The Control Method of Grid-Tied Photovoltaic Generation

Microgrid allows high penetration of renewable energy sources, and provides technical foundation for the grid connection and operation of distributed generations (DGs). The negative impacts caused by DGs should be reduced inside the microgrid. Photovoltaic (PV) generation is one of the major distributed energy sources, and the performance of PV generation systems connected to microgrid directly affects power quality and other technical indexes of the microgrid. Thus, the research of flexible microgrid connection control for PV generation system has both theoretical significance and practical value. This paper makes a concise exposition on the H_∞ control theory and applies this theory to the flexible microgrid connection control for PV generation systems. This paper focuses on the specific situation where the microgrid is grid tied to the main power grid. We establish the mathematical model of PV generation system and adopt the H_∞ control theory to design a voltage tracking controller. Theoretical analysis proved that our control system is internally stable. Simulations under six different conditions are performed using MATLAB/Simulink, and the results demonstrate that the grid-tied PV generation system using H_∞ controller has high control accuracy and robustness.