PowerPoint PresentationAlleviation of Extreme Blade Load by Individual Blade Control during Normal Wind Turbine Operation
W. E. LeitheadP, HAN YIF
University of Strathclyde
Active Blade Load Reduction
Spectra peaks at 1P, 2P rad/s
Reduction on blades, rotor, hub,
yaw,…
Spectral peaks at 1P rad/s, edge
mode
Partial projection onto various
directions on (My,Mx) plane
Each blade pitched individually
completely independent
Dominant at low wind speeds near rated
Key component is blade edge mode
L2: Combination of Mx and My
Dominant at high wind speeds
Key component is 1P
direction in (My,Mx) plane
direction in (My,Mx) plane
Acts on measured Mx
Regulates 1P spectral peak at high wind speed
Acts on measured
Full operational envelope including extreme
wind conditions, IEC 61400-1
from nine separate evaluation
Performance Assessment
IBC applied to alleviate extreme blade loads
Flexibility of IBC over choice of measured bending
moment exploited
A reduction of 20% to 30% in the most important
extreme loads is achieved for an example 3MW WT
Further refinement possible
colPitch [rad]
Time [s]