Control of wind turbines using nonlinear adaptive field excitation algorithms

Automatic control represents one of the most important factors responsible for the efficiency and reliability of wind power conversion systems. Thus far, only a few isolated applications of conventional control to wind power systems have appeared in the literature. To make wind power generation truly cost-effective and reliable, advanced control techniques are imperative. We develop a control scheme for wind turbines using nonlinear and adaptive control theory. Based on both mechanical and electrical dynamics, nonlinear and adaptive control algorithms are derived to online adjust the excitation winding voltage of the generator. This method is shown to be able to achieve smooth and asymptotic rotor speed tracking, as justified by both analysis and computer simulation.