A Study of Individual Pitch Control of a Horizontal Axis Wind Turbine in Atmospheric Boundary Layer

An Individual Pitch Control (IPC) system to reduce the yawing and tilting moments on the hub of Horizontal Axis Wind Turbines (HAWTs) in Atmospheric Boundary Layer (ABL) is constructed and a trim routine is numerically simulated to check the effectiveness of the system. With 1/rev cyclic pitch control, it is found that for a three-bladed turbine, the averages can be trimmed to nearly zero while the 3/rev fluctuations cannot be effectively reduced . However, for a two-bladed turbine, the averaged moments can be reduced to nearly zero, and furthermore, the load fluctuations on rotor hub can also be significantly reduced. For both type of HAWTs, the oscillations of flapwise bending moment on the blade root can be remarkably reduced when IPC is applied.