Power control strategies for grid connected converters applied to full-scale wind energy conversion systems during LVRT operation

Abstract Some grid codes establish that during voltage sags, the generation units employing static converters must favor the electrical mains support. Unbalanced voltage sags generate grid power oscillations with twice the fundamental frequency. This way, the converter control can be modified to mitigate the unbalanced sag effects to the grid converter. The present work analyzes different power control methods presented in literature, in order to study how they affect the active and reactive power oscillation and the generated current waveform. A case study with a simulation of a 2(MW) WECS is performed in order to analyze the strategies behavior in terms of power fluctuation and converter dc bus impacts. It is evaluated the system behavior over different operation points of reactive current injection curve, defined in the modern grid codes.