Sliding-Mode Control for Grid-Connected Inverter with a Passive Damped LCL Filter

This paper aims at finding a suitable strategy to control the LCL-based grid-connected inverter during the process of wind power grid-connection. LCL filter belongs to third-order system, which may introduce resonant peaks and lead to the instability of the system. Considering that active damping may sometimes negatively effect system ability and the grid current quality, in this paper, passive damping is introduced in the LCL filter to suppress the resonant peaks and simplify the controller design, and the mathematical model of the inverter is established based on it. The sliding-mode control strategy is adopted in the design process of the controller, as it has obvious advantages such as strong robustness and decent dynamic characteristics compared with traditional control method. Finally, the simulation is carried out in Matlab/Simulink software environment.