tested at this time is the short circuit current Isc. After entering the IV test phase, line 1 maintains a stable output; the electronic load is gradually adjusted from the short circuit state to the open circuit, that is, the external impedance in the test circuit (the electronic load can be understood as a sliding rheostat) gradually increases from zero to infinity. After each modulation of the corresponding electronic load, the state of the test circuit enters a stable period after a delay time before data collection, from Figure 1 It can be seen that after each adjustment of the electronic load, there is a long period of unstable period at the front end. If the data is collected at this time, the data will be unstable and the accuracy of the collection cannot be ensured.

[0031] The method for testing solar cells and components based on short pulse width described in the embodiment of the present disclosure is to perform two IV curve tests within one flash cycle; the two IV curve tests are respectively a first IV curve test and a second IV curve test.

[0032] The specific steps include:

[0033] Step 1: Through the first IV curve test, Voc, Isc and maximum power Pmax are obtained under set test parameters; according to the maximum power Pmax of the first IV curve test, the voltage and current corresponding to the maximum power Pmax are marked as point P; the test parameters include scanning area, sampling delay time and number of electronic load adjustments.

[0034] Step 2, adjust the test parameters; adjust the scanning area of ​​the second IV curve test backward from the aforementioned point P to 8% of the scanning area in the first IV curve test; adjust the number of electronic load adjustments in the second IV curve test to 5% of the number of electronic load adjustments in the first IV curve test, and the number of electronic load adjustments in the first test in the present disclosed embodiment is 400; adjust the sampling delay time of the second IV curve test according to a preset equivalent magnification, and the sampling delay time of the second IV curve test is equal to the product of the preset equivalent magnification and the sampling delay time in the first IV curve test; make the sampling time during the second IV curve test in a stable period within the test cycle.

[0035] Step 3: Perform a second IV curve test and output the test results.

[0036] During the first IV curve test, the starting point is determined based on the maximum value of Pmax obtained for the first time, and the scanning interval is adjusted backwards; because usually, the sampling delay during the first test data acquisition is not long enough, and the stable period is not entered, resulting in differences between the test data and the actual data.

[0037] The setting of the sampling interval time is determined by setting the equivalent magnification by the host computer in a specific application. For a specific test object, there is usually a relative test pulse width. Therefore, by setting the equivalent magnification accordingly, the problem of sufficient delay in data acquisition during the second IV curve test can be solved to ensure that the acquisition is in a stable period. In the embodiment disclosed in the present invention, the pulse width is selected as 20ms, and the number of sampling points for the first IV curve test is set to 400 points. Then the total time between each point is 0.05ms, and 0.05ms includes the sampling delay time and the data acquisition time. By setting the equivalent magnification corresponding to the test object by the host computer, the pulse width time required for the first IV curve test is 20ms, and the time for testing Voc is usually within 10ms, and the corresponding acquisition delay time is 0.044ms; the equivalent magnification multiplied by 0.044ms is the total sampling delay time in the second IV curve test. In the above manner, it can be ensured that the data acquisition can be ensured to a stable period by adjusting the equivalent magnification in the second IV curve test.

[0038] Embodiment 2

[0039] In the disclosed embodiment, taking the HJT component to be tested as an example, the test mode is IV as an example, the first scan point number is 400 points, the pulse width is selected as 10ms, the first scan obtains the corresponding points of Voc, Isc, and Pmax and the interval of the second scan, the test process is continuous within one light cycle, and the test interval is not interrupted during the test process; the second scan interval is 9% of the total sampling interval adjusted backward from the corresponding point of the first Pmax, and the number of electronic load adjustments in the scan interval is set to 7. The sampling delay is set by the host computer to set the equivalent magnification. Due to the large capacitance effect of the object under test, the equivalent magnification is set to 150 in the disclosed embodiment to obtain relatively accurate test data.

