Aerodynamic imbalances are a massive burden not only for the rotor but for the entire drive train. If they are not detected early it can result in high costs. To detect irregularities on the rotor that can lead to imbalances, such as misalignment of the rotor blades, the vibration signals of the main bearing are monitored for the diagnosis in addition to the operating parameters.
Essential components in the vibration signal of a wind turbine include rotor rotation frequency and the blade pass frequency. Based on the absolute amplitudes of these frequency components, and also by their relation to each other, conclusions about the behaviour of the rotor unbalance can be drawn. If these parameters turn up accordingly aerodynamic unbalanced loads such as those occurring in the rotor blade deformity can be detected. On the same basis the detectoin of further aerodynamic anomalies such as faulty incoming flow due to faulty yaw system is possible.