Design and Feasibility of Active Control Surfaces on Wind Turbine Blade Systems

Abstract

Wind energy has reached a level of maturity regarding its value as an alternative energy generation technology. However, inefficiencies in blade designs over a wide range of wind conditions are present. Some of this inefficiency comes from operation in transient and turbulent wind conditions. High maintenance costs and decreased reliability can result from continued use in turbulent wind conditions. Another source of inefficiency is the fact that the wind turbine blade is a “point design” which is optimized over a specified range of wind conditions. Active control surfaces, similar to conventional aircraft structures can be utilized to provide better efficiencies. The motivation of this study was to explore active control surfaces on wind turbine blades for improved reliability and efficiency. Blades become fatigued due to the cyclic loading and unloading of the wind. One way to prolong the life of these blades may be answered with an active control system that will mitigate the transient loading associated with erratic wind gusts. This reduction in loads is a combination of active control supported by transient, computational and experimental data, along with actuator concepts. Also, changing the aerodynamic configuration of the wind turbine blade can yield efficiencies over a wider range of wind speeds and conditions. In this paper we address the actuator portion of the system, which can be used for a variety of active control surfaces on wind turbine blades. Concept mechanisms are developed, demonstrated, and analyzed regarding their deployment in current and next generation wind turbine blades. Recommendations for future studies are provided.