Continuous demagnetisation assessment for triple redundant nine‐phase fault‐tolerant permanent magnet machine

Abstract

In this study, the risk of partial irreversible demagnetisation of a triple redundant, nine‐phase fault tolerant machine based on permanent‐magnet‐assisted synchronous reluctance machine topology has been comprehensively assessed under various faults, including the worst case scenario when the applied voltage vector is in the opposite direction of the back electromotive force due to sensing and inverter control failure, by employing a continuous demagnetisation model. The dynamic response during fault transients and the post‐demagnetisation performance, such as the demagnetisation distribution, reduction in the back EMF and torque, will also be analysed and compared.