[0040] The first step is to obtain Voc and Isc, and the second step is to obtain Pmax. This solution can quickly and efficiently obtain the accurate electrical performance parameters of the object being measured.

[0041] Embodiment 3

[0042] In the embodiments of the present disclosure, Figure 2The present invention provides a device for testing solar cells and components based on short pulse width, comprising a test module, an adjustment module and an output module connected in sequence; the test module is used to test the solar cells and components according to set test parameters; the adjustment module is used to adjust the second test parameters according to the first test parameters; the output module is used to output the test results of the test module.

[0043] When executing the test, the adjustment of the second test parameters is specifically as follows: the scanning area of ​​the second IV curve test is adjusted backward from the aforementioned point P to 1%-15% of the scanning area in the first IV curve test; the number of electronic load adjustments of the second IV curve test is adjusted to 0.1%-10% of the number of electronic load adjustments in the first IV curve test; the sampling delay time of the second IV curve test is adjusted according to the preset equivalent multiplier, so that the sampling time during the second IV curve test is in a stable period within the test cycle.

[0044] The method for testing solar cells and modules using the device for testing solar cells and modules based on short pulse width described in the embodiment of the present disclosure is the same as the method described in Embodiment 1 and Embodiment 2, and will not be described again here.

[0045] The solution of the present invention is not limited to the linear electronic load mode, but is also applicable to nonlinear and other electronic load modulation modes; at the same time, the solution of the present invention does not simply rely on pulse width to solve the capacitance effect of the object being measured.

[0046] The scheme and ideas described in the present invention can be used by engineering and technical personnel in this field to carry out relevant supporting test schemes under the guidance of the scheme and ideas described in the present invention.

Claims

1. A method for testing solar cells and components based on short pulse width, characterized in that: Performing two IV curve tests within one flash cycle; the two IV curve tests are a first IV curve test and a second IV curve test; Through the first IV curve test, Voc, Isc and maximum power Pmax are obtained under set test parameters; according to the maximum power Pmax of the first IV curve test, the voltage and current corresponding to the maximum power Pmax are marked as point P; The test parameters include scanning area, sampling delay time and number of electronic load adjustment; Adjust test parameters; The scanning area of ​​the second IV curve test is adjusted backward from the aforementioned point P to 1%-15% of the scanning area of ​​the first IV curve test; Adjust the electronic load adjustment times of the second IV curve test to 0.1%-10% of the electronic load adjustment times of the first IV curve test; The sampling delay time of the second IV curve test is adjusted according to the preset equivalent magnification, so that the sampling time during the second IV curve test is in a stable period within the test cycle; Perform a second IV curve test and output the test result; the sampling delay time of the second IV curve test is equal to the product of the preset equivalent magnification and the sampling delay time in the first IV curve test.

2. The method for testing solar cells and components based on short pulse width according to claim 1, characterized in that: The equivalent ratio ranges from 1 to 10,000 times.

3. The method for testing solar cells and components based on short pulse width according to claim 2, characterized in that: The number of electronic load adjustments in the first IV curve test is 10-2000.

4. A device for testing solar cells and components based on short pulse width according to any one of claims 1 to 3, characterized in that: It includes a test module, an adjustment module and an output module connected in sequence; The test module is used to test solar cells and components according to set test parameters; The adjustment module is used to adjust the second test parameters according to the first test parameters; The output module is used to output the test results of the test module.

5. The device for testing solar cells and components based on short pulse width according to claim 4, characterized in that: The adjustment of the second test parameters is specifically as follows: the scanning area of ​​the second IV curve test is adjusted backward from the aforementioned point P to 1%-15% of the scanning area in the first IV curve test; Adjust the electronic load adjustment times of the second IV curve test to 0.1%-10% of the electronic load adjustment times of the first IV curve test; The sampling delay time of the second IV curve test is adjusted according to the preset equivalent magnification so that the sampling time during the second IV curve test is in a stable period within the test cycle.

Images