Novel characterization of rotor magnet demagnetization in five-phase surface mounted permanent magnet machines

Multiphase permanent magnet machines are becoming attractive alternative for a wide range of industry applications owing to their reliability, dynamic performances, and its greater degrees of fault tolerability compared to three-phase machines. In this context, diagnosing rotor magnets degradation at incipient stage is crucial to guaranty the required efficiency of the machines. In the present paper the attention is focused on a five-phase surface-mounted permanent magnet synchronous generator, and a new technique is investigated for detecting possible demagnetization of the rotor magnets due to high stator currents. A new diagnostic technique, based on third-space power signature analysis, is presented. The validity of the proposed new approach is verified by numerical simulations.