Assessment of current and voltage signature analysis for the diagnosis of rotor magnet demagnetization in five-phase AC permanent magnet generator drives

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 two techniques suitable for quantifying the level of rotor demagnetization in closed-loop controlled five-phase AC permanent magnet machines. More specifically, the paper is aimed to identify the control impact on magnet demagnetization detectability based on voltage and current signature analysis. The analysis shows 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.