Active load control for wind turbine blades using MEM translational tabs

Abstract

Micro-electro-mechanical (MEM) translational tabs are proposed for active load control on utility-scale wind turbines. These microtabs are mounted near the trailing edge of the rotor blades, deploy approximately normal to the surface, and have a maximum deployment height on the order of the boundary-layer thickness. Deployment of this type of device effectively changes the camber on the rotor blade, thereby changing the lift generated by the surface. The effect of these tabs on lift has been shown to be as powerful as conventional control surfaces such as ailerons. Incorporation of this simple yet innovative lift enhancement and load control device with existing wind turbine power electronics and high-speed feedback sensors may permit the reduction of some of the bulky, conventional pitch control systems and result in overall reduction in system weight, complexity and cost. The minute size of these devices allows for response times much faster than conventional variable-pitch rotors allowing for improved wind turbine performance and load control at various wind speeds. This paper focuses on the experimental setup and comparison of computational and experimental data for a representative blade section. Both sets of data support previous proof of work that introduced the microtab concept and design methodology.