Electrical generators and other drive-train components experience significantly varying loads in wind turbines. This can lead to bearing failure due to unbalanced forces caused by misalignment and rotor eccentricity. This presentation describes an analytical model to determine the radial force induced in 50-KW air-gap winding permanent magnet generators in wind turbines due to static rotor eccentricity. The model has been verified with 2D electromagnetic finite element analysis software. Depending on the fault frequency, stator currents have been analysed in order to detect the bearing wear type (inner race defect, outer race defect or bearing defect).
