Comparison of current controllers based on repetitive-based control and second order generalized integrators for active power filters

In this paper, two current controller schemes, based on repetitive controllers and proportional+resonant controllers using second order generalized integrators connected in parallel, are proposed and compared for shunt active power filters. Both controllers are well suited due to their optimum tracking and harmonic rejection capability. The objectives of this paper are: to analyze both controllers in the continuous and discrete time-domains; to study how to tune the parameters of the controllers and other auxiliary elements like PI controller in the case of repetitive-based controller; to show questions related to real-time implementation for the two cases; and, finally, to present some experimental and comparative results.