The effects of static and dynamic imbalance on a horizontal axis wind turbine

In this note the differences between static and dynamic balancing of a wind turbine rotor are addressed. The paper begins with a definition of each type of balancing. It is demonstrated that even if a horizontal axis wind turbine rotor is in static balance. the rotor can still be dynamically imbalanced. Dynamic in?balance can result in a yaw and/or teeter producing torque. A turbine rotor is only in a state of dynamic balance when the principle axes of inertia are aligned with the angular velocity vector. This criteria is illustrated with a point mass model.