Research on Synchronous Control Method for Suppressing Nonlinear Impulse Perturbation of Photovoltaic Grid-Connected Inverter

Abstract

In this paper, the synchronous control problem of photovoltaic grid-connected inverter with nonlinear impulse perturbation is studied. The mathematical model of photovoltaic grid-connected converter is established by using Kirchhoff's law. The nonlinear impulse perturbation characteristics of grid-connected current are studied and analyzed. Controllers are designed to suppress nonlinear impulse perturbation. The effectiveness of the controller is verified by Lyapunov stability theory. Finally, the simulation design is carried out by simulink in Matlab and the test platform is constructed. In this paper, simulation verification and data comparison are carried out by using various control methods for suppressing nonlinear impulse perturbation of grid-connected currents. Compared with PI controller, PR controller and other controller, the output harmonic content of photovoltaic inverter can be controlled within 1%, which can effectively reduce the harmonic content. The power quality of grid-connected current is improved. The feasibility and effectiveness of the control strategy proposed are verified by simulation and experiments.

Keywords

• Nonlinear impulse perturbation
• harmonic content
• Lyapunov stability
• photovoltaic inverter