Effect of the closed-loop control on the diagnosis of rotor demagnetization in five-phase surface-mounted permanent magnet generators

Multiphase permanent-magnet generators are an attractive alternative for a variety of emerging applications owing to their reliability and dynamic performance such as hybrid traction systems. In this context, diagnosing the status of the rotor magnets is crucial for improving the reliability of the generators. The effect of the closed-loop control system cannot be neglected when the fault detection process is based on the signature analysis of electrical variables. Therefore, investigating the relevance of the bandwidth of the control system on the induced fault component is mandatory. In this paper, the detectability of the demagnetization of the rotor magnet trailing edges, due to large stator currents, in five-phase surface-mounted permanent magnet synchronous generators, is investigated. The theoretical analysis is validated by means of numerical simulations.