Control strategies for enhanced power smoothing in wind energy systems using a flywheel driven by a vector-controlled induction machine

This paper presents a novel control strategy for power smoothing in wind en ergy applications, especially those feeding a stand-alone load. The system is based on a vector-controlled induction machine driving a flywheel and ad dresses the problem of regulating the de-link system voltage against both i nput power surges/sags from a wind turbine or sudden changes in load demand . The control is based on a feedforward compensation scheme augmented by a nonlinear controller, Two feedforward compensation schemes are discussed an d the limitations and performance of each scheme are analyzed. Experimental results are presented which verify the excellent performance of the feedfo rward compensation technique.