Assessment of Different Techniques for the Diagnosis of Rotor Magnet Demagnetization in Five-Phase Surface Mounted Permanent Magnet Generators Drive

Multiphase permanent magnet generators are becoming attractive alternative for a variety of industry applications. In this context, diagnosing the status of the rotor magnets is necessary to guaranty the required efficiency of the generators. This paper deals with different techniques that can be adopted for quantifying the level of rotor demagnetization in closed-loop controlled five-phase permanent magnet generator. More specifically, a field oriented control scheme is investigated to identify the control impact on magnet demagnetization detectability based on voltage and current signature analysis. It will be shown that the last approach has the advantage of being less dependent on the operating point of the generator. The proposed comparative study is analytically established, and validated by means of numerical simulations thereby.