Research And Design Of Solar Cells Tester Based On Embedded Technology

The I-V tester of solar cells is one of the most important equipment of photovoltaic production. In the domestic, the research of I-V tester of solar cells focuses on the study of photovoltaic array tester, and is less concerned about the I-V tester for single solar cells and modules. The existing I-V tester of solar cells use the PC as the host computer and has the shortcomings of costliness, bulky, cumbrousness and not suitable for the situation that required frequent movements. In order to reduce the costs and improve the performance of the I-V tester, this paper researched a handheld I-V tester of solar cells based on embedded technology.At first, the physical characteristics and the mathematical description for physical models of solar cells was analyzed: the single exponential model and the double exponential model. Then the theories and methods of curve fitting based on mathematical was conducted in-depth study, Three methods were compared: single-exponential fitting, double exponential curve fitting and polynomial fitting, and the optimization of fitting methods was given. In the next, we described the design of hardware and software of the tester in detail. In the hardware section, the I-V signal sampling circuit, the temperature sampling circuit, the light intensity signal sampling circuit, power supply and storage management circuit were introduced. Next that, the paper discussed the principle and process of the bootloader migration, the operating system migration and interface program design. Finally, the stability of the hardware and the software of the testing system was analyzed and evaluated. The result shows that:the tester has the advantages of stable performance and lower power consumption, friendly interface, smooth and simple operation.