Power Smoothing of Doubly Fed Induction Generator for Wind Turbine Using Ultracapacitors

Wind energy is an unpredictable and fluctuating energy source. A nearly random wind speed and blade rotational turbulence can produce fluctuations in the output power and consequently voltage of the system. The output power of wind turbines fluctuates due to wind speed variations. This fluctuating power makes the wind power undispatchable, causing frequency deviations when wind power penetration is significant. The fluctuating power has an impact on power balance and voltage at the point of common coupling (PCC). Energy storage devices such as batteries, ultracapacitors, magnetic storage systems and flywheels can be utilized in a hybrid system to mitigate the effects of this problem. This paper uses Ultracapacitors in doubly-fed induction generators (DFIG) to support wind energy in short-term and mitigate high frequency power fluctuations.