Environmental Engineering Reference
In-Depth Information
Chapter 13
A Semi-active Control System for Wind
Turbines
N. Caterino, C.T. Georgakis, F. Trinchillo and A. Occhiuzzi
Abstract A semi-active (SA) control system based on the use of smart mag-
netorheological (MR) dampers to control the structural response of a wind turbine
is proposed herein. The innovative approach is based on the implementation and
use of a variable-properties base restraint. This is able to modify in real time its
mechanical properties according to the instantaneous decision of a given control
logic, the latter addressed to control one or more structural response parameters.
The smart base restraint is thought to be a combination of a smooth hinge, elastic
springs, large-scale adjustable MR dampers, and a control algorithm that instan-
taneously commands the latter during the motion, making them to modulate the
reactive force as needed to achieve the performance goals. The design and oper-
ation of such a system are shown with reference to a case study consisting of an
almost 100 m tall wind turbine, realized in a 1/20 scale model at the Denmark
Technical University (DTU). Shaking table tests have been performed under the
action of two different types of wind loads and by using two purposely written
control logics, highlighting the high effectiveness of the proposed SA control
technique and encouraging to further investigate in such direction.
Keywords Semi-active control
Wind turbine
Magnetorheological damper
Smart material
Control algorithm
