Mass and Aerodynamic Imbalance Estimates of Wind Turbines

Due to its effect on the operation time of wind turbines, rotor imbalances of a wind turbine have to be detected early enough. We present a method that determines inhomogeneous mass distributions of the rotor as well as deviations in the pitch angles of the rotor blades from vibrational data only. To this end, a mathematical model connecting the load caused by the imbalances to the resulting vibrations was developed. After discretization, the resulting vibration equation was solved analytically. The inverse problem, i.e., the calculation of the mass and aerodynamic imbalance from vibrational data, was solved by using nonlinear regularization theory. Numerical simulations were performed using artificial vibration data.