This work presents results of a parametric study regarding the effects of hinge spring restraints on the yaw damping and yaw position stability of two-bladed teetered wind turbine rotors with and without delta three angle of the teeter hinge. Such a rotor design almost eliminates gyroscopic hub moments due to yaw rates. However, a teetered rotor located upwind of the yaw axis produces negative yaw damping that can cause problems in the yaw control system. The present study uses a more refined analytical rotor model and adds the significant effects of rotor overhang and of rotor torque in the presence of teeter oscillations, effects which had previously been neglected. It is shown how teeter spring restraints can be used to reduce the natural negative yaw damping and yaw position stability of upwind rotors and what the penalties are in the form of increased hub moments.
|Number of pages||9|
|State||Published - 1985|