EID-based Robust Controller Design of PV Grid-Connected System with Parameter Uncertainty

In practice, the three-phase two-stage PV grid-connected system is interfered with by internal and external factors. How to improve the anti-interference ability of the grid-connected inverter has become more and more important. In this paper, a current robust controller design method based on equivalent input disturbance(EID) is proposed for the grid-connected PV inverter system with parameter uncertainty. Firstly, the uncertainty of the PV grid-connected system is analyzed, and the mathematical model of the parameter uncertainty system is constructed. Secondly, the block diagram of the robust control system with parameter uncertainty based on EID is built. The sufficient condition of robust stability of uncertain inverter system is given by using the Lyapnnov functional method in the form of LMI, and the controller parameters are also designed. Finally, the experimental results show that the current controller has good robustness with parameter uncertainty, and significantly improves the quality of grid-connected current.