Photovoltaic module defect EL tester is a special test equipment for monitoring and researching photovoltaic module production defects. The equipment usually includes computer system (test software), camera control system (temperature control system, camera, etc.), dark room, etc. Here is an example of Peide Optoelectronics EL-8.3MS-M photovoltaic module defect EL tester.
1. Technical features and working principle
The technical characteristics of Peide Optoelectronics EL-8.3MS-M photovoltaic module defect EL tester are as follows.
(1) Application type: production line.
(2) Monitoring points: before/after lamination.
(3) Applicable component size: 125mm/12×6pes, 156mm/10×6pes, 1l56mm/12×6pes or non-standard within 2000mm×1000mm.
(4) Camera Sensor Manufacturer: Kodak.
(5) Camera type: Cooled CCD (cooled to 30°C at room temperature).
(6) Resolution: 3200×2500.
(7) Image acquisition time: 1-60s adjustable.
(8) Maximum current/voltage drive: 8.5A/60V.
(9) Software functions: ① Scan and input barcodes, and automatically name and save with barcodes;
②Defect classification, automatic generation of date folders, automatic saving, query and printing functions.
(10) Extensibility: It can test the low light performance of the module and the power generation efficiency of the module under low light.
The working principle of the photovoltaic module defect EL tester is to use the property that the electroluminescence intensity of the solar cell is proportional to the diffusion length of the internal minority carriers, and the imaging system is used to send the signal to the computer software, and the EL image of the solar cell is processed after processing. displayed on the screen. Through the analysis of EL images, possible problems in all aspects of the production of silicon wafers and solar cells can be effectively found, which plays an important role in improving the process, improving the efficiency and stabilizing the production.
The photovoltaic module defect EL tester can be used to observe abnormal phenomena such as mismatch, welding defects, contamination, debris, and cracks in the photovoltaic module production, as shown in Figure 2-Figure 5. For these problems, process improvement and correction should be carried out before PV module lamination.
Cell mixing is one of the reasons for the mismatch of photovoltaic modules. In the EL test chart of a module, the luminous intensity of some cells is weaker than that of most cells in the module. This is because the current or voltage of this part of cells is divided from the current of most cells in the module. Or the voltage division is inconsistent.
Fragments in photovoltaic modules mostly appear in the welding and lamination process of the module packaging process. In the EL test chart, there are black blocks in the cell, because there is no current injection in the broken part of the cell after the cell is broken, resulting in this part. Does not emit light in the EL test.
The silicon material used in crystalline silicon solar cells is inherently fragile, so cracks are easily generated during cell production and module packaging. There are two types of lobes, one is a fissure, and the other is a fissure. Exposed cracks can be directly seen by the naked eye, and can be eliminated by the sorting process in the component production process; while hidden cracks cannot be directly seen by the naked eye, and are more prone to cracking problems during the production process of components. Since the dissociation surface of single crystal silicon has certain rules, it can be clearly seen from the EL test chart that the hidden cracks of the single crystal silicon cell are generally an “X”-shaped pattern along the diagonal direction of the cell. For polycrystalline silicon cells, due to the influence of grain boundaries, it is sometimes difficult to distinguish whether it is a polycrystalline silicon grain boundary or a hidden crack in the cell.
2. Operation steps
The simple operation steps of Peide Optoelectronics EL-8.3MS-M type photovoltaic module defect EL. tester are as follows:
(l) Press the switch to open the camera obscura cover.
(2) Put in the battery pack and connect the power connector (pay attention to the positive and negative poles).
(3) Confirm that the Camera is connected to the PC, and open the EL software. In the software mode of Engineer, set parameters, the main parameters are exposure time, gain, contrast and gamma.
Users can adjust it according to the needs of the production line. Generally, the exposure time is set to 5~15, the gain is set to a fixed 63, the contrast (black triangle) is set to the first trough, and the gamma (white triangle) is set to the last trough (double triangle). The camera is divided into camera 1 and camera 2, which need to be set separately). If the time needs to be modified, the corresponding gain value should also be changed accordingly, so as to obtain the subjective judgment of the best effect. For the convenience of use, the software can save and manage the parameters.
(4) Switch to the operator mode of the software, set the save path of the picture to the desired folder, and after entering the file name, press the button switch to close the camera obscura. At this time, the “Capture” in the software will be manually pressed to take the picture. Shoot (“Capture” is dimmed).
(4) After shooting, open the camera obscura.
(5) Remove the power connector, replace the battery pack, and repeat step (2).
The precautions for the use of Peide Optoelectronics El-8.3MS-M photovoltaic module defect EL tester are as follows:
(1) Make sure that the power supply is connected correctly before use, the positive pole is connected to the positive pole, and the negative pole is connected to the negative pole.
(2) It is forbidden to use U disk to copy data to avoid virus infection and loss of important data.
(3) Regularly remove the dust on the tempered glass.
(4) DC plugs represent different voltages and currents, and mixed plugs will cause the main components to burn out. Please do not plug or unplug the DC plug!
(5) If it is not used for a period of time, the computer and all power sources should be turned off at the same time.
(6) Do not place any objects on the camera obscura.
4. Use exceptions and solutions
The abnormal conditions that may occur during the use of Peide Optoelectronics EL-8.3MS-M photovoltaic module defect EL tester and the solutions are as follows:
(1) Images cannot be displayed in the software.
Check the regulated power supply to see if the voltage output button (OUTPUT) is pressed. Normally, the OUTPUT red light is on. Check whether the power cord is connected properly. If the current is normal and the voltage is small (<l0V), the positive and negative clips may be short-circuited; if the current is small or 0, the battery polarity may not match, and the positive and negative electrodes can be reversed; No improvement yet, component testing should be replaced.
(2) The image quality is not good.
① Check whether the current and voltage are within the specified range.
②Whether the parameters in the software settings are adjusted correctly.
③ Check whether there are foreign objects, such as dust, on the tempered glass.
④ Check whether the cooling power supply of the camera is connected (if it is not connected, there will be a lot of noise in the image).
(3) The software cannot perform normal shooting.
① Is the camera connected to the computer?
②Unplug the storage device such as the USB flash drive, the storage device such as the USB flash drive will conflict with the camera, and it will not be possible to shoot.
③ Check whether the two EL softwares are opened, which will affect the normal use of the software.
(4) The opening and closing of the upper cover is not smooth.
① Check whether the air pressure in the pressure reducing valve is within the normal range.
②Adjust the speed regulating valve at both ends of the cylinder to adjust the speed and the balance of both sides. Note: During the adjustment process, adjust the cylinders on both sides of the equipment at the same time to avoid distortion of the upper cover of the dark box in the case of unbalanced conditions.