Stability analysis of an active-damped LLCL filter- based grid-connected three-phase inverter

Power passive filters are a standard solution for grid-current harmonics attenuation. However, these types of filters may cause a resonance between the inverter and the grid. Passive and active damping techniques are employed for resonance ttenuation. Efficiency concerns have set active damping techniques as promising solution for the resonance problem compared to the passive damping techniques. In this paper, the characteristics, performance, and effect of different active damping schemes applied to an LLCL passive power filter interfacing a three-phase voltage source inverter (VSI) to the grid is investigated. Stablity analysis is conducted for the LLCL-based grid-connected VSI. The presented concept has been elucidated by simulation results using Matlab/Simulink platform.