Flicker mitigation strategy for DFIGs during variable wind conditions

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed control scheme mitigates flicker severity with different X/R ratios, distribution line lengths and different wind conditions. However, the proposed strategy is less effective with relatively low SCCs at the point of grid connection, due to large fluctuations of the voltage at the point of grid connection.