Abstract
Squirrel-cage induction generators are widely used as generators for windmill power systems, because they are inexpensive, of high durability, and capable of operating asynchronously to power systems. However, induction generators have the drawback that it cause the transient rush current several times as large as the rated value when it is connected to power systems. Also, since wind energy is influenced by geographic and weather conditions, start/stop operations occur frequently for windmill power systems. Therefore, connecting induction generators to power systems cause undesirable voltage vibration in power systems, which is the major obstacle against the practical use of the windmill generator systems. This motivates the study of transient rush current/voltage attenuation in windmill generator systems.
In this paper, a nonlinear state-feedback controller for windmill power systems is proposed. The proposed controller not only globally asymptotically stabilizes the plant, but also effectively attenuate the transient current/voltage of those systems. C omputer simulations using parameters of the actual windmill generator system also give good results.
