Adaptive Individual Blade Pitch Control of an Ocean Current Turbine for Load Reduction


  • Louis Lee Florida Atlantic University Digital Library
  • James VanZwieten


A Direct Adaptive Disturbance Rejection (DADR) control algorithm is evaluated using a numerical
simulation of an Ocean Current Turbine (OCT) for its ability to minimize the cyclic loadings
on the rotor blades caused by current shear. This control algorithm reduces these cyclic loadings
by individually altering the pitch angles of the rotor blades as a function of rotor rotation angle.
The OCT numerical model represents a system with a single 3 bladed 20 meter diameter rotor
operated in the Gulf Stream off the coast of Ft. Lauderdale, Florida for mean and maximum
measured current shear values of 0.004 and 0.03 (m/s)/m. The results indicate that the adaptive
controller reduced the amplitude of the cyclic axial blade loads on a rigidly mounted and moored
turbine by 91.18% and 92.3% in the mean current shear and by 94.12% and 81.88% in maximum
current shear demonstrating the value of this controls approach.