Robust control of shunt active filter based on the internal model principle

In this paper an advanced control strategy is proposed for shunt active filter (SAF) used in electric current harmonic compensation. Internal model principle is exploited to achieve asymptotic cancellation of harmonics generated by a nonlinear load connected to a three-phase electric main. Robustness with respect to electrical parameters uncertainties of the shunt active filter is achieved. A preliminary theoretical discussion about the stabilization of the internal voltage dynamics of the SAF is provided. The properties of the proposed solution are tested by simulations.