Power Smoothing Control of DFIG Based Wind Turbine using Flywheel Energy Storage System

in this paper, we present coordinated control strategies of a flywheel energy storage system (FESS) and a doubly fed induction generator (DFIG) in wind energy conversion application. The general aim is to enhance the wind energy conversion system’s capability to participate in ancillary services. The overall system control relies on the nonlinear backstepping approach applied, firstly, to the rotor side converter to regulate stator active and reactive powers. Then, to the grid side converter to regulate the DC link voltage and the rotor reactive power. Then finally, to the flywheel side converter allowing the FESS to serve as a buffer used to smooth the undesirable wind-induced output power fluctuations. A fuzzy logic supervisor is proposed to maintain the FESS within its operating limits. Numerical simulation in Matlab/Simulink demonstrates the effectiveness of the presented control strategies in terms of stability, tracking behavior and out power quality improvement.