Mitigation of Subsynchronous Resonance in DFIG based Wind. Farms using Fuzzy Controllers

DFIG based wind farm with Type III wind turbines are the most popular choice of wind power generation industry. Mostly, these wind farms are connected to load centers by series compensated long transmission lines. Series compensated lines offer cost effective way to evacuate large power from these wind farms. But these wind farms connected through series compensated lines may be affected by Sub Synchronous Resonance (SSR). Induction generator effect is the predominant cause of SSR in series compensated transmission lines or feeders as suggested by earlier researchers. Fuzzy logic control offers an effective way to mitigate the effect of SSR. In this paper application of fuzzy controllers instead of PI controllers in partially rated converter has been proposed to damp out SSR oscillations. First fuzzy controller parameters like number of membership functions and shape of membership functions have been studied for effectiveness of fuzzy controller for SSR control. Then fuzzy controllers for RSC, GSC and DC Link Voltage Controller have been studied and compared for their effectiveness to mitigate SSR phenomena.