Wind Shear Increases Radial Loads on Wind Turbine Drivetrains

In this paper, we use a simple mathematical model to directly investigate the effect of the wind shear exponent on drivetrain loads, particularly the pitch moment and its effect on the radial forces supported by the drivetrain. The idealized wind speed profile is illustrated in Figure 1 and assumes a power law distribution of the form: V(z) = a (b+z)m , where V is wind speed, b is the hub height, 2 is the distance above the hub, m is the wind shear exponent, and a is a constant that dictates the mean wind speed.