Investigation of the combined eccentricity and demagnetization fault in an AFPMSG

This paper investigates the partial demagnetization fault and the combined partial demagnetization and eccentricity fault in an Axial Flux Permanent Magnet Synchronous Generator (AFPMSG) that can be used for wind power applications. The study has been done using 3D-FEM due to machine 3D inherent nature. The machine has one stator and two rotors, while the single-sided machine is studied also for comparison purposes. The EMF spectrum is used as fault identification mean. Two different cases of combined faults are studied. In the first case the combined static angular eccentricity and partial demagnetization fault is studied, while in the second case the combined static axis eccentricity and partial demagnetization fault is investigated. Both combined faults are critical in AFPMSGs and for that reason should be early diagnosed in order to prevent further failures in the machine.