Investigation Of Solar Cell Test System Based On STM32 Microcontroller

Currently, the solar cell test equipment is bulky, expensive, etc. on the market. A solar cell test system based on STM32 microcontroller is designed. The main work of this paper is study of solar cell test system based on STM32 microcontroller. The detailed research contents are as follows:1. The basic principle, the equivalent circuit, the test principle, the test methods and the essential technical parameters of solar cell are introduced briefly. These rational principles are beneficial to understand for solar cell and test technology. So as to provide a theoretical basis for the system design.2. The core idea of the system design is as follows. The STM32 controls the DAC change, then the DAC controls the electronic load change. So that voltage and current of solar cell also will change. The ADC collects related data and analyses and processes data at the same time to complete the solar cell I-V curve measurement. Two sets of circuit design programs are made. And design idea and working principle of the programs are introduced. In addition to the main chip, electronic load compensation circuit, voltage, current, temperature, irradiance acquisition circuit and TFTLCD display circuit design have been described in detail.3. The system describes the overall system software to run the process. First of all, STM32F103ZET6 and MCU peripheral circuit is initialized. Initialization includes the STM32 GPIO port, timer module, DAC module, ADC module, DMA module and TFTLCD display module. Secondly, after the system is initialized, data is collected and processed. Then a mathematical model is designed, an iterative algorithm and a least squares algorithm are merged to fit the I-V curve, the Lambert W function solves differential equations to complete the solar cell parameters test in MATLAB.4. Two sets of solar cell test solutions are tested and analyzed. The experimental results show that scheme one is theoretically possible, but it does not work in the actual measurement, and scheme two is feasible. The scheme two is used for solar cell test system. The solar cell test system repeatedly measures a sample. The experimental data show that the solar cell test system has a certain accuracy and reliability.