Design Of A Programmable MPPT Control Technology Based On FPGA

Solar energy is so popular as a kind of green renewable energy that the photovoltaic technology has become the field which many countries compete to develop. But there is an important issue in the photovoltaic power generation which is the low utilization of photovoltaic cells, so how to enhance the efficiency of conversion for the photovoltaic energy system has become a main issue. MPPT control technology is an effective means to improve the efficiency of photovoltaic cells, therefore, MPPT control method becomes an important aspect of photovoltaic power generation.To enhance the conversion efficiency of the photovoltaic cells, perturbation and observation method is improved in this paper based on the traditional control method , and a digital design method of maximum power point tracking based on FPGA has been proposed. Detailed RTL-level design of this controller is carried out on Altera QuartusⅡsoftware with the top-to-down approach. The MPPT controller is comprised of six functional modules, easily transplanted and upgraded. And the entire control system is easy to extend and upgrade. After design of the RTL level, simulation is made on esch module. In order to verify the system function of the controller, the program is downloaded to EP1C3T144C8N chip at the FPGA kit.The maximum power point tracking experimental circuit based on MPPT controller is designed, and the boost converter is used to achieve the maximum power point tracking in this design. The traditional perturbation method and the improved perturbation method are used in the experiment. The results show that the tracking precision is better than using traditional methods. Specifically, the tracking precision rises to more than 75%, which increases at least 9 percentage points than the traditional methods.