Fast harmonics compensation in VSCs connected to the grid by synchronous-frame generalized integrators

The drawback of using a VSC as an interface with the grid is its sensitivity in presence of system disturbances as grid voltage harmonics. In this paper, a new current controller structure to harmonics compensation is proposed. It consists of using two control loops. The first is based in synchronous PI working in rotating coordinates with DC components; and the second uses synchronous-frame generalized integrators (Gl) tuned to the harmonics frequency. The proposed algorithm temporal responses under grid voltage harmonics are presented, and also, the proposed digital control electronics system, where the algorithms run, is shown.