Control of Rotor Geometry and Aerodynamics: Retractable Blades and Advanced Concepts

This research focuses on the combination of two areas: aerodynamics and controls for wind turbine load reduction. The goal of the study is to develop baseline estimates of the cost benefits available from the use of advanced control of wind turbine rotors. The first category includes devices or methods that can be used to actively alter the local aerodynamic properties of the rotor blade. These devices have response times at least as fast as a full-span, variable-pitch system. The second category is geometry control, based on extendable length blades. These technologies are applied to a virtual turbine design with a 90-m diameter and a 2.5 MW rating, variable-speed, and variable-pitch. The approach will include simulations using MSC-ADAMS and detailed cost modeling based on the simulated loads. The control algorithms will employ linear state space methods that include individual blade pitch and multi-input, multi-output control of the selected aerodynamic devices.