Assessment of Current and Voltage Signature Analysis for the Diagnosis of Open-Phase Faults in Asymmetrical Six-Phase AC Permanent Magnet Synchronous Motor Drives

Multiphase permanent-magnet motors are very attractive solutions for a large variety of applications, and specifically for electric vehicle applications. However, with a higher number of stator phases, multiphase permanent-magnet motors are more subjected to stator failures. Thus, diagnosing the stator status is necessary to guarantee the required efficiency of the motor. This paper deals with two techniques suitable for detecting and localizing open-phase faults in closed-loop controlled six-phase AC permanent-magnet motors. More specifically, this paper is aimed at assessing the diagnosis of open-phase faults based on current and voltage signature analysis. It is shown that the presence of specific harmonics can significantly affect the diagnosis process. Here, two diagnostic space vectors elaborated in the fifth α-β plane, based on the current and voltage signals, are proposed to cope with this limitation. The main contributions of the proposed approach are its implementation simplicity, and the effective immunity of the current-based analysis and voltage-based analysis against harmonic disturbances. The effectiveness of the proposed diagnostic space vector has been analyzed by numerical simulations, then experimentally validated.