Study On Control Method Of Three-Phase Off- Grid Inverter Based On MPC

Today, solar energy has become a new energy developed all over the world. Photovoltaic power is the most important applications and research points. Photovoltaic inverter is a very important part of photovoltaic power generation, which has a great impact on the performance and cost of the system. Therefore, it is significant to study the control method of inverter for the safe and reliable operation of photovoltaic power generation system. In this paper, a control method of the three-phase off-grid inverter which combines model predictive control (MPC) with PI control is studied. The main work of this thesis includes:1. The control method of three-phase off-grid inverter is discussed, including PID control, repetitive control, deadbeat control, fuzzy control. The model predictive control algorithm is studied. The development process and basic principle of MPC are introduced. The advantages and problems of model predictive control are analyzed.2. The topology and control method of three-phase off-grid inverter is studied. The main circuit model and mathematical model of the system are obtained.3. According to the advantages and disadvantages of MPC and PI control, we use model predictive PI control method which combines MPC with PI control is employed.4. Simulations of theoretical analyses are carried out by means of Matlab/Simulink software. An experimental test bench of three-phase off-grid inverter is set up. The realization of hardware and software is introduced, and the model predictive PI control algorithm is realized. The comparison results between model predictive PI control algorithm and traditional PI control are given. Simulation and experimental results verify the validity of model predictive PI control algorithm.