Fpga-based Self-tuning Fuzzy Mppt Controller Design

As a clean and renewable energy, solar energy has received more and more attention. As the output characteristic of a solar cell is non-linear, its output current and voltage value to a large extent is affected by sunlight intensity and temperature. When the light intensity, temperature or other conditions changes, the maximum power point of the photovoltaic cells changes a lot. Therefore, researching maximum power point tracking is of great significance for improving the utilization of photovoltaic cells.Conventional MPPT (Maximum Power Point Tracking) control algorithm can make the system work at the maximum power point, but the adaptation of the system is poor. In order to improve the response speed and anti-disturbance ability of the system, this paper develops a self-adjusting fuzzy MPPT controller based on FPGA (Field Programmable Gate Arrays), which improves the adaptive capacity of MPPT control algorithm under complex external conditions, response speed and stability of the system.This dissertation studies the FPGA implementation of fuzzy control module, PWM generated module, 8-bit data multiplier and self-adjustment tracking of the controller. The result of Modelsim simulation shows that the controller can change PWM duty cycle to control the DC-DC converter. The adaptive fuzzy algorithm is compared with P&O (Perturb and Observe) algorithm in Matlab/Simulink. The simulation results show that the adaptive fuzzy algorithm has better steady-state and dynamic-state behavior than traditional P&O algorithm and it's robustness is better.Finally, experiment circuit is constructed using FPGA-based adaptive fuzzy controller, and Photovoltaic arrays MPPT control experiment is performed. Simultaneously, experiments of self-adjusting control and P&O control are also carried out and the results are compared. The experiments prove that self-adjusting fuzzy MPPT controller has better control performance and can make the system work stably at the maximum power point under different light conditions. It also lays the foundation for SoC design of PV system.