Research And Design On The Power Optimizer Of Photovoltaic System

A solar power optimizer with Maximum Power Point Track (MPPT) function is researched and designed in this thesis. The main contents of this thesis are as follows:1. The working principle and the output characteristics of photovoltaic (PV) cells are introduced in this thesis. The simulation model of PV array is built based on Matlab/Simulink. The power output characteristics of PV array are researched. When PV array is under shadow, the multi-peak characteristic is analyzed.2. Several common topologies of PV power generation systems are compared. The advantages of modular MPPT power optimizer are discussed.3. The work principle of MPPT technique is introduced. The advantages and disadvantages of several common MPPT are analyzed and compared. A MPPT algorithm, which is based on variable-step and improved hysteresis comparison method, is used in the Power Optimizer design. This MPPT algorithm can effectively improve the system maximum power point tracking capability and stability.4. The experimental platform of power optimizer is built. The topology of main circuit is used by Buck circuit. The main control chip uses STM32F031F6P6 which is one of ARM Cortex-MO series chip. At the same time, the design of power supply is used by the switch power supply, which can improve the stability of the system.5. The system debugging of power optimizer is completed. Some experimental studies are carried out in this thesis. The experimental results verify the effectiveness of the control method.