Flywheel energy storage system with induction machine associated to a variable-speed wind generator

A serious problem of wind power generated is due to the important wind fluctuation. So, an energy storage system must be associated with the wind generator in the aim to improve the electric power quality and to increase the level of penetration in the network; in this paper a flywheel energy storage system (FESS) is considered. It is well adapted because of its high dynamic, long lifetime and good efficiency. A speed control of the FESS associated to a variable speed wind generator (VSWG) based on a doubly fed induction generator (DFIG) is investigated. FESS consists of a power electronic converter supplying a squirrel-cage induction machine coupled to a flywheel. In order to validate the control method, the model of the system is simulated for different wind generator operating modes.