A Hybrid Model of a Small Autofurling Wind Turbine

Abstract

Most small wind turbines are designed to autofurl in high winds under aerodynamic and gravity forces to provide overspeed protection. Although autofurling is a proven technology with a long history, this totally passive mechanism is unfortunately not well understood and can perhaps be improved through careful analysis and redesign. Moreover, including an active yaw actuator such as a linear motor to supplement the passive autofurling mechanism by supplying a yaw moment can improve the turbine performance in high winds and strengthen the protection function. This paper proposes a mathematical model of small wind turbines and their autofurling mechanism and discusses a fuzzy model of the aerodynamics based on learning from extensive simulations using YawDyn.